[Causes and risk factors of intraoperative anesthesia complications. A prospective study of 14,735 anesthesias]

Identification of risk factors is an essential part of our efforts to minimize problems during anesthesia. 14,735 patients were included in a prospective study in order to assess the magnitude of risk and identify risk factors. The rate of complications increased substantially after the age of 40, due mainly to a large number of patients with poor preoperative physical condition. High age in itself was not associated with increased risk of complications. Contrary to former belief, the maintenance period of anesthesia does represent a considerable risk of complications requiring emergency intervention by an anesthesiologist. The complications were related to the conduct of anaesthesia in 70% of the total number of cases and to poor physical status and the surgery in 30%. However, poor physical condition and the surgery were responsible for 50% of the very serious complications and for all the four deaths on the table. The results of the survey confirm that thorough preoperative preparation of the patient is extremely important in order to reduce intraoperative risk, especially in emergency surgery.