A pinhole method for measuring chest wall compliance.
We describe a method of measuring chest wall compliance (Cw) that readily detects whether respiratory muscles are relaxed. The method simulates a normal slow sigh, with the subject exhaling through a needle valve. Cw is calculated from the slope of the volume-esophageal pressure line. With relaxed subjects, repeated measurements yield similar slopes. When subjects cannot relax, the volume-pressure line is irregular and variable. In 26 subjects who could relax, Cw averaged 0.208 +/- 0.05 (SD) l/cmH2O.
D000328:Adult; D003187:Compliance; D004548:Elasticity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010827:Physiology / Q000379:methods*; D013909:Thorax / Q000502:physiology*