Background Aging is an irreversible, progressive and cumulative process that involves biological, anatomical, physiological, and functional changes that occur over a period of time. Emergency surgery in geriatrics is challenging due to the limited time for surgery planning. Charlson Age Comorbidity Index (CACI) can be used as a predictor of mortality in geriatric patients undergoing surgery. The study’s aim is to determine the association between CACI and mortality in geriatric patients undergoing emergency surgery. Methods This study was a prospective analytic observational multicenter study. This study was conducted from February 2021 to April 2021. This study used the whole sampling method and was followed up 30 days after surgery. The data were analyzed using regression and the ROC Curve test with a confidence interval of 95%. Results We obtained 116 geriatric patients undergoing emergency surgery with a 30-day mortality rate of 11.2%. CACI significantly correlated with 30 day-mortality in geriatric underwent emergency surgery (p = 0.000) with B = 4.831. The AUC of the CACI score was 0.966, with a cut-off value of 5.5. For geriatric patients with CACI scores > 5.5, the risk of mortality within 30 days of treatment is 125.33 times greater (95% CI: 14.58–1077.67) than for patients with CACI scores < 5.5. Conclusion CACI is associated with 30-day mortality in geriatric patients undergoing emergency surgery. CACI score also could be used to predict 30-day mortality in geriatric underwent emergency surgery.

In geriatric patients, emergency surgery is more common than elective surgery. The incidence of medical complications increases along with aging while the rate of surgical complications remains constant. Postoperative complications escalates short-term morbidity and mortality and also associated with decreasing long-term survival. The main purposes of geriatric patients' care were to maintain hemodynamics, speed up recovery, and perform an assessment to avoid any further decline in functional capacity. The choice of anesthesia and how to administer anesthesia agents should be adjusted for the geriatric patient.