High-Flow Oxygen and High-Flow Air for Dyspnea in Hospitalized Patients with Cancer: A Pilot Crossover Randomized Clinical Trial

Abstract

Background: The effect of high-flow oxygen (HFOx) and high-flow air (HFAir) on dyspnea in nonhypoxemic patients is not known. We assessed the effect of HFOx, HFAir, low-flow oxygen (LFOx), and low-flow air (LFAir) on dyspnea.

Subjects, materials, and methods: This double-blind, 4×4 crossover clinical trial enrolled hospitalized patients with cancer who were dyspneic at rest and nonhypoxemic (oxygen saturation >90% on room air). Patients were randomized to 10 minutes of HFOx, HFAir, LFOx, and LFAir in different orders. The flow rate was titrated between 20-60 L/minute in the high-flow interventions and 2 L/minute in the low-flow interventions. The primary outcome was dyspnea numeric rating scale (NRS) "now" where 0 = none and 10 = worst.

Results: Seventeen patients (mean age 51 years, 58% female) completed 55 interventions in a random order. The absolute change of dyspnea NRS between 0 and 10 minutes was -1.8 (SD 1.7) for HFOx, -1.8 (2.0) for HFAir, -0.5 (0.8) for LFOx, and - 0.6 (1.2) for LFAir. In mixed model analysis, HFOx provided greater dyspnea relief than LFOx (mean difference [95% confidence interval] -0.80 [-1.45, -0.15]; p = .02) and LFAir (-1.24 [-1.90, -0.57]; p < .001). HFAir also provided significantly greater dyspnea relief than LFOx (-0.95 [-1.61, -0.30]; p = .005) and LFAir (-1.39 [-2.05, -0.73]; p < .001). HFOx was well tolerated. Seven (54%) patients who tried all interventions blindly preferred HFOx and four (31%) preferred HFAir.

Conclusion: We found that HFOx and HFAir provided a rapid and clinically significant reduction of dyspnea at rest in hospitalized nonhypoxemic patients with cancer. Larger studies are needed to confirm these findings (Clinicaltrials.gov: NCT02932332).

Implications for practice: This double-blind, 4×4 crossover trial examined the effect of oxygen or air delivered at high- or low-flow rates on dyspnea in hospitalized nonhypoxemic patients with cancer. High-flow oxygen and high-flow air were significantly better at reducing dyspnea than low-flow oxygen/air, supporting a role for palliation beyond oxygenation.

Keywords: Clinical trial; Hospital equipment; Neoplasms; Oxygen; dyspnea.

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

Patient preferences. Abbreviations: HFAir, high‐flow air; HFOx, high‐flow oxygen; LFAir, low‐flow air; LFOx, low‐flow oxygen.