American Society of Anesthesiologists class and Charlson's comorbidity index as predictors of postoperative colorectal anastomotic leak: a single-institution experience.

Background: The American Society of Anesthesiologists (ASA) physical status classification and Charlson comorbidity index (CCI) was adopted to assess patients' physical condition before surgery. Studies suggest that ASA score and CCI might be a prognostic criterion (indicator) for patient outcome. The aim of this study is to determine if ASA classification and CCI can determine the risk of anastomotic leaks (AL) in patients who underwent colorectal surgery.

Methods: A retrospective analysis of 505 consecutive colorectal resections with primary anastomoses between 2008 and 2012 was performed at a university hospital. ASA score, CCI, surgical procedure, length of stay, age, body mass index (BMI), comorbidities, and postoperative outcomes were analyzed.

Results: Two hundred sixty-five patients had an ASA score of I and II, 227 patients had an ASA score of III, and 13 patients had an ASA score of IV. A total of 19 patients had an anastomotic leak (ASA I-II: 5 patients, 1.9%; ASA III: 12 patients, 5.58%; ASA IV: 2 patients, 18.18%). A higher ASA score was significantly associated with AL on further analysis (OR: 2.99, 95% CI: 1.345-6.670, P = 0.007). When matched for age, BMI, and CCI on logistic regression analysis, increased ASA level was independently related to an increased likelihood of leak (OR(steroids) = 14.35, P < 0.01; OR(ASA_III v I-II) = 2.02, P = 0.18; OR(ASA_IVvI-II) = 8.45, P = 0.03). There were no statistically significant differences in means between the leak and no-leak patients with respect to age (60.69 versus 65.43, P = 0.17), BMI (28.03 versus 28.96, P = 0.46), and CCI (6.19 versus 7.58, P = 0.09).

Conclusions: ASA score, but not CCI, is independently associated with anastomotic leak. Patients with a high ASA class should be closely followed postoperatively for AL after colorectal operations.