High-flow nasal cannula versus conventional oxygen therapy after endotracheal extubation: a randomized crossover physiologic study.

OBJECTIVE: Compare the short-term benefit of high-flow nasal cannula (HFNC) with non-rebreathing mask in terms of change in dyspnea, physiologic variables, and patient comfort in subjects after endotracheal extubation.

METHODS: A randomized crossover study was conducted in a 10-bed respiratory care unit in a university hospital. Seventeen mechanically ventilated subjects were randomized after extubation to either Protocol A (applied HFNC for 30 min, followed by non-rebreathing mask for another 30 min) or Protocol B (applied non-rebreathing mask for 30 min, followed by HFNC for another 30 min). The level of dyspnea, breathing frequency, heart rate, blood pressure, oxygen saturation, and patient comfort were recorded. The results were expressed as mean ± SD, frequency, or percentage. Categorical variables were compared by chi-square test or Fisher exact test, and continuous variables were compared by dependent or paired t test. Statistical significance was defined as P < .05.

RESULTS: Seventeen subjects were divided into 2 groups: 9 subjects in Protocol A and 8 subjects in Protocol B. The baseline characteristics and physiologic parameters before extubation were not significantly different in each protocol. At the end of study, HFNC indicated less dyspnea (P = .04) and lower breathing frequency (P = .009) and heart rate (P = .006) compared with non-rebreathing mask. Most of the subjects (88.2%) preferred HFNC to non-rebreathing mask.

CONCLUSIONS: HFNC can improve dyspnea and physiologic parameters, including breathing frequency and heart rate, in extubated subjects compared with conventional oxygen therapy. This device may have a potential role for use after endotracheal extubation.