title: End-tidal carbon dioxide and occult injury in trauma patients: ETCO2does not rule out severe injury.
abstract: OBJECTIVE
  To determine if early measurement of end-tidal carbon dioxide (ETCO2) in nonintubated patients triaged to a level 1 trauma center has utility in ruling out severe injury.
  
  
  METHODS
  We performed a prospective cohort study of adult patients triaged to our urban, academic, level 1 trauma center. Included patients had ETCO2measured within 30 minutes of arrival. Chart review was performed on enrolled patients to identify severe injury defined by: admission to an intensive care unit, need for an invasive procedure, blood product transfusion, acute blood loss anemia, and acute clinically significant finding on computed tomographic scan.
  
  
  RESULTS
  Of 170 patients enrolled, 115 met the outcome of no severe injury. Mean ETCO2for patients without and with severe injury was 33.1 mm Hg (SD, 5.8) and 30.3 mm Hg (SD, 6.7), respectively. This difference reached statistical significance (P=.05), but did not demonstrate added clinical utility when combined with Glasgow Coma Scale, systolic blood pressure, and age in predicting the primary outcome (area under curve, 0.70 with ETCO2vs area under curve, 0.68 without ETCO2, P=.5). Patients with ETCO2≤30 mm Hg were found to be older, more likely to require intensive care unit admission or emergency operative intervention, develop acute blood loss anemia, and have an acute finding on computed tomography than patients with a higher ETCO2.
  
  
  CONCLUSIONS
  End-tidal carbon dioxide cannot be used to rule out severe injury in patients meeting criteria for trauma center care. The ETCO2≤30 mm Hg may be associated with increased risk of traumatic severe injury.
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209. Electronic address: deborah.j.williams@jax.ufl.edu.
authors: Deborah J
authors: DJ
authors: Williams
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Faheem W
authors: FW
authors: Guirgis
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Thomas K
authors: TK
authors: Morrissey
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Jennifer
authors: J
authors: Wilkerson
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Robert L
authors: RL
authors: Wears
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Colleen
authors: C
authors: Kalynych
authors: Department of Surgery, Division of Acute Care Surgery, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Andrew J
authors: AJ
authors: Kerwin
authors: Department of Emergency Medicine, University of Florida, Jacksonville, Jacksonville, FL 32209.
authors: Steven A
authors: SA
authors: Godwin
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000209:etiology; D019296:Capnography; D002245:Carbon Dioxide / Q000032:analysis*; D003422:Critical Care; D005260:Female; D006470:Hemorrhage / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015599:Trauma Severity Indices; D014218:Triage / Q000379:methods*; D014947:Wounds and Injuries / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide