Oxygenation Impairment during Anesthesia

Abstract

PaO2/FIO2 ratio was impaired during anesthesia, and the impairment increased with age and body mass index. Shunt was related to atelectasis and was a more important cause of oxygenation impairment in middle-aged patients, whereas low(Equation is included in full-text article.), likely caused by airway closure, was more important in elderly patients. Shunt but not low(Equation is included in full-text article.)increased with increasing body mass index. Thus, increasing age and body mass index impaired gas exchange by different mechanisms during anesthesia.