Prediction of Pulmonary Embolism Extent by Clinical Findings, D-dimer Level and Deep Vein Thrombosis Shown by Ultrasound

Abstract
Pulmonary embolism (PE) may encompass a wide spectrum of severity. To determine whether clinical findings, D-dimer (DD) concentration, and deep vein thrombosis (DVT) shown by lower-limb venous compression ultrasonography (US) might predict the scintigraphic extent of PE, we studied 104 hemodynamically stable consecutive outpatients with acute PE diagnosed by a high-probability ventilation-perfusion lung scan. Scintigraphic extent of PE was classified into three categories: perfusion defects corresponding to 50% of the total lung area. Median respiratory and heart rates were found to be significantly related to the extent of PE. Higher median alveolar-arterial oxygen difference values were observed as the proportion of lung perfusion defects increased (>50% vs. 50% perfusion defects compared to 2731 g/L in those with 50% vs. 50% vs. <30% defects, OR 4.5; 95% CI 1.5–13.6). In conclusion, clinical signs such as tachypnea and tachycardia, alveolar-arterial oxygen difference, plasma DD concentration, and presence of DVT on US are predictors of a larger PE, as assessed by the extent of perfusion defects on high probability lung scans.
Funding Information
  • Swiss National Research Foundation (32-36064.92)
  • Fonds National de la Recherche Scientifique
  • Université Libre de Bruxelles