title: Sarcopenia in emergency abdominal surgery.
abstract: Sarcopenia, a loss of skeletal muscle mass associated with aging, is a practical measure of frailty and has been previously identified as a predictor of outcomes in surgical cohorts including cancer resection and elderly patients. We hypothesized that sarcopenia, as measured by preoperative computerized tomography (CT) scan, predicts mortality and morbidity in emergent laparotomy.
  
  
  
  Institutional American College of Surgeons National Surgical Quality Improvement Program data were queried for adult patients who underwent open emergency abdominal surgery between 2008 and 2013. Patients with abdominal CT scans within 30 d before surgery were included, and cross-sectional areas of the psoas muscles at vertebral level L4 were summed, normalized by patient height, and stratified by sex. The influence of this total psoas area (TPA) on postoperative morbidity and mortality was evaluated using univariate and multivariate analysis.
  
  
  
  Of 781 surgeries, 593 (75.9%) had appropriate preoperative CT scans. Median patient age was 61 years old, median TPA was 1719 mm2, and median body mass index was 26.7. Univariate analysis demonstrated a significant association between TPA and total postoperative morbidity (P = 0.0133), increased length of stay (<0.0001), and 90-d mortality (P = 0.0008) but not 30-d mortality (P = 0.26). In multivariate analysis, TPA lost its significance compared to more influential predictors of mortality, including American Society of Anesthesiologists classification.
  
  
  
  Sarcopenia, as measured by TPA, significantly predicted mortality in univariate analysis but lost significance in multivariate analysis when factors such as American Society of Anesthesiologists score were included. Because TPA is readily available at no additional risk or cost, it is a convenient additional tool for preoperative risk assessment and counseling.
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Dirks
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia.
authors.forename: Brandy L
authors.initials: BL
authors.lastname: Edwards
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tong
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia.
authors.forename: Basil
authors.initials: B
authors.lastname: Schaheen
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia.
authors.forename: Florence E
authors.initials: FE
authors.lastname: Turrentine
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia.
authors.forename: Amber
authors.initials: A
authors.lastname: Shada
authors.affiliation: Department of Surgery, University of Virginia, 3530 Hospital Dr, Charlottesville, Virginia. Electronic address: philipsmith@virginia.edu.
authors.forename: Philip W
authors.initials: PW
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004630:Emergencies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care; D007813:Laparotomy / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017063:Outcome Assessment, Health Care; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D057234:Preoperative Period; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055948:Sarcopenia / Q000150:complications* / Q000000981:diagnostic imaging; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed
keywords: Complications; Frailty; Morphometrics; Preoperative assessment; Sarcopenia