Non Invasive Ventilation on Peripheral Muscle Function and Aerobic Performance

Acute Effects of NIV on Peripheral Muscle Function and Aerobic Performance in Patients With Chronic Obstructive Pulmonary Disease: a Piloty Study

Background: Non-invasive ventilation (NIV) reduces respiratory load and demands on peripheral muscles. Methods: This study aims to evaluate the acute effects of bi-level NIV on peripheral muscle function during isokinetic exercise and aerobic performance in chronic obstructive pulmonary disease (COPD) patients. This is a pilot crossover study performed with a non-probabilistic sample of 14 moderate to very severe COPD patients. Procedures carried out in two days. Dyspnea, quality of life, lung function, respiratory muscle strength, functional capacity (6-minute walk test - 6MWT), and isokinetic assessment of the quadriceps were assessed. Blood samples (lactate, lactate dehydrogenase, and creatine kinase concentration) were also collected. Right after, NIV was performed for 30 minutes (bi-level or placebo, according to randomization) followed by new blood sample collection, 6MWT, and isokinetic dynamometer tests. Before and after evaluations, the subjective perception of dyspnea and fatigue in the lower limbs was quantified. After a wash-out period of seven days, participants returned, and all assessments were performed again.

Inclusion Criteria:

• Clinically stable COPD patients (diagnosed according to the Global Initiative for Obstructive Lung Disease), of both sexes, without exacerbation or changes in medication for at least one month before the study, and no dyspnea during daily activities (grades 2, 3, and 4 of the Medical Research Council - MRC scale) were included.

Exclusion Criteria:

• Those with a diagnosis of neoplasia, orthopedic or neurological conditions affecting exercise capacity, peripheral arterial obstructive disease, heart failure, kidney or liver disease, did not adapt, or failed to complete the study procedures, were excluded.