Incidence, Characteristics and Outcomes of Cardiac Tamponade in Patients on Extracorporeal Membrane Oxygenation for the Treatment of Refractory Cardiogenic Shock

Abstract

Background Extracorporeal membrane oxygenation(ECMO) for the treatment of refractory cardiogenic shock has gained popularity over the last decade. Cardiac tamponade(CT), a life threatening condition, has been reported to occur in patients after the initiation of ECMO therapy. However, there is a scarcity of data pertaining to the incidence, characteristics and outcomes of pericardial tamponade in non-cardiac surgery patients undergoing ECMO for the treatment of refractory cardiogenic shock. Methodology This is a single center retrospective review of all patients developing CT post ECMO for refractory cardiogenic shock presenting between January 1999-January 2020. Patients were excluded if they were on ECMO post cardiac surgery, aged less than 18 years or had a moderate to large pericardial effusion prior to ECMO initiation. Results Out of 220 patients presenting with cardiogenic shock, 8(3.6%) patients developed CT after being treated with ECMO. Patients were mostly male (7,78%) and 66±12.8 years old. 7(77.5%) patients were on VA ECMO, 1(12.5%) patient on VAV ECMO, all of which were accessed peripherally . 5(62.5%) patients were on additional mechanical support devices: Impella(2,25%), IABP(2,25%) and tandem heart with impella(1,12.5%). 6(75%) patients were supratherapeutic whilst on systemic anticoagulation preceding CT. Initial ECMO pump flow rates were 4±0.68ml/min, mean sheath size of 22±3.1 F. 5(62.5%) patients developed CT 24 hours after ECMO initiation, 3(37.5%) patients before 24 hours. Average size of pericardial effusion was 2.1±0.1cm. None of the patients had any evidence of myocardial/great vessel perforation. 4(50%) patients were treated with pericardiocentesis, 2(25%) patients required pericardial window, and 2(25%) required both. Fluid analysis in 6(87.5%) patients revealed hemorrhagic pericardial fluid, 1(12.5%) with serosanguinous fluid and 1(12.5%) with serous fluid .6(75%) of patients died during hospitalization, but not directly from CT. Conclusion 3.6% of patients on ECMO for refractory cardiogenic shock develop CT, with most cases occurring after 24 hours of therapy initiation. Most patients who develop this are coagulopathic and are on additional mechanical support devices. CT can occur in patients without evidence of cardiac/great vessel perforation. CT should be considered in all patients on ECMO with unexplained reductions in flow rates, and this should immediately be addressed to optimize cardio-pulmonary support. Although treatable, CT in this subset of patients is reflective of an overall grave prognosis.