Efficacy and Safety of Systemic Prophylactic Antibacterials in Mechanically Ventilated Patients: Systematic Review and Meta-Analysis.

Abstract

Previous studies have shown that selective decontamination of the digestive tract can reduce the incidence and mortality of ventilator-associated pneumonia (VAP) in mechanically ventilated patients. However, the prophylactic role of IV antibacterials, one of its essential components, remains unclear. Therefore, this study aims to evaluate the efficacy and safety of systemic prophylactic use of antibacterials in mechanically ventilated patients. We systematically searched PubMed, Embase, and The Cochrane Library from inception to November 30, 2025. Randomized controlled trials (RCTs) evaluating prophylactic use of systemic antibacterials in mechanically ventilated patients in the ICUs were included. Two researchers independently conducted literature screening, data extraction, and quality assessment. Meta-analysis was performed using RevMan 5.4, and the quality of the evidence was evaluated using the recommended Grading of Recommendations, Assessment, Development, and Evaluation method. Eleven RCTs with 5562 patients were included. Meta-analysis results showed that the systemic prophylactic use of antibacterials probably reduces the incidence of VAP (relative risk [RR], 0.65; 95% CI, 0.55-0.77; moderate certainty) and the incidence of early VAP (RR, 0.52; 95% CI, 0.41-0.66; moderate certainty), but probably does not reduce in-hospital mortality (RR, 0.85; 95% CI, 0.68-1.06; moderate certainty) or duration of mechanical ventilation (mean difference [MD], -0.32; 95% CI, -0.79 to 0.16; moderate certainty), and may not reduce length of hospital stay (MD, -1.56; 95% CI, -5.15 to 2.02; low certainty). Subgroup analyses suggested that systemic prophylactic antibacterials probably reduces VAP in brain injury patients. No increased risk of drug resistance and adverse events was observed. The systemic prophylactic antibacterials probably reduces early VAP and overall VAP incidence in mechanically ventilated patients, but probably does not reduce in-hospital mortality. Subgroup analyses suggested potential benefits in brain injury patients. Given incomplete safety reporting, future research should include comprehensive resistance surveillance and cost-effectiveness analyses.