ALGORITHM FOR SELECTING PATIENTS FOR PULMONARY ARTERY ANGIOGRAPHY IN CASE OF SUSPECTED PULMONARY EMBOLISM

Highlights We have developed an algorithm for selecting patients for CT pulmonary angiography in case of suspected pulmonary embolism. The algorithm is based on the results of laboratory studies, duplex ultrasound of the veins of the lower extremities and echocardiography. This algorithm makes it possible to reliably exclude pulmonary embolism in 21.2% of patients without performing CT pulmonary angiography. Aim . To develop an algorithm for excluding pulmonary embolism and selecting patients for pulmonary angiography based on the results of laboratory and ultrasound studies. Methods . The retrospective single-center study was conducted using the data of 113 patients admitted to the ICU with suspected pulmonary embolism. Patients underwent echocardiography and duplex ultrasound of the veins of both lower extremities, and computed tomography pulmonary angiography with contrast. Results . We carried out comparative analysis of clinical and anamnestic data depending on the presence of pulmonary embolism. There were significant differences between the groups by gender (p = 0.008) and age (p = 0.042). The concentration of D-dimer in the group with pulmonary embolism was significantly higher than in the control group (p < 0.001). Moreover, the left ventricular ejection fraction was higher in the group with pulmonary embolism compared to controls (p < 0.001). According to ultrasound data, 59% of patients with pulmonary embolism showed signs of acute deep vein thrombosis of the lower extremities, which was significantly more common compared to the control group (p < 0.001). Pulmonary angiography should be recommended to patients with suspected pulmonary embolism and signs of prior or acute deep vein thrombosis. In the absence of these signs and a D-dimer concentration of less than 1 500 ng/mL, pulmonary embolism can be reliably excluded. In cases where the concentration of D-dimer is less than 10 000 ng/mL and pulmonary artery systolic pressure is no more than 30 mmHg, then pulmonary embolism can be excluded as well. In all other cases, we recommend to perform pulmonary angiography. Conclusion . We have developed an algorithm for excluding pulmonary embolism and selecting patients for pulmonary angiography. The algorithm makes it possible to increase the specificity of the study from 45.1% to 57.3%. The algorithm is based on the concentration of D-dimer and the results of noninvasive ultrasound diagnostics. Ultrasound examination of the deep veins of the lower extremities and echocardiography allow differential diagnosis of cardiac pathology and other causes of symptoms. Moreover, these methods can become the basis for the selection of patients for pulmonary angiography.