Abstract
BACKGROUND: Hyperbaric oxygen (HBO(2)) therapy has been proposed to treat hypoxaemia and reduce inflammation in COVID-19. Our objective was to analyse safety and efficacy of HBO(2) in treatment of hypoxaemia in patients with COVID-19 and evaluate time to hypoxaemia correction. METHODS: This was a multicentre, open-label randomised controlled trial conducted in Buenos Aires, Argentina, between July and November 2020. Patients with COVID-19 and severe hypoxaemia (SpO(2) ≤90% despite oxygen supplementation) were assigned to receive either HBO(2) treatment or the standard treatment for respiratory symptoms for 7 days. HBO(2) treatment was planned for ≥5 sessions (1 /day) for 90 min at 1.45 atmosphere absolute (ATA). Outcomes were time to normalise oxygen requirement to SpO(2) ≥93%, need for mechanical respiratory assistance, development of acute respiratory distress syndrome and mortality within 30 days. A sample size of 80 patients was estimated, with a planned interim analysis after determining outcomes on 50% of patients. RESULTS: The trial was stopped after the interim analysis. 40 patients were randomised, 20 in each group, age was 55.2±9.2 years. At admission, frequent symptoms were dyspnoea, fever and odynophagia; SpO(2) was 85.1%±4.3% for the whole group. Patients in the treatment group received an average of 6.2±1.2 HBO(2) sessions. Time to correct hypoxaemia was shorter in treatment group versus control group; median 3 days (IQR 1.0-4.5) versus median 9 days (IQR 5.5-12.5), respectively (p<0.010). OR for recovery from hypoxaemia in the HBO(2) group at day 3 compared with the control group was 23.2 (95% CI 1.6 to 329.6; p=0.001) Treatment had no statistically significant effect on acute respiratory distress syndrome, mechanical ventilation or death within 30 days after admission. CONCLUSION: Our findings support the safety and efficacy of HBO(2) in the treatment of COVID-19 and severe hypoxaemia. TRIAL REGISTRATION NUMBER: NCT04477954.