Abstract
RESPIRATORY complications continue to play a significant part in postoperative morbidity and mortality in spite of important advances in anesthetic and surgical management. The reported incidence of these complications ranges from 1.2 per cent1 to 43.5 per cent,2 and the criteria for diagnosis are necessarily arbitrary. The wide margin of safety in the low-risk patient and the remarkable capacity of most patients to recover from complications tend to obscure the importance of the hazard in the ordinary surgical patient. The increase in volume of geriatric surgery and the recent introduction of high-risk cardiopulmonary surgery have again brought into focus the . . .