Effect of Obesity on 30-Day Mortality in Critically Ill Surgical Patients

Abstract

PURPOSE: This study was conducted to assess how extreme obesity affects 30-day mortality in this patient group. METHODS: A total of 802 patients who underwent emergency gastrointestinal surgery from January 2007 to December 2017 were retrospectively reviewed. Patients were divided into three groups according to their body mass index (BMI): group 1, normal weight (BMI: 18.5∼22.9 kg/m2): group 2, overweight (BMI: 23.0∼29.9 kg/m2): and group 3, obesity (BMI≥30 kg/m2). Patients with a BMI under 18.5 were excluded from the analysis. Chi-squared test, Fisher’s exact test, Kaplan-Meier survival analysis, and the log-rank test were used to assess and compare 30-day mortality rates between groups. RESULTS: The mortality rates of group 1, group 2, and group 3 were 11.3%, 9.0%, and 26.9%, respectively (P<0.017). The mortality rate did not differ significantly between group 1 and 2 (11.3% vs. 9.0%: P=0.341), but group 1 and 2 showed better survival rates than group 3 (11.3% vs. 26.9%: P=0.028, 9.0% vs. 26.9%: P=0.011). Kaplan-Meier survival analysis revealed that group 3 had higher mortality than the other two groups (P=0.001). CONCLUSION: Obesity (BMI≥30 kg/m2) was one of the risk factors influencing critically ill patients who underwent emergency surgery.