The relationship between anesthetic technique and thirty-day mortality in patients undergoing noncardiac- and nonneurosurgery: A retrospective, propensity score-matched cohort study

Background: Currently, 310 million patients undergo surgery every year worldwide, and there is still controversy over which anesthetic technique to choose for a considerable of surgeries. This study evaluates the association of the anesthetic technique with thirty-day mortality after noncardiac- and nonneurosurgery. Methods: Electronic medical records of 90,785 patients who underwent non-cardiac- and nonneurosurgery at the *** General Hospital from January 1, 2012 to October 31, 2016, were subject to secondary retrospective analysis. The principal exposure was regional versus general anesthesia. Outcome measures were death, intensive care unit (ICU) admission and blood transfusion requirement within 30 days after surgery. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics. Results: We identified 90,785 patients, of whom 76,442 received regional anesthesia and 14,343 received general anesthesia. A total of 11,351 patients in the general anesthesia group had propensity scores similar to those of patients who received regional anesthesia and were included in the analyses. In the propensity-score matched cohort, the postoperative 30-day mortality rate was 0.75% (n = 85) in the regional anesthesia group (Odds Ratio, 0.567; 95% CI, 0.434 to 0.741; P = 0.00003) compared with 1.31% (n = 149) in the general anesthesia group. Regional anesthesia was also associated with a reduced rate of ICU admission compared with that of patients who received general anesthesia (0.44% vs. 2.68%; OR, 0.161; 95% CI, 0.119 to 0.217, P < 0.00001). There was a nonsignificant relationship between the anesthetic technique and postoperative blood transfusion (P = 0.082). Conclusions: The results of this observational, propensity score-matched cohort study suggest a significant association between regional anesthesia and low thirty-day mortality and a worse postoperative prognosis in patients who underwent noncardiac- and nonneurosurgery, which provides information for anesthetic technique decision making in the clinical setting.