Breathing Hydrogen-Oxygen Mixture Decreases Inspiratory Effort In Patients With Tracheal Stenosis

Background: Hydrogen-oxygen mixture (H-2-O-2) may reduce airway resistance in patients with acute severe tracheal stenosis, yet data supporting the clinical use of H-2-O-2 are insufficient. Objectives: To evaluate the efficacy and safety of breathing H-2-O-2 in acute severe tracheal stenosis. Methods: Thirty-five consecutive patients with severe acute tracheal stenosis were recruited in this prospective self-control study. Air, H-2-O-2 and O-2 inhalation was given in 4 consecutive breathing steps: air for 15 min, H-2-O-2 (6 L per min, H-2:O-2 = 2: 1) for 15 min, oxygen (3 L per min) for 15 min, and H-2-O-2 for 120 min. The primary endpoint was inspiratory effort as assessed by diaphragm electromyography (EMGdi); the secondary endpoints were transdiaphragmatic pressure (Pdi), Borg score, vital signs, and impulse oscillometry (IOS). The concentration of H-2 in the ambient environment was obtained with 12 monitors. Adverse reactions during the inhalation were recorded. Results: The mean reduction in the EMGdi under H-2-O-2 was 10.53 +/- 6.83%. The EMGdi significantly decreased during 2 H-2-O-2 inhalation steps (Steps 2 and 4) compared with air (Step 1) and O-2 (Step 3) (52.95 +/- 15.00 vs. 42.46 +/- 13.90 vs. 53.20 +/- 14.74 vs. 42.50 +/- 14.12% for Steps 1 through 4, p < 0.05). The mean reduction in the Pdi under H-2-O-2 was 4.77 +/- 3.51 cmH(2)O. Breathing H-2-O-2 significantly improved the Borg score and resistance parameters of IOS but not vital signs. No adverse reactions occurred. H-2 was undetectable in the environment throughout the procedure. Conclusions: Breathing H-2-O-2 may reduce the inspiratory effort in patients with acute severe tracheal stenosis and can be used for this purpose safely. (C) 2018 S. Karger AG, Basel