A 53-year-old man with history of chronic hepatitis C and acquired immune deficiency syndrome (history of cryptococcal meningitis, last CD4 count 250 cells/µL on antiretroviral therapy with undetectable viral load) presents for open liver resection after he was diagnosed with liver cancer. Following an uncomplicated operation, he is recovering on surgical floor. On postoperative day 3, he develops fever (temperature, 38.9°C). Other vitals are notable for:
Abdominal examination is benign. Chest x-ray reveals likely infiltrate and/or atelectasis in the right lower lobe. Lactate level is 3 mmol/L.
Which of the following is the MOST appropriate initial antibiotic regimen for this patient?
Correct Answer: A
This patient most likely developed hospital-acquired pneumonia complicated by sepsis. Initial antimicrobial therapy should be broad while awaiting additional workup with consideration about localizing symptoms (pulmonary). The patient has been admitted to hospital for greater than 48 hours prior to infectious symptom onset, and treatment should cover MRSA and Pseudomonas. Therefore, the Correct Answer is A. Initial therapy with vancomycin (MRSA coverage), cefepime (gram-negative including pseudomonas), and azithromycin (atypical coverage) is appropriate.
Although patient previously had an AIDS-defining illness (cryptococcal meningitis), a CD4 count above 200 cells/µL makes him less susceptible to opportunistic infections such as PJP. Based on description, his CXR is not suggestive of PJP pneumonia. Therefore, empiric TMP-SMX is not indicated at this point. Treatment with TMP-SMX alone would leave gaps in gram-negative coverage including pseudomonas and therefore would not be the correct empiric regimen. Meropenem and levofloxacin are not correct treatments for potential MRSA infection.
There are some unique considerations in critically ill patients with HIV/AIDS. Prior antibiotic prophylaxis (ie, azithromycin for mycobacterium avium complex) and the potential for resistance should be considered when choosing an empiric regimen. Mycobacterium tuberculosis infection (TB) occurs in patients with HIV/AIDS. If there is clinical concern for TB, empiric fluoroquinolones (ie, levofloxacin) should be avoided. Fluoroquinolones may result in short-term improvement through partial treatment of TB followed by later clinical decompensation and bacterial resistance. Patients with HIV/AIDS and/or intravenous drug use are at greater risk of fungemia. Fungal coverage should be initiated in individuals who fail to improve with initial antimicrobial therapy. Additional caution for drug interactions is needed in patients taking antiretroviral therapy. Azoles and macrolides interact with some forms of antiretroviral therapy and consultation with a pharmacist should occur prior to initiation of these medications.
A 45-year-old female is admitted to the surgical ICU following liver transplantation. On postoperative day (POD) 3, she develops a tonic-clonic seizure which is terminated by intravenous midazolam. However, she requires intubation for persistently poor mental status. CT scan of the head is obtained immediately and is negative for bleeding or mass lesion. Lumbar puncture is deferred due to coagulopathy (INR 1.9, Plt 50). A brain MRI performed 6 hours later shows left temporal increased signal intensity in T2 and FLAIR weighted images.
Which of the following treatment is most effective to decrease patient mortality?
This patient most likely developed herpes simplex virus (HSV) encephalitis—the most common cause of viral encephalitis with significant morbidity and mortality. MRI brain is the most specific imaging modality for encephalitis. Findings consistent with HSV encephalitis on neuroimaging include temporal or inferior frontal lobe edema and increased signal intensity on T2 and fluid-attenuated inversion recovery (FLAIR) images. Suspected HSV is treated with empiric acyclovir while diagnostic CSF studies are pending. In this case, imaging and clinical presentation is highly suggestive and warrants treatment. Patients who are seropositive for HSV prior to transplant are often on HSV prophylaxis with oral acyclovir. In this case, high-dose intravenous acyclovir should be initiated.
Ganciclovir is used to treat viral encephalitis from varicella-zoster virus, human herpes virus 6, and cytomegalovirus (in conjunction with foscarnet) but is not the treatment for HSV. Treatment with levetiracetam may be initiated but would not be alone sufficient to improve patient outcome. Steroids are used to treat some types of encephalitis including Epstein-Barr virus and varicella-zoster virus, but they are not recommended for HSV encephalitis.
A 52-year-old female with severe COPD is admitted to the ICU for hypercarbic respiratory failure. She requires mechanical ventilation and is treated with methylprednisolone and azithromycin. She is extubated on ICU day 4. After extubation, she complains of leftsided flank pain, but her examination and labs are normal. On day 6, a vesicular rash with erythematous base develops diffusely across her abdomen, and additional lesions are noted on her face and arms.
Which of the following is the next best step to diagnose her condition?
Correct Answer: B
Herpes zoster is caused by reactivation of latent varicella-zoster virus in cranial nerves or dorsal root ganglia. Reactivation of the virus is caused by decreased T-cell immunity and may result from increased age, primary infection during the time of an immature immune system, transplantation, immunosuppressive agents (such as steroids), or HIV infection.
A diagnosis of herpes zoster is made by unroofing a vesicle and sending the fluid for direct fluorescent antibody testing and reflex viral culture. Distinguishing reactivation of varicella-zoster virus from the vesicular rash of disseminated herpes virus may pose challenges clinically. Therefore, testing for both is appropriate.
Latex allergies are common with manifestations ranging from contact dermatitis to anaphylaxis. While skin testing is used to diagnose a variety of allergens, a proportion of patients with latex allergy will develop anaphylaxis. Therefore, the best test for suspected latex allergy would be serologic evaluation with IgE-specific latex antibody. The prodromal pain makes a latex allergy less likely. Punch biopsy may be useful in a variety of dermatologic diseases but is not necessary to diagnose herpes zoster. A full dilated eye examination is necessary to rule out herpes zoster ophthalmicus but would not confirm the diagnosis of herpes zoster in the absence of ocular involvement.
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