A CROSS-VALIDATED MULTIFACTORIAL INDEX OF PERIOPERATIVE RISKS IN ADULTS UNDERGOING ANESTHESIA FOR NONCARDIAC SURGERY - ANALYSIS OF PERIOPERATIVE EVENTS IN 26907 ANESTHETIC PROCEDURES

Objective. To develop a severity index of anaesthetic risk that-predic ts relevant perioperative adverse events in adults. Design. Prospectiv e cross-sectional study. Setting. Department of anaesthesiology at one university hospital. Patients, 26907 consecutive anaesthetic procedur es in patients over 15 years of age and a complete preoperative evalua tion. Patients undergoing cardiac and obstetric surgery were excluded. Measurements and main results. Demographic data, preoperative health status, type of anaesthesia, operative procedures, and perioperative i ncidents (standardised on a national basis) were acquired by means of a computerised anaesthetic record system. Occurrence of at least one p erioperative event with impact on postanaesthetic care was computed by a multivariate logistic regression model against 17 variables with di fferent characteristics representing possible risk factors. Fourteen v ariables proved to be independent risk factors. The weighting of the v ariables was expressed in scores which added up to form a simple index for each patient. Patients without major risk factors (0-10 points) h ad a 0.3% risk of suffering from a relevant incident. Patients with mo re than 60 points had a 28.6% risk. The results were well demonstrated by cross-validation. Conclusions. The index seems to reflect the risk of relevant perioperative incidents. It can be used for audit purpose s. In daily routine, the index could focus our attention on patients w ith increased perioperative risk. However, it is limited in detecting particular constellations of factors which interact on each other with regard to perioperative risk.