Background: Hypoxemia and the need for oxygen administration are frequent causes of hospital admission. High-flow nasal cannula (HFNC) delivers heated humidified high-flow gas at an adjustable inspired oxygen fraction via a large-bore nasal cannula and provide specific physiological benefits. The efficacy of HFNC has been investigated in the intensive care unit but data in other care settings are scarce, especially in low- and middle-income countries.

Objective: To describe the safety and associated clinical outcomes of HFNC used in patients admitted to general medical wards.

Materials and Methods: The present study was a prospective cohort study that enrolled adult patients with acute respiratory failure and no other major organ failures admitted to the general medical wards at Siriraj Hospital in Bangkok and treated with HFNC. Enrolled subjects were managed by a multidisciplinary care team trained in HFNC usage. The primary outcome was to determine the rate of HFNC failure, defined as the subsequent need for endotracheal intubation, non-invasive ventilation (NIV), reintubation, or death within 48 hours. Secondary outcomes included determining the in-hospital mortality, 28-day mortality, and the factors associated with HFNC failure.

Results: Seventy-one subjects were enrolled. In these patients, acute de novo hypoxemic respiratory failure was the most common indication for HFNC (42.3%), followed by prophylaxis after extubation (38.0%), and cardiogenic pulmonary edema (19.7%). The overall rate of HFNC failure was 25.4%. The overall in-hospital and 28-day mortality rates were 14.1% and 21.1%, respectively. The only factor associated with HFNC failure was the respiratory rate at day 1.

Conclusion: The use of HFNC in general medical wards is feasible, but a 25% rate of failure within 48 hours can be expected. A higher respiratory rate at day 1 is associated with the failure of HFNC.

Keywords: Acute respiratory failure; General medical ward; High-flow oxygen therapy; Outcomes; Safety

DOI: doi.org/10.35755/jmedassocthai.2021.07.12689

Received 3 March 2021 | Revised 5 May 2021 | Accepted 14 May 2021