Background: In severe chronic obstructive pulmonary disease (COPD), interval training (IT) can be performed with oxygen support, which provides beneficial effect on metabolic processes, tissue perfusion, and peripheral muscle function.
Methods: A prospective cohort study with matched controls was performed on patients in Budapest at the Department of Pulmonary Rehabilitation of the National Koranyi Institute of Pulmonology between January 1, 2020 and March 1, 2020. After a complex condition assessment, both case and control patients participated in a 3-week long complex pulmonary rehabilitation (PR) program that included individual training, education, nutrition, and psychological counseling. Anthropometric and functional data of patients were recorded at both the beginning and end of the PR program. Our research aimed to assess the effect of non-invasive ventilation (NIV) in patients with severe COPD who underwent IT.
Results: A total of 18 [male/female: 10 (55.6%)/8 (44.4%)] patients were enrolled in our study. IT with NIV significantly improved the patients' 6-minute walking distance (6MWD) (m) [216.0 (211.5-233.7) vs. 274.0 (247.5-313.5); P<0.001] and quality of life [COPD Assessment Test (CAT): 29.0 (26.9-32.0) vs. 15.0 (13.5-17.5); P<0.001], [modified Medical Research Council (mMRC): 2.0 (1.5-2.0) vs. 1.0 (1.0-2.0); P=0.009]; in addition, there was a significant increase in inspiratory vital capacity (IVC) (ref%) [65.0 (63.0-69.0) vs. 74.7 (70.5-75.0); P=0.015], in chest kinematics (cm) [3.0 (2.5-4.0) vs. 5.5 (4.0-6.5); P<0.001], work rate (Watt) [25.0 (24.0-27.0) vs. 36.0 (35.0-38.0); P<0.001], volume of oxygen consumption [VO2/kg (mL/kg/min): 8.8 (8.5-9.2) vs. 10.3 (10.2-10.7); P<0.001], and Body-mass index, airflow Obstruction, Dyspnea, and Exercise (BODE) index [5.0 (5.0-6.7) vs. 4.0 (3.0-5.0); P=0.006], while the results of the control group were non-significant [6MWD, maximal inspiratory pressure (MIP), CAT, mMRC, BODE index].
Conclusions: In severe COPD, IT with NIV is well tolerated during PR, it has a significant beneficial effect on the quality of life, improves exercise capacity and respiratory functions, decreases dynamic hyperinflation and dyspnea.
Keywords: Chronic obstructive pulmonary disease (COPD); biphasic airway pressure (BIPAP); interval training (IT); non-invasive ventilation (NIV); pulmonary rehabilitation (PR); quality of life.