Clinical experience of using high‐flow nasal cannula oxygen therapy for treating SARS‐CoV‐2019 (COVID‐19)‐infected patients in the emergency medicine ward

Abstract Introduction During the fifth‐wave outbreak of COVID‐19 in Hong Kong in 2022, North Lantau Hospital (NLTH), as the designated COVID‐19 hospital in Kowloon West Cluster, offered medical support for COVID‐19 patients in the district and nearby isolation facilities. Intensive care units (ICUs) at that time were overwhelmed by the surge of patients. Training was provided to emergency medicine ward (EMW) staff for providing high‐flow nasal cannula (HFNC) oxygen therapy to severely ill COVID‐19 patients who developed hypoxemia and respiratory failure in a non‐ICU setting. Method Descriptive sharing of the clinical experience in managing patients with COVID‐19 infection who were admitted to the EMW of NLTH from March 1, 2022, to September 30, 2023, and required HFNC oxygen therapy. The associated factors for the clinical outcomes were also evaluated. Results During the study period, 22 COVID‐19 patients with hypoxemia and respiratory failure were offered HFNC oxygen therapy in the EMW of NLTH. All were elderly patients with an average age of 83.6 years and a background of multiple medical illnesses. Staff in the EMW were able to provide appropriate care for patients receiving HFNC after short training. There were no complications associated with the use of HFNC in any of the patients. Six (27.3%) patients survived their hospital admission. In general, patients with a higher ratio of peripheral saturation of oxygen (SpO 2 ) and fraction of inspired oxygen (FiO 2 ) (SF ratio) after the initiation of HFNC oxygen therapy were more likely to survive. Conclusion The use of HFNC for COVID‐19‐related acute hypoxemic respiratory failure is a feasible option for care in EMW settings. Our experience suggested that HFNC served as an initial life‐sustaining treatment for elderly COVID‐19 patients with fair premorbid status who were unlikely to benefit from invasive positive‐pressure ventilation, and their prognoses could be more objectively assessed by serial monitoring of the SF ratio.