Inhaled nitric oxide as rescue therapy in severe ARDS cases due to COVID-19 pneumonia: a single center experience

Inhaled NO (iNO) has been recommended as rescue therapy in acute respiratory stress syndrome (ARDS) cases. In this study, we aimed to demonstrate the efficacy of iNO as a rescue therapy in patients with severe ARDS due to COVID-19.

This retrospective study included patients with ARDS due to COVID-19 who were treated with iNO between March 2020 and January 2022 in the intensive care unit (ICU) of Inonu University. Patients' files were reviewed retrospectively, and demographic data, APACHE II and Sequential Organ Failure Assessment (SOFA) scores, initiation day of iNO and duration of iNO treatment, length of stay in hospital/ICU, blood biochemistry values, complete blood counts, inflammatory parameters, arterial blood gas values, lactate, PaO2/FiO2 ratios, anti-inflammatory drugs and outcome were recorded.

Data from 16 patients were reached. iNO was given at a dose of 20 ppm continuously. The mean duration of treatment with iNO was 3.5 days. All patients took the prone position except a single patient. While all patients received steroid therapy, four patients received anti-cytokine therapy, and five patients received intravenous immunoglobulin therapy. All patients were in severe ARDS with a mean PaO2/FiO2 ratio of 58 before iNO therapy. A significant increase in PaO2/FiO2 values was detected with the use of iNO (p<0.05). While three patients (19%) were discharged from the ICU, thirteen patients died.

In our study, it was determined that iNO applied as a rescue treatment in patients with severe ARDS improved oxygenation. Although the effect of iNO on survival was low, it may be interpreted as clinically significant considering the severity of the general clinical condition of the patients.