Do emergency physicians use serum D-dimer effectively to determine the need for CT when evaluating patients for pulmonary embolism? Review of 5,344 consecutive patients.

OBJECTIVE The purpose of our study was to investigate whether D-dimer screening is being used effectively to determine the need for MDCT in diagnosing acute pulmonary embolism (PE) in emergency department patients. MATERIALS AND METHODS We performed a retrospective review of all patients who underwent D-dimer testing or MDCT in the emergency department from January 1, 2003, through October 31, 2005. A D-dimer value of > 0.43 microg/mL was considered positive. Diagnosis of PE was made on the basis of the MDCT. Clinical algorithms for diagnosing PE mandate that patients with a low clinical suspicion for PE undergo D-dimer testing, then MDCT if positive. For patients with a high clinical suspicion for PE, MDCT should be performed without D-dimer testing. RESULTS Of 3,716 D-dimer tests, 1,431 (39%) were positive and 2,285 (61%) were negative. MDCT was performed in 166 (7%) patients with negative D-dimer results and in 826 (58%) patients with positive D-dimer results. The prevalence of PE in patients with a high clinical suspicion and no D-dimer testing was 9% (139/1,628), which was higher than the rate of PE in the positive D-dimer group at 2% (19/826) (p < 0.0001). There was no significant difference in the prevalence of PE in the positive and negative D-dimer groups (2% vs 0.6%, respectively) (p = 0.23). The sensitivity and negative predictive value of D-dimer for PE were 95% (95% CI, 73.1-99.7%) and 99% (95% CI, 96.2-99.9%), respectively. CONCLUSION D-dimer screening is not used according to established diagnostic algorithms to determine the need for MDCT in diagnosing acute pulmonary embolism in our emergency department.

[1]  X Marchandise,et al.  Diagnosis of pulmonary embolism with spiral CT: comparison with pulmonary angiography and scintigraphy. , 1996, Radiology.

[2]  K. Garg,et al.  Clinical validity of helical CT being interpreted as negative for pulmonary embolism: implications for patient treatment. , 1999, AJR. American journal of roentgenology.

[3]  E. Fishman,et al.  Pretest risk assessment in suspected acute pulmonary embolism. , 2008, Academic radiology.

[4]  S. Goldhaber,et al.  Normal D-dimer levels in emergency department patients suspected of acute pulmonary embolism. , 2002, Journal of the American College of Cardiology.

[5]  S. Swensen,et al.  Outcomes after withholding anticoagulation from patients with suspected acute pulmonary embolism and negative computed tomographic findings: a cohort study. , 2002, Mayo Clinic proceedings.

[6]  M. Prins,et al.  Diagnostic Strategies for Excluding Pulmonary Embolism in Clinical Outcome Studies , 2003, Annals of Internal Medicine.

[7]  N L Müller,et al.  Pulmonary embolism: prospective comparison of spiral CT with ventilation-perfusion scintigraphy. , 1997, Radiology.

[8]  T. McLoud,et al.  Acute pulmonary embolism: assessment of helical CT for diagnosis. , 1998, Radiology.

[9]  Pieter W Kamphuisen,et al.  Effectiveness of managing suspected pulmonary embolism using an algorithm combining clinical probability, D-dimer testing, and computed tomography. , 2006, JAMA.

[10]  M Gent,et al.  Derivation of a Simple Clinical Model to Categorize Patients Probability of Pulmonary Embolism: Increasing the Models Utility with the SimpliRED D-dimer , 2000, Thrombosis and Haemostasis.

[11]  H. Büller,et al.  Use of a clinical decision rule in combination with D-dimer concentration in diagnostic workup of patients with suspected pulmonary embolism: a prospective management study. , 2002, Archives of internal medicine.

[12]  Smita Patel,et al.  Pulmonary embolism: optimization of small pulmonary artery visualization at multi-detector row CT. , 2003, Radiology.

[13]  Mireya Diaz,et al.  CT pulmonary angiography: a comparative analysis of the utilization patterns in emergency department and hospitalized patients between 1998 and 2003. , 2004, AJR. American journal of roentgenology.

[14]  William A Ghali,et al.  d-Dimer for the Exclusion of Acute Venous Thrombosis and Pulmonary Embolism , 2004, Annals of Internal Medicine.

[15]  H. Büller,et al.  The Use of a Rapid D-dimer Blood Test in the Diagnostic Workup for Pulmonary Embolism: A Management Study , 1999, Thrombosis and Haemostasis.

[16]  M H Prins,et al.  Non‐invasive diagnostic work‐up of patients with clinically suspected pulmonary embolism; results of a management study , 2004, Journal of thrombosis and haemostasis : JTH.

[17]  Alexander Crispin,et al.  Subsegmental pulmonary emboli: improved detection with thin-collimation multi-detector row spiral CT. , 2002, Radiology.

[18]  M Gent,et al.  Use of a Clinical Model for Safe Management of Patients with Suspected Pulmonary Embolism , 1998, Annals of Internal Medicine.

[19]  V. Pankratz,et al.  Sensitivity and specificity of the semiquantitative latex agglutination D-dimer assay for the diagnosis of acute pulmonary embolism as defined by computed tomographic angiography. , 2004, Mayo Clinic proceedings.

[20]  A. Donato,et al.  Clinical outcomes in patients with suspected acute pulmonary embolism and negative helical computed tomographic results in whom anticoagulation was withheld. , 2003, Archives of internal medicine.

[21]  A. van Rossum,et al.  Pulmonary embolism: validation of spiral CT angiography in 149 patients. , 1996, Radiology.