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

Abstract

Background: Exertional dyspnea is common in patients with cancer and limits their function. The impact of high-flow nasal cannula on exertional dyspnea in nonhypoxemic 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 nonhypoxemic patients with cancer.

Patients and methods: Patients with cancer 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/minute. 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 dyspnea intensity scale at isotime. Secondary outcomes included dyspnea unpleasantness, exercise time, and adverse events.

Results: Seventy-four patients were enrolled, and 44 completed the study (mean age 63; 41% female). Compared with low-flow air at baseline, dyspnea intensity was significantly lower at isotime with high-flow oxygen (mean change, -1.1; 95% confidence interval [CI], -2.1, -0.12) and low-flow oxygen (-1.83; 95% CI, -2.7, -0.9), but not high-flow air (-0.2; 95% CI, -0.97, 0.6) or low-flow air (-0.5; 95% CI, -1.3, 0.4). Compared with low-flow air, high-flow oxygen also resulted in significantly longer exercise time (difference + 2.5 minutes, p = .009), but not low-flow oxygen (+0.39 minutes, p = .65) or high-flow air (+0.63 minutes, p = .48). The interventions were well tolerated without significant adverse effects.

Conclusion: Our preliminary findings support that high-flow oxygen improved both exertional dyspnea and exercise duration in nonhypoxemic patients with cancer. (ClinicalTrials.gov ID: NCT02357134).

Implications for practice: In this four-arm, double-blind, randomized clinical trial examining the role of high-flow nasal cannula on exertional dyspnea in patients with cancer 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.

Keywords: Clinical trial; Dyspnea; Exercise tolerance; Neoplasms; Oxygen.

Conflict of interest statement

Disclosures of potential conflicts of interest may be found at the end of this article.

© 2020 AlphaMed Press.

Figures

Figure 1

Study flow diagram.

Figure 2

Change in dyspnea scores. (A): During the second cycle ergometry test, all patients received low‐flow air at 2 L/minute. This serves as a baseline test. (B): During the third cycle ergometry test, patients were given the assigned intervention. In mixed model analysis adjusting for baseline function, the slope of dyspnea intensity was 0.87/minute, 0.58/minute, 0.64/minute, and 0.78/minute for high‐flow air, high‐flow oxygen, low‐flow air, and low‐flow oxygen, respectively. Pairwise comparison showed that high‐flow oxygen had a significantly lower rate of dyspnea increase (p < .001) and significantly longer exercise duration (p = .009) compared with low‐flow air. Low‐flow oxygen also had significantly a lower rate of dyspnea increase (p = .01) compared with low‐flow air. Abbreviations: HFAir, high‐flow air; HFOx, high‐flow oxygen; LFAir, low‐flow air; LFOx, low‐flow oxygen.