Domiciliary high-flow nasal cannula oxygen therapy for stable hypercapnic COPD patients: a prospective, multicenter, open-label, randomized controlled trial
Authors: Nagata Kazuma , Horie Takeo , Chohnabayashi Naohiko , Jinta Torahiko , Tsugitomi Ryosuke , Shiraki Akira , Tokioka Fumiaki , Kadowaki Toru , Watanabe Akira , Fukui Motonari , Kitajima Takamasa , Sato Susumu , Tsuda Toru , Kishimoto Nobuhito , Kita Hideo , Mori Yoshihiro , Nakayama Masayuki , Tsuboi Tomomasa , Yoshida Makoto , Hataji Osamu , Fuke Satoshi , Kagajo Michiko , Nishine Hiroki , Kobayashi Hiroyasu , Nakamura Hiroyuki , Okuda Miyuki , Tachibana Sayaka , Takata Shohei , Osoreda Hisayuki , Minami Kenichi , Nishimura Takashi , Ishida Tadashi , Terada Jiro , Takeuchi Naoko , Kohashi Yasuo , Inoue Hiromasa , Nakagawa Yoko , Kikuchi Takashi , Tomii Keisuke ,   FLOCOP study investigators
Published: May 2021

Background

The effectiveness of the domiciliary use of high-flow nasal cannula oxygen therapy (HFNC) in patients with chronic hypercapnic respiratory failure due to chronic obstructive pulmonary disease (COPD) remains controversial.

Objectives

To investigate the efficacy and safety of domiciliary HFNC use in stable hypercapnic COPD patients.

Methods

This multicenter, open-label, randomized controlled trial enrolled patients with stable hypercapnic COPD. Over 52 weeks, we compared long-term oxygen therapy (LTOT) alone versus domiciliary HFNC plus LTOT (HFNC/LTOT). The primary endpoint was the frequency of moderate/severe COPD exacerbations. We also compared changes from baseline levels in arterial blood gas, SpO2, pulmonary function, health-related quality of life (HRQOL), and a six-minute walk test.

Results

We enrolled 104 patients in total; from these, we removed mismatching patients and then assigned 49 and 50 patients to HFNC/LTOT and LTOT groups, respectively, for safety analysis; 47 and 46 patients for HFNC/LTOT and LTOT groups, respectively, for efficacy analysis. Thirty-seven (79%) and 41 patients (89%) in HFNC/LTOT and LTOT, respectively, completed the final evaluation. HFNC significantly reduced the frequency of COPD exacerbations and prolonged the duration without moderate or severe COPD exacerbations over the 52-week study period (p = 0.002, p = 0.032, respectively). The adjusted odds ratios (95% confidence intervals [CIs]) of the frequency of COPD exacerbations in LTOT against HFNC/LTOT was 2.85 (1.48, 5.47). The median survival time (95% CI) to the first COPD exacerbation with moderate or severe for the LTOT group was 25 weeks (14.1, 47.4); however, the HFNC/LTOT group did not reach the median survival time. HFNC also caused statistically significant differences (p < 0.05) in the SpO2, FVC (%FVC), and FEV1 (%FEV1); however, these improvements were transient. There were no other improvements in arterial blood gas, pulmonary function, HRQOL, or six-minute walk test parameters. In addition, no safety concerns were identified for HFNC.

Conclusions

HFNC may be a reasonable therapeutic choice in stable hypercapnic COPD patients with a history of exacerbations.

Trial registration number: UMIN000028581, NCT03282019 (http://www.umin/ac.jp, https://clinicaltrials.gov/)