Use of high-flow nasal cannula oxygen therapy at home may reduce COPD exacerbations
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The addition of high-flow nasal cannula to long-term oxygen therapy may decrease exacerbations among patients with stable hypercapnic COPD, according to a study published in American Journal of Respiratory and Critical Care Medicine.
“For COPD patients with repeated exacerbations and hypercapnia, the use of high-flow nasal cannula (HFNC) in addition to home oxygen therapy may reduce exacerbations and improve quality of life,” Kazuma Nagata, MD, of the department of respiratory medicine at Kobe City Medical Center General Hospital in Kobe, Japan, told Healio. “Until now, noninvasive ventilation (NIV) has been the mainstay of respiratory management in hypercapnic COPD patients, but I suspect that HFNC could be effective for that target group as well. However, the comparison between NIV and HFNC needs to be further validated.”
In a randomized clinical trial, Nagata and colleagues analyzed data of 93 patients who were receiving long-term oxygen therapy (LTOT) for 16 hours a day or more for at least 1 month to determine if long-term HFNC use decreases COPD exacerbations and improves physiological parameters.
Patients included in this study were aged 40 years or older, met criteria for daytime hypercapnia and had stage 2-4 disease according to the Global Initiative for Chronic Obstructive Lung Disease.
Researchers randomly assigned patients to receive HFNC plus LTOT (n = 47; mean age, 72.9 years; 89.8% men) or LTOT alone (n = 46; mean age, 75.16 years; 88% men).
Patients in the HFNC/LTOT group were instructed to use HFNC for at least 4 hours while they slept at flow rates of 30 L/minute to 40 L/minute in addition to their daytime use of LTOT and the myAIRVO 2 (Fisher & Paykel) device.
In order to observe differences between the two groups, researchers looked at changes in baseline arterial blood gas values, peripheral oxygen saturation, pulmonary function and health-related quality-of-life scores by the end of the 52-week study period.
The rate of moderate/severe COPD exacerbations over the study period served as the primary endpoint, and time to the first COPD exacerbation and changes in physiological parameters were secondary outcomes.
In an unadjusted mean count, researchers observed a reduction in the rate of moderate/severe exacerbations in the HFNC/LTOT use group compared with the LTOT group (1 exacerbation vs. 2.5 exacerbations), which Nagata told Healio was surprising “even though they were to be expected.”
In a multivariate generalized linear regression model, researchers also found that the ratio of the adjusted mean count for the LTOT group compared with the HFNC/LTOT group was 2.85 moderate/severe exacerbations (95% CI, 1.48-5.47), which indicated that the study met its primary endpoint (P = .002).
In terms of secondary endpoints, researchers found that the HFNC/LTOT group did not reach a median time to first moderate/severe COPD exacerbation, whereas the median time for the LTOT group was 25 weeks (95% CI, 14.1-47.4).
According to researchers, health-related quality of life scores, peripheral oxygen saturation and specific pulmonary function parameters also significantly improved in the HFNC/LTOT group.
Analyzing data from the St. George’s Respiratory Questionnaire, using the least squared mean by mixed models repeated measurements, researchers observed significant differences between the treatment groups for the total score at 24 weeks (P = .044) and the impact score at 12 weeks (P = .028).
“Health-related quality of life was improved, which we believe is sufficient evidence that HFNC is effective in this population,” Nagata told Healio.
The only significant difference found between HFNC/LTOT and LTOT regarding oxygen saturation, or SpO2, was at the end of study period (least squared mean: HFNC/LTOT, 1.01 ± 0.33%; LTOT, –0.2 ± 0.32%).
In terms of pulmonary function, the HFNC/LTOT group showed significant improvements in mean FVC at week 24 (HFNC/LTOT, 2.14 ± 0.54 L vs. LTOT, 2.07 ± 0.62 L; P = .017) and mean FEV1 at week 12 (HFNC/LTOT, 0.68 ± 0.23 L vs. LTOT, 0.65 ± 0.21 L; P = .045).
Mean percent predicted FVC at 24 weeks (HFNC/LTOT, 66.74 ± 15.74% vs. LTOT, 65.41 ± 17.79%; P = .015) and FEV1 at 12 weeks (HFNC/LTOT, 26.89 ± 9.23% vs. LTOT, 26.86 ± 9.32%; P = .026) also significantly differed.
“Larger clinical trials are desirable to see if the results of this study can be replicated,” Nagata told Healio. “It would also be desirable to conduct trials to test whether it is effective in more severe hypercapnia and to compare it with NIV.”
This study by Nagata and colleagues adds to the literature indicating that HFNC as a treatment option for patients with COPD has been proven safe, according to an accompanying editorial by Jean-Pierre Frat, MD, PhD, and Arnaud W. Thille, MD, PhD, of Centre Hospitalier Universitaire de Poitiers in France.
“Although additional trials are needed to determine the effect of HFNC on hospital admissions and mortality, this trial ... showed that long-term HFNC at home was feasible and safe with benefits in terms of reduction of exacerbation, leading to consideration of HFNC at home as a supplement to long-term oxygen therapy in the management of patients with severe COPD,” Frat and Thille wrote.
For more information:
Kazuma Nagata, MD, can be reached at kazuma_n1101@yahoo.co.jp.