Relative importance of preoperative health status versus intraoperative factors in predicting postoperative adverse outcomes in geriatric surgical patients

OBJECTIVES: To determine the prevalence and predictors of adverse postoperative outcomes in older surgical patients undergoing noncardiac surgery. DESIGN: Prospective cohort study of consecutive patients undergoing noncardiac surgery in 1997. SETTING: A medical school-affiliated teaching community hospital. PARTICIPANTS: Patients age 70 and older undergoing noncardiac surgery. Patients presenting for surgery requiring only local anesthesia or monitored anesthesia care were excluded. MEASUREMENTS: Potential pre- and intra-operative risk factors were measured and evaluated for their association with the occurrence of predefined in-hospital postoperative adverse outcomes. Univariate predictors of postoperative outcomes were first measured using the chi-square or Fisher's exact tests followed by multivariate logistic regression. Odds ratios (OR) with 95% confidence interval (CI), and two-sided P-values were reported. RESULTS: Five hundred forty-four consecutive patients were studied. Overall, 21% of patients developed one or more postoperative adverse outcomes and 3.7% died during the in-hospital postoperative period. Of all the adverse outcomes, cardiovascular complications (10.3%) were the leading cause of morbidity, followed by neurological (7.7%) and pulmonary complications (5.5%). By multivariate logistic regression analysis, American Society of Anesthesiologists (ASA) classification (OR = 2.7, CI = 1.6-4.4), emergency surgery (OR 2.0, CI 1.1-3.4), and intraoperative tachycardia (OR 3.8, CI 1.9-7.6) were the most important predictors of postoperative adverse outcomes. Of all the preoperative physical symptoms and signs, decreased functional status (OR = 3.0, CI = 1.4-6.4) and clinical signs of congestive heart failure (OR = 2.1, CI = 1.1-5.1) were the two most important predictors of postoperative adverse neurological and cardiac outcomes, respectively. The median hospital stay was 4 days. The patients who developed postoperative adverse outcomes had significantly longer median hospital stays (9 days) than those without complications (3 days), (P < .0001). CONCLUSION: Our study demonstrates that the postoperative mortality rate in geriatric surgical patients undergoing noncardiac surgery is low. Despite the prevalence of preoperative chronic medical conditions, most patients do well postoperatively. The ASA classification (a reflection of the severity of preoperative comorbidities), emergency surgery, and intraoperative tachycardia increase the odds of developing any postoperative adverse events. Future studies aimed at modifying some of the potentially reversible risk factors, such as preoperative heart function and intraoperative heart rate are warranted.