SEARCH RESULTS FOR: Pulmonary-Embolism-Pathogenesis-and-Clinical-Findings

Pulmonary Embolism Pathogenesis and Clinical Findings

Pulmonary Embolism: Pathogenesis and Clinical Findings Virchow’s Triad Body attempts to break down clot Fibrinogen breakdown products in blood Lab: Positive D-Dimer D-Dimer only performed if clinical suspicion of PE low (Well’s Criteria) Authors: Mackenzie Gault Mao Ding Reviewers: Midas (Kening) Kang Usama Malik Kevin Solverson* *MD at time of publication Hypercoagulable State Blood clot develops (commonly in deep veins of legs) Venous stasis = Deep Vein Thrombus (95% of PE) Vessel injury Ultrasound: Presence of Clot in Deep Vein of Leg Clot dislodges & migrates to inferior vena cava (IVC)àright atrium of heartàright ventricleàlodges in pulmonary arteries/arterioles Pulmonary Embolism (PE) Thromboembolic blockage of pulmonary vasculature ↓ perfusion to lung parenchyma Clot occludes pulmonary arteries/ arterioles ↑ dead space ventilation and V/Q mismatching Blood pumped from RV to pulmonary arteries cannot pass clot ↑ pulmonary and right ventricle (RV) pressure RV Strain ↑ RV workload, ↓ right coronary artery perfusion Computed Tomography- Pulmonary Angiogram (CTPA): Filling Defect (*see Radiology slide for CTPA findings) Echo: ↑ RV size + ↓ RV function ECG: S1Q3T3 Pattern (McGinn-White Sign: a large S wave in lead I, a Q wave in lead III and an inverted T wave in lead III together indicate acute right heart strain Lab: ↑ Brain natriuretic peptide (BNP) Chest Pain Tachycardia Dyspnea (shortness of breath) Pleuritic chest pain (worsens during breathing) Ischemia of lung tissue distal to clot X-Ray: usually normal, except Hampton’s Hump (↑ opacity in pleural based area), a rare but specific sign of PE) Air flow/ventilation to lungs unaffected VQ Scan (performed when CT contrast is contraindicated): Ventilation- perfusion ratio (V/Q) mismatch Chemoreceptors detect ↑ CO2 and ↓ O2 Signal brain to ↑ breathing rate Tachypnea (rapid breathing) ↓ Arterial O2 Lab: ↑Troponin BP: Hypotension Lab: ↑ Lactate Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published Feb 7, 2018, updated Oct 15, 2023 on www.thecalgaryguide.com Pulmonary Embolism: Pathogenesis and Laboratory Findings Virchow’s Triad Authors: Mackenzie Gault Reviewers: Midas (Kening) Kang Usama Malik Kevin Solverson * * MD at time of publication Body attempts to break down clot Fibrinogen breakdown products in blood Positive D-Dimer ↓ perfusion to lung parenchyma Vessel injury = Deep Vein Thrombus (95% of PE) Ultrasound: Presence of Clot in Deep Vein of Leg Notes: Hypercoagulable State Venous stasis Blood clot develops (commonly in deep veins of legs) Clot dislodges, migrates to IVCàright atrium of heartà right ventricleàlodges in pulmonary artery Pulmonary Embolism (PE): Thromboembolic blockage of pulmonary vasculature Clot occludes pulmonary artery/ arterioles • D-Dimer is only performed if clinical suspicion of PE low (Well’s Criteria) • CT-PA is the current diagnostic test for PE • V/Q Scan is performed when CT contrast is contraindicated • X-Ray is usually normal in PE (Except Hampton’s Hump, a rare but specific sign of PE) Ischemia of lung tissue distal to clot X-Ray: Hampton’s Hump pleural based area of ↑ opacity Air flow/ ventilation to lungs unaffected Pleuritic Chest Pain + Dyspnea VQ Scan: V/Q Mismatch ↑ dead space ventilation and V/Q mismatching Chemoreceptors detect ↑ CO2 and ↓ O2 Signal brain to ↑ breathing rate Tachypnea ↓ Arterial O2 Blood pumped from RV to pulmonary arteries cannot pass clot ↑ pulmonary and RV pressure RV Strain CT-PA: Filling Defect Echo: ↑ RV size + ↓ RV Function ECG: S1Q3T3 Pattern Lab:↑ BNP Chest Pain Tachycardia ↑ RV work load, ↓ right coronary artery perfusion Abbreviations: • BNP – Brain Natriuretic Peptide • CT-PA – Computed Tomography-Pulmonary Angiogram • ECG – Electrocardiogram • IVC – Inferior Vena Cava • RV – Right Ventricle • V/Q – Ventilation-Perfusion ratio ↑ Troponin Hypotension ↑ Lactate Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published February 07, 2018 on www.thecalgaryguide.com