Work

Performance of Unmodified Mechanical Ventilators With 2% Hydrogen Gas Mixtures

Year: 2025

Type: article

Abstract: Background: Molecular hydrogen (H 2 ) is a breathable gas that has been shown to have anti-oxidative, anti-inflammatory, and anti-apoptotic properties that may positively impact ischemia-reperfusion injury. The provision of 2% H 2 through unmodified mechanical ventilators may facilitate the clinical translation of H 2 as a therapeutic in critical illness. The effect of 2% H 2 on ventilator performance is unknown. Methods: Unmodified Maquet Servo-i, Maquet Servo-u, Dräger Evita Infinity V500, and Dräger Evita Babylog VN500 ventilators from clinical stock were tested in an experimental closed system using certified, premixed air and O 2 containing 2% H 2 gas. Wall air and O 2 supply were used as control. Ventilator settings were varied across the spectrum of neonatal to adult settings. End points included (1) difference between set and delivered tidal volume (V T ) (Douglas method), (2) difference between set versus delivered O 2 concentration, (3) delivered H 2 concentration (gas chromatography), and (4) ventilator pre-use check malfunction. Correlation between set and measured end points were quantified by linear regression analysis and bias by Bland-Altman analysis. Results: During H 2 administration, the average bias in measured versus set V T was within ± 10% for all ventilators except for the Babylog VN500, which exhibited an average bias of −89.2% (95% CI −107.0 to −71.3). The average bias in measured F IO 2 was within ± 10% of set for all ventilators. Except for the Babylog VN500, all ventilators passed the pre-use check. Conclusions: Unmodified Servo-i, Servo-u, and Evita V500 ventilators deliver 2% H 2 mixtures with acceptable accuracy in V T and F IO 2 . The Babylog VN500, which uses hot-wire anometry and a higher set operating temperature, exhibits unacceptably inaccurate delivery of V T with H 2 mixtures.

Source: Respiratory Care

DOI: 10.4187/respcare.12371