High-flow nasal therapy (HFNT), often used for stable patients, can reduce hospital readmission for acute exacerbations for chronic obstructive pulmonary disease (COPD).
High-flow nasal therapy (HFNT) during exercise in early pulmonary rehabilitation increases exercise tolerance and can also reduce systemic inflammation among hospitalized patients with severe acute exacerbation (AE) in chronic obstructive pulmonary disease (COPD), according to a paper published in Respiratory Research.
Investigators from Taiwan enrolled 44 COPD patients that were hospitalized due to AE between April 2017 and April 2019 in order to determine the effects of HFNT use during exercise when used in a pulmonary rehabilitation (PR) program. Most PR programs are provided to stable patients, the study authors explained, and there are fewer offered to AE COPD patients. The PR programs are comprehensive and non-pharmacological which offers a benefit for the management of COPD patients. Previous reports of PR program use for AE COPD patients offer mixed results, the study authors said.
The patients enrolled in the study were between 40 and 90 years of age and were ambulatory by hour 48 after their hospitalization for AE COPD. The patients were required to do PR every day during their hospitalization period and twice per week until 3 months after discharge, the study authors reported. Then, the investigators followed the patients for 12 months.
The patients were all taught to use a pursed-lip/diaphragmatic breathing exercise during their PR exercises, including limb muscle training, pacing waking, and bronchial hygiene, the study authors said. The patients also received information from a respiratory therapist about best practices.
Then, the respiratory therapist was interviewed to collect demographic, lifestyle, and disease-related information, like smoking habits, number of exacerbations in the past 12 months, medications used in stable and AE periods, and comorbidities.
The investigators additionally measured baseline blood samples for arterial blood gas, white blood cells, and C-reactive protein, and pulmonary function with FEV1 and FVC measurements after a 6-minute walking test.
Half of the patients were put in the HFNT group and half were not enrolled, but there were no statistically significant differences between the 2 cohorts, the study authors said. Patients in both groups had poor exercise tolerance demonstrated by their 6-minute walking tests, more-severe dyspnea sensation, and worse health status. Most patients had comorbidities, especially cardiovascular disease, the study authors learned.
By the end of the study, there was no significant difference in pulmonary function test between the 2 groups, the study authors wrote. Both groups saw improvement in white blood cells and C-reactive protein levels after 4 and 12 weeks of intervention, but laboratory data did not differ significantly between the 2 groups.
There was improved exercise tolerance in the 6-minute walking test after 4 and 12 weeks of the PR program, and those patients experienced decreased dyspnea sensation and inflammation (as evidenced by the C-reactive protein level) after 12 weeks of the PR program.
The study authors examined hospital admissions for AE in the year prior to and the year following participation in the PR program. They discovered a significant reduction in the number of admissions, they reported.
“Exercise training with HFNT can support an increased exercise capacity, decreased dyspnea sensations, and reductions in systemic inflammatory biomarkers in hospitalized patients with severe AE COPD,” the study authors concluded. “Our study also raises the possibility that HFNT during exercise enhances the training effect through decreased lung hyperinflation and increased pulmonary function.”
Tung, L., Shen, S., Shih, H. et al. Effect of high-flow nasal therapy during early pulmonary rehabilitation in patients with severe AECOPD: a randomized controlled study. Respir Res. 2020.21(84 doi.org/10.1186/s12931-020-1328-z.