Effect of Ward-Based High-Flow Nasal Cannula (HFNC) Oxygen Therapy on Critical Care Utilization During the COVID-19...

Hospitals expanded critical care capacity during the COVID-19 pandemic by treating COVID-19 patients with high-flow nasal cannula oxygen therapy (HFNC) in non-traditional settings, including general internal medicine (GIM) wards. The impact of this practice on intensive care unit (ICU) capacity is unknown.

To describe how our hospital operationalized the use of HFNC on GIM wards, assess its impact on ICU capacity, and examine the characteristics and outcomes of treated patients.

Retrospective cohort study of all patients treated with HFNC on GIM wards at a Canadian tertiary care hospital.

All patients admitted with COVID-19 and treated with HFNC on GIM wards from December 28, 2020, to June 13, 2021, were included.

We combined administrative data on critical care occupancy daily with chart-abstracted data for included patients to establish the total number of patients receiving ICU-level care at our hospital per day. We also collected data on demographics, medical comorbidities, illness severity, COVID-19 treatments, HFNC care processes, and patient outcomes.

We treated 124 patients with HFNC on the GIM wards (median age 66 years; 48% female). Patients were treated with HFNC for a median of 5 days (IQR 3 to 8); collectively, they received HFNC for a total of 740 hospital days, 71% of which were on GIM wards. At peak ICU capacity strain (144%), delivering HFNC on GIM wards added 20% to overall ICU capacity by managing up to 14 patients per day. Patients required a median maximal fraction of inspired oxygen of 80% (IQR 60 to 95). There were 18 deaths (15%) and 85 patients (69%) required critical care admission; of those, 40 (47%) required mechanical ventilation.

With appropriate training and resources, treatment of COVID-19 patients with HFNC on GIM wards appears to be a feasible strategy to increase critical care capacity.