Frailty is associated with poor surgical outcomes in elderly patients but is difficult to measure in the emergency setting. Sarcopenia, or the loss of lean muscle mass, is a surrogate for frailty and can be measured using cross-sectional imaging. We sought to determine the impact of sarcopenia on 1-year mortality after emergency abdominal surgery in elderly patients.METHODS
Sarcopenia was assessed in patients 70 years or older who underwent emergency abdominal surgery at a single hospital from 2006 to 2011. Average bilateral psoas muscle cross-sectional area at L3, normalized for height (Total Psoas Index [TPI]), was calculated using computed tomography. Sarcopenia was defined as TPI in the lowest sex-specific quartile. Primary outcome was mortality at 1 year. Secondary outcomes were in-hospital mortality and mortality at 30, 90, and 180 days. The association of sarcopenia with mortality was assessed using Cox proportional hazards regression and model performance judged using Harrell's C-statistic.RESULTS
Two hundred ninety-seven of 390 emergency abdominal surgery patients had preoperative imaging and height. The median age was 79 years, and 1-year mortality was 32%. Sarcopenic and nonsarcopenic patients were comparable in age, sex, race, comorbidities, American Society of Anesthesiologists classification, procedure urgency and type, operative severity, and need for discharge to a nursing facility. Sarcopenic patients had lower body mass index, greater need for intensive care, and longer hospital length of stay (p < 0.05). Sarcopenia was independently associated with increased in-hospital mortality (risk ratio, 2.6; 95% confidence interval [CI], 1.6–3.7) and mortality at 30 days (hazard ratio [HR], 3.7; 95% CI, 1.9–7.4), 90 days (HR, 3.3; 95% CI, 1.8–6.0), 180 days (HR, 2.5; 95% CI, 1.4–4.4), and 1 year (HR, 2.4; 95% CI, 1.4–3.9).CONCLUSION
Sarcopenia is associated with increased risk of mortality over 1 year in elderly patients undergoing emergency abdominal surgery. Sarcopenia defined by TPI is a simple and objective measure of frailty that identifies vulnerable patients for improved preoperative counseling, setting realistic goals of care, and consideration of less invasive approaches.LEVEL OF EVIDENCE
Prognostic study, level III.