High Flow Nasal Cannula for Acute Hypoxic Respiratory Failure in COVID-19

Abstract

Background:

In the United States, limited understanding of COVID-19 pathophysiology and disease trajectory, along with fear of transmission to healthcare workers, has led to an “intubate early” approach. High flow nasal cannula (HFNC) therapy is an alternative respiratory support modality for patients with acute hypoxic respiratory failure (AHRF), and this device has been standard of care for management of AHRF in both the Intensive Care Unit (ICU) and on all general inpatient wards of the study hospital since 2017. The purpose of this study is to describe our recent experience using HFNC as the escalation of care support device for adults with confirmed COVID-19.

Methods:

This study is a retrospective chart review of adult patients consecutively admitted to hospitals in a regional health system in the Midwest. All patients had SARS-CoV2 confirmed by lab testing, required escalation of care due to AHRF demanding > 4 L/min oxygen to maintain saturations above 90%, and were managed with HFNC in the ICU or on the ward. The study was approved by the Institutional Review Board at the study hospital. Descriptive statistics were reported for continuous data as means and standard deviations (SD); categorical data were reported as counts and percentages.

Results:

At the time of writing, 116 of 321 (36%) of hospitalized COVID-19 patients required escalation of care due to AHRF and 96 (83%) patients received HFNC as the escalation support modality. Sixty-one percent of patients (n=58) were male, mean age was 64 years (SD=18), and mean BMI was 32 (SD=9). Of patients dispositioned at the time of writing (n=70), 49 (70%) did not require invasive mechanical ventilation at any time during hospitalization and 61% (n=43) discharged to home or a skilled nursing or rehabilitation facility. HFNC patients averaged 5 total days in the ICU, however 23 (33%) patients avoided the ICU altogether. For patients who were intubated after HFNC, average ROX score at the time of intubation was 3.81 and they averaged 25 hours (SD=1.5) of HFNC therapy prior to intubation.

Conclusions:

Use of HFNC in the ICU and on general wards has been a safe, resource-sparing, and lifesaving option for patients who would have otherwise required invasive ventilation. During the COVID-19 pandemic, the study hospital has not experienced an overwhelmed ICU or depleted the supply of mechanical ventilators. There are no known cases of virus transmission to healthcare workers caring for patients using the therapy.