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.

Abstract

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.

• Authors: Michael T Corwin, Jay H Donohoo, Robert Partridge, Thomas K Egglin, William W Mayo-Smith
• Journal: AJR. American journal of roentgenology (AJR Am J Roentgenol) Vol. 192 Issue 5 Pg. 1319-23 (May 2009) ISSN: 1546-3141 [Electronic] United States
• PMID: 19380556 (Publication Type: Journal Article)

Chemical References

• Biomarkers
• Fibrin Fibrinogen Degradation Products
• fibrin fragment D

Topics

• Algorithms
• Biomarkers (blood)
• Emergency Service, Hospital
• Female
• Fibrin Fibrinogen Degradation Products
• Humans
• Male
• Predictive Value of Tests
• Prevalence
• Pulmonary Embolism (blood, diagnostic imaging, epidemiology)
• Retrospective Studies
• Sensitivity and Specificity
• Tomography, X-Ray Computed