INHALED NITRIC OXIDE IN COVID-19-INDUCED HYPOXEMIC RESPIRATORY FAILURE

Abstract

TOPIC: Critical Care TYPE: Original Investigations PURPOSE: Inhaled nitric oxide (iNO) is a potent vasodilator that has been studied as a treatment for acute respiratory distress syndrome (ARDS). However, clinical trials have not been able to demonstrate a survival benefit, and its use in clinical practice has been relegated to “rescue” or “bridging” therapy in refractory hypoxemia. However, it’s early use prior to endotracheal intubation and invasive mechanical ventilation for patients with ARDS has not been investigated. As a result of the COVID-19 pandemic causing resource constraints, as well as the potential anti-viral effects of iNO, our center had a significant number of patients who were treated with iNO prior to intubation, often in combination with a high-flow nasal cannula (HFNC) system. Given this large cohort, we aimed to explore whether pre-intubation iNO resulted in any improved clinical outcomes among patients with COVID-19 induced hypoxic respiratory failure. METHODS: This is a descriptive study of patients admitted with COVID-19 pneumonia at a single tertiary care center. The COVID-19 population was surveyed to gather data on iNO delivered via a high-flow nasal cannula (HFNC). We collected information on patient demographics, co-morbidities, iNO treatment, need for intubation, ABG values, patient labs, hospital length of stay, and mortality. Patients were divided into two groups based on the timing of iNO initiation: group 1 - “post-intubation” (i.e. iNO started on the same day as or after endotracheal intubation and mechanical ventilation) and group 2 - “pre-intubation” (i.e. iNO started at least 1 day prior to endotracheal intubation, if any). RESULTS: We had a total of 45 COVID-19 patients (group 1, n=20 [44.4%] vs group2, n=25 [65.6%]) who had iNO use. Age and gender were similar between the groups. On comparing the two groups (group 1 vs group 2), iNO was started at a median of 1(IQR, 1-6) day vs 2(IQR, 1-3) days from hospital admission. The number of Ventilation-free days (VFD) was 6.7 [mean(x̅)] in group 1 as opposed to 4.7 (x̅) in group 2. The total length of mechanical ventilation (days) was 17.8(x̅) vs 11.6 (x̅) in group 1 vs group 2. The mean hospital length of stay from the beginning of iNO treatment until discharge or death was 23.5 vs 17.2 days, with 11 deaths (55%) vs 7 deaths (28%) in group 1 vs group 2, respectively. Severity of illness as indicated by the mean SOFA score was higher in group 1 (7.8) than in group 2 (3.3). CONCLUSIONS: The use of iNO prior to intubation among patients with COVID-19 hypoxic respiratory failure appears to be safe and comparable on important clinical outcomes, including the duration of mechanical ventilation, hospital length of stay, and possibly mortality. This suggests that a formal prospective investigation on the earlier pre-intubation use of iNO for patients affected by ARDS is warranted. CLINICAL IMPLICATIONS: This study suggests that pre-intubation use of iNO in COVID patients with hypoxemic respiratory failure is feasible and that a formal prospective clinical trial is warranted. DISCLOSURES: No relevant relationships by Israr Baloch, source=Web Response No relevant relationships by Anirban Bhattacharyya, source=Web Response No relevant relationships by Abhishek Giri, source=Web Response No relevant relationships by Pramod Guru, source=Web Response No relevant relationships by Scott Helgeson, source=Web Response No relevant relationships by Alexander Hochwald, source=Web Response No relevant relationships by Nirmaljot Kaur, source=Web Response No relevant relationships by Augustine Lee, source=Web Response No relevant relationships by Pablo Moreno Franco, source=Web Response No relevant relationships by Neal Patel, source=Web Response No relevant relationships by Devang Sanghavi, source=Web Response No relevant relationships by Siva Naga Yarrarapu, source=Web Response