D-Dimer as a Screening Tool for Ultrasound Examination for Diagnosis of Deep Vein Thrombosis

Abstract

Ultrasound (US) examinations have become the standard for evaluation of deep venous thrombosis (DVT). Evaluation for a possible DVT constitutes more than 40% of the daily ultrasound examinations performed at St. John's Regional Health Center. Of the US examinations performed for DVT, 80% are negative. The addition of D-dimer testing to the diagnostic algorithm has the potential to make the diagnosis of DVT in outpatients more convenient and economical. Ultrasound examination and interpretation is expensive. This project was to evaluate the D-dimer determination as a screening tool to indicate the need for US evaluation for DVT. The focus of this evaluation was the negativity of the D-dimer as a predictor of a normal venous examination. This study found that with a negative D-dimer result, more than 90% of the venous examinations were negative for DVT.