ABSTRACT
INTRODUCTION: High-flow nasal cannula oxygen therapy (HFNC) has gained attention as an alternative respiratory support for critically ill COVID-19 patients, however, the evidence behind HFNC has been unbalanced as it covers various comorbidities in hypoxic and hypercapnic respiratory failure. We sought to identify what group of patients needed HFNC and to assess whether its use impacted length of stay and survival. METHODS: A retrospective cohort study was performed at a single center urban academic center. Data collected included age, gender, BMI, medical comorbidities, length of hospital stay and mortality for all patients hospitalized with COVID-19. We compared the characteristics of the patients who received HFNC at any point during their hospitalization to all patients hospitalized with COVID-19. RESULTS: The total number of COVID-19 patients was 363. HFNC was used in 115 admitted patients, of which, 74 were in the ICU with a mean length of stay of 7 days. Overall this group had an average hospital length of stay of 15 days in total as opposed to 10.2 days in non-HFNC utilizers. The most common comorbidities seen in the cohort were hypertension (76.4%), diabetes mellitus (37.4%), asthma (14.6%), COPD (11.24%), and obstructive sleep apnea (4.5%). In patients who received HFNC, 41.2% survived compared to 71.8% of all COVID-19 patients. CONCLUSIONS: Factors determining the outcome of patients using HFNC are not well understood. Our patients who received HFNC were more likely to have underlying cardiopulmonary disease than non-HFNC utilizers. Furthermore, they had a longer length of stay and a higher mortality rate in comparison to all COVID-19 patients. While we specifically identified patients who received HFNC, some of these patients received other forms of supplemental oxygen therapy during their hospital stay which may confound the characteristics of this group. It is also possible that patients receiving HFNC were sicker in general, which may explain their disparity in mortality and hospital stay duration. Further research needs to be done in order to clarify if HFNC in COVID-19 patients, particularly those with cardiopulmonary comorbidities, is beneficial in delaying escalation of oxygen therapy and potentially prolonging survival.