High-Flow Nasal Cannula Versus Conventional Oxygen Therapy in Relieving Dyspnea in Emergency Palliative Patients With Do-Not-Intubate Status: A Randomized Crossover Study.

STUDY OBJECTIVE: Palliative patients often visit the emergency department (ED) with respiratory distress during their end-of-life period. The goal of management is alleviating dyspnea and providing comfort. High-flow nasal cannula may be an alternative oxygen-delivering method for palliative patients with do-not-intubate status. We therefore aim to compare the efficacy of high-flow nasal cannula with conventional oxygen therapy in improving dyspnea of palliative patients with do-not-intubate status who have hypoxemic respiratory failure in the ED.

METHODS: This randomized, nonblinded, crossover study was conducted with 48 palliative patients aged 18 years or older with do-not-intubate status who presented with hypoxemic respiratory failure to the ED of Siriraj Hospital, Bangkok, Thailand. The participants were randomly allocated to conventional oxygen therapy for 60 minutes, followed by high-flow nasal cannula for 60 minutes (n=24) or vice versa (n=24). The primary outcome was modified Borg scale score. The secondary outcomes were numeric rating scale score of dyspnea and vital signs.

RESULTS: Intention-to-treat analysis included 44 patients, 22 in each group. Baseline mean modified Borg scale score was 7.6 (SD 2.2) (conventional oxygen therapy first) and 8.2 (SD 1.8) (high-flow nasal cannula first). At 60 minutes, mean modified Borg scale score in patients receiving conventional oxygen therapy and high-flow nasal cannula was 4.9 (standard of mean 0.3) and 2.9 (standard of mean 0.3), respectively (mean difference 2.0; 95% confidence interval 1.4 to 2.6). Results for the numeric rating scale score of dyspnea were similar to those for the modified Borg scale score. Respiratory rates were lower with high-flow nasal cannula (mean difference 5.9; 95% confidence interval 3.5 to 8.3), and high-flow nasal cannula was associated with a significantly lower first-hour morphine dose.

CONCLUSION: High-flow nasal cannula was superior to conventional oxygen therapy in reducing the severity of dyspnea in the first hour of treatment in patients with do-not-intubate status and hypoxemic respiratory failure.