When traditional research fails - the case for veno-arterial ECMO in postcardiotomy cardiogenic shock

The challenges of venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock

Postcardiotomy cardiogenic shock describes the syndrome of refractory cardiac performance following cardiac surgery. The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for the management of postcardiotomy cardiogenic shock is controversial, and there are at least three scenarios where it may be necessary: first, pre-emptive postoperative VA-ECMO, where the decision for postoperative mechanical support is made prior to surgery, for example, in the context of poor pre-operative cardiac function; second, early yet unplanned post-cardiopulmonary bypass VA-ECMO following a long duration of cardiopulmonary bypass due to, for example, unexpected surgical complications; third, late rescue VA-ECMO following several attempts at weaning, either immediately following cardiopulmonary bypass or following transfer to the intensive care unit. The use of mechanical circulatory support for postcardiotomy cardiogenic shock is further complicated by the wide range of available devices, the availability of VA-ECMO in different centres, variations in experience and expertise as a function of local VA-ECMO workload, and regional variations in the diagnosis and management of postcardiotomy cardiogenic shock. Furthermore, survival appears to be low for such patients and it is not yet possible to predict who will survive. Many questions remain, however, such as those in relation to practices around patient selection, how best to study long-term outcomes, the ethics and efficacy of ECMO in such patients, and on all aspects of clinical decision-making. This review sets these clinical challenges in the context of the available evidence, including that from our centre.

Venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock-A six-year service evaluation

Only a small number of English hospitals provide postcardiotomy venoarterial extracorporeal membrane oxygenation (VA-ECMO) and there are doubts about its efficacy and safety. The aim of this service evaluation was to determine local survival rates and report on patient demographics. This was a retrospective service evaluation of prospectively recorded routine clinical data from a tertiary cardiothoracic center in the United Kingdom offering services including cardiac and thoracic surgery, heart and lung transplantation, venovenous extracorporeal membrane oxygenation (VV-ECMO) for respiratory failure, and all types of mechanical circulatory support. In six years, 39 patients were supported with VA-ECMO for refractory postcardiotomy cardiogenic shock (PCCS). We analyzed survival data and looked for associations between survival rates and patient characteristics. The intervention was venoarterial-ECMO in patients with PCCS either following weaning from cardiopulmonary bypass or following a trial of inotropes and intra-aortic balloon counterpulsation on the intensive care unit. 30-day, hospital discharge, 1-year and 2-year survivals were 51.3%, 41%, 37.5%, and 38.5%, respectively. The median (IQR [range]) duration of support was 6 (4-9 [1-35]) days. Nonsurvival was associated with advanced age, shorter intensive care length of stay, and the requirement for postoperative hemofiltration. Reasonable survival rates can be achieved in selected patients who may have been expected to have a worse mortality without VA-ECMO. We suggest postoperative VA-ECMO should be available to all patients undergoing cardiac surgery be it in their own center or through an established pathway to a specialist center.

Perioperative Extracorporeal Cardiopulmonary Resuscitation: The Defibrillator of the 21st Century?: A Case Report

Veno-arterial-extracorporeal membrane oxygenation (ECMO) for cardiopulmonary resuscitation (ECMO-CPR) has been recommended by new resuscitation guidelines in the United Kingdom. Our recently established yet unfunded ECMO-CPR service has thus far treated 6 patients, with 3 making a good recovery. One patient suffered a catastrophic perioperative complication through glycine absorption and we are in no doubt that she would not have survived without ECMO. We argue for a pragmatic approach to funding of ECMO-CPR because observational evidence suggests superiority over traditional resuscitation and there exists major methodological and ethical barriers to randomized controlled studies. We also call for high-quality observational evidence in the perioperative setting.