Hyperbaric oxygen was safe and effective for treating patients with COVID-19 and severe hypoxemia, according to new findings published in Emergency Medicine Journal.

“Our findings suggest that supplementing oxygen through hyperbaric oxygen treatment contributed to an increased SpO₂ in patients with COVID-19 with severe hypoxemia, with no significant adverse effects,”Mariana Cannellotto,MD, from the research department in the Argentine Association of Hyperbaric Medicine and Research in Buenos Aires, and colleagues wrote. “Cases of severe COVID-19 that need mechanical ventilation have a high mortality risk. Therefore, novel therapeutic strategies are needed, and this study offers evidence supporting hyperbaric oxygen treatment.”

The multicenter, open-label, randomized controlled trial enrolled 40 patients (mean age, 55.2 years; 65% men) in Buenos Aires, Argentina, with COVID-19 and severe hypoxemia with an oxygen saturation of 90% or greater despite oxygen supplementation. The study was conducted from July to November 2020. All patients were randomly assigned to receive hyperbaric oxygen in addition to the standard treatment (n = 20) or standard treatment for respiratory symptoms (n = 20) for 7 days. Hyperbaric oxygen treatment was planned for at least five sessions of 90 minutes (1.45 atmosphere absolute) once daily.

Study outcomes included time to normalize oxygen requirement to a pulse oximetry value in ambient air of 93% or more, need for mechanical respiratory assistance, development of acute respiratory distress syndrome and mortality within 30 days.

The study was stopped at interim analysis due to the clinical benefit observed.

The most frequent symptoms observed at admission in the hyperbaric oxygen and standard treatment groups were dyspnea (95% and 90%, respectively), fever (85% and 90%) and odynophagia (50% and 35%).

Mean SpO₂ at admission was 85.1%.

Patients who received hyperbaric oxygen underwent an average of 6.2 sessions. The researchers reported a shorter median time to correct hypoxemia among patients who received hyperbaric oxygen compared with standard treatment only (3 days vs. 9 days; P < .01).

Researchers observed higher odds of recovery from hypoxemia among those who received hyperbaric oxygen compared with standard treatment at day 3 (OR = 23.2; 95% CI, 1.6-329.6; P = .001) and at day 5 (OR = 28.5; 95% CI, 1.8-447.4; P < .001).

Hyperbaric oxygen treatment had no significant effect on acute respiratory distress syndrome, mechanical ventilation or mortality within 30 days.

According to a related press release, the researchers had limited ability to assess other outcomes due to early cessation of the study.

“This treatment could be easily available in various settings. Portable hyperbaric chambers offer a fast setup to avoid transferring patients to other hospital areas, attenuating the risk of virus transmission,” the researchers wrote. “In conclusion, our findings support the efficacy of hyperbaric oxygen in the treatment of COVID-19 with severe hypoxemia; larger trials are needed to further confirm the treatment effects on survival.”