Prevention of ventilator-associated pneumonia by metal-coated endotracheal tubes: a meta-analysis

This study aimed to evaluate whether endotracheal tubes (ETTs) with a metal coating reduce the incidence of ventilator-associated pneumonia (VAP) compared to uncoated ETTs. An extensive literature review was conducted to find studies that compared metal-coated ETT with uncoated ETT across four databases: PubMed, Embase, Cochrane Library, and Web of Science. The search parameters were set from the inception of each database until June 2024. The primary outcome measures were the rates of VAP and hospital mortality. Two independent researchers carried out the literature selection, data extraction, and quality evaluation. Data analysis was performed with RevMan 5.4.1. Furthermore, a Deeks funnel plot was used to evaluate potential publication bias in the studies included. Following the screening process, five randomized controlled trials (RCTs) encompassing a total of 2157 patients were identified. In terms of the primary outcome, the VAP incidence was found to be lower in the group utilizing metal-coated ETT compared to those with uncoated ETT, demonstrating a statistically significant difference [RR = 0.71, 95% CI (0.54–0.95), P = 0.02]. No notable difference in mortality rates was observed between the two groups [RR = 1.05, 95% CI (0.86–1.27), P = 0.65]. Concerning secondary outcomes, two studies were evaluated to compare the mechanical ventilation duration (RR = 0.60, 95% CI (− 0.52, 1.72), P = 0.29, I2 = 97%) and intensive care unit (ICU) stay for both patient groups (RR = 0.47, 95% CI (− 1.02, 1.95), P = 0.54, I2 = 50%). Due to the marked heterogeneity, a comparison of mechanical ventilation length between the two patient groups was not feasible. However, both studies suggested no significant difference in ventilation duration between patients using metal-coated ETT and those with uncoated ETT. Metal-coated ETT show a lower occurrence of VAP compared to the uncoated ETT. Nevertheless, they do not considerably decrease the length of mechanical ventilation, the duration of ICU admission, nor do they reduce hospital mortality rates. Systematic review registration: https://www.crd.york.ac.uk/prospero/ , identifier CRD42024560618.