Inhaled nitric oxide in moderate-to-severe COVID-19 acute respiratory distress syndrome: a retrospective cohort study.

Objective: In this study, we present the findings from a cohort of patients with COVID-19 with acute respiratory distress syndrome who underwent standard therapy, including prone positioning, with or without adjunctive inhalation of nitric oxide. Our investigation sought to determine whether inhaled nitric oxide administration yielded clinical enhancement in this population. Remarkably, nitric oxide administration elevated the PaO2/FiO2 ratio, which is indicative of improved oxygenation. Despite this improvement, discernible mortality benefits did not emerge in association with the inhaled nitric oxide treatment. To evaluate the responsiveness of COVID-19 acute respiratory distress syndrome patients to inhaled nitric oxide as part of their standard therapy.

Methods: This retrospective cohort study included critically ill adult patients with confirmed COVID-19 treated between March 2020 and May 2021. Eligible patients with moderate-to-severe acute respiratory distress syndrome due to COVID-19 were subsequently categorized into two groups based on inhaled nitric oxide use throughout their stay in the intensive care unit. The primary endpoints were overall mortality and improvement in oxygenation parameters 6 hours after inhaled nitric oxide use.

Results: A total of 481 patients admitted to the intensive care unit due to COVID-19 acute respiratory distress syndrome were screened, 105 of which were included. Among the 105 patients, inhaled nitric oxide therapy was used in 33 patients, will 72 did not undergo inhaled nitric oxide therapy. No significant difference in mortality was observed between the groups (67% for the treatment and 82% for the no-treatment groups respectively, p=0.173). Among the patients who used inhaled nitric oxide, 17 (51%) were considered responsive to therapy. There was no significant difference in the length of stay in the intensive care unit (p=0.324) or total hospitalization time (p=0.344).

Conclusion: Inhaled nitric oxide rescue therapy improved oxygenation in patients with COVID-19 with moderate-to-severe acute respiratory distress syndrome but did not affect mortality.