Prophylactic Antibiotics Show Limited Impact on Mortality in ICU Patients with Acute Brain Injury: Meta-Analysis

"There is ongoing uncertainty about the use of prophylactic antibiotics in adults with acute brain injuries invasively ventilated in intensive care units (ICUs). Although this practice is common, conclusive evidence supporting its ability to significantly lower mortality rates in these critically ill patients is lacking," the researchers wrote in the CHEST Journal.

Invasive mechanical ventilation, often required for patients with acute brain injuries, carries a high risk of ventilator-associated infections. Prophylactic antibiotics are sometimes administered as a preventative measure to mitigate this. However, the benefits of this approach remain unclear, with studies yielding mixed results regarding its impact on patient outcomes.

To fill this knowledge gap, Anthony P. Delaney, Critical Care Program, The George Institute for Global Health and UNSW, Barangaroo, NSW, Australia, and colleagues aimed to investigate whether administering prophylactic parenteral antibiotics, compared to placebo or usual care, is associated with reduced mortality in adults with acute brain injury receiving invasive mechanical ventilation in an ICU.

For this purpose, the researchers conducted a systematic review and meta-analysis by searching electronic databases and unpublished trials for randomized clinical trials (RCTs).

The primary outcome assessed was hospital mortality, while secondary outcomes included the incidence of ventilator-associated pneumonia, ICU length of stay, and duration of mechanical ventilation. A random effects model was applied to estimate the pooled risk ratio (RR) with 95% confidence intervals (CI) for binary outcomes and the mean difference (MD) with 95% CI for continuous outcomes. The certainty of evidence was evaluated using the Grading of Recommendations Assessment Development and Evaluation (GRADE) methods.

The following were the key findings of the study:

• One thousand seven hundred twenty-eight study reports were screened, with seven randomized clinical trials (RCTs) involving 835 participants included.
• None of the trials were considered to have a high risk of bias.
• The pooled estimated risk ratio (RR) for mortality with prophylactic antibiotics was 0.91, indicating low certainty.
• The pooled RR for ventilator-associated pneumonia was 0.56, with low certainty.
• The mean difference (MD) in the duration of mechanical ventilation between prophylactic antibiotics and control groups was –2.0 days, with very low certainty.
• The MD admission duration in ICU was –2.2 days, with very low certainty.

"Current evidence from randomized clinical trials does not conclusively establish the impact of prophylactic antibiotics on mortality in patients undergoing invasive mechanical ventilation in the ICU," the researchers concluded.

Reference:

Hadley-Brown K, Hailstone L, Devane R, Chan T, Devaux A, Davis JS, Hammond N, Li Q, Litton E, Myburgh J, Poole A, Santos J, Seppelt I, Tong SYC, Udy A, Venkatesh B, Young PJ, Delaney AP. Prophylactic Antibiotics in Adults With Acute Brain Injury Who Are Invasively Ventilated in the ICU: A Systematic Review and Meta-Analysis. Chest. 2024 Oct 28:S0012-3692(24)05420-5. doi: 10.1016/j.chest.2024.10.031. Epub ahead of print. PMID: 39490972.