The Effects of Home High-Flow Nasal Cannula Oxygen Therapy on Clinical Outcomes in Patients with Severe COPD and Frequent Exacerbations

Abstract

Background: Chronic Obstructive Pulmonary Disease (COPD) is a disease with high morbidity and mortality globally. Exacerbations of COPD are major contributors to disease progression and a decline in health-related quality of life (HRQoL). High-flow nasal cannula (HFNC) oxygen therapy is an innovative therapy that provides humidified and heated blended air and oxygen through a nasal cannula. There is some preliminary evidence supporting the effectiveness of HFNC in managing COPD exacerbations, but there are limited data on its effectiveness when used at home for patients with stable, severe COPD. The aim of the present study is to test the hypothesis that home HFNC can decrease the COPD exacerbations rate and hospital admissions and improve HRQoL measures in severe COPD patients with frequent COPD exacerbations. Methods: In a prospective proof-of-concept interventional multicenter study, 40 GOLD stage III and IV COPD patients with a high disease burden (≥2 exacerbations treated with antibiotics and/or corticosteroids) and ≥1 hospital admission in the last year were included. Patients were given instructions on the usage of HFNC by a ventilation practitioner during a group session. The flow rate was 25-30 L/min and FiO₂ was 21-35%. Outcome measures included the COPD exacerbations rate, hospital admissions, in-hospital days, Medical Research Council dyspnea (MRC) score, Clinical COPD Questionnaire (CCQ) score, Hospital Anxiety Depression Scale (HADS) scores and capillary pCO₂. Repeated analysis of variance (ANOVA) was used to analyze the data. Significant effects identified in the ANOVA were further examined using Student's t-tests. Results: After 1 year, 27 patients could be evaluated. The COPD exacerbations rate decreased by 1.40 (mean difference ± SD: 1.40 ± 2.09; p = 0.002), hospital admissions decreased by 0.96 admissions per year (0.96 ± 1.37; p = 0.001), and in-hospital days decreased by 7.22 days (7.22 ± 9.26; p = 0.001). Capillary pCO₂ decreased by 0.02 kPa (0.02 ± 0.52; p = 0.85). The CCQ score decreased by 0.06 (0.06 ± 0.96; p = 0.76). The MRC dyspnea score decreased by 0.04 (0.04 ± 0.80; p = 0.81). The HADS anxiety score decreased by 0.63 (0.63 ± 3.12; p = 0.31). And finally, the HADS depression score decreased by 0.32 (0.32 ± 3.48; p = 0.64). There was a significant difference between the normocapnic (capillary pCO₂ < 6.0 kPa) group and the hypercapnic group in terms of change in the CCQ score (-0.24 ± 0.55 and 0.49 ± 1.32 decrease, respectively, p = 0.05) and the HADS depression score (-0.76 ± 1.86 and 2.20 ± 4.75 decrease, respectively, p = 0.03) after 1 year of HFNC treatment. Conclusions: One-year-long HFNC therapy significantly decreased the COPD exacerbations rate, hospital admissions, and in-hospital days in severe COPD patients with a high disease burden and frequent COPD exacerbations irrespective of them having hypercapnia and with the HRQoL measures only improving in the hypercapnic group. This may imply that severe COPD patients with a high disease burden and frequent COPD exacerbations, irrespective being hypercapnic, are candidates for treatment with home HFNC oxygen therapy.

Keywords: COPD; COPD exacerbations; domiciliary; high flow nasal cannula; hospitalization.

Figure 1

Flow Chart Design of the Study.

Figure 2

Flow chart of patient enrollment.

Figure 3

Mean hospital admissions, in-hospital days, and COPD exacerbation rate at baseline and after 1 year of HFNC treatment. HFNC; high-flow nasal cannula oxygen treatment, admission days; in-hospital days, exacerbations; COPD exacerbation rate.

Figure 4

Kaplan–Meier curves for time to first COPD exacerbation one year before the start of high-flow nasal cannula (HFNC) oxygen treatment (blue line), and one year after start of HFNC oxygen treatment (green line). Mean time to first COPD exacerbation before HFNC treatment was 93.2 ± 15.4 days and after HFNC oxygen treatment it was 180.9 ± 20.8 days. The log-rank test showed a significance of p = 0.002.

Figure 5

Mean MRC Dyspnea score, CCQ score and HADS score at baseline and after 1 year of HFNC treatment in the hypercapnic (pCO₂ ≥ 6 kPa) group. HFNC; high-flow nasal cannula oxygen treatment, MRC; Medical Research Council, CCQ; Clinical COPD Questionnaire, HADS; Hospital Anxiety Depression Scale.