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SCORE School Surgical Infection
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SCORE School Surgical Infection
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Segment:0 .
AMIT JOSHI: Good evening, everyone. It's just past the hour. Welcome to SCORE School. My name is Ahmed Joshi, I'm the associate editor of SCORE, and will serve as your moderator tonight. A few quick things before we get started, as usual we will be using the chat box for questions and comments. We'll be using the QR code for attendance tracking a couple of times during the presentation, and you only need to submit your form once to get an email receipt.
AMIT JOSHI: As [AUDIO OUT] --for later viewing on the website. There have been over 22,000 views of all of these sessions since we started in the summertime, and we encourage you to view them as your schedule allows. Because over 95% of the views have been off the website, as opposed to live, we're going to be moving the time of these live broadcasts to the Friday preceding the corresponding TWIS week. So for example, today's session will be recorded-- will have been recorded last Friday, so that it's available for all programs and trainees to be using in the corresponding TWIS week.
AMIT JOSHI: So please keep posted with the school website for the change of times. There'll still be at availability for people to log in, if they prefer to interact with the speakers, and the login information will likely stay the same. So for tonight's SCORE School, surgical infection is the topic of the week, we'll be discussing six modules. Hospital Acquired Infections was authored by Dr. Saira Nasar, [? Mai ?] [? al-Karam, ?] and [? Shadi ?] [? abu-Asawi. ?] Diagnostic Approach to Infections, authored by Brandy Padilla-Jones and Lillian Kale.
AMIT JOSHI: Anti-microbial Stewardship and Prevention, as well as Treatment of Surgical Site Infections, authored by Kevin Sullivan, and Heather Evans, and E Patchen Dellinger. Anti-microbial Agents and Surgical Infections, authored by Jessica Kramer and Sara Buckman, and Abdominal Infections, authored by Stephanie Goldberg and Therese Duane. We're obviously very grateful to all these authors of the over 600 modules on SCORE, which are updated every two to three years.
AMIT JOSHI: So without further ado, it is my distinct pleasure to introduce our faculty presenter tonight, Dr. Laura Brown, is a critical care trauma surgeon at Metro Health Medical Center, and an assistant professor at Case Western Reserve University in Cleveland, Ohio. She earned her undergraduate degree from Colorado State University, a PhD from the University of Colorado, in biophysics and molecular genetics, and her medical degree from the University of Michigan.
AMIT JOSHI: She Then completed a surgical residency, a surgical critical care and acute care fellowship at Michigan in that time as well. 21 years of education and training. After three years of practice and-- [LAUGHS] sorry for the reminder-- after three years of practice in Toledo, Ohio, she moved to Cleveland in 2018, where she currently serves as the associate program director of the Surgical Critical Care Fellowship.
AMIT JOSHI: She is a leader in the Surgical Infection Society and the Association of Surgical Education, and has won Teaching Award at every institution she has been affiliated with. Thank you, Dr. Brown, for lending your expertise to us, and take it away please.
LAURA BROWN: Oh, thank you so much for that wonderful introduction. I am very excited to be here with you today, to talk about one of my very favorite topics. The PhD in biophysics molecular genetics was actually in virology. So I've had a longstanding interest in all things infectious. Long before my surgical career, I thought I would [INAUDIBLE] through the wilds of Africa, chasing the next virus.
LAURA BROWN: I didn't know that it was going to come to me. I found my training in BSL-2 and -3 labs very helpful for the donning and doffing that we're undergoing during the midst of this pandemic. I am hoping today, to share a couple important things with you. Next slide, please. My disclosures are that I have no specific love of any microbe more than any others, but there are so many to choose from that are so important to surgical patients.
LAURA BROWN: So I'd like to give you a brief overview. Next slide, please. The goal of this talk, really, is to give you key highlights covered in these six SCORE modules. I've kept in mind where we are in TWIS and where we are in the year. We've got new interns, all the way to a very experienced chiefs, and so I've highlighted the most important concepts and goals and learning objectives.
LAURA BROWN: But it's not supposed to be a comprehensive compendium of every surgical infection. In fact, you're going to see that instead, what I did was include the best evidence and guideline recommendations. My goal, really, is that you are able to reference these later, as you're trying to manage patients on the wards. I recommend that you keep a copy of these guidelines in your literature library.
LAURA BROWN: My goal is really here to choose the cases that cover the most commonly missed questions from tests, on rounds, during discussions, and in the patient management decisions that are made every day that I see. Even sometimes by other attendings that are incorrect. So, what you're going to see here from me-- next slide-- oh I'm sorry, hold on. I want to pause real quick, here.
LAURA BROWN: My hope is that everyone listening tonight gets a little golden nugget of information that will aid them in their pathway to surgical Nirvana. And I want to say that, the only thing that I'm more passionate about than surgery and microbes, or microbes in surgical patients, is the neuroscience behind learning. And I specifically designed the session to not only convey this information to you, but to help you learn it faster and smarter.
LAURA BROWN: Anything that you see in italics is a question that I'd like for you to answer yourself. You might want a piece of paper, or you can use the chat function if you'd like. But the deal is that if you can watch and listen in your pj's, I want you to make an effort to write it down, and use the neuroscience of learning involved in engaging your brain, and writing things down to help lock this information into place.
LAURA BROWN: I purposely didn't include multiple choice, because I want you to actually write what you know, and then fill in what you don't based on our discussion tonight. And you might-- multiple choice does give me valuable feedback, it tells me whether or not I'm getting this information across you. But it doesn't work as well for the type of asynchronous setup and learning, or for multiple viewings by the same user, if you want to go back and retest yourself when you listen to it again.
LAURA BROWN: In virtual learning, we're only limited by our imagination, and the amount of engagement that we bring to the table. So if you're wearing your pj's, just put a pencil in your hand, and let's get started. Let's start with our first case. Next slide, please. This is an actual case that was brought to me by an intern on call.
LAURA BROWN: He was looking for the chief resident [INAUDIBLE] in the next room [INAUDIBLE] to the thigh. He had a page from the, night nurse, and comes into my room where we're doing an ex lap, and he tells me, hey I got this call. And he's clearly-- it's clearly one of his first pages during his intern year. And, so, I asked him, well what's running through your head?
LAURA BROWN: You have a 42-year-old man who had a laparoscopic left hemicolectomy. And that's all the information you've given me so far. So what do you think? Obviously, some things are running through my head, right off the bat, why did he get a left hemicolectomy? Turns out, that was for cancer. He's only 42. That makes me a little bit concerned.
LAURA BROWN: Does he have other comorbidities? What risk factors do you need to know about? OK, next slide, please. Obviously, these are the most common patient risk factors for infection. And this is age, is especially important in the coming decade or two, as we have our baby boomers advancing into geriatric status.
LAURA BROWN: And we'll see more and more geriatric patients. And one of the things we're very interested in-- what are the specific frailty markers that make someone more susceptible to infection? But other comorbidities, such as COPD any renal dysfunction, especially if the patient [INAUDIBLE].. We all probably listed diabetics and steroids, or transplant patients who are immunosuppressed. But I also want you to note those last two.
LAURA BROWN: You need to file away in your noggin, which is that any patient who has recently been hospitalized, or been in long term care, has been exposed to a different microbiome than their own. And they are more likely to have [INAUDIBLE] pathogens. Especially if they've had recent antibiotics, or if they've had prior resistant pathogens. So, those patients are going to be higher risk for you, and you need to pay closer attention to those two risk factors.
LAURA BROWN: It's not something that we commonly report. OK. Let's go on to the next slide. So, now that we have the information on our patient, no other real major comorbidities, this was obviously a new diagnosis. So, I asked the intern then, what things are you expecting from a post-op, day two patient?
LAURA BROWN: What things are you worried about? How does fever change over the postoperative course? Let's jot something down. Just think about what you are worried about. OK, I'm going to move quickly, because I have a feeling that in the next slide, that you guys all jotted this timeline down. We all learned W's of postoperative fever, right?
LAURA BROWN: And it's either that, or some variation in this. I still remember being pinned on the cytokines involved in fever as a medical student by chief resident. Who, by the way, is now a very affable certainly enigmatic Surgery Department chair. He has an awesome book case on Twitter. And, I remember very, very vividly, this experience as a medical student. And I think, although it was painful, the point of that review of the physiology, and making me use my immunology background to trace the pathways, was to point out to me that the majority of postoperative fever is due to inflammation.
LAURA BROWN: It's not necessarily infection. And so, I think that you have to remember that we're going to talk a lot about surgical infections, but one of our toughest jobs to dissect out whether this is really inflammation, or infection. And this classic description was written in all of our pre-intern surgery survival books. So we know it's a good place to start, but not long into practice, you begin to realize that there is some complexity and subtlety of a postoperative course.
LAURA BROWN: I'm going to propose a slightly different way of looking at this timeline. It's the Dr. Brown perspective. I'm going to include the infectious diagnoses that really can't afford to miss. And the reason that I do this, is that I try to highlight to the residents that the most important tools in your armamentarium is the review of the history, and a great physical exam.
LAURA BROWN: So, let's see if you would add anything to my diagram on the next slide. So, again, these are the things that I don't want you to miss, or that we can't afford to miss. And you'll notice I removed the times on the timeline. [INAUDIBLE] where these complications might present in real life. They can start at the beginning.
LAURA BROWN: It's general timeline from when they will present, but it's not always where they're going to present. And so, there's a little line there. But I want you to think of it more as a bracket. I coach the residents to specifically focus on and examine the skin around incisions in the abdominal exam, in that immediately post-op day zero surgery exam. I want you to think about NSTIs-- Necrotizing Soft Tissue Infections-- and leaks, there.
LAURA BROWN: Those are the two things that you absolutely have to rule out and can't afford to miss. And then, over the next few days in a patient, you may see a new onset hypoxia, cough, purulent sputum, or you might see leg swelling. Those might be other important factors that are going to be really important, when you're presenting this patient to your staff. Or, when you're thinking about what might be causing this.
LAURA BROWN: And then a little bit after this, you really start to worry about a surgical site infection. Whether it's just superficial, in the skin and subcutaneous tissue, or deep at the fascia, just below it. Or, is it an organ space surgical site infection, which are a little bit harder to detect. Part of the miracle of the body, is that, especially an abdominal surgery, the body will work to contain those bacteria by sequestration, isolation, and then the acidify the abscess pocket.
LAURA BROWN: That whole process takes anywhere from five to seven days, before you get that nice, rim-enhancing-- enhancing rim that you see on imaging. And that's why we sometimes wait to do the CAT scan. So that it's easier to see, and we have a better target, and it's easier to convince interventional radiology that we want to drain it. If we're really concerned about a leak, that may move may prioritize a CAT scan earlier in our diagnostic algorithm.
LAURA BROWN: All of this, everything that we've talked about, depends on the stability of the patient. So, the presumption is that the vitals are stable and patient is stable, and that may change how quickly you do things. I'm an intensivist, and acute care surgeon, so all of these diagnoses are right up my alley, and part of my life. And obviously, they changed the weight of importance for me.
LAURA BROWN: I say these things that you should not miss, but the most likely cause is what? Inflammation. The last thing I didn't mention, and I do want to mention it, I put implants far down the list. And that's because you may see a patient in clinic, even years after you've done a hernia repair with mesh, that presents with a delayed surgical site infection, or a delayed mesh infection.
LAURA BROWN: So don't forget that that's always a possibility. Let's talk a little bit-- I want to summarize a couple of key points about the workup and evaluation. And what are the key points of diagnosis? There was something that was just that on the chat, and I want to point it out to the whole group in case you're not also following the chat.
LAURA BROWN: It is absolutely important to take down the dressing. Even if it's before post-op day two, if you are really concerned about an NSTI. I know that we're taught that we shouldn't take down that dressing without our chief resident, but if you are concerned enough, if the patient is looking sick and you have spreading inflammation, you should look. You will be forgiven, I promise. OK, let's talk about-- next slide-- let's talk about diagnosis a little bit.
LAURA BROWN: Some of the factors that are important in diagnosis, and some things that may help you. These are tips and tricks, this is not a comprehensive list, but I want to point out a couple of things to you that I don't want you to forget. Gram stain is not perfect. You guys all remember from micro lab, how easy it was to stain the organism wrong. Most important is for you to get a culture with that Gram stain.
LAURA BROWN: The behavior on agar may actually help us isolate the organism quicker. And you give us more information-- infectious disease experts, about which class of microbe we're treating, and how likely it is to be resistant. Many diagnoses in this day and age are based on immunochemistry. So, the use of antibodies to an antigen, or an antibody detection itself in response to the antigen.
LAURA BROWN: That a patient's immune response, or production of those antibodies. And these antibodies or immunoglobulins are first produced as a pentad of IgM, and I told you have a strong immunology background, so don't let me lose you here, because it's a little bit of basic science, but remember that it comes out with five copies in a circle that are all connected.
LAURA BROWN: And that actually very strongly activates a complement cascade, and that tells you that it's an active infection. And as the B cells produce more immunoglobulin, and as the immune response matures, they often transition to making IgG, which is a dyad. And, one of the most common tested of examples of serology, the thing you're going to see on boards time and time again, is the hepatitides, and that's just plural for hepatitis. Everybody says that hepatitises, and I don't think that's right, so.
LAURA BROWN: Hepatitides is correct from a virologist, that the correct-- --and in hepatitis A, IgM indicates active infection, with [INAUDIBLE] indicates immunity. In hepatitis B we may test for a different part of the antigen of the virus itself. So if we're testing for the core antigen that indicates an active infection if the core antigen's positive, whereas at if surface the antigen indicates that the patient has already achieved immunity for hepatitis B.
LAURA BROWN: There is a technology, not listed here, that I want you to think about in your head. It's revolutionized the detection of microbes. And it's making a real difference in patient survival. The common example is the use of PCR to detect specific microbes in bloodstream infections, within two hours of arrival to the hospital. So that blood culture is drawn, [INAUDIBLE] and within two hours, we have an isolated organism.
LAURA BROWN: And that is life changing for intensivists. This is so important, because we know that the time to first dose of appropriate antibiotic is one of the single most important factors in surviving sepsis. This technology is a game-changer for you. And for me, and for the patient. Next slide.
LAURA BROWN: So, a couple other points that I want to make to you about a few other tests-- oh, before I forget-- you guys have all heard about the detection of C. diff toxin in stool, and why this is important, and that many people may carry the antigen. They actually need to colonize the C. diff, and they never show disease. And so, we may be detecting them as C. diff positive by immunoassay, but they are not PCR toxin positive.
LAURA BROWN: Meaning that they are not producing that toxin. And so, they don't have active infection. And this is super important, cause and what happens is we end up treating them as though they're C. diff positive, we all have to wear the boots, the isolation gowns, and isolate the patient. So, by using that genetic sequence of the toxin, we can determine whether the microbe is in fact producing the toxin, and whether it's likely an active infection.
LAURA BROWN: So, that's a good example of where PCR is changing your life. Let's talk a little bit about a couple other key points on these other diagnostic tests. So, we do need to know the components of a UA. So, the signs that are concerning for infection include leukocyte esterase, it's produced by the white blood cells, especially if that number of white blood cells is greater than the number of red blood cells.
LAURA BROWN: Keep in mind that if hematuria, or red blood cells spilled, you maybe look esterase positive, but only because you have blood in the urine. Nitride is specific to certain species of bacteria, so it's not sensitive necessarily, but more specific. The absence of nitrate doesn't tell you anything. It's only if it's positive, will it be important to you. And then, the presence of bacteria is obviously important.
LAURA BROWN: The patient may be colonized with bacteria, so you have to clinically decide whether or not patient's symptomatic. And any single species greater than 10 to the fifth is concerning, but you don't treat if it's yeast. When you're sending blood cultures, what do you need to remember? Try to send a peripheral.
LAURA BROWN: And if you can, send two. If Gram-positive cells come back on it, Gram-positive cocci come back on it, then it's very likely a contaminated skin for us, that'll help you rule that out. If you're sending a bronchial alveolar lavage, BAL for short. It's more invasive than tracheal aspirate. We need it for very sick patients, when they need to isolate the organism.
LAURA BROWN: If I'm really concerned about a multidrug resistant organism, I'll do a BAL, even though it's more invasive. Especially if the infiltrate on chest X-ray is in the left lobe. Sputum's not very helpful in that case, because you're just more likely to get the many bacteria found in the oral and nasopharyngeals. So, quick note about imaging, this is one that sits on the trauma service a lot.
LAURA BROWN: We tend to just get chest x-rays, and we get serial chest x-rays because we know the infiltrate's not going anywhere. If you see an infiltrate for two days in a row, I challenge you to grab your ultrasound and go see if that's an effusion or an infiltrate. I want you guys to get very comfortable with ultrasound, it's going to become a big part of your lives. If you can't get-- if your ultrasound isn't an option, or if you're sending the patient down for a CT of its abdomen and pelvis, get the chest, as well.
LAURA BROWN: But don't hesitate to look about what's going in the chest, get that information. It may be useful to you.
AMIT JOSHI: Dr. Brown, could I ask you one question? One of the controversies that came up in our program this morning, with the difference between a BAL and a tracheal aspirate. So could you just, maybe, precisely define the difference?
LAURA BROWN: Yes. So, a tracheal aspirate is taken from the upper portion of the trachea. So it does have more of the normal flora that are found. So you may have contaminated flora in that location. It's taken-- it's basically an irrigation aspirate from the inline suction from the ET tube. The difference with the BAL, is that it can be either a mini BAL, where the tube is directed far down into the right mainstem bronchus, past the majority of the normal flora.
LAURA BROWN: And you direct the lavage into the distal bronchus. And are able to aspirate back from that location. So, it's much more specific to those organisms that you would expect an infection in, in that case, as opposed to contaminants from the trachea. You may have patients who are colonized with organisms in the trachea, so that's why that's important. A BAL can also, as I mentioned, be directed to the left lobe, which is very imporant.
LAURA BROWN: You have a patient with a left lobe infiltrate. You're not going to get there with a mini BAL, with the tube that you just passed down there, you're not going to get down there with your suction cap. So you really need to put a bronchoscope in through the ET tube, target that bronchoscope over to the left lobe, and then you'll get a better recovery of organisms. BAL, It's often hard to recover organisms. And so, in that case, a BAL that's positive is 10 to the fourth organisms.
LAURA BROWN: And that's something that's different than some of your other clinical criteria. So, remember, we said UTI was 10 to the fifth, and BAL is positive if it's greater than 10 to the fourth organisms. Both of those, even if you do a tracheal aspirate, is still much, much, much, much better than sputum. Obviously, because there are many more organisms that are involved in the production of sputum.
LAURA BROWN: Normal flora. Any other great questions about diagnosis? This is just an overview.
AMIT JOSHI: Do you routinely use bedside ultrasound in the ICU?
LAURA BROWN: I do. So, this has become even more important in the COVID era, but I was a big fan of ultrasound long before that. I think that it's going to be a technology that becomes even more important. One of the issues in a lot of our patients is that they're too unstable for transport, and so you're limited in terms of what you can absorb. So, my fellows are challenged to ultrasound patients every day. So they do both the BLUE protocol, which looks at lungs, in the setting of-- to evaluate the consolidation and edema.
LAURA BROWN: Sometimes I find that very helpful in the setting of severe hypoxemia, where I can't transport the patient down to CAT scan, I don't even want to put a chest X-ray board behind him, but I can get an ultrasound probe on him. And it may help me determine whether this is truly all just consolidation, and I need to optimize recruitment of the alveoli a little bit better, or whether it's more edema, and I need to diurese the patient.
LAURA BROWN: So it can be very, very helpful in that setting. I strongly encourage people to get very comfortable with it. Obviously, it's well described, using ultrasound for the setting-- in shock, to help you isolate whether it's hypovolemic shock, or whether it's cardiogenic shock. Very useful for ICU patients. So I strongly recommend that you get comfortable. I carry that little pocket ultrasound that you can plug in to your phone.
LAURA BROWN: So, to me, it's become almost like my second stethoscope. Very useful technology. And the advantage of some of the newer technologies in ultrasound is that they're not as much not knobology involved, so you don't have to know all that in-points about how to change this to get the better view, it's one probe. One probe that you hold in your hand, but it essentially functions as everything from a cardiac phased array, or a linear probe, or an abdominal probe.
LAURA BROWN: So [INAUDIBLE] probe. So you get the advantage of all those different technologies in one tool. Super cool. It was my Christmas present, I saved up. We should all have dreams. All right, any other big questions about diagnosis that anybody wants to talk about?
LAURA BROWN: OK, the next slide I'll give you should hopefully be the QR code, I believe.
AMIT JOSHI: I'll just say one comment here, we had one listener last week whose program was not appearing on the QR code login. And so we've added that in. So if you're a SCORE-subscribing program, just let us know if for some reason your program is not appearing. OK, go ahead Dr. Brown, thanks.
LAURA BROWN: OK. So let's move on to another case, then, in our next slide. All right, this is a real case. Oops, sorry, next slide. Slightly altered to protect the innocent, obviously, but it highlights the importance of surgical site infections to our practice as surgeons. And I've given it away that it's a surgical site infection, but there's so much more value to this discussion.
LAURA BROWN: And there is a little bit in here for you about systemic-based practice, and practice-based learning. In addition to just surgical infections. And that's because all of the surgical infections you are going to encounter, are going to change the way you practice. And it's going to change reimbursement for your hospital. So, I want you-- this is why you need to know this information.
LAURA BROWN: Here's the information. 62-year-old woman, history of morbid obesity. She's got bad COPD, and she's now post-op day 10 from your emergency ex lap for a closed loop small bowel obstruction. Now, she's being seen at an urgent care, and the nurse notes purulent drainage, and starts antibiotics. And the hospital infection monitor calls you and says, this patient got tagged for a superficial SSI.
LAURA BROWN: Do you think she has a superficial SSI? And jot down what you think are those risk factors. If you can, I want you to just quickly, yes or no, weigh in on whether or not you think this patient has a surgical site infection.
LAURA BROWN: OK, great. Let's move on to the next slide. Hopefully you got a chance to jot. How many of these things you get? Were you close? Obviously this isn't completely inclusive, but the major risk factors known to contribute to superficial surgical site infections include age, obesity or malnutrition.
LAURA BROWN: So either spectrum. Diabetes, that's an obvious one. Smoking, that's also an obvious one. Some surgeons won't operate on a person who is smoking for an elective procedure, and will check the cotinine level preoperatively. Other hospitals have actually declined to schedule elective cases for A1c that's greater than 6.5. So, both of those are modifiable risk factors that we could manage preoperatively for elective cases.
LAURA BROWN: And so I want to encourage you to think about rehabilitating your patients, if you have that luxury, especially for those two diagnoses. OK, next slide. Let's jot down what we think are the diagnostic criteria for a superficial SSI.
LAURA BROWN: OK. Let's see what you got. Next slide. So, the problem here for this, is this was an advanced practice provider who didn't understand what fat necrosis looks like. It actually wasn't purulent, it was just broken down fat cells.
LAURA BROWN: There was no surrounding erythema. The patient had pain at the incision, but it wasn't any more pain than anywhere else in the incision. And they attributed the swelling to the adipose tissue that-- could be attributed to the adipose tissue that was nearby. So, the challenge was that this patient was started on antibiotics for probably what was just a little bit of drainage of fat necrosis. Now the hard part is that once it's said that there was purulent drainage anywhere in the chart, even at an outside hospital, or by another provider, that gets dinged, that gets tagged.
LAURA BROWN: Now, the only way that you can then say that this was not a surgical site infection is if you do not culture organisms from it. So, if you open a wound, I strongly recommend that you get in the habit of culturing it. And, the reason why, is that if that culture is negative-- you're already going to get dinged-- once you've opened it, once you've opened the wound, it's considered a superficial SSI.
LAURA BROWN: But, if that culture comes back negative, you can then get it removed from that list. So this is important I think this has changed our practice. And we now have a rule that only chief residents and attendings can open wounds, and that's so that they get cultured as we go. And now it turned out that this patient came to clinic right after this happened. The day after, we did open the wound and cultured it, and nothing grew.
LAURA BROWN: Which is how I can be convinced that that was just fat necrosis. So, it is fascinating to me that we have gotten to an age where it's not necessarily based on what was necessary for the patient, we didn't culture this patient because we needed know what organism was there, but because we needed to prove to them that it wasn't a surgical site infection.
LAURA BROWN: What an age we've come to.
AMIT JOSHI: It's the tail wagging the dog.
LAURA BROWN: Yes, yes it is. OK, this is part of learning to practice in a system that you have, and working hard to change it at the upper levels. All right, let's talk about how superficial site infections differ from deep surgical site infections, or organs space surgical site infections. What are the criteria that are different between them? And this is not an italic slide, so I want you to just quickly, on chat, give me an idea of what you think are the big differences.
LAURA BROWN: Absolutely, so deep to the fascia. All right, let's move on to the next slide. So, deep to the fascia, or fascia and/or below, especially if it comes with a spontaneous dehiscence.
LAURA BROWN: And it has to be diagnosed by the surgical attending so that actually, the APP, or another provider, or even a resident, can't diagnose that as a surgical site infection. The attending has to note it in their operative report or in their notes, and sign it. So now, if the resident writes it in the note in the attending co-signs, and says I agree with the resident's plan, then that does count as diagnosed by the surgical attending.
LAURA BROWN: So, I want you to be careful, if you really write that there's a surgical site infection, and you mean it, and you discussed it with the attending before you put it in the notes, because that's very, very important to the hospital system. All of these are within 30 days. Again, a deep SSI, if your culture comes back negative, there are no bacteria. Let's say you take the patient back for a dehiscence, spontaneous dehiscence, you think there's an SSI, you send deep tissue culture and it doesn't come back with something, then that's removed as well.
LAURA BROWN: I would strongly suggest, too, you that you do the same practice for organ space surgical site infections, to make sure that if, for instance, IR places a drain that they culture, I had a little bit of time there, where I was having trouble getting IR to actually send the culture, because they didn't feel that it was important, and then I explained to them that if it comes back negative, and we don't get dinged for the SSI, that's super important to our hospital system.
LAURA BROWN: So we're back to culturing, thank goodness. You're going to have some infection. We can't completely remove it. We can do our best to prevent it. We can optimize our patients. Especially if I'm scooping corn and Lima beans from the retroperitoneum, that's a true story. Although, my best ever was an entire pumpkin's worth of pumpkin seeds scooped from the retroperitoneum.
LAURA BROWN: So, we're going to get infection. No pumpkin seed is perfect. How can we balance that when we're dealing with bacteria? Especially in emergency cases. And so, the goal is to very clearly define in our wound classification at the outset, so we can accurately predict what the wound infection rate will be. So, in our next slide, we-- this is something you guys have all probably seen at your M&M, because I think we talk about it fairly frequently.
LAURA BROWN: In our next slide, the surgical wound classification. Now, obviously, there is a difference between a clean case, which represents little to no contamination, no containing tract is open, versus [INAUDIBLE] case, like a PEG, where you've actually opened an alimentary tract. Contaminated cases, and open fresh wounds, that includes trauma cases, which absolutely drives me crazy, here.
LAURA BROWN: Because if I'm scooping stool from the subhepatic space, I feel-- and I'm trying to get to that hole in the IVC-- I don't get any points for that, because it's fresh. It's not a dirty or infected wound. Because it's been there for a while, and there's nearby inflammation or devitalized tissue. That's how you get a dirty classification. So, sometimes, that's frustrating for me, but it does actually correlate out.
LAURA BROWN: So, the rates of infection differ significantly based on the classification. So, if your hospital's rates are higher than is acceptable, that hospital can lose reimbursement from CMS. So, for small hospitals, actually any hospital in this day and age, that can be a disaster for them. So you need to know about SSIs, you need to know about these risk factors, and what you can do to modify the patient's factors beforehand.
LAURA BROWN: And you need to accurately document the wound class. One of the most important rules for residents, is to accurately order the surgical prophylaxis. This is one of the biggest places where you can make a difference, is to make sure that we give the right antibiotics before we even start the case. So, let's take another case real quick in the next slide, and talk about some of those antibiotics.
AMIT JOSHI: Dr. Brown, just before you go to that, I have a question about different kinds of surgical site infections. So, let's say you're the patients who, you do open a wound, so they get dinged with a superficial site infection. If you then subsequently go and, let's say, they get an IR drain for a deep organ space infection. Do you get double dinged? Or is it just the most-- the deepest that you get dinged for?
LAURA BROWN: Oh, that's a great question. I don't know the answer to that. That would be a good question for our infection control officer. I plan to have an answer for you.
AMIT JOSHI: Thanks. Things have gone really badly if we have three infections, but clearly the dietary habits of your patients in Ohio are different than ours in Philadelphia. We'd be scooping out cheese steak.
LAURA BROWN: Oh I see, I see. Well, that's a fair point. We have had fair share of sausage, too, so. OK, so let's talk about our next case. We have an 85-year-old man, who's admitted for a left MCA stroke. You're being consulted for the PEG, you like the PEG, right. I'm going to tell you, that sometimes, these cases end up being the most sphincter-tightening for trauma surgeons.
LAURA BROWN: Because usually I get called when it's an emergency. So, when it's not an emergency, it changes the rules a little bit. And these patients can be high risk. So, my question for you, though, is does this patient need antibiotics at the beginning of the case? Give a dose of antibiotics, and what do you give? Let's put this one on the chat. And, this should be an easy yes or no.
LAURA BROWN: Absolutely. That's great, guys. I agree. So, let's move on to the next slide. Yes, you should. And the reason why, is because you're opening the alimentary tract. This is one of those guidelines in the next slide that I mentioned to you that I was going to include.
LAURA BROWN: If we can have the next slide, please. So, this is published by the Surgical Infections Society, and these are guidelines for antimicrobial prophylaxis. This is from 2013. They're being worked on. I anticipate that you'll get a revised version, but if you're able to download this, I recommend that you keep a copy in your literature library.
LAURA BROWN: If you don't have one, I strongly recommend that you do this, that you start keeping papers that are relevant you, so you that you can go back and find them. Here's what I want to point out to you. There is a little known fact about the duration of common beta-lactam based antibiotics in the OR. And it's in very tiny print, but I want you to look over there, so you see that the antimicrobial is ampicilim-sulbactam.
LAURA BROWN: And you'll look at the recommended redosing interval, from the initiation of the preoperative dose. Two hours. Same thing for Zosyn. So, as a resident, I remember how many times that we gave Unasyn and Zosyn in the ED. And that may not last for the whole perforated viscus case. And I changed my pattern, to use a cefalosporin, such as cefotetan, so that I get that four- to six-hour redosing interval.
LAURA BROWN: And this is actually-- I've seen anecdotal change in the number of SSIs, but I do think that it is important that we recognize that some antibiotics are cleared faster in the operating room. Now, some hospitals don't know this information, and so they ask you crazily why you're insisting that you have to have a redose of Zosyn, since you just got one in ED.
LAURA BROWN: So either redose your Zosyn at two hours, you can reference this paper, and that's why I gave it to you. Or, change to a third or fourth generation cefalosporin. Clean and head, neck cases, they don't usually need prophylaxis. And, the risk of even dosing that antibiotic is higher than the risk of surgical site infection. Or any gastroduodenal case, I tend to use the cefazolin, or Unasyn if it's a really bad case.
LAURA BROWN: Sometimes, I'll switch to Zosyn, just if it's easier to get that, because sometimes Unasyn can be harder to get your hands on. There was a shortage for a while. If you're entering a tract, you're at a slightly higher risk. So you need to have something on board. So, please remember that that is a common board question. I'm seeing it over and over again.
LAURA BROWN: I can't remember the last time I had just a plain old symptomatic cholelithiasis case. They all come to me with a wall thickening of a centimeter and terribly inflamed. So I tend to give at least cefoxitin for my cases. Definitely, if you get spillage, you should upgrade your antibiotic from ancef, if that's all you've given. So, remember that.
LAURA BROWN: If you have biliary spillage, if you have overall contamination, you should probably upgrade your antibiotic [INAUDIBLE].. And for colon cases, please remember to dose something for anaerobes, such as flagyl, you should do ancef and flagyl as a standard. Or, you can do cefotetan. I put Unasyn in parentheses, because I actually don't recommend Unasyn anymore. The standard of care is to do that mechanical bowel prep preoperatively.
LAURA BROWN: This is where that information comes from. I'm going to wrap up, here, on this prevention and treatment of SSI. Next slide should have a QR code for that section. And then we're going to move on into another case.
AMIT JOSHI: And I just put those clinical practice guidelines out, that's the download link, if you want it.
LAURA BROWN: Thank you. Oh, that's awesome. That's even better. OK, when we're ready, let's move on to our next case. So this is a 64-year-old woman with a history of diabetes, end-stage renal on IHD, COPD, and the consults for nec fasc. That was what was kind of billed across the pager. So, at the start of every rotation, I specifically tell our consult resident, if you get a consult for nec fasc, you need to let the chief and I know immediately, and we go see the consult with you.
LAURA BROWN: The problem is, my friends, that there's no time for a resident to go by, then the chief, and for trauma to come in, and then we meander over to look at this infection, that's then going to take half an hour to get up to the operating room. Oftentimes, we're seeing the patients just as the labs are coming back. Hopefully the ED has sent a CDC BNP, but they've often forgotten the CRP, which is a critical predictor for the LRINEC score.
LAURA BROWN: This score, as you're going to see over and over again, this also shows up in exams. It's actually highly predictive for-- it's been validated for necrotizing fasciitis. Couple of things that I want to point out in this score to you. See, obviously, the propensity is higher for C-reactive protein, the factor is higher. So you get a score of 4 for that. But you also get [INAUDIBLE] points for leukocytosis greater than 15 or 25.
LAURA BROWN: For anemia, especially significant anemia, and hyponatremia, also, as the risk factor. So, if I see hyponatremia AKI, anemia, and leukocytosis, even if they haven't found the C-reactive protein, my hair is standing on end, and I'm usually pretty worried about that patient. You don't need imaging for these patients. If you're suspicious, and this patient is considered high risk, especially the diabetes, you should go look.
LAURA BROWN: Sometimes it's a very clear cut presentation. And so, on the next slide, I'm going to show you a case that, the resident said, I'm not quite sure, and I think you will be. Go ahead, next slide. So, the very clear cut presentation here, is the black eschar, with the surrounding erythema. The flatulence and malodor that comes with it.
LAURA BROWN: When we opened the wound, there was a dishwater fluid, with significant purulent and malodorous output. Obviously your goal is to send the cultures. Empiric antibiotics, and this is for NSTIs, are Zosyn, vancomycin, and Clindamycin. So Clindamycin is not great for treating infections, but it is very good for suppressing toxin production from group A streptococcus. So, I encourage you to include Clindamycin.
LAURA BROWN: That's considered the standard of care. Now, if my cultures come back, and I don't have group A streptococcus, or if the patient's starting to improve, I'll often stop the Clindamycin. In your operative debridement, you really-- I've done three mastectomies this year, as an acute care surgeon. That's not a common operation for me, let me tell you. I think two of them have been since COVID, because people aren't seeking care, and they're waiting longer and longer.
LAURA BROWN: Time is critical for patient survival, and to preserve tissue. I wanted to remind you, debride widely. That's why I included this picture. You should be down to the level of the fascia, you may even need to take the fascia. Send the deep tissue cultures from the operating room, not just superficial cultures from the wound, you may have multiple contaminants due to the necrotic tissue at the top.
LAURA BROWN: So make sure you send deep tissue cultures, too. Let's talk a little bit more about some of those key concepts. Why certain antibiotics are better. Why Zosyn, why vancomycin? Why does it matter? In our next slide. So, this is just a reminder to you, that the most important thing we do as surgeons is source control.
LAURA BROWN: You're going to see that at the top of every slide. That's because I don't want you to forget that. All of your antibiotics will work better if you decrease the bacterial load. But, you do need to remember how the antibiotics work, and to pick the right antibiotic for the job. Starting at the top, your cell wall agents are going to be your beta lactams, or your glycopeptides like vancomycin.
LAURA BROWN: Following around, you have fluoroquinolones that target DNA gyrase. You can have antibiotics that specifically target folate synthesis. And these tend to be more bacteriostatic, so they slow bacterial growth, not necessarily bactericidal, where they kill the bacteria. That one might be Bactrim. I always like to remember that a lot of people like to use Bactrim for MRSA coverage, but remember that it's just a bacteriostatic antibiotics.
LAURA BROWN: You can have other antibiotics that target protein synthesis. Some of the most famous ones [INAUDIBLE] ribosome are aminoglycocides. It also works there. The factors that are involved in this-- it's multifactorial. So, the first thing you want to do is consider those patient factors, like what is the disease, is it really infection or colonization, how sick is the patient.
LAURA BROWN: And you also need to consider how well that antibiotic works for that pathogen. Do you broad spectrum or narrow spectrum? Does the patient have known resistance? You may also need to consider institutional guidelines. For instance, now you can't get fluoroquinolones in most of the Southeast-Michigan, Northwest-Ohio, because we overused them in the 90s and the early aughts. And so, there's still such high resistance in this area, that most hospitals have shut down access.
LAURA BROWN: You can't get a fluoroquinolone, even if it matters. So, one of the most important things, is to consider the logistics of dosing. So, I'm going to ask you a question, now. What is the MIC? Jot it down real fast. Now, let's go to the next slide.
LAURA BROWN: MIC is the lowest serum drug concentration that inhibits bacterial growth. This is important, so on this graph the x-axis is time, and concentration is on the y-axis. I practically have this graph tattooed on my upper arm for ICU rounds. And that's because I want this to stick in your brains. A bolus dose gives you a higher concentration, which is really important for your aminoglycocides, for instance.
LAURA BROWN: In panel B, you're going to see the difference, here. In that red line, you see continuous infusion. With or without the bolus, you achieve the MIC for a longer period of time, so you get more antimicrobial activity. So you're above MIC for a longer period of time. This is called an extended infusion. It's nurse and patient and time intensive, but is very important for critically ill patients.
LAURA BROWN: So we do these extended infusions pretty commonly for beta-lactams like Zosyn in ICU patients. If your patient is critical, this is something we consider. A couple other quick points about dosing antibiotics, clearance. First let's talk about bioavailability. So, that's the amount of the dose that's available from the PO administration, after the first past hepatic clearance.
LAURA BROWN: Other alteration of the antibiotic, and absorption into the serum. So, bioavailability obviously, for fluoroquinolones is 1 to 1, but it's not true for every antibiotic, so that's something that you might need to consider. A quick note about clearance, so, when you're dosing antibiotics, you need to take the patient's estimated GFR into account. A very easy target to remember, is if there GFR is less than 30 you probably need to change the dose of antibiotic.
LAURA BROWN: I need that as a cutoff, and obviously, anything less than 30, you should probably touch base with pharmacy, or look up the appropriate dosing. I also want to make you aware of this other phenomenon, that we're seeing pretty frequently. Primarily in young male patients, who have had a pretty traumatic event or are in a highly catabolic state, and that's called augmented renal clearance.
LAURA BROWN: They're actually clearing antibiotics faster. These are the patients that you can't get a vancomycin trough into your target zone. You're giving them 3 grams of vancomycin, and they're just peeing it all out, it feels like. So, this is a known phenomenon we're seeing it more and more, and I want to encourage you to be aware of that, so that if you have a young patient who seems to not be getting better, consider that they may have augmented renal clearance.
LAURA BROWN: And that you may need to change the dosing of your antibiotics based on that. OK, I think this wraps up our section here on treatment. So, let's do our QR code in the next slide. And then, we're going to do a quick section on anti-microbial agents and surgical infection. So, again, you remember, I told you I was going to put source control at the top.
LAURA BROWN: Make sure you choose the right antibiotics, know how that antibiotic works. But I want you to also consider, as you're choosing your antibiotics, you need to watch out for resistance. So, I always ask the team, does the patient have any known multidrug resistance? And that means you have to look up all of their prior cultures if you can, especially in EMR.
LAURA BROWN: Find out if they have known previous infections where they were resistant, because they tend to carry those bugs with them. So, these patients, sometimes, have been bathing in antibiotics, depending on what they've been treating. You've all met that patient in ICU who lingers. And, they develop that resistance profile.
LAURA BROWN: And it means that you're very limited in choice of antibiotics. And, when you're picking for a patient, you need to consider that they're either resistant historically, or that there is high community resistance. And, you also need to consider your hospital microbiome. So, as part of your introduction to the hospital, you were introduced to a clinical home page, or some page that has that information available to you.
LAURA BROWN: You need to know the resistance profile in your community, in that hospital, and in your surrounding community. Because it's a real problem for surgical patients. Let's talk a little bit about how it affects patients in the next slide. OK, so the risks of MRSA site surgical infection-- MRSA surgical site infection, sorry. So, this is a great paper that characterized almost 300 surgical patients.
LAURA BROWN: And, you can see a significant difference in mortality. You start in the upper left panel, you'll see that MRSA patients are in the blue column on the left, and MSSA patients are in the yellow column on the right. You can see that it's drastically, pretty significant difference in mortality. Moving over to the right, you see a change in length of stay, and you also see a difference in the total charges per case, in that bottom panel.
LAURA BROWN: So, pretty significant difference in mortality, hospital stay, and cost, overall. And that's just from MRSA. Next slide. We are now really starting to describe risk factors associated with vancomycin resistance. You're seeing this more, I don't know if you guys have a blue gown brigade like we do, where every other room is in isolation, even before COVID.
LAURA BROWN: And these patients, the biggest risk factors for development of a vancomycin resistance, obviously, is patients treated with IV vancomycin. And you can think about how often we give IV vancomycin in the hospital. Or even if they've just been in the hospital for 72 hours, or been in ICU, if they have plastic in, so get your plastic out. These patients have increased mortality, a longer length of stay, and a higher ICU cost.
LAURA BROWN: You're going to hear about some other enteric organisms, depending on where you practice. The ones that you need to be aware of, I haven't necessarily put these in order, I want you to know that carbapenem-resistant Enterobacteriaceae, the CRE, require an ID consult. Just get ID on your side, you need them on board. You may have some options with MDR Pseudomonas and Acinetobacter, there are some antibiotics that you can choose.
LAURA BROWN: But let me tell you, you probably want to just call ID for them, too. And the reason why, is because these Pseudomonas is that I call him the great actor. He will figure out how to either efflux your antibiotic, or alter your antibiotic. Pseudomonas is famous for gathering resistance as it goes. So get ID onboard.
LAURA BROWN: Let's move on, to talk about some other components of antimicrobial stewardship. Remembering that resistance is so costly. So, we want to try and avoid it in our patients. So, in our next slide, we're going to talk about some of the key things that you need to remember as surgeons, about preventing resistance. You need to know when is the right time to start antibiotics.
LAURA BROWN: This is where you have to develop that sixth sense about whether it's inflammation or infection. You need to select the right drug, and you need to know the appropriate dose, route, and duration of that drug. And this is one of the most important, we're going to hit on this in the next section, so don't forget that. Make sure you culture your wounds and your infections so that you can de-escalate.
LAURA BROWN: If you figure out that you can narrow the spectrum a little bit, that's better for patients. Respect the bundles that are developed. So, we have VAP bundles-- ventilator associated pneumonia bundles-- we have efforts to remove lines and tubes, plastic from patients. The faster you get the plastic out, the harder it is for the bacteria to crawl along it and get inside.
LAURA BROWN: You can monitor for resistance. Your best effort is to know how to prescribe drugs. So, please look them up if you're new to prescribing them. Make sure you look them up. Make sure you know how that antibiotic should be dosed. A lot of pharmacies actually produce a little booklet for residents and trainees, that kind of talk about appropriate dosing, common antibiotics that are used, based on that hospital microbiome, and the dosing based on GFR.
LAURA BROWN: So, if you can, get your hands on one of those books. Resistance is so important to us, because it really plays a big factor in all three of those factors that are shown there. Mortality, length of stay, and cost. OK, this should end this section for us in the antimicrobial steward. One of my favorite topics.
AMIT JOSHI: One quick question about the LRINEC score in the chat. Can you see it?
LAURA BROWN: Yes, I saw that. So, January 2020, they actually published a study that suggested that perhaps there is a high false positive and false negative rate. So, I'm going to suggest to you, I think your clinical evaluation is the most important, in terms of your decision to go to the operating room. And, I'm going to also suggest to you, what false positive rate would be acceptable to you-- or false-- what rate would be acceptable for you to miss?
LAURA BROWN: You cannot afford to miss it. You cannot afford to miss nec fasc. Now, it may be that there can be a significant change in your clinical evaluation, just from the time that you got the consult to the time that you see the patient, that you actually physically get to see the patient. And that may be enough to push your clinical diagnosis, I would suggest to you, though, you need to at least take the patient to the operating room.
LAURA BROWN: You can make a small cut down incision, if you get watery fluid back, you know. You know already, that you need to do a wide operative debridement. So, I think that there is some newer data that may be suggesting that the LRINEC score is probably overused. One of the issues, is that not everybody send the CRP, or a very-- obviously, osteomyelitis, you can have a highly elevated CRP as well.
LAURA BROWN: So you have to use your clinical acumen, there. All right, let's move on to case five. OK, 76-year-old man, history of-- I'm sorry-- presents with perforated diverticulitis, Hinchey class IIa in ED. So this was a case of AB-CT scan. Patient came in with pain, got their CAT scan. Patient's obviously uncomfortable on exam. Has a heart rate of 120, blood pressure is pretty normal, but has focal peritonitis in the left lower quadrant.
LAURA BROWN: So what risk factors are you worried about in this patient for a intraabdominal infection? What things do you need to know about that factor here? And I'm going to move quickly onto the next slide, in this case. So, these are the Surgical Infection Society guidelines on the management of intraabdominal infection. These guidelines are also available from that SIS and IDSA website.
LAURA BROWN: It was done in conjunction with a IDSA, but these are available to you. These guidelines were published in 2017. Risk factors that I want you to know about. These patients should tighten your sphincter tone. Anybody in septic shock, with diffuse peritonitis is a higher risk patient. Any patient who is at risk for an opportunistic infection, is any patient in the hospital for more than 48 hours within the last 90 days, or who has had IV antibiotics, or renal replacement therapy.
LAURA BROWN: That's what RRT stands for. I'm going to show-- that this is a very tiny table-- these are the risk factors. I just want to point out to you, I've arrowed Apache, and SOFA score. So SOFA is the score that we use, now, to define sepsis. And that SOFA score greater than two, multiple studies have demonstrated that it's a high risk factor for dying.
LAURA BROWN: So, if they're already septic, that's worrisome. And, obviously inadequate source control, you'll see it circled down at the bottom. Those are also risk factors. So, when you are seeing patients who have an isolated abscess, I want you to consider these things in the background. If the patient's in shock, if the patient meets criteria for severe sepsis, that these are high risk patients.
LAURA BROWN: Let's move on to the next slide. What treatment plan would you recommend? So rather than get into the details of diverticulitis, I'm going to give you just a pause for a second, so that you can think about what you would do. The very top thing at the top of your list should be-- next slide.
AMIT JOSHI: Source control.
LAURA BROWN: Yes. So, whether that's via operative intervention, if they have diffuse peritonitis, I would favor operative intervention, based on the data. The first thing you need to do in these patients, is resuscitate them. You need to get them early antibiotics. Now, there is-- and I've included the guidelines and the grades, so that you can see the quality of the data.
LAURA BROWN: Source control within 24 hours. And more urgently, if they're in shock. So, I've used these guidelines sometimes, to motivate IR, when they feel like they can just let it sit on a Friday afternoon. Now, if you do a damage control laparotomy, the recommendation is not to schedule the re-laparoscopy, based on the guidelines. I will tell you that we do this in practice, so that we have OR time.
LAURA BROWN: But don't let that determine whether or not you have to. If you can, obtain cultures. Especially in these high risk patients, it's not recommended that you routinely obtain cultures, but that you obtain cultures in these high risk patients, which is why I wanted you to know those risk factors that we just talked about. So, if you have those two things, and you're taking the patient for operative, drainage or for damage control laparotomy, any patient, then you should probably obtain cultures from the operating room.
LAURA BROWN: Let's move on to the next slide. These antibiotics, I have bolded, underlined, and starred for you, this first line. It is still pretty common that I'm seeing that ED docs are using Unasyn or Augmentin. Recommendation is for Zosyn, or something that covers some more of your enteric organisms. We're seeing an increasing resistance in the Enterobacteriaceae, and so Zosyn is the first line antibiotic for these patients.
LAURA BROWN: Or, you can use the third or fourth generation cephalosporin with flagyl, so that you get in anaerobic coverage. You can use or ertapenem in low risk patients, meropenem in high risk. If they have a severe beta-lactam allergy, you can use aztreonam with flagyl. And vancomycin for Gram-positive coverage. Now, vancomycin, I don't tend to use in the belly, but this is the one time when you do vancomycin, is you're not otherwise going to have Gram-positive coverage with just aztreonam on board.
LAURA BROWN: Now, fluoroquinalones and flagyl at the bottom. And I'm going to tell you, I never recommend fluoroquinalones and flagyl. One, because the resistance I told you about, but also because there's a black box warning on fluoroquinalones. And also, because I don't think they work as well for it. So, I want to suggest to you, that perhaps we shouldn't be using them as-- you know, they're fourth on the list-- fifth on the list.
LAURA BROWN: So, you have many other excellent agents to use. Now, I've included whether or not you might add vancomycin, if you think that there's a risk of Gram-positive MRSA in the patients. So, those high risk patients, who are known MRSA positive. If you're not sure, if that's potentially one of the causes, you might need include that. You might include an antifungal. So, fluconazol in low risk patients, and echinocandin in the high risk patients.
LAURA BROWN: Echinocandin with a caspofungin, micafungin, one of those. So, those are your antibiotics that you would pick. Now, how long do you give them? Chat me up. We only have a few more minutes, so I'm going to try and speed us through. Good job, guys. We've got some stopping people, here.
LAURA BROWN: Let's go to the next slide. This is a trial that you need to know about. One, because of that resistance and that antimicrobial stewardship that we just talked about. This was an open label multi-center trial with more than 500 patients. And, it compared standard care, conventional therapy based on decrease in white blood cell count, resolution of fever, or resolution of ileus.
LAURA BROWN: Max 10 day course, versus four days attaining source control. No change in mortality or-- it was-- I think it was a very important factor. And I've included it getting here for you, so that you can know it. If you don't know it, it didn't increase the diagnosis of surgical site infection or recurrent intraabdominal infection. It's very important-- or whether they needed antibiotics later for another infection.
LAURA BROWN: It's very important for you to know this. It has changed our practice. We get source control, we stop antibiotics in four days. It's an automatic stop-it. And I'm not convinced that we're very good about doing this yet, our studies have shown that we actually only have about 60% adoption, even in the institutions that participated in the trial. So spread the word.
LAURA BROWN: Please, put this in your literature file, and share it with others around you. All right, let's wrap up intraabdominal infection, and then I'm going to hit quickly on two hospital-acquired infections in the last 4 minutes. OK, let's talk about hospital acquired infections. So, this is just a list of the most common microorganisms.
LAURA BROWN: So, you want to target antibiotics for that, most common microorganisms. Let's move on to the next slide. So, this is going to be a quick case on C. diff. So, we have an 84-year-old man who has a history of aortic stenosis, with a recent UTI, who presents from a SNF, with diffuse watery diarrhea, no bowel movements times 2 days. What does this guy have?
LAURA BROWN: Right. Right? He's now worse though, he's definitely in shock. And his heart, we talked about how this was going to be such a risk factor, the aortic stenosis, it's going to be a big problem for his chance of survival. So the first thing you have to do for the patient is resuscitate him.
LAURA BROWN: So, take him to the ICU, give him some fluid. Let's go to the next slide. You need to give him antibiotics and resuscitate him. Now, sometimes, you'll see an improvement, and the patient will resolve, they've just been dehydrated. Sometimes, it's not enough. And so, you may need operative intervention. And, in that case, the recommendation at this point is still total abdominal colectomy.
LAURA BROWN: I have seen, and had even some personal success, with what I call FECMO, which is the creation of a debriding loop ileostomy, and forward antegrade flushes with vancomycin, which was described in Pittsburgh. I come from an ECMO center, which is where that comes from. But I think the recommendation, still, at this point, is for total abdominal colectomy. And now, you have to understand that the risk of dying from toxic megacolon, balanced with the risk of an 84-year-old who has severe aortic stenosis.
LAURA BROWN: And so, obviously, that's a conversation you have with the family, beforehand, and make sure that you know patient's goals of care, before you even take us to the operating room. Goal is to just bring up that-- sometimes, I even just do the damage control, get the colon, out and get out of Dodge, and then go back and the-- mature the ostomy later.
LAURA BROWN: That might be your best chance of getting the patient through the operating room. Let's go on to the next slide. These are the recommendations. So, these are the IDSA guidelines for treatment for C. diff. Two things that are missing from this list, flagyl. Flagyl is missing. Flagyl is no longer our first line agent.
LAURA BROWN: It's only given if you suspect ileus. The other thing is that we used to be much more aggressive about giving rectal vancomycin, and now it's kind of reserved for those patients who are in shock with an ileus. And so, that should be given as a retention enema, 500 milligrams in saline, and then given into retention. So, to dwell up in the colon. I think the thing that's most important, and where we've seen the most success, is with early surgical consultation.
LAURA BROWN: So, you guys, sometimes, are the best people to teach these patients early on, and to make sure you know these recommendations for treatment of these patients. Any white cell count greater than 15,000, you should be involved. You should be watching that patient. Because sometimes you are their chance of survival. Let's move on to the next case, and talk about pneumonia, real quick.
LAURA BROWN: I want to just highlight for you, the criteria that are important for diagnosis in pneumonia. I'm going to go through this quickly, because again, this is guideline space, and I want you to have access to this. So this is up 87-year-old, afib on Coumadin, multiple rib fractures, he's intubated for respiratory failure. In the next slide, we talk a little bit about the criteria. This is a new definition, CDC based definition.
LAURA BROWN: So an increase in oxygen demand, as indicated there with an FiO2 of more than 0.2, or PEEP greater than three for two days. It is a ventilator-associated condition, VAC for short. If it comes with leukocytosis and fever, that's IVAC. OK, I put new infiltrate on chest X-ray, because that's still technically part of the definition, it's clinical diagnosis of pneumonia. It does not require the lavage to diagnose pneumonia.
LAURA BROWN: So, repeat after me, does not require lavage. Some institutions are not doing lavages anymore, and we talked a little bit about this in the diagnosis section. We talked about the criteria being greater than 10 to the fourth, and recovery of organisms. If you get a positive lavage, or you get an increase in the volume of secretions, and it's noted that they changed to purulent, that qualifies as a VAP.
LAURA BROWN: Recommended duration of antibiotics for these patients is eight days, with the exception of non-lactose fermenting organisms. So, non-lactose fermenters. Shouldn't have a-- higher risk for recurrence. And so, you may want to be more aggressive about treating those patients longer, but right now recommendations for treatment is seven to eight days. So, let's move on to what antibiotics you should pick, in the next slide.
LAURA BROWN: So, these are risk factors for multidrug resistant organisms on the left. So, any of these indications, you should be covering in an ICU level patient. You should be covering with a drug from column A, which includes your vancomycin or linezolid. Plus a drug from column B, which is your typical antipseudomonal penicillin or a cephalosporin. Now, you can pick anything from this list.
LAURA BROWN: I tend to go down the list. Now, this is the part that's a little bit more controversial. According to the guidelines, you should also pick from column C. So, that includes a fluoroquinalone, or an aminoglycoside. My favorite from that list is tobramycin, just because I feel like it's easier to dose and monitor the levels. Obviously, that can be risky in the setting of renal failure, and fluoroquinalones can be risky in the setting of other-- actors.
LAURA BROWN: Other liver drugs. So, amioderone, for instance, in the ICU. So, I want you to be careful, but the recommendation is that you pick from column C, as well. Now, I usually only do a five-day course of those, until I get the patient better. Now, I'm much more aggressive about picking from column C, in a patient who is septic from their pneumonia, and that's not every patient.
LAURA BROWN: So, you may have to use your clinical judgment to decide whether or not you should have another antibiotic on. Now, I have seen this come up in more questions, so I want you to be aware of this table, that the recommendation is for that third agent. Just briefly, we talked about this last slide, here, after pneumonia, is other HAI, other hospital acquired infections.
LAURA BROWN: We've already talked about, the culture is positive in a catheter-associated UTI if it's greater than 10 to the fifth organisms. That don't treat with yeast, get that fully out. CLABSI, we recommend culturing from peripheral lines. Remove the lines, if you can. This is the end of hospital acquired infections. And I'm going to just highlight a couple take home points, for you, as we go through these last two slides.
LAURA BROWN: Because we've run over. As I said, I love talking about this. So here is the scoop. Inflammation does not equal infection. Source control is your most important factor. Send cultures. Send them, send them, send them. Choose your antibiotics wisely, and dose them correctly. Call a pharmacist if you need help.
LAURA BROWN: Consider the resistance of either your patient, or the hospital microbiome, or the surrounding community. And lastly, based on that culture data, stop-- deescalate the antibiotic, or stop it completely, if you have culture data that suggests that you can. It was so much fun to talk with you about this. I don't know if my last slide of the picture of Cleveland made it into the slide deck. It's did.
LAURA BROWN: Isn't it beautiful? It's really been a pleasure to talk with you. If you have any other questions, please feel free to email me, contact me. And, if you got really interested in surgical infections and want to do critical care fellowship, I'm happy to help guide you in that route.
AMIT JOSHI: Dr. Brown, this is amazing. I think, after over a decade of practice of mine, I may go back and do a surgical critical care fellowship, I got so excited.
LAURA BROWN: That would be awesome. We'd love to have you.
AMIT JOSHI: Your excitement is contagious. It's amazing. This would be a great lecture to go back and listen to a couple times, because there was so much information. It was really wonderful.
LAURA BROWN: Yeah, I'm sorry it was so fast.
AMIT JOSHI: No, it was great. And I think we all know what to get you for Christmas. You need that dosing diagram on a shirt, so you don't have to tattoo it on your arm anymore.
LAURA BROWN: There you go, there you go.
AMIT JOSHI: This is amazing. Thank you so much, and good night everyone. We'll see you next week at SCORE school.
Segment:0 .
AMIT JOSHI: Good evening, everyone. It's just past the hour. Welcome to SCORE School. My name is Ahmed Joshi, I'm the associate editor of SCORE, and will serve as your moderator tonight. A few quick things before we get started, as usual we will be using the chat box for questions and comments. We'll be using the QR code for attendance tracking a couple of times during the presentation, and you only need to submit your form once to get an email receipt.
AMIT JOSHI: As [AUDIO OUT] --for later viewing on the website. There have been over 22,000 views of all of these sessions since we started in the summertime, and we encourage you to view them as your schedule allows. Because over 95% of the views have been off the website, as opposed to live, we're going to be moving the time of these live broadcasts to the Friday preceding the corresponding TWIS week. So for example, today's session will be recorded-- will have been recorded last Friday, so that it's available for all programs and trainees to be using in the corresponding TWIS week.
AMIT JOSHI: So please keep posted with the school website for the change of times. There'll still be at availability for people to log in, if they prefer to interact with the speakers, and the login information will likely stay the same. So for tonight's SCORE School, surgical infection is the topic of the week, we'll be discussing six modules. Hospital Acquired Infections was authored by Dr. Saira Nasar, [? Mai ?] [? al-Karam, ?] and [? Shadi ?] [? abu-Asawi. ?] Diagnostic Approach to Infections, authored by Brandy Padilla-Jones and Lillian Kale.
AMIT JOSHI: Anti-microbial Stewardship and Prevention, as well as Treatment of Surgical Site Infections, authored by Kevin Sullivan, and Heather Evans, and E Patchen Dellinger. Anti-microbial Agents and Surgical Infections, authored by Jessica Kramer and Sara Buckman, and Abdominal Infections, authored by Stephanie Goldberg and Therese Duane. We're obviously very grateful to all these authors of the over 600 modules on SCORE, which are updated every two to three years.
AMIT JOSHI: So without further ado, it is my distinct pleasure to introduce our faculty presenter tonight, Dr. Laura Brown, is a critical care trauma surgeon at Metro Health Medical Center, and an assistant professor at Case Western Reserve University in Cleveland, Ohio. She earned her undergraduate degree from Colorado State University, a PhD from the University of Colorado, in biophysics and molecular genetics, and her medical degree from the University of Michigan.
AMIT JOSHI: She Then completed a surgical residency, a surgical critical care and acute care fellowship at Michigan in that time as well. 21 years of education and training. After three years of practice and-- [LAUGHS] sorry for the reminder-- after three years of practice in Toledo, Ohio, she moved to Cleveland in 2018, where she currently serves as the associate program director of the Surgical Critical Care Fellowship.
AMIT JOSHI: She is a leader in the Surgical Infection Society and the Association of Surgical Education, and has won Teaching Award at every institution she has been affiliated with. Thank you, Dr. Brown, for lending your expertise to us, and take it away please.
LAURA BROWN: Oh, thank you so much for that wonderful introduction. I am very excited to be here with you today, to talk about one of my very favorite topics. The PhD in biophysics molecular genetics was actually in virology. So I've had a longstanding interest in all things infectious. Long before my surgical career, I thought I would [INAUDIBLE] through the wilds of Africa, chasing the next virus.
LAURA BROWN: I didn't know that it was going to come to me. I found my training in BSL-2 and -3 labs very helpful for the donning and doffing that we're undergoing during the midst of this pandemic. I am hoping today, to share a couple important things with you. Next slide, please. My disclosures are that I have no specific love of any microbe more than any others, but there are so many to choose from that are so important to surgical patients.
LAURA BROWN: So I'd like to give you a brief overview. Next slide, please. The goal of this talk, really, is to give you key highlights covered in these six SCORE modules. I've kept in mind where we are in TWIS and where we are in the year. We've got new interns, all the way to a very experienced chiefs, and so I've highlighted the most important concepts and goals and learning objectives.
LAURA BROWN: But it's not supposed to be a comprehensive compendium of every surgical infection. In fact, you're going to see that instead, what I did was include the best evidence and guideline recommendations. My goal, really, is that you are able to reference these later, as you're trying to manage patients on the wards. I recommend that you keep a copy of these guidelines in your literature library.
LAURA BROWN: My goal is really here to choose the cases that cover the most commonly missed questions from tests, on rounds, during discussions, and in the patient management decisions that are made every day that I see. Even sometimes by other attendings that are incorrect. So, what you're going to see here from me-- next slide-- oh I'm sorry, hold on. I want to pause real quick, here.
LAURA BROWN: My hope is that everyone listening tonight gets a little golden nugget of information that will aid them in their pathway to surgical Nirvana. And I want to say that, the only thing that I'm more passionate about than surgery and microbes, or microbes in surgical patients, is the neuroscience behind learning. And I specifically designed the session to not only convey this information to you, but to help you learn it faster and smarter.
LAURA BROWN: Anything that you see in italics is a question that I'd like for you to answer yourself. You might want a piece of paper, or you can use the chat function if you'd like. But the deal is that if you can watch and listen in your pj's, I want you to make an effort to write it down, and use the neuroscience of learning involved in engaging your brain, and writing things down to help lock this information into place.
LAURA BROWN: I purposely didn't include multiple choice, because I want you to actually write what you know, and then fill in what you don't based on our discussion tonight. And you might-- multiple choice does give me valuable feedback, it tells me whether or not I'm getting this information across you. But it doesn't work as well for the type of asynchronous setup and learning, or for multiple viewings by the same user, if you want to go back and retest yourself when you listen to it again.
LAURA BROWN: In virtual learning, we're only limited by our imagination, and the amount of engagement that we bring to the table. So if you're wearing your pj's, just put a pencil in your hand, and let's get started. Let's start with our first case. Next slide, please. This is an actual case that was brought to me by an intern on call.
LAURA BROWN: He was looking for the chief resident [INAUDIBLE] in the next room [INAUDIBLE] to the thigh. He had a page from the, night nurse, and comes into my room where we're doing an ex lap, and he tells me, hey I got this call. And he's clearly-- it's clearly one of his first pages during his intern year. And, so, I asked him, well what's running through your head?
LAURA BROWN: You have a 42-year-old man who had a laparoscopic left hemicolectomy. And that's all the information you've given me so far. So what do you think? Obviously, some things are running through my head, right off the bat, why did he get a left hemicolectomy? Turns out, that was for cancer. He's only 42. That makes me a little bit concerned.
LAURA BROWN: Does he have other comorbidities? What risk factors do you need to know about? OK, next slide, please. Obviously, these are the most common patient risk factors for infection. And this is age, is especially important in the coming decade or two, as we have our baby boomers advancing into geriatric status.
LAURA BROWN: And we'll see more and more geriatric patients. And one of the things we're very interested in-- what are the specific frailty markers that make someone more susceptible to infection? But other comorbidities, such as COPD any renal dysfunction, especially if the patient [INAUDIBLE].. We all probably listed diabetics and steroids, or transplant patients who are immunosuppressed. But I also want you to note those last two.
LAURA BROWN: You need to file away in your noggin, which is that any patient who has recently been hospitalized, or been in long term care, has been exposed to a different microbiome than their own. And they are more likely to have [INAUDIBLE] pathogens. Especially if they've had recent antibiotics, or if they've had prior resistant pathogens. So, those patients are going to be higher risk for you, and you need to pay closer attention to those two risk factors.
LAURA BROWN: It's not something that we commonly report. OK. Let's go on to the next slide. So, now that we have the information on our patient, no other real major comorbidities, this was obviously a new diagnosis. So, I asked the intern then, what things are you expecting from a post-op, day two patient?
LAURA BROWN: What things are you worried about? How does fever change over the postoperative course? Let's jot something down. Just think about what you are worried about. OK, I'm going to move quickly, because I have a feeling that in the next slide, that you guys all jotted this timeline down. We all learned W's of postoperative fever, right?
LAURA BROWN: And it's either that, or some variation in this. I still remember being pinned on the cytokines involved in fever as a medical student by chief resident. Who, by the way, is now a very affable certainly enigmatic Surgery Department chair. He has an awesome book case on Twitter. And, I remember very, very vividly, this experience as a medical student. And I think, although it was painful, the point of that review of the physiology, and making me use my immunology background to trace the pathways, was to point out to me that the majority of postoperative fever is due to inflammation.
LAURA BROWN: It's not necessarily infection. And so, I think that you have to remember that we're going to talk a lot about surgical infections, but one of our toughest jobs to dissect out whether this is really inflammation, or infection. And this classic description was written in all of our pre-intern surgery survival books. So we know it's a good place to start, but not long into practice, you begin to realize that there is some complexity and subtlety of a postoperative course.
LAURA BROWN: I'm going to propose a slightly different way of looking at this timeline. It's the Dr. Brown perspective. I'm going to include the infectious diagnoses that really can't afford to miss. And the reason that I do this, is that I try to highlight to the residents that the most important tools in your armamentarium is the review of the history, and a great physical exam.
LAURA BROWN: So, let's see if you would add anything to my diagram on the next slide. So, again, these are the things that I don't want you to miss, or that we can't afford to miss. And you'll notice I removed the times on the timeline. [INAUDIBLE] where these complications might present in real life. They can start at the beginning.
LAURA BROWN: It's general timeline from when they will present, but it's not always where they're going to present. And so, there's a little line there. But I want you to think of it more as a bracket. I coach the residents to specifically focus on and examine the skin around incisions in the abdominal exam, in that immediately post-op day zero surgery exam. I want you to think about NSTIs-- Necrotizing Soft Tissue Infections-- and leaks, there.
LAURA BROWN: Those are the two things that you absolutely have to rule out and can't afford to miss. And then, over the next few days in a patient, you may see a new onset hypoxia, cough, purulent sputum, or you might see leg swelling. Those might be other important factors that are going to be really important, when you're presenting this patient to your staff. Or, when you're thinking about what might be causing this.
LAURA BROWN: And then a little bit after this, you really start to worry about a surgical site infection. Whether it's just superficial, in the skin and subcutaneous tissue, or deep at the fascia, just below it. Or, is it an organ space surgical site infection, which are a little bit harder to detect. Part of the miracle of the body, is that, especially an abdominal surgery, the body will work to contain those bacteria by sequestration, isolation, and then the acidify the abscess pocket.
LAURA BROWN: That whole process takes anywhere from five to seven days, before you get that nice, rim-enhancing-- enhancing rim that you see on imaging. And that's why we sometimes wait to do the CAT scan. So that it's easier to see, and we have a better target, and it's easier to convince interventional radiology that we want to drain it. If we're really concerned about a leak, that may move may prioritize a CAT scan earlier in our diagnostic algorithm.
LAURA BROWN: All of this, everything that we've talked about, depends on the stability of the patient. So, the presumption is that the vitals are stable and patient is stable, and that may change how quickly you do things. I'm an intensivist, and acute care surgeon, so all of these diagnoses are right up my alley, and part of my life. And obviously, they changed the weight of importance for me.
LAURA BROWN: I say these things that you should not miss, but the most likely cause is what? Inflammation. The last thing I didn't mention, and I do want to mention it, I put implants far down the list. And that's because you may see a patient in clinic, even years after you've done a hernia repair with mesh, that presents with a delayed surgical site infection, or a delayed mesh infection.
LAURA BROWN: So don't forget that that's always a possibility. Let's talk a little bit-- I want to summarize a couple of key points about the workup and evaluation. And what are the key points of diagnosis? There was something that was just that on the chat, and I want to point it out to the whole group in case you're not also following the chat.
LAURA BROWN: It is absolutely important to take down the dressing. Even if it's before post-op day two, if you are really concerned about an NSTI. I know that we're taught that we shouldn't take down that dressing without our chief resident, but if you are concerned enough, if the patient is looking sick and you have spreading inflammation, you should look. You will be forgiven, I promise. OK, let's talk about-- next slide-- let's talk about diagnosis a little bit.
LAURA BROWN: Some of the factors that are important in diagnosis, and some things that may help you. These are tips and tricks, this is not a comprehensive list, but I want to point out a couple of things to you that I don't want you to forget. Gram stain is not perfect. You guys all remember from micro lab, how easy it was to stain the organism wrong. Most important is for you to get a culture with that Gram stain.
LAURA BROWN: The behavior on agar may actually help us isolate the organism quicker. And you give us more information-- infectious disease experts, about which class of microbe we're treating, and how likely it is to be resistant. Many diagnoses in this day and age are based on immunochemistry. So, the use of antibodies to an antigen, or an antibody detection itself in response to the antigen.
LAURA BROWN: That a patient's immune response, or production of those antibodies. And these antibodies or immunoglobulins are first produced as a pentad of IgM, and I told you have a strong immunology background, so don't let me lose you here, because it's a little bit of basic science, but remember that it comes out with five copies in a circle that are all connected.
LAURA BROWN: And that actually very strongly activates a complement cascade, and that tells you that it's an active infection. And as the B cells produce more immunoglobulin, and as the immune response matures, they often transition to making IgG, which is a dyad. And, one of the most common tested of examples of serology, the thing you're going to see on boards time and time again, is the hepatitides, and that's just plural for hepatitis. Everybody says that hepatitises, and I don't think that's right, so.
LAURA BROWN: Hepatitides is correct from a virologist, that the correct-- --and in hepatitis A, IgM indicates active infection, with [INAUDIBLE] indicates immunity. In hepatitis B we may test for a different part of the antigen of the virus itself. So if we're testing for the core antigen that indicates an active infection if the core antigen's positive, whereas at if surface the antigen indicates that the patient has already achieved immunity for hepatitis B.
LAURA BROWN: There is a technology, not listed here, that I want you to think about in your head. It's revolutionized the detection of microbes. And it's making a real difference in patient survival. The common example is the use of PCR to detect specific microbes in bloodstream infections, within two hours of arrival to the hospital. So that blood culture is drawn, [INAUDIBLE] and within two hours, we have an isolated organism.
LAURA BROWN: And that is life changing for intensivists. This is so important, because we know that the time to first dose of appropriate antibiotic is one of the single most important factors in surviving sepsis. This technology is a game-changer for you. And for me, and for the patient. Next slide.
LAURA BROWN: So, a couple other points that I want to make to you about a few other tests-- oh, before I forget-- you guys have all heard about the detection of C. diff toxin in stool, and why this is important, and that many people may carry the antigen. They actually need to colonize the C. diff, and they never show disease. And so, we may be detecting them as C. diff positive by immunoassay, but they are not PCR toxin positive.
LAURA BROWN: Meaning that they are not producing that toxin. And so, they don't have active infection. And this is super important, cause and what happens is we end up treating them as though they're C. diff positive, we all have to wear the boots, the isolation gowns, and isolate the patient. So, by using that genetic sequence of the toxin, we can determine whether the microbe is in fact producing the toxin, and whether it's likely an active infection.
LAURA BROWN: So, that's a good example of where PCR is changing your life. Let's talk a little bit about a couple other key points on these other diagnostic tests. So, we do need to know the components of a UA. So, the signs that are concerning for infection include leukocyte esterase, it's produced by the white blood cells, especially if that number of white blood cells is greater than the number of red blood cells.
LAURA BROWN: Keep in mind that if hematuria, or red blood cells spilled, you maybe look esterase positive, but only because you have blood in the urine. Nitride is specific to certain species of bacteria, so it's not sensitive necessarily, but more specific. The absence of nitrate doesn't tell you anything. It's only if it's positive, will it be important to you. And then, the presence of bacteria is obviously important.
LAURA BROWN: The patient may be colonized with bacteria, so you have to clinically decide whether or not patient's symptomatic. And any single species greater than 10 to the fifth is concerning, but you don't treat if it's yeast. When you're sending blood cultures, what do you need to remember? Try to send a peripheral.
LAURA BROWN: And if you can, send two. If Gram-positive cells come back on it, Gram-positive cocci come back on it, then it's very likely a contaminated skin for us, that'll help you rule that out. If you're sending a bronchial alveolar lavage, BAL for short. It's more invasive than tracheal aspirate. We need it for very sick patients, when they need to isolate the organism.
LAURA BROWN: If I'm really concerned about a multidrug resistant organism, I'll do a BAL, even though it's more invasive. Especially if the infiltrate on chest X-ray is in the left lobe. Sputum's not very helpful in that case, because you're just more likely to get the many bacteria found in the oral and nasopharyngeals. So, quick note about imaging, this is one that sits on the trauma service a lot.
LAURA BROWN: We tend to just get chest x-rays, and we get serial chest x-rays because we know the infiltrate's not going anywhere. If you see an infiltrate for two days in a row, I challenge you to grab your ultrasound and go see if that's an effusion or an infiltrate. I want you guys to get very comfortable with ultrasound, it's going to become a big part of your lives. If you can't get-- if your ultrasound isn't an option, or if you're sending the patient down for a CT of its abdomen and pelvis, get the chest, as well.
LAURA BROWN: But don't hesitate to look about what's going in the chest, get that information. It may be useful to you.
AMIT JOSHI: Dr. Brown, could I ask you one question? One of the controversies that came up in our program this morning, with the difference between a BAL and a tracheal aspirate. So could you just, maybe, precisely define the difference?
LAURA BROWN: Yes. So, a tracheal aspirate is taken from the upper portion of the trachea. So it does have more of the normal flora that are found. So you may have contaminated flora in that location. It's taken-- it's basically an irrigation aspirate from the inline suction from the ET tube. The difference with the BAL, is that it can be either a mini BAL, where the tube is directed far down into the right mainstem bronchus, past the majority of the normal flora.
LAURA BROWN: And you direct the lavage into the distal bronchus. And are able to aspirate back from that location. So, it's much more specific to those organisms that you would expect an infection in, in that case, as opposed to contaminants from the trachea. You may have patients who are colonized with organisms in the trachea, so that's why that's important. A BAL can also, as I mentioned, be directed to the left lobe, which is very imporant.
LAURA BROWN: You have a patient with a left lobe infiltrate. You're not going to get there with a mini BAL, with the tube that you just passed down there, you're not going to get down there with your suction cap. So you really need to put a bronchoscope in through the ET tube, target that bronchoscope over to the left lobe, and then you'll get a better recovery of organisms. BAL, It's often hard to recover organisms. And so, in that case, a BAL that's positive is 10 to the fourth organisms.
LAURA BROWN: And that's something that's different than some of your other clinical criteria. So, remember, we said UTI was 10 to the fifth, and BAL is positive if it's greater than 10 to the fourth organisms. Both of those, even if you do a tracheal aspirate, is still much, much, much, much better than sputum. Obviously, because there are many more organisms that are involved in the production of sputum.
LAURA BROWN: Normal flora. Any other great questions about diagnosis? This is just an overview.
AMIT JOSHI: Do you routinely use bedside ultrasound in the ICU?
LAURA BROWN: I do. So, this has become even more important in the COVID era, but I was a big fan of ultrasound long before that. I think that it's going to be a technology that becomes even more important. One of the issues in a lot of our patients is that they're too unstable for transport, and so you're limited in terms of what you can absorb. So, my fellows are challenged to ultrasound patients every day. So they do both the BLUE protocol, which looks at lungs, in the setting of-- to evaluate the consolidation and edema.
LAURA BROWN: Sometimes I find that very helpful in the setting of severe hypoxemia, where I can't transport the patient down to CAT scan, I don't even want to put a chest X-ray board behind him, but I can get an ultrasound probe on him. And it may help me determine whether this is truly all just consolidation, and I need to optimize recruitment of the alveoli a little bit better, or whether it's more edema, and I need to diurese the patient.
LAURA BROWN: So it can be very, very helpful in that setting. I strongly encourage people to get very comfortable with it. Obviously, it's well described, using ultrasound for the setting-- in shock, to help you isolate whether it's hypovolemic shock, or whether it's cardiogenic shock. Very useful for ICU patients. So I strongly recommend that you get comfortable. I carry that little pocket ultrasound that you can plug in to your phone.
LAURA BROWN: So, to me, it's become almost like my second stethoscope. Very useful technology. And the advantage of some of the newer technologies in ultrasound is that they're not as much not knobology involved, so you don't have to know all that in-points about how to change this to get the better view, it's one probe. One probe that you hold in your hand, but it essentially functions as everything from a cardiac phased array, or a linear probe, or an abdominal probe.
LAURA BROWN: So [INAUDIBLE] probe. So you get the advantage of all those different technologies in one tool. Super cool. It was my Christmas present, I saved up. We should all have dreams. All right, any other big questions about diagnosis that anybody wants to talk about?
LAURA BROWN: OK, the next slide I'll give you should hopefully be the QR code, I believe.
AMIT JOSHI: I'll just say one comment here, we had one listener last week whose program was not appearing on the QR code login. And so we've added that in. So if you're a SCORE-subscribing program, just let us know if for some reason your program is not appearing. OK, go ahead Dr. Brown, thanks.
LAURA BROWN: OK. So let's move on to another case, then, in our next slide. All right, this is a real case. Oops, sorry, next slide. Slightly altered to protect the innocent, obviously, but it highlights the importance of surgical site infections to our practice as surgeons. And I've given it away that it's a surgical site infection, but there's so much more value to this discussion.
LAURA BROWN: And there is a little bit in here for you about systemic-based practice, and practice-based learning. In addition to just surgical infections. And that's because all of the surgical infections you are going to encounter, are going to change the way you practice. And it's going to change reimbursement for your hospital. So, I want you-- this is why you need to know this information.
LAURA BROWN: Here's the information. 62-year-old woman, history of morbid obesity. She's got bad COPD, and she's now post-op day 10 from your emergency ex lap for a closed loop small bowel obstruction. Now, she's being seen at an urgent care, and the nurse notes purulent drainage, and starts antibiotics. And the hospital infection monitor calls you and says, this patient got tagged for a superficial SSI.
LAURA BROWN: Do you think she has a superficial SSI? And jot down what you think are those risk factors. If you can, I want you to just quickly, yes or no, weigh in on whether or not you think this patient has a surgical site infection.
LAURA BROWN: OK, great. Let's move on to the next slide. Hopefully you got a chance to jot. How many of these things you get? Were you close? Obviously this isn't completely inclusive, but the major risk factors known to contribute to superficial surgical site infections include age, obesity or malnutrition.
LAURA BROWN: So either spectrum. Diabetes, that's an obvious one. Smoking, that's also an obvious one. Some surgeons won't operate on a person who is smoking for an elective procedure, and will check the cotinine level preoperatively. Other hospitals have actually declined to schedule elective cases for A1c that's greater than 6.5. So, both of those are modifiable risk factors that we could manage preoperatively for elective cases.
LAURA BROWN: And so I want to encourage you to think about rehabilitating your patients, if you have that luxury, especially for those two diagnoses. OK, next slide. Let's jot down what we think are the diagnostic criteria for a superficial SSI.
LAURA BROWN: OK. Let's see what you got. Next slide. So, the problem here for this, is this was an advanced practice provider who didn't understand what fat necrosis looks like. It actually wasn't purulent, it was just broken down fat cells.
LAURA BROWN: There was no surrounding erythema. The patient had pain at the incision, but it wasn't any more pain than anywhere else in the incision. And they attributed the swelling to the adipose tissue that-- could be attributed to the adipose tissue that was nearby. So, the challenge was that this patient was started on antibiotics for probably what was just a little bit of drainage of fat necrosis. Now the hard part is that once it's said that there was purulent drainage anywhere in the chart, even at an outside hospital, or by another provider, that gets dinged, that gets tagged.
LAURA BROWN: Now, the only way that you can then say that this was not a surgical site infection is if you do not culture organisms from it. So, if you open a wound, I strongly recommend that you get in the habit of culturing it. And, the reason why, is that if that culture is negative-- you're already going to get dinged-- once you've opened it, once you've opened the wound, it's considered a superficial SSI.
LAURA BROWN: But, if that culture comes back negative, you can then get it removed from that list. So this is important I think this has changed our practice. And we now have a rule that only chief residents and attendings can open wounds, and that's so that they get cultured as we go. And now it turned out that this patient came to clinic right after this happened. The day after, we did open the wound and cultured it, and nothing grew.
LAURA BROWN: Which is how I can be convinced that that was just fat necrosis. So, it is fascinating to me that we have gotten to an age where it's not necessarily based on what was necessary for the patient, we didn't culture this patient because we needed know what organism was there, but because we needed to prove to them that it wasn't a surgical site infection.
LAURA BROWN: What an age we've come to.
AMIT JOSHI: It's the tail wagging the dog.
LAURA BROWN: Yes, yes it is. OK, this is part of learning to practice in a system that you have, and working hard to change it at the upper levels. All right, let's talk about how superficial site infections differ from deep surgical site infections, or organs space surgical site infections. What are the criteria that are different between them? And this is not an italic slide, so I want you to just quickly, on chat, give me an idea of what you think are the big differences.
LAURA BROWN: Absolutely, so deep to the fascia. All right, let's move on to the next slide. So, deep to the fascia, or fascia and/or below, especially if it comes with a spontaneous dehiscence.
LAURA BROWN: And it has to be diagnosed by the surgical attending so that actually, the APP, or another provider, or even a resident, can't diagnose that as a surgical site infection. The attending has to note it in their operative report or in their notes, and sign it. So now, if the resident writes it in the note in the attending co-signs, and says I agree with the resident's plan, then that does count as diagnosed by the surgical attending.
LAURA BROWN: So, I want you to be careful, if you really write that there's a surgical site infection, and you mean it, and you discussed it with the attending before you put it in the notes, because that's very, very important to the hospital system. All of these are within 30 days. Again, a deep SSI, if your culture comes back negative, there are no bacteria. Let's say you take the patient back for a dehiscence, spontaneous dehiscence, you think there's an SSI, you send deep tissue culture and it doesn't come back with something, then that's removed as well.
LAURA BROWN: I would strongly suggest, too, you that you do the same practice for organ space surgical site infections, to make sure that if, for instance, IR places a drain that they culture, I had a little bit of time there, where I was having trouble getting IR to actually send the culture, because they didn't feel that it was important, and then I explained to them that if it comes back negative, and we don't get dinged for the SSI, that's super important to our hospital system.
LAURA BROWN: So we're back to culturing, thank goodness. You're going to have some infection. We can't completely remove it. We can do our best to prevent it. We can optimize our patients. Especially if I'm scooping corn and Lima beans from the retroperitoneum, that's a true story. Although, my best ever was an entire pumpkin's worth of pumpkin seeds scooped from the retroperitoneum.
LAURA BROWN: So, we're going to get infection. No pumpkin seed is perfect. How can we balance that when we're dealing with bacteria? Especially in emergency cases. And so, the goal is to very clearly define in our wound classification at the outset, so we can accurately predict what the wound infection rate will be. So, in our next slide, we-- this is something you guys have all probably seen at your M&M, because I think we talk about it fairly frequently.
LAURA BROWN: In our next slide, the surgical wound classification. Now, obviously, there is a difference between a clean case, which represents little to no contamination, no containing tract is open, versus [INAUDIBLE] case, like a PEG, where you've actually opened an alimentary tract. Contaminated cases, and open fresh wounds, that includes trauma cases, which absolutely drives me crazy, here.
LAURA BROWN: Because if I'm scooping stool from the subhepatic space, I feel-- and I'm trying to get to that hole in the IVC-- I don't get any points for that, because it's fresh. It's not a dirty or infected wound. Because it's been there for a while, and there's nearby inflammation or devitalized tissue. That's how you get a dirty classification. So, sometimes, that's frustrating for me, but it does actually correlate out.
LAURA BROWN: So, the rates of infection differ significantly based on the classification. So, if your hospital's rates are higher than is acceptable, that hospital can lose reimbursement from CMS. So, for small hospitals, actually any hospital in this day and age, that can be a disaster for them. So you need to know about SSIs, you need to know about these risk factors, and what you can do to modify the patient's factors beforehand.
LAURA BROWN: And you need to accurately document the wound class. One of the most important rules for residents, is to accurately order the surgical prophylaxis. This is one of the biggest places where you can make a difference, is to make sure that we give the right antibiotics before we even start the case. So, let's take another case real quick in the next slide, and talk about some of those antibiotics.
AMIT JOSHI: Dr. Brown, just before you go to that, I have a question about different kinds of surgical site infections. So, let's say you're the patients who, you do open a wound, so they get dinged with a superficial site infection. If you then subsequently go and, let's say, they get an IR drain for a deep organ space infection. Do you get double dinged? Or is it just the most-- the deepest that you get dinged for?
LAURA BROWN: Oh, that's a great question. I don't know the answer to that. That would be a good question for our infection control officer. I plan to have an answer for you.
AMIT JOSHI: Thanks. Things have gone really badly if we have three infections, but clearly the dietary habits of your patients in Ohio are different than ours in Philadelphia. We'd be scooping out cheese steak.
LAURA BROWN: Oh I see, I see. Well, that's a fair point. We have had fair share of sausage, too, so. OK, so let's talk about our next case. We have an 85-year-old man, who's admitted for a left MCA stroke. You're being consulted for the PEG, you like the PEG, right. I'm going to tell you, that sometimes, these cases end up being the most sphincter-tightening for trauma surgeons.
LAURA BROWN: Because usually I get called when it's an emergency. So, when it's not an emergency, it changes the rules a little bit. And these patients can be high risk. So, my question for you, though, is does this patient need antibiotics at the beginning of the case? Give a dose of antibiotics, and what do you give? Let's put this one on the chat. And, this should be an easy yes or no.
LAURA BROWN: Absolutely. That's great, guys. I agree. So, let's move on to the next slide. Yes, you should. And the reason why, is because you're opening the alimentary tract. This is one of those guidelines in the next slide that I mentioned to you that I was going to include.
LAURA BROWN: If we can have the next slide, please. So, this is published by the Surgical Infections Society, and these are guidelines for antimicrobial prophylaxis. This is from 2013. They're being worked on. I anticipate that you'll get a revised version, but if you're able to download this, I recommend that you keep a copy in your literature library.
LAURA BROWN: If you don't have one, I strongly recommend that you do this, that you start keeping papers that are relevant you, so you that you can go back and find them. Here's what I want to point out to you. There is a little known fact about the duration of common beta-lactam based antibiotics in the OR. And it's in very tiny print, but I want you to look over there, so you see that the antimicrobial is ampicilim-sulbactam.
LAURA BROWN: And you'll look at the recommended redosing interval, from the initiation of the preoperative dose. Two hours. Same thing for Zosyn. So, as a resident, I remember how many times that we gave Unasyn and Zosyn in the ED. And that may not last for the whole perforated viscus case. And I changed my pattern, to use a cefalosporin, such as cefotetan, so that I get that four- to six-hour redosing interval.
LAURA BROWN: And this is actually-- I've seen anecdotal change in the number of SSIs, but I do think that it is important that we recognize that some antibiotics are cleared faster in the operating room. Now, some hospitals don't know this information, and so they ask you crazily why you're insisting that you have to have a redose of Zosyn, since you just got one in ED.
LAURA BROWN: So either redose your Zosyn at two hours, you can reference this paper, and that's why I gave it to you. Or, change to a third or fourth generation cefalosporin. Clean and head, neck cases, they don't usually need prophylaxis. And, the risk of even dosing that antibiotic is higher than the risk of surgical site infection. Or any gastroduodenal case, I tend to use the cefazolin, or Unasyn if it's a really bad case.
LAURA BROWN: Sometimes, I'll switch to Zosyn, just if it's easier to get that, because sometimes Unasyn can be harder to get your hands on. There was a shortage for a while. If you're entering a tract, you're at a slightly higher risk. So you need to have something on board. So, please remember that that is a common board question. I'm seeing it over and over again.
LAURA BROWN: I can't remember the last time I had just a plain old symptomatic cholelithiasis case. They all come to me with a wall thickening of a centimeter and terribly inflamed. So I tend to give at least cefoxitin for my cases. Definitely, if you get spillage, you should upgrade your antibiotic from ancef, if that's all you've given. So, remember that.
LAURA BROWN: If you have biliary spillage, if you have overall contamination, you should probably upgrade your antibiotic [INAUDIBLE].. And for colon cases, please remember to dose something for anaerobes, such as flagyl, you should do ancef and flagyl as a standard. Or, you can do cefotetan. I put Unasyn in parentheses, because I actually don't recommend Unasyn anymore. The standard of care is to do that mechanical bowel prep preoperatively.
LAURA BROWN: This is where that information comes from. I'm going to wrap up, here, on this prevention and treatment of SSI. Next slide should have a QR code for that section. And then we're going to move on into another case.
AMIT JOSHI: And I just put those clinical practice guidelines out, that's the download link, if you want it.
LAURA BROWN: Thank you. Oh, that's awesome. That's even better. OK, when we're ready, let's move on to our next case. So this is a 64-year-old woman with a history of diabetes, end-stage renal on IHD, COPD, and the consults for nec fasc. That was what was kind of billed across the pager. So, at the start of every rotation, I specifically tell our consult resident, if you get a consult for nec fasc, you need to let the chief and I know immediately, and we go see the consult with you.
LAURA BROWN: The problem is, my friends, that there's no time for a resident to go by, then the chief, and for trauma to come in, and then we meander over to look at this infection, that's then going to take half an hour to get up to the operating room. Oftentimes, we're seeing the patients just as the labs are coming back. Hopefully the ED has sent a CDC BNP, but they've often forgotten the CRP, which is a critical predictor for the LRINEC score.
LAURA BROWN: This score, as you're going to see over and over again, this also shows up in exams. It's actually highly predictive for-- it's been validated for necrotizing fasciitis. Couple of things that I want to point out in this score to you. See, obviously, the propensity is higher for C-reactive protein, the factor is higher. So you get a score of 4 for that. But you also get [INAUDIBLE] points for leukocytosis greater than 15 or 25.
LAURA BROWN: For anemia, especially significant anemia, and hyponatremia, also, as the risk factor. So, if I see hyponatremia AKI, anemia, and leukocytosis, even if they haven't found the C-reactive protein, my hair is standing on end, and I'm usually pretty worried about that patient. You don't need imaging for these patients. If you're suspicious, and this patient is considered high risk, especially the diabetes, you should go look.
LAURA BROWN: Sometimes it's a very clear cut presentation. And so, on the next slide, I'm going to show you a case that, the resident said, I'm not quite sure, and I think you will be. Go ahead, next slide. So, the very clear cut presentation here, is the black eschar, with the surrounding erythema. The flatulence and malodor that comes with it.
LAURA BROWN: When we opened the wound, there was a dishwater fluid, with significant purulent and malodorous output. Obviously your goal is to send the cultures. Empiric antibiotics, and this is for NSTIs, are Zosyn, vancomycin, and Clindamycin. So Clindamycin is not great for treating infections, but it is very good for suppressing toxin production from group A streptococcus. So, I encourage you to include Clindamycin.
LAURA BROWN: That's considered the standard of care. Now, if my cultures come back, and I don't have group A streptococcus, or if the patient's starting to improve, I'll often stop the Clindamycin. In your operative debridement, you really-- I've done three mastectomies this year, as an acute care surgeon. That's not a common operation for me, let me tell you. I think two of them have been since COVID, because people aren't seeking care, and they're waiting longer and longer.
LAURA BROWN: Time is critical for patient survival, and to preserve tissue. I wanted to remind you, debride widely. That's why I included this picture. You should be down to the level of the fascia, you may even need to take the fascia. Send the deep tissue cultures from the operating room, not just superficial cultures from the wound, you may have multiple contaminants due to the necrotic tissue at the top.
LAURA BROWN: So make sure you send deep tissue cultures, too. Let's talk a little bit more about some of those key concepts. Why certain antibiotics are better. Why Zosyn, why vancomycin? Why does it matter? In our next slide. So, this is just a reminder to you, that the most important thing we do as surgeons is source control.
LAURA BROWN: You're going to see that at the top of every slide. That's because I don't want you to forget that. All of your antibiotics will work better if you decrease the bacterial load. But, you do need to remember how the antibiotics work, and to pick the right antibiotic for the job. Starting at the top, your cell wall agents are going to be your beta lactams, or your glycopeptides like vancomycin.
LAURA BROWN: Following around, you have fluoroquinolones that target DNA gyrase. You can have antibiotics that specifically target folate synthesis. And these tend to be more bacteriostatic, so they slow bacterial growth, not necessarily bactericidal, where they kill the bacteria. That one might be Bactrim. I always like to remember that a lot of people like to use Bactrim for MRSA coverage, but remember that it's just a bacteriostatic antibiotics.
LAURA BROWN: You can have other antibiotics that target protein synthesis. Some of the most famous ones [INAUDIBLE] ribosome are aminoglycocides. It also works there. The factors that are involved in this-- it's multifactorial. So, the first thing you want to do is consider those patient factors, like what is the disease, is it really infection or colonization, how sick is the patient.
LAURA BROWN: And you also need to consider how well that antibiotic works for that pathogen. Do you broad spectrum or narrow spectrum? Does the patient have known resistance? You may also need to consider institutional guidelines. For instance, now you can't get fluoroquinolones in most of the Southeast-Michigan, Northwest-Ohio, because we overused them in the 90s and the early aughts. And so, there's still such high resistance in this area, that most hospitals have shut down access.
LAURA BROWN: You can't get a fluoroquinolone, even if it matters. So, one of the most important things, is to consider the logistics of dosing. So, I'm going to ask you a question, now. What is the MIC? Jot it down real fast. Now, let's go to the next slide.
LAURA BROWN: MIC is the lowest serum drug concentration that inhibits bacterial growth. This is important, so on this graph the x-axis is time, and concentration is on the y-axis. I practically have this graph tattooed on my upper arm for ICU rounds. And that's because I want this to stick in your brains. A bolus dose gives you a higher concentration, which is really important for your aminoglycocides, for instance.
LAURA BROWN: In panel B, you're going to see the difference, here. In that red line, you see continuous infusion. With or without the bolus, you achieve the MIC for a longer period of time, so you get more antimicrobial activity. So you're above MIC for a longer period of time. This is called an extended infusion. It's nurse and patient and time intensive, but is very important for critically ill patients.
LAURA BROWN: So we do these extended infusions pretty commonly for beta-lactams like Zosyn in ICU patients. If your patient is critical, this is something we consider. A couple other quick points about dosing antibiotics, clearance. First let's talk about bioavailability. So, that's the amount of the dose that's available from the PO administration, after the first past hepatic clearance.
LAURA BROWN: Other alteration of the antibiotic, and absorption into the serum. So, bioavailability obviously, for fluoroquinolones is 1 to 1, but it's not true for every antibiotic, so that's something that you might need to consider. A quick note about clearance, so, when you're dosing antibiotics, you need to take the patient's estimated GFR into account. A very easy target to remember, is if there GFR is less than 30 you probably need to change the dose of antibiotic.
LAURA BROWN: I need that as a cutoff, and obviously, anything less than 30, you should probably touch base with pharmacy, or look up the appropriate dosing. I also want to make you aware of this other phenomenon, that we're seeing pretty frequently. Primarily in young male patients, who have had a pretty traumatic event or are in a highly catabolic state, and that's called augmented renal clearance.
LAURA BROWN: They're actually clearing antibiotics faster. These are the patients that you can't get a vancomycin trough into your target zone. You're giving them 3 grams of vancomycin, and they're just peeing it all out, it feels like. So, this is a known phenomenon we're seeing it more and more, and I want to encourage you to be aware of that, so that if you have a young patient who seems to not be getting better, consider that they may have augmented renal clearance.
LAURA BROWN: And that you may need to change the dosing of your antibiotics based on that. OK, I think this wraps up our section here on treatment. So, let's do our QR code in the next slide. And then, we're going to do a quick section on anti-microbial agents and surgical infection. So, again, you remember, I told you I was going to put source control at the top.
LAURA BROWN: Make sure you choose the right antibiotics, know how that antibiotic works. But I want you to also consider, as you're choosing your antibiotics, you need to watch out for resistance. So, I always ask the team, does the patient have any known multidrug resistance? And that means you have to look up all of their prior cultures if you can, especially in EMR.
LAURA BROWN: Find out if they have known previous infections where they were resistant, because they tend to carry those bugs with them. So, these patients, sometimes, have been bathing in antibiotics, depending on what they've been treating. You've all met that patient in ICU who lingers. And, they develop that resistance profile.
LAURA BROWN: And it means that you're very limited in choice of antibiotics. And, when you're picking for a patient, you need to consider that they're either resistant historically, or that there is high community resistance. And, you also need to consider your hospital microbiome. So, as part of your introduction to the hospital, you were introduced to a clinical home page, or some page that has that information available to you.
LAURA BROWN: You need to know the resistance profile in your community, in that hospital, and in your surrounding community. Because it's a real problem for surgical patients. Let's talk a little bit about how it affects patients in the next slide. OK, so the risks of MRSA site surgical infection-- MRSA surgical site infection, sorry. So, this is a great paper that characterized almost 300 surgical patients.
LAURA BROWN: And, you can see a significant difference in mortality. You start in the upper left panel, you'll see that MRSA patients are in the blue column on the left, and MSSA patients are in the yellow column on the right. You can see that it's drastically, pretty significant difference in mortality. Moving over to the right, you see a change in length of stay, and you also see a difference in the total charges per case, in that bottom panel.
LAURA BROWN: So, pretty significant difference in mortality, hospital stay, and cost, overall. And that's just from MRSA. Next slide. We are now really starting to describe risk factors associated with vancomycin resistance. You're seeing this more, I don't know if you guys have a blue gown brigade like we do, where every other room is in isolation, even before COVID.
LAURA BROWN: And these patients, the biggest risk factors for development of a vancomycin resistance, obviously, is patients treated with IV vancomycin. And you can think about how often we give IV vancomycin in the hospital. Or even if they've just been in the hospital for 72 hours, or been in ICU, if they have plastic in, so get your plastic out. These patients have increased mortality, a longer length of stay, and a higher ICU cost.
LAURA BROWN: You're going to hear about some other enteric organisms, depending on where you practice. The ones that you need to be aware of, I haven't necessarily put these in order, I want you to know that carbapenem-resistant Enterobacteriaceae, the CRE, require an ID consult. Just get ID on your side, you need them on board. You may have some options with MDR Pseudomonas and Acinetobacter, there are some antibiotics that you can choose.
LAURA BROWN: But let me tell you, you probably want to just call ID for them, too. And the reason why, is because these Pseudomonas is that I call him the great actor. He will figure out how to either efflux your antibiotic, or alter your antibiotic. Pseudomonas is famous for gathering resistance as it goes. So get ID onboard.
LAURA BROWN: Let's move on, to talk about some other components of antimicrobial stewardship. Remembering that resistance is so costly. So, we want to try and avoid it in our patients. So, in our next slide, we're going to talk about some of the key things that you need to remember as surgeons, about preventing resistance. You need to know when is the right time to start antibiotics.
LAURA BROWN: This is where you have to develop that sixth sense about whether it's inflammation or infection. You need to select the right drug, and you need to know the appropriate dose, route, and duration of that drug. And this is one of the most important, we're going to hit on this in the next section, so don't forget that. Make sure you culture your wounds and your infections so that you can de-escalate.
LAURA BROWN: If you figure out that you can narrow the spectrum a little bit, that's better for patients. Respect the bundles that are developed. So, we have VAP bundles-- ventilator associated pneumonia bundles-- we have efforts to remove lines and tubes, plastic from patients. The faster you get the plastic out, the harder it is for the bacteria to crawl along it and get inside.
LAURA BROWN: You can monitor for resistance. Your best effort is to know how to prescribe drugs. So, please look them up if you're new to prescribing them. Make sure you look them up. Make sure you know how that antibiotic should be dosed. A lot of pharmacies actually produce a little booklet for residents and trainees, that kind of talk about appropriate dosing, common antibiotics that are used, based on that hospital microbiome, and the dosing based on GFR.
LAURA BROWN: So, if you can, get your hands on one of those books. Resistance is so important to us, because it really plays a big factor in all three of those factors that are shown there. Mortality, length of stay, and cost. OK, this should end this section for us in the antimicrobial steward. One of my favorite topics.
AMIT JOSHI: One quick question about the LRINEC score in the chat. Can you see it?
LAURA BROWN: Yes, I saw that. So, January 2020, they actually published a study that suggested that perhaps there is a high false positive and false negative rate. So, I'm going to suggest to you, I think your clinical evaluation is the most important, in terms of your decision to go to the operating room. And, I'm going to also suggest to you, what false positive rate would be acceptable to you-- or false-- what rate would be acceptable for you to miss?
LAURA BROWN: You cannot afford to miss it. You cannot afford to miss nec fasc. Now, it may be that there can be a significant change in your clinical evaluation, just from the time that you got the consult to the time that you see the patient, that you actually physically get to see the patient. And that may be enough to push your clinical diagnosis, I would suggest to you, though, you need to at least take the patient to the operating room.
LAURA BROWN: You can make a small cut down incision, if you get watery fluid back, you know. You know already, that you need to do a wide operative debridement. So, I think that there is some newer data that may be suggesting that the LRINEC score is probably overused. One of the issues, is that not everybody send the CRP, or a very-- obviously, osteomyelitis, you can have a highly elevated CRP as well.
LAURA BROWN: So you have to use your clinical acumen, there. All right, let's move on to case five. OK, 76-year-old man, history of-- I'm sorry-- presents with perforated diverticulitis, Hinchey class IIa in ED. So this was a case of AB-CT scan. Patient came in with pain, got their CAT scan. Patient's obviously uncomfortable on exam. Has a heart rate of 120, blood pressure is pretty normal, but has focal peritonitis in the left lower quadrant.
LAURA BROWN: So what risk factors are you worried about in this patient for a intraabdominal infection? What things do you need to know about that factor here? And I'm going to move quickly onto the next slide, in this case. So, these are the Surgical Infection Society guidelines on the management of intraabdominal infection. These guidelines are also available from that SIS and IDSA website.
LAURA BROWN: It was done in conjunction with a IDSA, but these are available to you. These guidelines were published in 2017. Risk factors that I want you to know about. These patients should tighten your sphincter tone. Anybody in septic shock, with diffuse peritonitis is a higher risk patient. Any patient who is at risk for an opportunistic infection, is any patient in the hospital for more than 48 hours within the last 90 days, or who has had IV antibiotics, or renal replacement therapy.
LAURA BROWN: That's what RRT stands for. I'm going to show-- that this is a very tiny table-- these are the risk factors. I just want to point out to you, I've arrowed Apache, and SOFA score. So SOFA is the score that we use, now, to define sepsis. And that SOFA score greater than two, multiple studies have demonstrated that it's a high risk factor for dying.
LAURA BROWN: So, if they're already septic, that's worrisome. And, obviously inadequate source control, you'll see it circled down at the bottom. Those are also risk factors. So, when you are seeing patients who have an isolated abscess, I want you to consider these things in the background. If the patient's in shock, if the patient meets criteria for severe sepsis, that these are high risk patients.
LAURA BROWN: Let's move on to the next slide. What treatment plan would you recommend? So rather than get into the details of diverticulitis, I'm going to give you just a pause for a second, so that you can think about what you would do. The very top thing at the top of your list should be-- next slide.
AMIT JOSHI: Source control.
LAURA BROWN: Yes. So, whether that's via operative intervention, if they have diffuse peritonitis, I would favor operative intervention, based on the data. The first thing you need to do in these patients, is resuscitate them. You need to get them early antibiotics. Now, there is-- and I've included the guidelines and the grades, so that you can see the quality of the data.
LAURA BROWN: Source control within 24 hours. And more urgently, if they're in shock. So, I've used these guidelines sometimes, to motivate IR, when they feel like they can just let it sit on a Friday afternoon. Now, if you do a damage control laparotomy, the recommendation is not to schedule the re-laparoscopy, based on the guidelines. I will tell you that we do this in practice, so that we have OR time.
LAURA BROWN: But don't let that determine whether or not you have to. If you can, obtain cultures. Especially in these high risk patients, it's not recommended that you routinely obtain cultures, but that you obtain cultures in these high risk patients, which is why I wanted you to know those risk factors that we just talked about. So, if you have those two things, and you're taking the patient for operative, drainage or for damage control laparotomy, any patient, then you should probably obtain cultures from the operating room.
LAURA BROWN: Let's move on to the next slide. These antibiotics, I have bolded, underlined, and starred for you, this first line. It is still pretty common that I'm seeing that ED docs are using Unasyn or Augmentin. Recommendation is for Zosyn, or something that covers some more of your enteric organisms. We're seeing an increasing resistance in the Enterobacteriaceae, and so Zosyn is the first line antibiotic for these patients.
LAURA BROWN: Or, you can use the third or fourth generation cephalosporin with flagyl, so that you get in anaerobic coverage. You can use or ertapenem in low risk patients, meropenem in high risk. If they have a severe beta-lactam allergy, you can use aztreonam with flagyl. And vancomycin for Gram-positive coverage. Now, vancomycin, I don't tend to use in the belly, but this is the one time when you do vancomycin, is you're not otherwise going to have Gram-positive coverage with just aztreonam on board.
LAURA BROWN: Now, fluoroquinalones and flagyl at the bottom. And I'm going to tell you, I never recommend fluoroquinalones and flagyl. One, because the resistance I told you about, but also because there's a black box warning on fluoroquinalones. And also, because I don't think they work as well for it. So, I want to suggest to you, that perhaps we shouldn't be using them as-- you know, they're fourth on the list-- fifth on the list.
LAURA BROWN: So, you have many other excellent agents to use. Now, I've included whether or not you might add vancomycin, if you think that there's a risk of Gram-positive MRSA in the patients. So, those high risk patients, who are known MRSA positive. If you're not sure, if that's potentially one of the causes, you might need include that. You might include an antifungal. So, fluconazol in low risk patients, and echinocandin in the high risk patients.
LAURA BROWN: Echinocandin with a caspofungin, micafungin, one of those. So, those are your antibiotics that you would pick. Now, how long do you give them? Chat me up. We only have a few more minutes, so I'm going to try and speed us through. Good job, guys. We've got some stopping people, here.
LAURA BROWN: Let's go to the next slide. This is a trial that you need to know about. One, because of that resistance and that antimicrobial stewardship that we just talked about. This was an open label multi-center trial with more than 500 patients. And, it compared standard care, conventional therapy based on decrease in white blood cell count, resolution of fever, or resolution of ileus.
LAURA BROWN: Max 10 day course, versus four days attaining source control. No change in mortality or-- it was-- I think it was a very important factor. And I've included it getting here for you, so that you can know it. If you don't know it, it didn't increase the diagnosis of surgical site infection or recurrent intraabdominal infection. It's very important-- or whether they needed antibiotics later for another infection.
LAURA BROWN: It's very important for you to know this. It has changed our practice. We get source control, we stop antibiotics in four days. It's an automatic stop-it. And I'm not convinced that we're very good about doing this yet, our studies have shown that we actually only have about 60% adoption, even in the institutions that participated in the trial. So spread the word.
LAURA BROWN: Please, put this in your literature file, and share it with others around you. All right, let's wrap up intraabdominal infection, and then I'm going to hit quickly on two hospital-acquired infections in the last 4 minutes. OK, let's talk about hospital acquired infections. So, this is just a list of the most common microorganisms.
LAURA BROWN: So, you want to target antibiotics for that, most common microorganisms. Let's move on to the next slide. So, this is going to be a quick case on C. diff. So, we have an 84-year-old man who has a history of aortic stenosis, with a recent UTI, who presents from a SNF, with diffuse watery diarrhea, no bowel movements times 2 days. What does this guy have?
LAURA BROWN: Right. Right? He's now worse though, he's definitely in shock. And his heart, we talked about how this was going to be such a risk factor, the aortic stenosis, it's going to be a big problem for his chance of survival. So the first thing you have to do for the patient is resuscitate him.
LAURA BROWN: So, take him to the ICU, give him some fluid. Let's go to the next slide. You need to give him antibiotics and resuscitate him. Now, sometimes, you'll see an improvement, and the patient will resolve, they've just been dehydrated. Sometimes, it's not enough. And so, you may need operative intervention. And, in that case, the recommendation at this point is still total abdominal colectomy.
LAURA BROWN: I have seen, and had even some personal success, with what I call FECMO, which is the creation of a debriding loop ileostomy, and forward antegrade flushes with vancomycin, which was described in Pittsburgh. I come from an ECMO center, which is where that comes from. But I think the recommendation, still, at this point, is for total abdominal colectomy. And now, you have to understand that the risk of dying from toxic megacolon, balanced with the risk of an 84-year-old who has severe aortic stenosis.
LAURA BROWN: And so, obviously, that's a conversation you have with the family, beforehand, and make sure that you know patient's goals of care, before you even take us to the operating room. Goal is to just bring up that-- sometimes, I even just do the damage control, get the colon, out and get out of Dodge, and then go back and the-- mature the ostomy later.
LAURA BROWN: That might be your best chance of getting the patient through the operating room. Let's go on to the next slide. These are the recommendations. So, these are the IDSA guidelines for treatment for C. diff. Two things that are missing from this list, flagyl. Flagyl is missing. Flagyl is no longer our first line agent.
LAURA BROWN: It's only given if you suspect ileus. The other thing is that we used to be much more aggressive about giving rectal vancomycin, and now it's kind of reserved for those patients who are in shock with an ileus. And so, that should be given as a retention enema, 500 milligrams in saline, and then given into retention. So, to dwell up in the colon. I think the thing that's most important, and where we've seen the most success, is with early surgical consultation.
LAURA BROWN: So, you guys, sometimes, are the best people to teach these patients early on, and to make sure you know these recommendations for treatment of these patients. Any white cell count greater than 15,000, you should be involved. You should be watching that patient. Because sometimes you are their chance of survival. Let's move on to the next case, and talk about pneumonia, real quick.
LAURA BROWN: I want to just highlight for you, the criteria that are important for diagnosis in pneumonia. I'm going to go through this quickly, because again, this is guideline space, and I want you to have access to this. So this is up 87-year-old, afib on Coumadin, multiple rib fractures, he's intubated for respiratory failure. In the next slide, we talk a little bit about the criteria. This is a new definition, CDC based definition.
LAURA BROWN: So an increase in oxygen demand, as indicated there with an FiO2 of more than 0.2, or PEEP greater than three for two days. It is a ventilator-associated condition, VAC for short. If it comes with leukocytosis and fever, that's IVAC. OK, I put new infiltrate on chest X-ray, because that's still technically part of the definition, it's clinical diagnosis of pneumonia. It does not require the lavage to diagnose pneumonia.
LAURA BROWN: So, repeat after me, does not require lavage. Some institutions are not doing lavages anymore, and we talked a little bit about this in the diagnosis section. We talked about the criteria being greater than 10 to the fourth, and recovery of organisms. If you get a positive lavage, or you get an increase in the volume of secretions, and it's noted that they changed to purulent, that qualifies as a VAP.
LAURA BROWN: Recommended duration of antibiotics for these patients is eight days, with the exception of non-lactose fermenting organisms. So, non-lactose fermenters. Shouldn't have a-- higher risk for recurrence. And so, you may want to be more aggressive about treating those patients longer, but right now recommendations for treatment is seven to eight days. So, let's move on to what antibiotics you should pick, in the next slide.
LAURA BROWN: So, these are risk factors for multidrug resistant organisms on the left. So, any of these indications, you should be covering in an ICU level patient. You should be covering with a drug from column A, which includes your vancomycin or linezolid. Plus a drug from column B, which is your typical antipseudomonal penicillin or a cephalosporin. Now, you can pick anything from this list.
LAURA BROWN: I tend to go down the list. Now, this is the part that's a little bit more controversial. According to the guidelines, you should also pick from column C. So, that includes a fluoroquinalone, or an aminoglycoside. My favorite from that list is tobramycin, just because I feel like it's easier to dose and monitor the levels. Obviously, that can be risky in the setting of renal failure, and fluoroquinalones can be risky in the setting of other-- actors.
LAURA BROWN: Other liver drugs. So, amioderone, for instance, in the ICU. So, I want you to be careful, but the recommendation is that you pick from column C, as well. Now, I usually only do a five-day course of those, until I get the patient better. Now, I'm much more aggressive about picking from column C, in a patient who is septic from their pneumonia, and that's not every patient.
LAURA BROWN: So, you may have to use your clinical judgment to decide whether or not you should have another antibiotic on. Now, I have seen this come up in more questions, so I want you to be aware of this table, that the recommendation is for that third agent. Just briefly, we talked about this last slide, here, after pneumonia, is other HAI, other hospital acquired infections.
LAURA BROWN: We've already talked about, the culture is positive in a catheter-associated UTI if it's greater than 10 to the fifth organisms. That don't treat with yeast, get that fully out. CLABSI, we recommend culturing from peripheral lines. Remove the lines, if you can. This is the end of hospital acquired infections. And I'm going to just highlight a couple take home points, for you, as we go through these last two slides.
LAURA BROWN: Because we've run over. As I said, I love talking about this. So here is the scoop. Inflammation does not equal infection. Source control is your most important factor. Send cultures. Send them, send them, send them. Choose your antibiotics wisely, and dose them correctly. Call a pharmacist if you need help.
LAURA BROWN: Consider the resistance of either your patient, or the hospital microbiome, or the surrounding community. And lastly, based on that culture data, stop-- deescalate the antibiotic, or stop it completely, if you have culture data that suggests that you can. It was so much fun to talk with you about this. I don't know if my last slide of the picture of Cleveland made it into the slide deck. It's did.
LAURA BROWN: Isn't it beautiful? It's really been a pleasure to talk with you. If you have any other questions, please feel free to email me, contact me. And, if you got really interested in surgical infections and want to do critical care fellowship, I'm happy to help guide you in that route.
AMIT JOSHI: Dr. Brown, this is amazing. I think, after over a decade of practice of mine, I may go back and do a surgical critical care fellowship, I got so excited.
LAURA BROWN: That would be awesome. We'd love to have you.
AMIT JOSHI: Your excitement is contagious. It's amazing. This would be a great lecture to go back and listen to a couple times, because there was so much information. It was really wonderful.
LAURA BROWN: Yeah, I'm sorry it was so fast.
AMIT JOSHI: No, it was great. And I think we all know what to get you for Christmas. You need that dosing diagram on a shirt, so you don't have to tattoo it on your arm anymore.
LAURA BROWN: There you go, there you go.
AMIT JOSHI: This is amazing. Thank you so much, and good night everyone. We'll see you next week at SCORE school.
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