Assessing the use of heated high flow nasal cannula in COVID-19

ABSTRACT

Background: Previous studies have suggested that the use of heated high-flow nasal canula (HHFNC) may reduce intubation rates in severely hypoxemic patients (PaO2/FiO2 <200). Early in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, HHFNC was underutilized due to concern for viral aerosolization. Studies have since shown that HHFNC has a similar aerosolization risk as a standard oxygen mask prompting increased usage of HHFNC in patients with SARS-CoV-2. We sought to determine if the usage of HHFNC reduced the odds of intubation or the number of ventilator days for patients with acute hypoxemic respiratory failure due to SARS-CoV-2 pneumonia (COVID-19). Methods: We conducted a retrospective cohort study utilizing electronic health record data from the University of Colorado Health System. We included all adult patients admitted to intensive care units between February 1st, 2020 and May 3rd, 2020 with a diagnosis of acute hypoxemic respiratory failure and COVID-19. We divided patients into two groups patients who received HHFNC and patients who did not receive HHFNC. Patient demographics, clinical characteristics and clinical outcomes were compared. Results: A total of 193 patients were included, of which 41 (21.2%) received HHFNC support. Age, sex, ethnicity, BMI, and comorbidities were similar between both groups. CRP was slightly higher and creatinine lower in the HHFNC group. We found that patients who used HHFNC were 76.5% less likely to receive mechanical ventilation (p<0.001). Patients who were supported with HHFNC spent an average of 5.1 more days on mechanical ventilation (p=0.025). The odds of death were estimated to be 39.4% lower for those who used HHFNC after adjusting for confounders (age, sex, BMI, ethnicity, smoking, alcohol use, prone positioning, corticosteroid use and Remdesivir use) however this effect estimate was not statistically significant. Conclusions: We found that patients with COVID-19 who received HHFNC were less likely to be intubated, which is consistent with previously published data. Those who did require intubation remained on mechanical ventilation for a longer duration. Our study did not detect any differences in mortality between the HHFNC group and the non-HHFNC group. These findings suggest HHFNC may be a useful modality for treatment of acute hypoxemic respiratory failure due to SARS-CoV-2 that may reduce the need for mechanical ventilators during local shortages.