Predictive value of ASA classification for the assessment of the perioperative risk.

To assess the predictive value of the ASA classification for morbidity and mortality during the whole time of post-operative hospitalization, data of 2248 patients undergoing elective surgery were analyzed prospectively. The incidence of post-operative morbidity, considering surgical as well as non-surgical complications, rose from 3.9% in ASA class I to 33.7% in ASA class IV. No patient died in ASA I, whereas 7.2% died in ASA IV. Furthermore, the ASA classes corresponded with the postoperative outcome of the patients, taking into account both the length of stay at the ICU and the postoperative hospitalization. The duration at the ICU increased an average of 0.1 to nearly 4 days and hospitalization from 11.8 to 27.3 in ASA classes I and IV, respectively. The results were confirmed considering separated groups with a different operative stress and risk. ASA-classification is also of conceivable value in estimating the perioperative risk and should therefore be considered prior to surgical intervention.