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← September 2026 edition

A11 · PMID:41837717

Inhaled Antibiotics to Treat Ventilator-Associated Pneumonia: A Systematic Review and Meta-Analysis

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Bottom line

In a meta-analysis of 32 RCTs (plus 41 non-randomized studies in sensitivity analysis), adjunctive inhaled antibiotics improved clinical cure (RR 1.24) and reduced mortality (RR 0.84) vs placebo/blank, with both benefits confirmed VAP-only by meta-regression.

PICO at a glance

Clinical question and design

Ventilator-associated pneumonia (VAP) remains one of the most common and morbid ICU-acquired infections in mechanically ventilated patients, and rising multidrug resistance makes every antibiotic-escalation decision a stewardship decision too. Adjunctive inhaled antibiotics have been studied for years, but the evidence has been fragmented across small trials with inconsistent findings, and many prior reviews pooled mixed pneumonia populations that can dilute a VAP-specific signal.

Published in Critical Care Medicine (2026;54(6):1293-1308; DOI 10.1097/CCM.0000000000007072), investigators searched PubMed, Web of Science, Embase, Cochrane Library, and ClinicalTrials.gov through May 31, 2025. Two independent groups screened studies, extracted data, and assessed risk of bias; analyses used random-effects models with meta-regression, TSA, and GRADE. The primary analysis pooled 32 RCTs vs placebo/blank or IV antibiotics; adding 41 non-randomized studies in sensitivity analysis found consistent results.

Intervention and outcomes measured

The intervention was adjunctive inhaled antibiotics added to standard VAP treatment; agents, doses, and delivery devices varied across the included trials. Versus placebo/blank, adjunctive inhaled antibiotics significantly improved clinical cure (16 RCTs; n=1,425; RR, 1.24; 95% CI, 1.07-1.43) and reduced all-cause mortality (21 RCTs; n=1,855; RR, 0.84; 95% CI, 0.71-0.98), with consistent findings when the 41 non-randomized studies were folded into a sensitivity analysis.

Results

Both benefits held in the VAP-only subset - clinical cure (11 RCTs; n=775; RR, 1.29; 95% CI, 1.10-1.52) and all-cause mortality (15 RCTs; n=1,152; RR, 0.77; 95% CI, 0.65-0.90) - but were not statistically significant in studies that pooled mixed pneumonia populations; meta-regression confirmed VAP-only population status as a significant effect modifier, meaning the mortality benefit is population-specific rather than generalizable to all ventilator-associated lower-respiratory-tract infection.

Safety and additional findings

Microbiological eradication also improved (20 RCTs; n=1,805; RR, 1.42; 95% CI, 1.27-1.58), and emergence of new drug resistance was markedly reduced (4 RCTs; n=182; RR, 0.20; 95% CI, 0.06-0.64) - though this last estimate rests on only 4 small trials and should be read as hypothesis-supporting rather than definitive. No differences were found in ICU length of stay, ventilator duration, or other adverse events versus placebo/blank. Against IV antibiotics specifically - an exploratory, more limited comparison - inhaled antibiotics shortened ventilator duration (3 RCTs; n=322; mean difference, -2.11 days; 95% CI, -3.73 to -0.49) and reduced nephrotoxicity (3 RCTs; n=292; RR, 0.42; 95% CI, 0.26-0.68).

Uncertainty and limitations

The full review provides certainty and sequential-analysis information. In 16 placebo-controlled RCTs (1,425 participants), adjunctive inhaled antibiotics increased clinical cure (RR 1.24, 95% CI 1.07-1.43; moderate certainty). The trial-sequential analysis’s required information size was 1,518 and was nearly reached; the cumulative Z-curve crossed conventional and O’Brien-Fleming monitoring boundaries, not futility boundaries. Mortality in 21 RCTs (1,855 participants) had RR 0.84 (95% CI 0.71-0.98; moderate certainty). In the VAP-only subgroup, clinical cure and mortality findings were high certainty. Regimens, nebulization techniques, and patient characteristics still varied considerably, so use this as adjunctive-evidence synthesis rather than a device/dose directive.

Literature review and evidence synthesis

This 2026 systematic review extends a decade-plus evidence base on antibiotic strategy for VAP. A 2016 Cochrane review, "Antibiotics for ventilator-associated pneumonia" (PMID 27763732), established earlier foundational evidence on antibiotic treatment for VAP broadly, not specific to the inhaled route.

More directly, a 2021 Journal of Critical Care systematic review and meta-analysis on adjunctive inhaled antibiotics for VAP (PMID 34144265) addressed the identical intervention question and represents the immediate predecessor evidence this 2026 analysis builds on with a larger pooled sample, added meta-regression, TSA, and GRADE methodology.

How this fits with the broader evidence

The pooled results support further assessment of adjunctive inhaled therapy in the studied VAP populations, but they do not establish routine use for every patient with VAP. Regimens and delivery techniques varied, and the resistance-emergence estimate rests on only four small trials. IDSA antimicrobial-resistance guidance does not suggest routine nebulized antibiotics for pneumonia caused by difficult-to-treat resistant Pseudomonas aeruginosa or carbapenem-resistant Acinetobacter baumannii; any selected exception requires attention to the guidance, active systemic options, susceptibility, delivery feasibility, and specialist input. This meta-analysis does not establish a universal drug, dose, or device protocol.

ACPE UAN: 0683-0000-26-036-H01-P

Study source: PMID:41837717