An analysis of pre-operative Pao2 in a general surgical population

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.