Worldwide Clinical Practice of High-Flow Nasal Cannula and Concomitant Aerosol Therapy among Adult Critical Care Subjects

BACKGROUND: Therapy with high-flow nasal cannula (HFNC) has been broadly utilized. However, no consensus has been achieved on practical implementation of HFNC and how to provide aerosol delivery during HFNC therapy in adult subjects.

METHODS: An online anonymous questionnaire survey, endorsed by four academic societiesfrom America, Europe, mainland China and Taiwan, was administered from May to December, 2019.Clinicians who had worked in adult intensive care unit for more than one year and had used HFNC to treat subjects within 30 days were included.

RESULTS: 2,279 participants clicked on the survey link, 1358 respondents completed the HFNC section, while 1014 completed the whole survey. Post-extubation hypoxemia and moderate hypoxemia were major indications for HFNC. Initial flow was set mainly at 40-50 L/min. Aerosol delivery via HFNC was utilized by 24% (248/1014) of participants, 30% (74/248) of whom reported reducing flow during aerosol delivery. For subjects who required aerosol treatment during HFNC therapy, 40% (403/1014) of participants reported placing a nebulizer with a mask or mouthpiece while pursuing HFNC (a method shown to reduce inhaled dose) while 33% (331/1014) discontinued HFNC to use conventional aerosol devices. Vibrating mesh nebulizer (VMN) was the most commonly used nebulizer (40%) and was mainly placed at the inlet of the humidifier.

CONCLUSIONS: The clinical utilization of HFNC was variable, as were indications, flow settings, and criteria for adjustment. Many practices associated with concomitant aerosol therapy were not consistent with available evidence for optimal use. More efforts are warranted to close the knowledge gap.