Computed Tomography Angiography in Patients Evaluated for Acute Pulmonary Embolism with Low Serum D-dimer Levels: A Prospective Study.

CONTEXT: Pulmonary computed tomography angiography (CTA) and the Wells criteria both have interobserver variability in the assessment of pulmonary embolism (PE). Quantitative D-dimer assay findings have been shown to have a high negative predictive value in patients with low pretest probability of PE. OBJECTIVE: Evaluate roles for clinical probability and CTA in Emergency Department (ED) patients suspected of acute PE but having a low serum D-dimer level. DESIGN: Prospective observational study of ED patients with possible PE who underwent pulmonary CTA and had D-dimer levels

A prospective evaluation of a quantitative D-dimer assay in the evaluation of acute pulmonary embolism.

PURPOSE: A prospective study was designed to determine if a screening quantitative serum D-dimer measurement of 1.0 microg/mL or less precludes pulmonary computed tomographic (CT) angiography in patients with possible acute pulmonary embolism (PE). MATERIALS AND METHODS: Over a period of 16 months, every patient seen in the emergency department in whom there was clinical suspicion of PE sufficient to warrant pulmonary CT angiography was also requested to have a quantitative serum D-dimer level measurement taken. All pulmonary CT angiography procedures were performed on a four-slice scanner and every examination was overread by a radiologist who was blinded to the D-dimer assay results. Three-month medical record and telephone follow-up was carried out for all participants who had a serum D-dimer level of 1.0 microg/mL or less to verify no new diagnosis or death from PE. RESULTS: In this prospective study, 361 consecutive patients who received pulmonary CT angiography had a D-dimer level of 1.0 microg/mL or less. There were 310 patients who had negative pulmonary CT angiography results and 50 patients who had indeterminate CT angiography results. Only one patient had positive pulmonary CT angiography findings. Minimum 3-month follow-up information was available for 349 patients, none of whom reported subsequent PE, including those with indeterminate pulmonary CT angiography results. CONCLUSION: The use of a screening D-dimer measurement of 1.0 microg/mL or less precludes pulmonary CT angiography in patients with possible acute PE. The use of this quantitative D-dimer assay would decrease radiation exposure, contrast medium toxicity, cost, and time for patients seen in the emergency medicine department.

Correlation and consistency of pain severity ratings by teens using different pain scales.

100 teens ranked pain experienced for their most recent "shot"on three different scales: casual 0-10 scale (mean 3.3), faces scale (mean 2.8), and 10 cm visual analog scale (mean 2.4). All pain scores showed wide variation (poor validity). Pain severity values were not equivalent across the different pain scales with the casual 10 scale most likely to overestimate pain values.