Effectiveness of antibiotic prophylaxis for ventilator-associated pneumonia in acute brain injury: a systematic review and meta-analysis.

BACKGROUND

Ventilator-associated pneumonia (VAP) affects 30-50% of mechanically ventilated patients with acute brain injury (ABI), exceeding general ICU rates (10-20%) due to aspiration risks and immunosuppression, prolonging ICU stays and morbidity. Although short-course antibiotic prophylaxis (AP; e.g., ceftriaxone) targets early VAP, efficacy in ABI remains debated amid mixed evidence, resistance concerns, and non-endorsement by IDSA/ATS guidelines.

METHODS

We searched PubMed, Cochrane Library, and Web of Science (inception to October 2024) for RCTs and non-RCTs on systemic AP (short-course beta-lactams) for VAP prevention in ABI (TBI, SAH, stroke, post-arrest coma) requiring ventilation ≥ 48 h.

PRIMARY OUTCOMES: early-onset VAP (≤ 96 h), late-onset VAP (> 96 h), overall VAP, ICU mortality. Secondaries: mechanical ventilation duration, ICU/hospital length of stay (LOS), time to first VAP. Random-effects meta-analysis; heterogeneity via I2; risk of bias (RoB 2.0/ROBINS-I).

RESULTS

Ten studies (5 RCTs [n = 586], 5 non-RCTs [n = 1,087]; total n = 1,673) were included. AP reduced overall VAP (RR = 0.65, 95% CI: 0.48-0.90, P < 0.001; I2 = 75.9%) and early-onset VAP (RR = 0.41, 95% CI: 0.33-0.52, P < 0.001; I2 = 0%; events: 88/754 AP vs. 240/832 control). No effect on late-onset VAP (RR = 1.13, 95% CI: 0.72-1.78, P = 0.07; I2 = 64.8%) or ICU mortality (RR = 0.91, 95% CI: 0.76-1.08, P = 0.27; I2 = 0%). Secondaries: Reduced ICU LOS (MD = - 2.05 days, 95% CI: - 3.73 to - 0.37, P = 0.01; I2 = 46%) and hospital LOS (MD = - 5.02 days, 95% CI: - 9.20 to - 0.85, P = 0.02; I2 = 70.8%); no difference in ventilation duration (MD = - 1.36 days, 95% CI: - 2.91 to 0.19, P = 0.09) or time to VAP (MD = 1.04 days, 95% CI: - 0.87 to 2.95, P = 0.29). RCTs showed low-moderate bias; non-RCTs moderate-serious (confounding).

CONCLUSION

Short-course AP reduces early/overall VAP and LOS in ABI without impacting late VAP or mortality, supporting targeted use in high-risk cases (e.g., GCS < 8) per stewardship principles. However, heterogeneity, resistance gaps, and guideline caution warrant larger RCTs with non-ABI comparatives to mitigate selection bias and confirm specificity.