Many patients started on antibiotics for possible ventilator-associated pneumonia (VAP) do not have pneumonia. Patients with minimal and stable ventilator settings may be suitable candidates for early antibiotic discontinuation. We compared outcomes amongst patients with suspected VAP but minimal and stable ventilator settings treated with 1-3 versus >3 days of antibiotics.
We identified consecutive adult patients started on antibiotics for possible VAP with daily minimum PEEPs ≤5cm H2O and FiO2s ≤40% for at least 3 days within a large tertiary care hospital between 2006-2014. We compared time to extubation alive versus ventilator death and time to hospital discharge alive versus hospital death using competing risks models amongst patients prescribed 1-3 days versus >3 days of antibiotics. All models were adjusted for patients' demographics, comorbidities, severity of illness, clinical signs of infection, and pathogens.
There were 1,290 eligible patients, 259 treated for 1-3 days and 1,031 treated for >3 days. The two groups had similar demographics, comorbidities, and clinical signs. There were no significant differences between groups in time to extubation alive (HR 1.16 for short versus long course treatment, 95% CI 0.98-1.36), ventilator death (0.82, 95% CI 0.55- 1.22), time to hospital discharge alive (HR 1.07, 95% CI 0.91-1.26), or hospital death (HR 0.99, 95% CI 0.75-1.31).
Very short antibiotic courses (1-3 days) were associated with outcomes similar to longer courses (>3 days) in patients with suspected VAP but minimal and stable ventilator settings. Assessing serial ventilator settings may help clinicians identify candidates for early antibiotic discontinuation.