Name:
Harrison's Podclass - Episode 93- A 33-Year-Old with Fever, Headache, and Neck Pain
Description:
Harrison's Podclass - Episode 93- A 33-Year-Old with Fever, Headache, and Neck Pain
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T00H07M28S
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https://cadmoreoriginalmedia.blob.core.windows.net/1a83d7b3-6c5d-479e-bfb7-e8a759975253/Harrison%27s Podclass - Episode 93- A 33-Year-Old with Fever%2c .mp3?sv=2019-02-02&sr=c&sig=ri81IrQEVzMYBMjK3BUMhSSeq5g1fFuxzD4akYm90AA%3D&st=2024-05-03T21%3A19%3A18Z&se=2024-05-03T23%3A24%3A18Z&sp=r
Upload Date:
2022-06-12T00:00:00.0000000
Transcript:
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 to episode 93, a 33-year-old with fever, headache, and neck pain. Okay, Cathy, today's patient is a 33-year-old high school physics teacher, who presents to the emergency department with one day of fever, severe headache and neck pain.
She has no medical history and has had no head trauma. Her only medication is an oral contraceptive. On examination, she appears acutely unwell. Her temperature is 40 degrees centigrade, her heart rate is 122, her blood pressure is 105/65. She has a markedly stiff neck that resists passive movement. She communicates normally, has normal strength in her upper and lower extremities and has normal reflexes and sensation.
There's no skin rash. You draw blood cultures. What should your next step be? So the options are, A. perform a lumbar puncture; B. order a CT of the head; C. initiate vancomycin and ceftriaxone; D. initiate vancomycin, ceftriaxone, acyclovir, and dexamethasone; or. E. initiate vancomycin, ceftriaxone, ampicillin, and dexamethasone.
[Dr. Handy] All right, so clearly we're worried that this young woman has acute meningitis, and that is based on the history that she provided, and then also the vital signs and physical examination. And the question is asking about diagnostics and therapeutics. So, before we go on, tell me what part of the country this is taking place in and what time of the year. [Dr. Wiener] Before I tell you that, you tell me why that's important.
[Dr. Handy chuckles] Well, it'll help us think about some of the viral or vector-borne illnesses that might be causing these symptoms. [Dr. Wiener] Okay, she lives in urban Chicago, and it is winter. She's also a dedicated non-outdoors person, who's a nationally ranked Scrabble player, and her exercise is only on an indoor bicycle. [Dr. Handy] All right, well, that eliminates many of the outdoor exposures I was thinking of.
So in that case, I would go with option D. so I'd initiate vancomycin, ceftriaxone, acyclovir, and dexamethasone. [Dr. Wiener] Okay, tell me more, and tell me why you're not getting a lumbar puncture. Tell me why this is important stuff, go ahead. [Dr. Handy] All right, so we already said that her presentation is suspicious for acute meningitis. Now, when bacterial meningitis is suspected, blood culture should be immediately obtained, like you did, and empirical antimicrobial and adjunctive dexamethasone therapy initiated really without delay.
Bacterial meningitis is a medical emergency, and the goal is to begin antibiotic therapy within 60 minutes of a patient's arrival in the emergency room. So if this is bacterial meningitis, then any delay can worsen outcomes. [Dr. Wiener] So, delay the lumbar puncture, which would be really diagnostic. [Dr. Handy] Yes, so empiric antimicrobial therapy should be initiated in patients with suspected bacterial meningitis before the results of CSF or cerebral spinal fluid Gram stain and culture are known.
[Dr. Wiener] So, what are your suspected organisms that guide the empirical therapy that you mentioned? [Dr. Handy] Streptococcus pneumoniae and Neisseria meningitidis are the most common etiologic organisms of community-acquired bacterial meningitis. Due to the emergence of penicillin and cephalosporin-resistant Strep pneumo, empirical antimicrobial therapy of community-acquired suspected bacterial meningitis in children and adults without risk factors for drug-resistant organisms should include a combination of a third-generation cephalosporin, like ceftriaxone, and should also include vancomycin.
Ceftriaxone or cefotaxime provide good coverage for susceptible Strep pneumo, group B Streptococci, and Haemophilus influenzae coverage and adequate coverage too for Neisseria meningitidis. [Dr. Wiener] Okay, the correct answer also included acyclovir, why is that included? [Dr. Handy] Yeah, acyclovir should also be included as well because herpes simplex virus encephalitis is a leading disease in the differential diagnosis.
And again, delays in therapy can increase the likelihood of bad neurologic outcomes. [Dr. Wiener] What about the dexamethasone? That was also part of the empiric therapy in the answer. [Dr. Handy] Yeah, the release of bacterial cell wall components by bactericidal antibiotics leads to the production of the inflammatory cytokines IL-1 beta and TNF-alpha in the subarachnoid space.
Dexamethasone exerts its beneficial effect by inhibiting the synthesis of IL-1 beta and TNF-alpha at the level of mRNA, it decreases CSF outflow resistance and stabilizes the blood-brain barrier. But dexamethasone must be given before or at least concurrent with the empiric antibiotics. Clinical trials of dexamethasone therapy in meningitis due to H. influenzae, Neisseria meningitidis, and particularly Strep pneumo have demonstrated its efficacy in decreasing meningeal inflammation, unfavorable outcomes, and neurologic sequelae, such as the incidence of sensorineural hearing loss.
[Dr. Wiener] How do you dose the dexamethasone? [Dr. Handy] Typically, you give dexamethasone 10 mg intravenously 15 to 20 minutes before or concurrent with the first dose of an antimicrobial agent, and then every six hours for four days. It's unlikely to be a significant benefit if it started more than six hours after antimicrobial therapy has been initiated. [Dr. Wiener] Also, you mentioned vector-borne illnesses.
[Dr. Handy] Yeah, during tick season, doxycycline is also reasonable to start empirically to treat tick-borne bacterial infections. [Dr. Wiener] The question mentioned imaging, you've told us why we should not delay the LP, but is there a role for a CT or an MRI? [Dr. Handy] Okay, now that we've started empiric therapy, we have time to think about the diagnostics. So the diagnosis of bacterial meningitis is made by examining the CSF.
The need to obtain neuroimaging studies, so that's either CT or MRI, prior to a lumbar puncture requires clinical judgment. In an immunocompetent patient with no known history of recent head trauma, a normal level of consciousness and no evidence of papilloedema or focal neurologic deficits, it's considered safe to perform an LP without prior neuroimaging studies.
In any event, I just want to reiterate that even if the LP is delayed to obtain neuroimaging studies, the antibiotic therapy should be initiated after blood cultures are obtained. Antibiotic therapy initiated a few hours prior to LP will not significantly alter the CSF white blood cell count or glucose concentration, nor is it likely to prevent visualization of organisms by Gram stain or detection of bacterial nucleic acid by PCR assay.
[Dr. Wiener] Okay, finally, option E. included ampicillin, but that was not one of the choices for this patient. Tell us why. [Dr. Handy] Ampicillin should be added to the empiric regimen for coverage of Listeria monocytogenes in individuals who are less than three months of age and those over 55, or those with suspected impaired cell-mediated immunity because of chronic illness or organ transplantation, pregnancy, malignancy, or immunosuppressive therapy.
[Dr. Wiener] And this woman was a young Scrabble-playing, physics teacher. [Dr. Wiener] Right, with no other comorbidities that we heard of. [Dr. Wiener] Okay, so the teaching points in this case are in a patient with suspected acute meningitis, empiric antimicrobial therapy plus dexamethasone should be instituted immediately after drawing blood cultures, and even before any diagnostic interventions.
The choice of empiric antibiotics will be determined by the patient's immune status and local epidemiology. [Dr. Handy] And you can read more about this in the chapter on acute meningitis. [upbeat outro music] [Mr. Shanahan] This is Jim Shanahan, publisher at McGraw Hill. Harrison's PodClass is brought to you by McGraw Hill's AccessMedicine, the online medical resource that delivers the latest trusted content from the best minds in medicine.
Go to accessmedicine.com to learn more.