High Flow Nasal Cannula Therapy for Exertional Dyspnea in Cancer Patients: A Pilot Randomized Clinical Trial.

BACKGROUND Exertional dyspnea is common in cancer patients and limits their function. The impact of high-flow nasal cannula (HFNC) on exertional dyspnea in non-hypoxemic patients is unclear. In this double-blind, parallel-group, randomized trial, we assessed the effect of flow rate (high vs. low) and gas (oxygen vs. air) on exertional dyspnea in non-hypoxemic cancer patients. PATIENTS AND METHODS Cancer patients with oxygen saturation >90% at rest and exertion completed incremental and constant work (80% maximal) cycle ergometry while breathing low-flow air at 2 L/min. They were then randomized to receive high-flow oxygen, high-flow air, low-flow oxygen or low-flow air while performing symptom-limited endurance cycle ergometry at 80% maximal. The primary outcome was modified 0-10 Borg scale dyspnea intensity at isotime. Secondary outcomes included dyspnea unpleasantness, exercise time and adverse events. RESULTS 74 patients were enrolled and 44 completed the study (mean age 63; 41% female). Compared to low-flow air at baseline, dyspnea intensity was significantly lower at isotime with high-flow oxygen (mean change [95% CI]: -1.1 [-2.1, -0.12]) and low-flow oxygen (-1.83 [-2.7, -0.9]), but not high-flow air (-0.2 [-0.97, 0.6]) nor low-flow air (-0.5 [-1.3, 0.4]). Compared to low-flow air, high-flow oxygen also resulted in significantly longer exercise time (difference +2.5 min, P=0.009), but not low-flow oxygen (+0.39 min, P=0.65) nor high-flow air (+0.63 min, P=0.48). The interventions were well tolerated without significant adverse effects. CONCLUSIONS Our preliminary findings support that high-flow oxygen improved both exertional dyspnea and exercise duration in non-hypoxemic cancer patients (Clinicaltrials.gov NCT02357134). IMPLICATIONS FOR PRACTICE In this 4-arm, double-blind randomized clinical trial examining the role of high-flow nasal cannula on exertional dyspnea in cancer patients without hypoxemia, high-flow oxygen, but not high flow air, resulted in significantly lower dyspnea scores and longer exercise time. High-flow oxygen delivered by high-flow nasal cannula devices may improve clinically relevant outcomes even in patients without hypoxemia.