High-flow nasal cannula treatment reduces COPD exacerbations, symptoms
Patients with chronic obstructive pulmonary disease (COPD) and chronic hypoxemic respiratory failure experienced fewer exacerbations and symptoms when treated with humidified high-flow therapy via a nasal cannula (HFNC) in addition to long-term oxygen therapy (LTOT) compared with those treated with LTOT alone, according to a study from Denmark.
“[F]or COPD patients who were prescribed LTOT, consistent use of HFNC significantly reduced acute exacerbations of COPD and hospitalization,” said the researchers.
“[T]his study suggests that HFNC should be a treatment used in conjunction with LTOT in COPD patients with hypoxic failure to reduce exacerbations and maintain health status in general,” they said.
Two hundred patients with COPD and chronic hypoxemic respiratory failure who were receiving LTOT (initiated ≥3 months before study onset) were randomized to continue receiving LTOT either alone (usual care, mean age 70.4 years, 63 percent female) or in combination with the home-based HFNC (20 L/min, average use 6 hours/day; mean age 71.0 years, 56 percent female) for 12 months.
Patients provided information on modified Medical Research Council (mMRC) score and acute COPD exacerbations through phone interviews at months 1, 3, and 9, and at clinic visits at months 6 and 12, while St George’s Respiratory Questionnaire (SGRQ) scores and arterial blood gases were assessed at months 6 and 12.
Patients who used the HFNC had a lower acute exacerbation rate compared with those on usual care alone (3.12 vs 4.95/patient/year; p<0.001), with rates decreasing with increased use of the HFNC (p<0.001). [Int J Chron Obstruct Pulmon Dis 2018;13:1195-1205]
Compared with patients on usual care alone, patients who used HFNC also demonstrated improvements in COPD symptoms such as dyspnoea as demonstrated by their mMRC scores beginning at 3 months (p<0.001) and quality of life as demonstrated by SGRQ scores at 6 and 12 months (p=0.002 and p=0.033, respectively).
Patients using the HFNC also demonstrated reductions in PaCO2* levels while those on usual care had increased PaCO2 levels (p=0.005 at 12 months); 6-minute walk test at 12 months was also improved in HFNC-users compared with those on usual care alone (p=0.005).
All-cause mortality rates did not differ between patients on usual care and HFNC (12 percent vs 15 percent; p=0.636), nor did hospitalization rates (1.22 vs 1.08/patient/year; p=0.373), though a significant difference was noted when comparing 12 and 1 months of HFNC use (p<0.001). There was also little difference observed pertaining to lung function with HFNC use, though there was a trend towards increased FEV1** percentage with HFNC vs controls (p=0.084 and p=0.056 at 6 and 12 months, respectively).
According to the researchers, treatment adherence is an issue in patients with advanced COPD. “Despite improved survival when treated with LTOT, life expectancy is limited when in need of LTOT, in part due to concomitant comorbidities and hypercapnic failure,” they said. Patients are also prone to acute exacerbations which can be recurrent and result in poor outcomes, they said.
“In our opinion, [the decrease in exacerbations with HFNC] strongly supports the preventive effect of HFNC treatment on exacerbations, even in very severe COPD patients. HFNC may therefore prove to be a novel and an effective non-pharmacological treatment adjunct for this group of very severely ill patients,” said the researchers.
They called for further study into determining the optimal duration of HFNC use, difference between day- and night-time use of HFNC, and the use of other symptom scoring systems such as the COPD assessment test.