Antibiotic prescribing for aspiration pneumonia in the intensive care unit

Background: Antibiotics are frequently prescribed for aspiration pneumonia in ICU patients. We sought to determine the proportion of ICU patients treated for aspiration pneumonia who meet the diagnostic criteria. Methods: A retrospective review of electronic medical records was conducted in adult patients who were admitted to one of two intensive care units at an Ontario tertiary care hospital between June 1, 2022, and October 1, 2023. Patients who were exposed to antibiotics were first identified and then systematically assessed using electronic medical records to identify occurrences in which aspiration was suspected and antibiotics were potentially used to treat aspiration pneumonia within 14 days of the aspiration event. For each episode, we assessed whether patients met the criteria for either confirmed or suspected aspiration pneumonia. Factors associated with inappropriate prescribing were determined. Results: Of 497 patients treated with antibiotics, 104 (22.0%) were treated for aspiration pneumonia. More than one-half (67 patients, 64.4%) were categorized as either confirmed or suspected aspiration pneumonia. There were 35.6% cases (37 of 104) in which antibiotic courses were prescribed for aspiration pneumonia without meeting the criteria for confirmed or suspected cases. Factors associated with not meeting criteria included prescribing by attending physicians compared with residents or fellows (OR 1.53, 95% CI 0.63–3.67, p = 0.34) and admitting patients from the emergency department compared with other non-ICU areas (OR 1.96, 95% CI 0.86–4.65, p = 0.12). Intubation was associated with a higher odds of confirmed or suspected aspiration pneumonia (OR 1.11, 95% CI 0.47–2.57, p = 0.81). Conclusions: Inappropriate antibiotic prescribing for aspiration pneumonia remains common in the ICU.