Comparison of two preoperative indices to predict perioperative mortality in non-cardiac thoracic surgery

OBJECTIVE: The preoperative classifications: physical status of the American Society of Anesthesiologists (ASA-PS) and/or cardiac risk index (CRI) of Goldman are widely used to estimate the perioperative risk in patients undergoing noncardiac throacic surgery. We tried to determine the validity of both methods in predicting the perioperative mortality in 845 consecutive patients scheduled for major elective noncardiac thoracic surgery. METHODS: Preoperatively, each patient was assigned 2 independent estimations of risk according to the ASA-score (ASA grade, I-IV) and CRI score (CRI grade, I-IV), respectively. RESULTS: Twenty-five patients died within 4 weeks after the operation, the others survived the perioperative period. The grading according to ASA as well as to the CRI score showed a direct correlation with the outcome: The higher the preoperative score, the higher was the mortality rate. When various combinations of ASA and CRI were tested, the lowest mortality rate was found in presence of ASA < or = III and CRI = I. Multivariate regression analysis showed that the ASA score had an independent correlation with perioperative mortality, whereas such a relationship was absent for CRI. CONCLUSIONS: The subjective assessment by an experienced anesthesiologist as expressed by the ASA-score is a valid method in the determination of the perioperative risk. CRI does not contribute additional information for the general perioperative risk.