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Episode 81: A 45-Year-Old with Lethargy and Confusion
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Episode 81: A 45-Year-Old with Lethargy and Confusion
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T00H08M23S
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2022-02-28T00:00:00.0000000
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Language: EN.
Segment:0 .
[upbeat intro music] [Dr. Handy] Hi, welcome to Harrison's Podclass, where we discuss important concepts in internal medicine. I'm Cathy Handy. [Dr. Wiener] And I'm Charlie Wiener, and we're coming to you from the Johns Hopkins School of Medicine. Welcome back. Today's patient is a 45-year-old with lethargy and confusion. Okay Cathy, today we're seeing a 45-year-old man with a history of alcoholism and presumed cirrhosis who is brought to the emergency department by his friend complaining of two to three days of increasing lethargy and confusion.
His friend reports that the patient has stayed in bed and has been sleepy for the past two days, and when they talk sports, which is one of their favorite topics, he's been repeating himself and repeating things from many years ago. The patient has not consumed alcohol for the past two years. He currently takes zero medications and works at home as a video game designer.
He was referred by his primary care physician for liver transplant evaluation and is scheduled to begin his evaluation next month. [Dr. Handy] All right, so we have a man with presumed cirrhosis with a change in mental status. Now, there's a very broad differential for altered mental status, but can narrow it a little bit in someone with cirrhosis and a more acute change.
Infection, worsening renal or liver function, and toxicity would be high on that differential. A physical examination in this patient would also be very helpful. [Dr. Wiener] Okay, so his blood pressure is 90/60, his heart rate is 105, his temperature is 38.5 centigrade, his respiratory rate is 10, and his room air saturation is 97%. He's somnolent but he's oriented a little bit, he's able to answer simple questions accurately.
But he gets confused with complicated questions and is not able to do serial seven subtractions. His skin is notable for many spider telangiectasias, and he has palmar erythema. His lungs are clear and his cardiac examination is normal. His jugular veins are flat at 45 degrees, though. He has distended diffusely tender abdomen with a positive fluid wave. There's no peripheral edema and he has no asterixis.
[Dr. Handy] So he's febrile with a borderline blood pressure and some tachycardia with a flat JVP suggesting intravascular volume depletion, but he has a distended abdomen with a fluid wave which is from ascites. You mentioned in the history that he has presumed cirrhosis, but he clearly has the quality of chronic liver disease and decompensated cirrhosis with the spider telangiectasias, the palmar erythema and ascites.
[Dr. Wiener] Okay, well, what would you do at this point for more treatment or diagnostics? [Dr. Handy] To begin, I would start with some fluid resuscitation in addition to basic labs, but he definitely needs a paracentesis to rule out infection. [Dr. Wiener] Okay, let's jump to the paracentesis because the question is going to relate to that. A paracentesis reveals slightly cloudy fluid with a white blood cell count of 1,000 per microliter and 40% neutrophils on the differential.
His blood pressure increases to 100/65 and his heart rate decreases to 95 after one liter of IV fluids. So the question asks, which of the following statements regarding his condition and treatment is true? Option A says, fever is present in greater than 50% of cases; option B says, initial empiric antibiotic therapy should include metronidazole or clindamycin for anaerobes; option C says, the diagnosis of primary or spontaneous bacterial peritonitis is not confirmed because the percentage of neutrophils in the peritoneal fluid is less than 50%; option D says, the most likely causative organism for his condition is enterococcus; and option E says, the yield of peritoneal fluid cultures for diagnosis is greater than 90%.
[Dr. Handy] All right, so this question is asking about spontaneous bacterial peritonitis or SBP in a patient with cirrhosis, good topic. [Dr. Wiener] Okay, tell me more about it. [Dr. Handy] So primary or spontaneous bacterial peritonitis, which is often referred to as SBP or PBP, occurs when the peritoneal cavity becomes infected without an apparent source of contamination. In adults, it most commonly occurs in conjunction with cirrhosis of the liver, but it has also been described in patients with metastatic malignant disease, chronic active hepatitis, acute viral hepatitis, congestive heart failure, systemic lupus, and lymphedema, as well as in patients with no underlying disease.
Now, although it mostly develops in patients with pre-existing ascites, it is in general an uncommon event occurring in fewer than 10% of cirrhotic patients. [Dr. Wiener] So how does the peritoneum get infected in these cases? [Dr. Handy] The cause of SBP has not been established definitively, but is believed to involve hematogenous spread of organisms in a patient in whom a diseased liver and altered portal circulation results in a defect in the usual filtration function.
Organisms multiply in ascites, which is a good medium for growth. [Dr. Wiener] So this question is also asking about the physical findings. [Dr. Handy] Yeah, so to answer the question, it's A, so fever is present in up to 80% of patients and it is the most common sign. Some other signs, abdominal pain and acute onset of symptoms and peritoneal irritation during physical examination can be helpful diagnostically, but the absence of any of these findings does not exclude this often subtle diagnosis.
In an at-risk patient, non-localizing symptoms such as malaise, fatigue, or encephalopathy without any other clear etiology, as in this patient, should also prompt consideration of SBP. [Dr. Wiener] I assume the diagnosis is made with paracentesis. What are the exact criteria to make the diagnosis? [Dr. Handy] Yeah, it is vital to sample the peritoneal fluid of any cirrhotic patient with ascites and a fever.
The diagnosis requires the exclusion of an intra-abdominal source of infection. Blood cultures are seldom positive and in fact, peritoneal cultures are also seldom positive. The yields of peritoneal cultures may be increased by inoculating into blood culture bottles. [Dr. Wiener] So in that sense, how do we make the diagnosis? [Dr. Handy] The findings of over 250 PMNs per microliter is diagnostic, so in this case he had 40% of 1,000 white blood cells so that would be 400, so he has SBP.
[Dr. Wiener] Okay, I know that getting a definitive organism is not common, but what are thought to be the most common organisms to direct therapy? [Dr. Handy] Entero Gram negative bacilli, such as E. coli are most commonly encountered, however, Gram positive organisms such as streptococci, enterococci, or even pneumococci are sometimes found. Anaerobes are almost never thought to be causative in SBP whereas in an intra-abdominal source, such as a perforated viscus, anaerobes are an important pathogen.
[Dr. Wiener] Okay, that gets us to the optimal empiric therapy. The question mentioned metronidazole, clindamycin, but you already mentioned that anaerobes are not common so we know that that is wrong. [Dr. Handy] Third generation cephalosporins, such as cefotaxime or ceftriaxone, or piperacillin/tazobactam provide reasonable initial coverage in moderately ill patients.
Interestingly, the etiology of infections in patients with cirrhosis has changed in recent years, with more Gram positive bacteria and ESBL-producing gut bacteria being the causative agents. And this is probably because of widespread use of quinolones that have been used to prevent SBP in high-risk subgroups of patients, frequent hospitalizations, and more exposure to broad spectrum antibiotics.
Risk factors for multi-drug resistant infections include nosocomial origin of infection, long term norfloxacin prophylaxis, recent infection with multi-resistant bacteria, and recent use of beta-lactam antibiotics. So the empiric choice should be tailored to your patient in the clinical situation. [Dr. Wiener] Okay, great. So the teaching points here are that in a patient with underlying cirrhosis and particularly those with ascites, primary bacterial peritonitis or spontaneous bacterial peritonitis can present subacutely with subtle clinical signs.
Paracentesis is important and the diagnosis is made by the presence of greater than 215 neutrophils per microliter, even if cultures are negative. Broad empiric antibiotics should be started promptly. [Dr. Handy] And you can read more about this in Harrison's chapter on intra-abdominal infections. [outro music] [Dr. Shanahan] This is Jim Shanahan, publisher at McGraw Hill.
Harrison's Podclass is brought to you by McGraw Hill's Access Medicine, the online medical resource that delivers the latest trusted content from the best minds in medicine. Go to accessmedicine.com to learn more.