West Nile Virus Infection in the Intensive Care Unit: A Case Series and Literature Review

BACKGROUND: West Nile virus (WNV) is a rapidly spreading infectious disease in North America. Critical care issues related to WNV are not well described. OBJECTIVES: Three cases of severe WNV meningoencephalitis with flaccid paralysis are reported and relevant critical care issues are highlighted. METHODS: Case series and a review of the literature. RESULTS: Three patients with WNV meningoencephalitis and flaccid paralysis were admitted to the authors' academic, tertiary-care intensive care unit (ICU) in the late summer of 2002. All three patients were middle-aged or elderly and presented with a febrile illness that preceded or coincided with their neurological symptoms. Confirmation of WNV infection was problematic because each patient had at least one initial negative serum serology test. Radiological testing yielded nonspecific results. Serial electroencephalograms were consistent with severe toxic metabolic encephalopathy in all cases. All patients had a severe, diffuse axonal polyneuropathy demonstrated by nerve conduction studies and electromyography. Prolonged mechanical ventilation resulted in ICU lengths of stay of 44 to 118 days. At one point, 21% of the ICU beds were dedicated for these patients. All three patients died in hospital - two following the withdrawal of life support. One patient demonstrated resolving encephalitis and was discharged from the ICU after a 118-day ICU stay, but later died in a step-down unit. CONCLUSIONS: The management of WNV-related critical illness creates challenges in making a timely and accurate diagnosis, and predicting patient morbidity and mortality. As a consequence, end-of-life discussions with families are especially difficult. The prolonged ICU length of stay and growing incidence of this disease may challenge limited critical care resources.