title: Using critical administration thresholds to predict abbreviated laparotomy.
abstract: BACKGROUND
  Early identification of trauma patients requiring abbreviated laparotomy (AL) is key to prevent prolonged operative times with associated hypothermia and acidosis. The critical administration threshold (CAT) is a novel method to define large-volume transfusion, accounting for rate and volume simultaneously. CAT may also serve as a simple trigger to distinguish patients benefiting from AL. The purpose of this study was to determine if CAT was predictive of the need for AL.
  
  
  METHODS
  Trauma patients receiving at least 1 U of blood during Day 1 of admission were eligible. Patients were classified by the number of times they met CAT (≥ 3 U of blood in 1 hour) for 24 hours. Basic demographics, time to CAT+ status and completion of operative therapy, need for AL, and mortality were quantified. A multivariate Cox proportional hazard ratio with a time-varying covariate was used to compare CAT and AL.
  
  
  RESULTS
  One hundred sixty-nine patients were included (70% new Injury Severity Score [ISS] > 10, 83% male). Significantly more AL patients (79%) were CAT+ compared with the patients with closed fascia (36%, p < 0.0001), and 94% of the patients reached CAT+ status before the end of their operative therapy (mean time to CAT+ status, 163 minutes; mean end operative time, 356 minutes). A Cox proportional hazard ratio demonstrated a nearly threefold increased risk for AL when a patient was CAT+ (odds ratio, 2.723; 95% confidence interval, 1.256-5.906). Failure to opt for an open abdomen with increasing CAT+ status was associated with a trend toward higher mortality.
  
  
  CONCLUSIONS
  Severely injured patients requiring large-volume transfusions typically reach the first CAT threshold quickly, on average, in less than 3 hours. Further, CAT+ patients have a higher odds of AL and a trend toward greater mortality if time is taken to close the fascia. As such, CAT+ status serves as a logical early trigger to identify patients benefiting from AL.
  
  
  METHODS
  Therapeutic outcome study, level III.
authors.affiliation: From the University of Tennessee Health Sciences Center, Memphis, Tennessee.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Savage
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Sumislawski
authors.forename: Martin A
authors.initials: MA
authors.lastname: Croce
authors.forename: Ben L
authors.initials: BL
authors.lastname: Zarzaur
mesh_terms: D000328:Adult; D001803:Blood Transfusion / Q000379:methods / Q000706:statistics & numerical data; D002985:Clinical Protocols; D005260:Female; D006760:Hospitalization; D006801:Humans; D007813:Laparotomy; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D014947:Wounds and Injuries / Q000601:surgery*