Background and purpose: Current literature reports that half of critically ill patients are continued on broad-spectrum antibiotics beyond 72 hours despite no confirmed infection. The purpose of this retrospective study was to identify the incidence of and risk factors for prolonged empiric antimicrobial therapy (PEAT) in adult neurocritical care (NCC) patients treated for pneumonia, hypothesizing that NCC patients will have a higher incidence of PEAT.
Methods: This is a retrospective chart review of adult NCC patients treated for pneumonia. Antibiotic therapy was classified as restrictive, definitive, or PEAT based on culture results and timing of discontinuation or de-escalation.
Results: A total of 95 patients (median age: 57 years; 28.4% female; admission diagnosis: 73.7% cerebrovascular, 10.5% neuromuscular, and 15.8% seizure-related) were included in this study. Overall, 59% of antibiotic regimens were considered PEAT, with vancomycin and piperacillin/tazobactam being most commonly prescribed. Median duration of therapy was 6.8 days, with shorter duration in patients with negative culture results compared to those with positive culture results (6.1 days [interquartile range, IQR 4.0-8.3] vs 7.2 days [IQR 5.8-10.3], P < .05). On multivariable analysis, elevated baseline white blood cell count, meeting Centers for Disease Control criteria for pneumonia, and negative bacterial culture were significantly associated with PEAT.
Conclusion: The incidence of prolonged empiric antibiotic use was high in the NCC population. Patients are at particular risk for PEAT if they have negative cultures. All but one patient did not meet criteria for central fever, highlighting the challenges in identifying fever etiology in the NCC population.
Keywords: critical illness; culture negative; neurocritical care; pneumonia; prolonged empiric antibiotic therapy.