Low skeletal mass predicts poor prognosis of elderly patients after emergency laparotomy: A single Asian institution experience

Introduction: Sarcopenia, defined as low skeletal muscle mass and poor muscle function, has been associated with worse postoperative recovery. This study aims to evaluate the significance of low muscle mass in the elderly who require emergency surgeries and the postoperative outcomes. 
Method: Data from the emergency laparotomy database were retrieved from Khoo Teck Puat Hospital, Singapore, between 2016 and 2019. A retrospective analysis was performed on patients aged 65 years and above. Data collected included skeletal muscle index (SMI) on computed tomography scan, length of stay, complications and mortality. Low muscle mass was determined based on 25th percentile values and correlation with previous population studies. 
Results: A total of 289 patients were included for analysis. Low muscle mass was defined as L3 SMI of <22.09cm2/m2 for females and <33.4cm2/m2 for males, respectively. Seventeen percent of our patients were considered to have significantly low muscle mass. In this group, the length of stay (20.8 versus 16.2 P=0.041), rate of Clavien-Dindo IV complications (18.4% vs 7.5% P=0.035) and 1-year mortality (28.6% vs 14.6%, P=0.03) were higher. Further multivariate analysis showed that patients with low muscle mass had increased mortality within a year (odds ratio 2.16, 95% confidence interval 1.02–4.55, P=0.04). Kaplan-Meier analysis also shows that the 1-year overall survival was significantly lower in patients with low muscle mass. 
Conclusion: Patients with low muscle mass have significantly higher post-surgical complication rates and increased mortality. 

Keywords: Emergency laparotomy, geriatrics, mortality, postoperative outcome, sarcopenia