Treatment of Acute Pulmonary Embolism Kevin Pham May 2014

Objective T o review the management of acute pulmonary embolism.

Case A 48-year-old woman is brought to the emergency room complaining of a sudden onset of dyspnea. She reports she was standing in the kitchen making dinner, when she suddenly felt as if she could not get enough air, her heart started racing, and she became lightheaded and felt as if she would faint. On examination, she is tachypneic with a respiratory rate of 28 breaths per minute, oxygen saturations 84% on room air, heart rate 124 bpm, and blood pressure 118/89 mm Hg. She appears uncomfortable, diaphoretic, and frightened. Her right leg is moderately swollen from mid-thigh to her feet, and her thigh and calf are mildly tender to palpation. Her chest x-ray is interpreted as normal. Access Medicine

Case The CT and V/Q scan are broken. What is the next best step? A. Treat empirically with anticoagulation if you cannot obtain a definitive work up for pulmonary embolism within 4 hours. B. Treat empirically with anticoagulation now. C. Treat empirically with anticoagulation if you cannot get a definitive work up for pulmonary embolism within 24 hours. D. Do not treat empirically Have the audience give an answer and let them know that you come back to the case.

Introduction Mortality without treatment: 30% Mortality with effective treatment: 3-8% Most deaths are due to recurrent pulmonary embolism (PE) within the first few hours of the initial event.

Initial Resuscitation Hypoxia: routine management. Hypotension: routine management with IVF. Be cautious in patients with RV failure. Vasopressors: Levophed is usually first line. Others can be considered depending on clinical scenario. Dobutamine can cause hypotension at low doses since vasodilation>inotropic effects. Consider concurrent use with Levophed until higher dose of dobutamine is obtained. -Too much IVF can cause significant RV wall stress and ischemia. Cautious give 500-1000 L NS bolus and monitor closely. -There is no clinical trials for regarding vasopressors in obstructive shock.

Empiric Anticoagulation Go through algorithm. This algorithm utilizes Wells criteria to determine pretest probability of acute PE. UpToDate

Risk of Bleeding Risk Factors for bleeding Age >65 Previous bleeding Thrombocytopenia Antiplatelet therapy Recent surgery Frequent falls Previous stroke Diabetes Anemia Cancer Renal failure Liver failure Alcohol abuse Empiric anticoagulation therapy should be considered on a case-by-case basis for patient with moderate or high risk for bleeding. 1 risk factor (moderate):3.2 percent risk of bleeding in the first three months and 1.6 percent per year thereafter 2 risk factors (high): 12.8 percent in the first three months and ≥6.5 percent per year thereafter -There is little evidence regarding empirical anticoagulation in pulmonary embolism

Anticoagulation Anticoagulation improves mortality in clinical trials Barritt, DW and Jorder, SC. Anticoagulant drugs in the treatment of pulmonary embolism. A controlled trial. Lancet. 1960;1(7138):1309. Initiation of anticoagulation LMWH is preferred in hemodynamically stable patient. Subcutaneous fondaparinux is next in line. UFH is preferred in setting of persistent hypotension, poor subcutaneous absorption (morbid obesity), mod-high bleeding risk, possible thrombolysis, and renal failure (Cr eatinine clearance <30) ****You can always quiz the audience before elaborating -Based on 1 and only randomized clinical trial and multiple uncontrolled trials. -The goal is to be therapeutic within the 1st hour when the decision is made to start anticoagulation.

Anticoagulation Long-term therapy Warfarin is recommended due to extensive prior clinical experience. Rivaroxaban and other new oral agents can be considered if warfarin is not an option. LMWH is preferred in those with active malignancy.

Anticoagulation Duration 1st episode PE with provoked etiologies (immobility, surgery, trauma, etc): at least 3 months. (Grade 1B) 1st episode unprovoked with low-mod bleeding risk: indefinite. (Grade 2B) 1st episode unprovoked with high bleeding risk: at least 3 months. (Grade 1B) Recurrent with low/mod bleeding risk: indefinite. (Grade 1A/2B respectively) Recurrent with high bleeding risk: at least 3 months. (Grade 2B)

IVC Filter Indications Contraindications to anticoagulation Failed anticoagulation Developed a complication due to anticoagulation Severe cardiopulmonary compromise where the next PE will be lethal

Case A 48-year-old woman is brought to the emergency room complaining of a sudden onset of dyspnea. She reports she was standing in the kitchen making dinner, when she suddenly felt as if she could not get enough air, her heart started racing, and she became lightheaded and felt as if she would faint. On examination, she is tachypneic with a respiratory rate of 28 breaths per minute, oxygen saturations 84% on room air, heart rate 124 bpm, and blood pressure 118/89 mm Hg. She appears uncomfortable, diaphoretic, and frightened. Her right leg is moderately swollen from mid-thigh to her feet, and her thigh and calf are mildly tender to palpation. Her chest x-ray is interpreted as normal. Access Medicine

Case The CT and V/Q scan are broken. What is the next best step? A. Treat empirically with anticoagulation if you cannot obtain a definitive work up for pulmonary embolism within 4 hours. B. Treat empirically with anticoagulation now. C. Treat empirically with anticoagulation if you cannot get a definitive work up for pulmonary embolism within 24 hours. D. Do not treat empirically Answer: B Patient is high risk for PE and should be treat empirically now when imaging is contraindicated or cannot be done.

Case The CT scan was fixed, and CTA chest shows evidence of pulmonary embolism. What is the best next step? A. Start subcutaneous LMWH only B. Start warfarin only C. Start subcutaneous LMWH and bridge to warfarin D. Start parenteral unfractionated heparin E. Start rivaroxaban Answer: C Patient is hemodynamically stable without any indications for UFH or long term use of LMWH. She should be bridged to warfarin.

Summary Initial resuscitation is key . Empiric anticoagulation should be considered when the diagnosis cannot be a made in a timely manner. Anticoagulation should be prompted with appropriate agent(s). IVF filter should be considered when anticoagulation is not an option.

References Kearon, C. Antithrombotic therapy for VTE disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Barritt, DW and Jorder, SC. Anticoagulant drugs in the treatment of pulmonary embolism. A controlled trial. Lancet. 1960;1(7138):1309. Tapson, VF. Fibrinolytic (thrombolytic) therapy in acute pulmonary embolism and lower extremity deep vein thrombosis. UpToDate. Tapson, VF. Treatment of acute pulmonary embolism. UpToDate.