Abstract

Two hundred and thirty one patients awaiting elective surgery were divided on the basis of spirometric examination into normal (group A) and those with increased airway resistance (group B). The mean arterial oxygen tension for the 151 normal subjects was 96·3 (± 11·6) mm. Hg. There was a significant inverse correlation of Pao₂ with age and dynamic lung volumes. The 80 patients in group B were significantly older and their mean Pao₂ was 88·7 (± 12·9) mm. Hg. There was, however, no correlation between Pao₂ and age in this group, probably because the increased airway resistance had a greater influence in lowering the arterial oxygen tension than did the age factor alone.