WEST NILE ENCEPHALITIS: MISGIVINGS ABOUT LUMBAR PUNCTURE IN A PATIENT WITH ICU DELIRIUM ON DUAL ANTIPLATELET THERAPY

Abstract

SESSION TITLE: Fellows Critical Care Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Delirium in the critically ill is common, reported in over 80% of ICU patients. When associated with fever, it warrants investigation. West Nile is an arbovirus that can cause neuroinvasive disease ranging from mild and self-limited to severe encephalitis with mortality rate of 10%. It is diagnosed with positive IgM antibody on cerebrospinal fluid (CSF), so lumbar puncture (LP) is important for this diagnosis. Traditionally, LP was thought to increase risk of serious bleeding complications such as spinal hematomas in patients on dual antiplatelet therapy (DAPT). We present a case of a patient with West Nile encephalitis whose symptoms were attributed to drug fever and ICU delirium after negative infectious workup and significant delay in LP due to DAPT. CASE PRESENTATION: A 59 year old male presented to the ER with chest pain. He was intubated on arrival and managed for acute myocardial infarction causing cardiogenic shock. He required percutaneous coronary intervention with drug-eluting stents and temporary mechanical circulatory support with Impella. Impella was removed 3 days later. He began to exhibit daily high-grade fevers. Antibiotics were started. He developed encephalopathy and could not be extubated, necessitating tracheostomy. Extensive infectious work-up including complete body imaging, blood, BAL, pleural fluid and urine cultures, respiratory viral panel, malaria, brucella, fungal tests were all negative. LP was considered but deferred as he was on DAPT after stent placement. Hyperthermic toxidromes were excluded. Drug fever in the setting of ICU delirium was considered and non-essential medications were eliminated. Fever persisted and LP was performed 3 weeks later. CSF studies were positive for West Nile Virus IgM antibody. Antibiotics were stopped. Supportive care was provided for West Nile encephalitis. The patient improved and was eventually discharged. DISCUSSION: Clinicians often lack crucial information needed to treat infections, with 30-60% of antibiotics prescribed in the ICU thought to be inappropriately broad or inappropriately narrow. Attributing an alarm symptom like fever to non-infectious causes in the setting of ICU delirium is a pitfall that can be avoided by completing infectious workup with LP. Recent studies do not show a significant increase in complications in patients who undergo LP while on antiplatelet therapy, with incidence of spinal hematomas ranging from 0-0.7%. CONCLUSIONS: While a risk benefit discussion is essential, our case underscores the importance of pursuing early microbiological diagnosis with LP in a patient with fever and encephalopathy, even when on DAPT. This allows de-escalation of antibiotics with their associated side effects, tailored therapy and data to inform prognosis. Reference #1: Lee, Paul W, and Michael Levy. "Risk of Hematoma From Aspirin or Clopidogrel Owing to Lumbar Puncture." Mayo Clinic Proceedings 94.8 (2019): 1552-555. DISCLOSURES: No relevant relationships by Abdul Khan, source=Web Response No relevant relationships by Sumit Patel, source=Web Response No relevant relationships by Nehan Sher, source=Web Response No relevant relationships by Tonya Whiting, source=Web Response