Mô hình 61,3 bảng để xác định nghi ngờ lâm sàng của thuyên tắc phổi (Wells et al 123) biến các dấu hiệu lâm sàng và các triệu chứng của huyết khối tĩnh mạch sâu (tối thiểu chân sưng tấy và đau đớn với sự xem mạch của các tĩnh mạch sâu) | Evidence-based Cardiology Table Model for determining a clinical suspicion of pulmonary embolism Wells et al123 Variables Points Clinical signs and symptoms of deep vein 3-0 thrombosis minimum leg swelling and pain with palpation of the deep veins An alternative diagnosis is less likely than 3 0 pulmonary embolism Heart rate 100 beats min 1 5 Immobilization or surgery in the 1 5 previous 4 weeks Previous deep vein thrombosis pulmonary 1 5 embolism Hemoptysis 1 0 Malignancy treatment ongoing or within 1 0 previous 6 months or palliative Total points Pretest probability calculated as follows High 6 Moderate 2-6 Low 2 with size and number and the presence of a normal ventilation scan mismatched defect .42 45 A lung scan with mismatched segmental or larger perfusion defects is termed high probability .45 A single mismatched defect is associated with a prevalence of PE of about 80 .46 Three or more mismatched defects are associated with a prevalence of PE of 90 .46 Lung scan findings are highly age dependent with a relatively high proportion of normal scans and a low proportion of non-diagnostic scans in younger Lung scanning and clinical assessment Clinical assessment of PE is complementary to ventilationperfusion lung scanning a moderate or high clinical suspicion in a patient with a high probability lung scan is diagnostic prevalence of PE of 90 however a low clinical suspicion with a high probability defect requires further investigation because the prevalence of PE with these findings is only about 50 .42 45 Grade A The prevalence of PE with subsegmental matched perfusion defects low probability scan and a low clinical suspicion is expected to be less than 10 see below .27 30 42 Helical spiral computerized tomography CT Helical CT following intravenous injection of radiographic contrast can be used to visualize the pulmonary arteries. Although widely used to diagnose PE the technique has yet to be definitively evaluated for this 48 Grade
