Pulmonary Embolism: Pathogenesis and Laboratory Findings
Virchow’s Triad
Hypercoagulable State
Venous stasis Vessel injury
Body attempts to Blood clot develops (commonly in deep veins of legs) break down clot = Deep Vein Thrombus (95% of PE)
Fibrinogen breakdown Clot dislodges, migrates to IVC4 right atrium of heart4 products in blood right ventricle4 lodges in pulmonary artery
Positive D-Dimer
1
Pulmonary Embolism (PE):
Ultrasound: Presence of Clot in Deep Vein of Leg
Authors: Mackenzie Gault Reviewers: Midas (Kening) Kang Usama Malik Kevin Solverson * * MD at time of publication
Notes: • 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)
Nj, perfusion to lung parenchyma Ischemia of lung Air tissue distal to clot Thromboembolic ventilation unaffected Clot • blockage occludes to ventilation Chemoreceptors 1 Signal pulmonary 1` dead mismatching CO2 and brain breathing of pulmonary artery/ space and V/Q detect 02 • to I` rate arterioles vasculature Blood pumped pass • pulmonary pressure RV Strain 4, right perfusion from RV CT-PA: Filling A— flow/ lungs to pulmonary cannot I` RV work load, artery • arteries clot and RV Defect Echo: l• RV size 4, Arterial 02 + 4, RV Function I` coronary X-Ray: Pleuritic ECG: S1g3T3 Hampton’s Chest Pain Pattern Hump + Dyspnea Lab:I` BNP pleural based area of 1` opacity Peptide ratio VCI Scan: V/Q Chest Pain Mismatch Abbreviations: • BNP—Brain Natriuretic • CT-PA — Computed Tomography-Pulmonary • ECG — Electrocardiogram • IVC — Inferior Vena Cava • RV — Right Ventricle • V/Q — Ventilation-Perfusion Angiogram Tachycardia Tachypnea Troponin Hypotension 1% Lactate