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EKG at presentation
EKG next day
Initial EKG
F/u EKG
Massive PE
Matt White
November 3, 2009
Objectives
• PE Basics
• Massive PE
• Medical treatment
• Lytics
• Embolectomy
• IVC Filters
• Follow-up
Virchow’s triad
• Thrombosis: triggered by venostasis, hypercoagulability, and vessel wall inflammation.
• All clinical risk factors for DVT/PE have their basis in one or more elements of the triad.
PE Incidence
• In the United States, incidence is 1 per 1000
• 250,000 new cases annually in US
Is that enough?
• autopsy studies show that equal number of patients are diagnosed with PE at autopsy vs. diagnosis by clinicians
• Easy diagnosis to miss
Massive PE
• occlusion of the pulmonary artery that exceeds 50% of its cross-sectional area, resulting in progressive hemodynamic compromise
• Usually defined as presenting with systolic blood pressure < 90 mmHg.
• In two large international studies, this accounted for 4 - 4.5% of all PE patients.
Clinical course
• obstruction of the PA to this degree initiates a cascade of physiologic events, which if not interrupted early, ultimately results in cardiac arrest and death in up to 70% of patients in the first hour
• Not solely dependent on size of clot, rather on clot and functional capability of the patient's cardiovascular system.
Medical treatment of massive PE
• Supplemental oxygen • High dose IV heparin• Hemodynamic support
– IV fluids (empiric 500 mL) • increased right ventricular (RV) wall stress can decrease the
ratio of RV oxygen supply to demand. (ischemia, deterioration of RV function, and worse RV failure)
– Vasopressors (no evidence for which one) • Norepinephrine, epinephrine, or dopamine usually first line
• Thrombolytics (if no contraindications)
Thrombolytics
• No clinical trial with conclusive mortality benefit. – Meta analysis of 8 RCTs (n=679); heparin & lytics vs
heparin, no difference in mortality (OR 0.89 [0.45-1.78]), major hemorrhage (OR 1.61 [0.91-2.86]), or minor hemorrhage (OR 1.98 [0.68-5.75])
• Transient improvement in hemodynamics – Improved RV function (after 12hrs, gone by 7 days)– Lower PA pressures
ICOPER (International Cooperative Pulmonary Embolism Registry)
• 108 patients with massive PE• Thrombolysis was performed in 33 patients,
surgical embolectomy in 3, and catheter embolectomy in 1
• Thrombolytic therapy did not reduce 90-day mortality (46.3%; [31-64.8%] vs. 55.1% [44.3-66.7%]. Hazard Ratio of 0.79.
• Recurrent PE rates at 90 days similar in patients with and without thrombolytic therapy (12% for both).
Indications for thrombolytics
• Persistent hypotension due to PE (ie, massive PE) is most widely accepted indication
• Other considerations – severe hypoxemia – large perfusion defects – right ventricular dysfunction – free-floating right atrial or ventricular embolus – patent foramen ovale
• Thrombolysis should be considered only after PE has been confirmed (in most cases)
Risks of thrombolytics
• Increased risk of major hemorrhage (19% of patients)– intracranial hemorrhage (5%)– retroperitoneal hemorrhage (15%)– GI bleed (30%)– Unknown site of bleeding (45%)
• Menstruation not a contraindication
• Allergic reactions– More with streptokinase (0.5%, mild reaction in 10%)
•From retrospective analysis of 104 patients
Administering thrombolytics
• Bolus infusion may be effective more quickly without increase risk of bleeding
• No evidence that intrapulmonary arterial infusion of greater benefit than peripheral venous infusion
Pearls of thrombolytics
• Avoid unnecessary invasive procedures (especially arterial punctures)
• Discontinue anticoagulant therapy (usually)
• No evidence for superiority between different thrombolytic agents
Embolectomy
• considered when patient's presentation is severe enough to warrant thrombolysis (e.g., persistent hypotension), but thrombolysis either fails or is contraindicated.
Catheter embolectomy
• Rheolytic: injecting pressurized saline through the catheter's distal tip, which macerates the emboli – large venous sheath or a venous cut-down is
required to insert the large catheter, which increases the risk of bleeding at the insertion site
Catheter embolectomy
• Rotational: rotational catheter fragmentation – uses conventional catheters
Surgical embolectomy
Surgical embolectomy
• first successful surgical pulmonary embolectomy was performed by Kirschner in 1924
• Initially performed blindly as a closed cardiac procedure
• Now performed on cardiopulmonary bypass with clots extracted from the opened PAs under direct visualization
Surgical embolectomy Indication
• Main: systemic hypotension due to PE in a patient in whom thrombolysis is contraindicated– Possible: echocardiographic evidence of an
embolus trapped within a patent foramen ovale, the right atrium, or the right ventricle
• Limited to large medical centers because an experienced surgeon and cardiopulmonary bypass are required
Procedural logistics
• Transesophageal echocardiography (TEE) to look for extrapulmonary thrombi (ie, RA, RV or vena cava).
• In series of 50 patients with PE, TEE detected extrapulmonary thrombi in 13 patients (26%), which altered the surgical management of five patients (10%)
Mortality of surgical embolectomy
• Estimates of mortality vary widely from 10-60%
• Mortality after cardiac arrest due to PE is extremely high in the nonsurgical setting as well.
Indicators of Mortality
IVC Filter Indications
• Absolute contraindication to anticoagulation (e.g., active bleeding)
• Recurrent PE despite adequate anticoagulant therapy
• Complication of anticoagulation (e.g., severe bleeding)
• Hemodynamic or respiratory compromise that is severe enough that another PE may be lethal
Algorithm (from surgeons)
• Large thrombus in pulmonary artery + hemodynamic instability requiring vasopressor support and evidence of impending right ventricular failure = open embolectomy.
• Mild hemodynamic instability (without evidence of severe RV strain) = thrombolytic therapy ( if no contraindications)– Serial echocardiograms should be performed to evaluate for
improvement. – If thrombolytic therapy is contraindicated and catheter
thrombectomy is readily available, then consideration for this technique is appropriate.
– If patient has large proximal thrombus and is hemodynamically stable but cannot receive thrombolytics or catheter thrombectomy, open embolectomy is then indicated.
References
• Kucher N, Rossi E, De Rosa M, Goldhaber SZ. Massive pulmonary embolism. Circulation 2006;113:577-582.
• Dauphine C, Omari B. Pulmonary Embolectomy for Acute Massive Pulmonary Embolism. The Annals of Thoracic Surgery. 2005; 79(4) 1240-1244
• Up to Date
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