Bartels_Hensley's Practical Approach to Cardiothoracic Anesthesia, 7e

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8. Extracorporeal Membrane Oxygenation for Pulmonary or Cardiac Support

V. Indications for Extracorporeal Membrane Oxygenation in Cardiac Failure A. Bridge to Recovery

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1. Cardiogenic shock: Several mechanical circulatory support systems can restore or gan perfusion in the setting of cardiogenic shock. Venoarterial ECMO has two notable advantages of being able to be initiated at the bedside and providing gas exchange. The success of ECMO support as a bridge to recovery largely depends on the etiology, with cardiac failure due to acute sepsis-induced cardiomyopathy, fulminant myocarditis, re fractory ventricular arrhythmias, myocardial infarction, and post–cardiac transplant al lograft failure having the most favorable outcomes. The data for ECMO in cardiogenic shock are largely limited to case series, small cohort studies, and retrospective propen sity analyses. 12 Pre-ECMO prognostication scores have been proposed to help maximize patient outcomes by identifying those most likely to benefit from ECMO support. a. Postcardiotomy cardiogenic shock is a complication of cardiac surgery that is associated with significant mortality. Postcardiotomy shock may be secondary to ischemia from coronary artery disease, poor preservation of the myocardium while the aorta is cross clamped, or changes in valve function after separating from cardiopulmonary bypass. ECMO may be considered as temporary postoperative support when a patient cannot be weaned from cardiopulmonary bypass in the operating room. b. Primary graft failure (PGF), a complication of heart transplantation that is associated with a high rate of mortality, may be supported with venoarterial ECMO. Patients with PGF who are supported on ECMO and who survive beyond the early posttransplant period have comparable long-term survival to transplant recipients who never developed PGF. c. Evidence suggests that venoarterial ECMO may offer a significant mortality benefit for sepsis-induced cardiomyopathy. A multicenter cohort study with propensity score– weighted analysis demonstrated that patients receiving ECMO for sepsis-induced car diomyopathy had significantly higher survival than those who did not receive ECMO (51% vs 14%; adjusted RR for mortality 0.57; 95% CI 0.35-0.93; P = .0029). 13 d. A randomized controlled trial of immediate venoarterial ECMO versus conventional management (with allowance for ECMO later in their course) in patients with severe or rapidly deteriorating cardiogenic shock—the majority of whom had cardiogenic shock related to myocardial infarction or acute decompensated heart failure—failed to show a statistically significant difference in the primary 30-day composite outcome of death, resuscitated circulatory arrest, or use of other mechanical circulatory support (hazard ratio [HR] 0.72; 95% CI 0.46-1.12; P = .21). 14 2. Extracorporeal cardiopulmonary resuscitation: ECPR (the use of ECMO in refractory cardiac arrest) is a rapidly expanding indication for venoarterial ECMO with evolving data. a. A phase 2, single-center, open-label, randomized controlled trial of early ECPR (at hos pital arrival) versus standard advanced cardiac life support (ACLS) for out-of-hospital cardiac arrest (OHCA) and refractory ventricular fibrillation demonstrated improved survival to hospital discharge and 6-month survival in patients receiving early ECPR versus those receiving standard ACLS. 15 Of note, the trial was terminated early—after enrollment of 30 patients—based on prespecified superiority criteria. b. A larger single-center randomized controlled trial of 256 patients with refractory OHCA of presumed cardiac origin did not find a significant improvement in survival with neurologically favorable outcome at 180 days in patients who received early ECPR versus those who received standard ACLS. However, this trial was possibly underpow ered to detect a clinically relevant difference. Additionally, in a secondary analysis of patients who did not achieve prehospital return of spontaneous circulation, ECPR was associated with a significantly lower risk of death at 180 days compared to prolonged conventional ACLS alone (23.9% vs 1.2%). 16 Similarly, a multicenter, randomized controlled trial of 160 patient with OHCA of presumed cardiac origin did not find a significant difference in survival with a neuro logically favorable outcome at 30 days in patients who received early ECPR versus those who received standard ACLS. However, early randomization led to a considerable

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