title: Serial hematocrit testing does not identify major injuries in trauma patients in an observation unit.
abstract: BACKGROUND
  Routine serial hematocrit measurements are a component of the trauma evaluation for patients without serious injury identified on initial evaluation. We sought to determine whether serial hematocrit testing was useful in detecting significant intra-abdominal injuries in trauma patients in our observation unit.
  
  
  METHODS
  We performed a retrospective chart review of all trauma patients placed in our observation unit over a 14-month period. Patients had received trauma surgery evaluation before placement in the observation unit and routinely received serial hematocrit testing (>or=2 hematocrit levels) while in the observation unit. We compared trauma patients with a hematocrit drop of 5 points or more to those without a significant hematocrit drop.
  
  
  RESULTS
  Three hundred sixty-five trauma patients were placed in the observation unit, and 310 patients (85%) had at least 2 hematocrits drawn during their stay. Of these patients, 20.6% had a hematocrit drop of 5 or more. Of patients with the hematocrit change, 18.8% were admitted to an inpatient unit from the observation unit compared to 9.3% of patients without a significant hematocrit change (P = .034). In one of these patients who had a computed tomography scan before observation admission, which demonstrated free fluid, the hematocrit drop assisted in diagnosing significant intra-abdominal injury.
  
  
  CONCLUSIONS
  Although serial hematocrit testing may be useful in specific situations, routine use of serial hematocrit testing in trauma patients at a level I trauma center's observation unit did not significantly aid in the detection of occult injury.
authors.affiliation: Division of Emergency Medicine, University of Utah, Salt Lake City, UT 84132, USA. troy.madsen@hsc.utah.edu
authors.forename: Troy
authors.initials: T
authors.lastname: Madsen
authors.forename: Matthew
authors.initials: M
authors.lastname: Dawson
authors.forename: Joseph
authors.initials: J
authors.lastname: Bledsoe
authors.forename: Philip
authors.initials: P
authors.lastname: Bossart
mesh_terms: D000007:Abdominal Injuries / Q000097:blood / Q000175:diagnosis*; D000328:Adult; D016001:Confidence Intervals; D004636:Emergency Service, Hospital; D005260:Female; D006400:Hematocrit; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic; D016017:Odds Ratio; D012189:Retrospective Studies; D013997:Time Factors