[Dependence of regional lung function on posture: radiospirometric findings in health]

Ten healthy volunteers were examined radiospirometrically using 133Xenon in physiologic saline i.v. and with 133Xenon gas inhalation. The measurements were done using a gamma camera (Nuclear Chicago, Pho/Gamma III) in the PA projection in both sitting and supine positions. For evaluation, each lung was divided into three regions: upper, middle, and lower fields. Using a computer (DEC, GAMMA 11), the minute exhalation value, the perfusion and ventilation indices, and the ventilation/perfusion quotient were calculated. In the upright position the ventilation and perfusion indices increase from cranial to caudal. In the horizontal position the regional lung functions tend to equalize. The vital capacity is larger in the vertical position than in the horizontal position, particularly in the right lung. The values are shown in tabular form.