title: Normal D-dimer levels do not exclude thrombotic complications in trauma patients.
abstract: BACKGROUND
  Deep venous thrombosis (DVT) and pulmonary embolism (PE) are common complications in trauma patients. These diagnoses can be difficult and expensive to make. Recent studies report that a negative D-dimer test excludes thrombotic complications. We questioned the predictive value of a D-dimer test to exclude DVT and PE.
  
  
  METHODS
  Adult trauma patients admitted March 1999 to March 2001, with an Injury Severity Score > or =9 and expected length of stay >3 days, were approached for enrollment. Bilateral lower extremity duplex ultrasounds and d-dimer levels were performed within 36 hours of admission, day 3-4, day 7, and weekly until discharge.
  
  
  RESULTS
  Twenty-three patients were diagnosed with DVTs, with 18 DVTs detected within the first week of admission. Five DVT patients had normal D-dimer levels. One of three PE patients tested had a normal D-dimer level. The false negative rate for DVT by d-dimer assay was 24%, and the sensitivity was 76%. The negative predictive value for D-dimers was 92%. All false negative d-dimer tests occurred in patients diagnosed with DVT or PE within the 4 days after admission.
  
  
  CONCLUSIONS
  In the early postinjury phase, a negative d-dimer test does not exclude DVT or PE. However, the negative predictive value of a D-dimer test after the first 4 days from admission rose to 100%. Patients with clinical signs and symptoms of DVT or PE in the immediate postinjury phase should undergo further screening to exclude thromboembolic complications.
authors: Department of Surgery, Trauma Burn Center, University of Michigan Health System, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0033, USA.
authors: Wendy L
authors: WL
authors: Wahl
authors: Karla S
authors: KS
authors: Ahrns
authors: Paul J
authors: PJ
authors: Zajkowski
authors: Mary-Margaret
authors: MM
authors: Brandt
authors: Mary
authors: M
authors: Proctor
authors: Saman
authors: S
authors: Arbabi
authors: Lazar J
authors: LJ
authors: Greenfield
mesh_terms: D005188:False Negative Reactions; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D012680:Sensitivity and Specificity; D013997:Time Factors; D020246:Venous Thrombosis / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D014947:Wounds and Injuries / Q000150:complications*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products