Introduction Defined as occlusion of a pulmonary artery from embolization of a thrombus from a distal site size of embolism determines proximity of occlusion to pulmonary trunk Saddle embolus large clot that occludes central pulmonary arteries most commonly due to a thromboembolism from the deep veins of the leg highest number originate from femoral vein Risk factors Virchow's triad stasis immobility CHF obesity surgery hypercoagulability pregnancy OCP protein C/S deficiency factor V Leiden severe burns cancer endothelial damage exposed collagen stimulates clotting cascade trauma fracture previous DVT Presentation Dyspnea and tachycardia common presenting findings May see hypoxemia on pulse oximetry and ABG ABG often shows ↓ PO2, ↓ PCO2, ↑ A-a gradient Pleuritic chest pain Sudden death acute right heart failure from rapid increase in pulmonary artery pressure more common with saddle embolism Pleural friction rub Fever if pulmonary infarct Deep vein thrombosis Homans' sign dorsiflexion of foot leads to tender calf muscle not present in the majority of cases (not sensitive or specific) erythematous, swollen, warm, lower extremity Imaging Chest CT with angiography test of choice in most circumstances visualize filling defect in pulmonary artery V/Q radionuclide scan ↓ pulmonary perfusion without decreased ventilation to given area used when patient cannot tolerate CT contrast (renal failure, pregnancy) requires a normal chest xray to be useful pulmonary angiogram gold-standard confirmatory test rarely used Studies Labs serum D-dimers result of clot degradation only useful if low pretest probability (Wells criteria) high sensitivity but low specificity Treatment Pharmacologic anticoagulation heparin or low-molecular weight heparin (LMWH) warfarin begin for long term anticoagulation thrombolysis in cases of hemodynamic compromise Operative inferior vena cava filter indicatied if anticoagulation is contraindicated or if patient develops a PE while on anticoagulants thrombectomy in cases of hemodynamic compromise and contraindication to thrombolytic therapy Prevention Subcutaneous heparin or LMWH most effective for immobile patients or patients at high risk early ambulation as able Sequential compression devices when pharmacologic prophylaxis is contraindicated Complications Pulmonary infarction most cases do not result in infarction due to large degree of collateral circulation in the lungs occur when patient has a reduction in pulmonary blood flow secondary to decreased cardiac output or obstructive lung disease Death Due to right ventricular failure
QUESTIONS 1 of 6 1 2 3 4 5 6 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.PL.13.20) A 73-year-old female is hospitalized following a pelvic fracture. She undergoes surgical repair without complication. Four days into her hospital stay, she develops acute dyspnea and chest pain accompanied by oxyhemoglobin desaturation. Which of the following arterial blood gas values is the patient most likely to have? (normal values: pH 7.35 - 7.45, PaO2 80 - 100 mm Hg, PaCO2 35-45 mm Hg, HCO3 22-26) QID: 100823 Type & Select Correct Answer 1 pH 7.5, PaO2 60, PaCO2 30, HCO3 22 38% (16/42) 2 pH 7.3, PaO2 60, PaCO2 30, HCO3 20 2% (1/42) 3 pH 7.5, PaO2 60, PaCO2 50, HCO3 28 12% (5/42) 4 pH 7.3, PaO2 60, PaCO2 50, HCO3 24 38% (16/42) 5 pH 7.4, PaO2 60, PaCO2 40, HCO3 24 5% (2/42) M 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (M1.PL.13.4) Four days after undergoing an elective total hip replacement, a 65-year-old woman develops a DVT that embolizes to the lung. Along with tachypnea, tachycardia, and cough, the patient would most likely present with a PaO2 of what? QID: 100807 Type & Select Correct Answer 1 120 mmHg 2% (1/55) 2 110 mmHg 4% (2/55) 3 100 mmHg 16% (9/55) 4 85 mmHg 15% (8/55) 5 60 mmHg 64% (35/55) M 2 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK