Ventilator-associated pneumonia and prior antibiotic exposure in intubated patients due to depressed consciousness

To evaluate the impact of antibiotic therapy within the first 24 h of admission on the development of VAP occurring in the first week (VAPFW) in patients admitted with low level of consciousness.

Cohort retrospective observational study, from January 1, 2014, to December 1, 2024 SETTING: 24-bed general Intensive Care Unit of a secondary hospital.

Admitted with decreased level of consciousness or TBI with or without other trauma associated, who required mechanical ventilation for >48 h. A total of 449 patients were included. Median age was 57.2 years, and 67.4% were male.

No interventions were performed.

Demographic variables, APACHE and SAPS II scores, reason for ICU admission, antibiotic administration in the first 24 h, development of VAPFW. Length of stay, days of mechanical ventilation and ICU mortality.

Only 38 (8.5%) were diagnosed with VAP. A total of 242 patients (53.8%) received antibiotic treatment. There were no differences in the incidence of VAPFW between patients with and without antibiotic (8.2% vs 8.7%, p = 0.99). After Propensity Score matching, Cox proportional hazards model showed that antibiotic administration was associated with a 62% lower proportional daily risk of developing VAPFW (HR = 0.38; 95% CI 0.17-0.83). This protective effect was not confirmed in multiple logistic regression (OR 0.45, CI 95% 0.18-1.1, P = 0.08).

In ICUs with low incidence of VAPFW, administration of prophylactic antibiotics to patients intubated for low level of consciousness does not appear to confer a meaningful reduction in VAPFW risk.