In spite of rapid advances in the care of surgical patients, pulmonary complications, especially atelectasis, continue to occur. In 1954, Thoren4 found pulmonary complications in 41.9% of a group of patients who had gallbladder surgery. Kurzweg1 states that the incidence of postoperative pulmonary complications is 20% to 30% in upper abdominal surgery. Factors which may contribute to the incidence of atelectasis in the postoperative patient include the age of the patient, duration of the operation, type of operation, and the type and location of the incision.
There are many methods used in the prophylaxis of postoperative atelectasis. Patients are urged to cough, to inspire deeply, and are turned from side to side at frequent intervals. The beneficial effect of hyperventilation induced by carbon dioxide rebreathing was initially demonstrated by Scott and Cutler3 in 1928. Methods of administration include 5% carbon dioxide, via a close-fitting face mask. Another