Position affects distribution of ventilation in the lungs of older people: an experimental study.

ABSTRACT

QUESTION What is the effect of sitting and side-lying on the distribution of ventilation during tidal breathing in healthy older people? DESIGN: Randomised, within-participant, experimental study. PARTICIPANTS: Ten healthy people more than 65 years old. INTERVENTION Tidal breathing during sitting and right side-lying. OUTCOME MEASURES: Distribution of ventilation as a percentage of total counts using Technetium-99m Technegas lung ventilation imaging. RESULTS: In sitting, the ratio of the distribution of ventilation to apical middle basal regions was 1 3.5 3.3 in the right lung, and 1 2.9 2.3 in the left lung. In right side-lying, 32% (95% CI 22 to 43) more ventilation was distributed to the right lung than to the left lung. The ratio of the distribution of ventilation to apical middle basal regions was 1 2.8 2.2 in the right lung, and 1 2.4 1.9 in the left lung. CONCLUSIONS: In both sitting and right side-lying, ventilation was distributed more to the middle than to the basal region, which may be related to age-associated changes in the respiratory system.