Factors associated with posoperative mortality in high perioperative risk patients. Cohort study

Introduction: Determining perioperative risk is part of the strategies implemented with the aim of reducing morbidity and mortality in the surgical population in the world. Although there is no established definition, high perioperative risk is associated with the group of patients with the highest disease burden. Objective: To determine postoperative mortality and its associated factors in patients with high perioperative risk. Methods: Analytical observational cohort study of high perioperative risk patients included in the database (n = 843) of the anesthesia program in a high complexity hospital in Colombia, between January 2011 and April 2018. Pre and postoperative variables were analyzed using uni and multivariate logistic regression per protocol. Overall and stratified mortality were estimated and factors associated with their occurrence were analyzed. Finally, survival was analyzed, the primary outcome being overall cohort mortality and stratified high cardiovascular risk mortality. Results: Cumulative 7-day mortality was 3.68% (95% CI 2.40-4.95%) and 30-day mortality was 10.08% (95% CI 8.05-12.12%). Perioperative mortality in the high cardiovascular risk group in the first 7 days was 3.60% (95% CI 1.13-6.07%) and 14.86% (95% CI 10.15-19.58%) at 30 days. The following preoperative variables were associated with mortality: chronic obstructive pulmonary disease, chronic kidney disease, limited functional class and abdominal aortic aneurysm. A strong association was observed between postoperative complications and a significant increase in mortality rate; the most relevant complications were cerebrovascular events and cardiogenic shock. Conclusions: In this group of high perioperative risk patients,  and in the subgroup of high cardiovascular risk patients, overall mortality at 7 and at 30 days was estimated to be above values reported in various countries. Mortality was significantly increased by the presence of preoperative factors and postoperative complications.