Normal d-dimer levels do not exclude thrombotic complications in trauma patients

• Published in: Surgery 2003-10, Vol.134 (4), p.529-532
• Main Authors: Wahl, Wendy L, Ahrns, Karla S, Zajkowski, Paul J, Brandt, Mary-Margaret, Proctor, Mary, Arbabi, Saman, Greenfield, Lazar J
• Format: Article
• Language: English
• Subjects: False Negative Reactions; Fibrin Fibrinogen Degradation Products - metabolism; Humans; Predictive Value of Tests; Pulmonary Embolism - blood; Pulmonary Embolism - diagnosis; Pulmonary Embolism - etiology; Sensitivity and Specificity; Time Factors; Venous Thrombosis - blood; Venous Thrombosis - diagnosis; Venous Thrombosis - etiology; Wounds and Injuries - complications
• ISSN: 0039-6060; 1532-7361
• DOI: 10.1016/S0039-6060(03)00271-X

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. Adult trauma patients admitted March 1999 to March 2001, with an Injury Severity Score ≥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. 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. 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.