Effects of body position, hyperinflation, and blood gas tensions on maximal respiratory pressures in patients with chronic obstructive pulmonary disease.

Abstract

Inspiratory muscle strength in patients with COPD is influenced by mechanical factors (body position, lung volumes) and non-mechanical factors (BMI, FEV1, and blood gases). PImax and PEmax are lower in the supine position while, in contrast to healthy subjects, PDI is higher in the supine position than in the sitting position.