Measurements of chest wall volume variation during tidal breathing in the supine and lateral positions in healthy subjects.

ABSTRACT

PURPOSE: To study the feasibility and the laterality of measurements of chest wall volume variation during tidal breathing in the lateral position in healthy subjects. METHODS: Eighteen normal subjects were studied. Chest wall volume changes were measured by optoelectronic plethysmography in the supine and right and left lateral positions during quiet breathing. The accuracy of measuring lung volume was also examined using hot wire spirometry in 10 of the subjects. RESULTS: The measurement errors between lung volume changes and chest wall volume changes were not significantly different in all positions. There was no significant difference between right and left compartmental volume changes in the supine position. However, chest wall volume changes were lower on the dependent side in the lateral position than on the non-dependent side because of the decrease in abdominal rib cage and abdomen volume changes. CONCLUSION: Chest wall volume measurements during quiet breathing in the lateral position have high measuring accuracy and show laterality.