Pulmonary complications, ventilation and blood gases after upper abdominal surgery.

Forty patients who underwent elective cholecystectomy were examined preoperatively and during the first postoperative week by physical examination, measurement of FVC and FEV1, arterial pH and blood gas analyses, and chest x-ray. Postoperative pulmonary complications (p.p.c.) were detected in 30 (75%) of the patients. Simple auscultation was the most sensitive tool in discovering p.p.c., but 18 of the 30 patients with complications also had a pathological chest x-ray. Obesity, smoking postoperative naso-gastric tube and postoperative wound infection were predisposing factors for p.p.c. Six patients with preoperative pulmonary disease all had a progress in their lung pathology. There was no definite relationship of duration of anaesthesia or drainage of the abdominal wound to development of p.p.c. The patients with p.p.c. showed a deeper and more prolonged fall in Pao2 postoperatively than the normal group. None of the normals showed an arterial Po2 below 70 mmHg in the postoperative course, while 63% of the p.p.c. group did. FVC and FEV1 showed marked reductions from preoperative values on the first postoperative day, and then gradually increased to near preoperative values after 1 week. Arterial pH and Pco2 showed no definite changes during the postoperative course.