The Outcomes of COVID-19 Patients with ARDS Who Received High Flow Nasal Oxygen in Medical Wards Outside Intensive Care Units under Supervision of Non-intensivists.

Objective: Efficacy of high flow nasal oxygen (HFNO) use in COVID-19 patients who developed ARDS in medical wards is poorly studied. We aimed to investigate whether use of HFNO in wards outside intensive care unit under supervision of non-intensivists has clinical effects on acute respiratory failure and whether it reduces ICU workload. Methods: COVID 19 patients who received HFNO therapy for ARDS in medical wards of an academic hospital were analyzed retrospectively. Primary outcome was the proportion of patients who were successfully weaned from HFNO. Results: 43 patients ( 32 male, median age 61 [54-70] years) were investigated. 14 (33 %) patients weaned from HFNO and 29 (67%) patients failed HFNO and were tranferred to ICU. HFNO was applied in the group of HFNO with success with a median duration of 7 days (4-9) and in the failed group with median 3 days (2-5), p=0.002. Median SpO2 after HFNO was higher in patients with HFNO success compared to with HFNO failure [95 (94-97) vs 93 (92-95), p=0.015]. In the group of HFNO with success, there were more hypocapnic patients than in the group of HFNO with failure [19/29 (66 %) vs 3/14 (21%); p=0.015]. Logistic regression analysis indicated that patients with hypocapnia had 9.8 times the odds of having HFNO failure compared with patients with normocapnia.No patient died among the patients succeded HFNO however 90% of patients who transferred to ICU died. Conclusion: Use of HFNO for COVID-19 patients with ARDS at a non-critical setting seemed to be beneficial in avoiding intubation and reducing workload of ICU. However due to high mortality rate among the HFNO failed group, it would be better to be used undersupervision of intensivists and by skilled team.