Effect of posture on inter-regional distribution of pulmonary ventilation in man.
Regional ventilation per unit alveolar volume (V/VA) and regional lung expansion (FRCR/TLCR) were measured in twelve normal male human subjects in seated, supine, lateral decubitus and prone postures using a gamma camera and inhalation of the radioactive gases 81Krm (half-life 13 sec) and 85Krm (half-life 4.4 h). FRCR/TLCR decreased from superior to inferior in all postures except prone where it was uniform; V/VA increased from superior to inferior except in the prone position where it was uniform. In the horizontal axis FRCR/TLCR and V/VA were uniformly distributed except for cranial to caudal gradients (with lower values caudally) in supine and lateral decubitus postures. In the prone posture V/VA tended to be higher in caudal lung zones.
D000328:Adult; D005652:Functional Residual Capacity; D006801:Humans; D007726:Krypton; D008168:Lung / Q000502:physiology*; D008297:Male; D011187:Posture; D011650:Pulmonary Alveoli / Q000502:physiology; D011868:Radioisotopes; D012119:Respiration; D014018:Tissue Distribution; D014109:Total Lung Capacity
D011868:Radioisotopes; D007726:Krypton