Chapter 73: Extracorporeal Membrane Oxygenation

INTRODUCTION

Extracorporeal life support (ECLS) has been used as a rescue therapy for patients presenting with acute cardiopulmonary failure. The use of ambulatory extracorporeal support parallels the growth and development of cardiopulmonary bypass during open heart surgery over the past 40 years. The first successful use of a cardiopulmonary bypass circuit occurred in the early 1950s.¹ It was not until 1971 that an extracorporeal membrane oxygenator was used for an extended period to support a patient with “shock-lung syndrome.”² Portable extracorporeal membrane oxygenation (ECMO) was used in the late 1970s to rescue 39 patients with a variety of conditions (e.g., cardiac trauma, cardiogenic shock after myocardial infarction, drug overdose, and massive pulmonary embolus).³ Portable cardiopulmonary support was largely abandoned due to poor outcomes after early reports.

Literature supporting the initiation of ECMO in adult medical patients comes from two modern trials examining outcomes in patients with acute respiratory distress syndrome (ARDS) and refractory cardiac arrest.^4,5 The literature supporting the use of ECMO remains sparse with only scattered case reports published over the past 10 years. Hesitancy to embrace ECMO as a rescue therapy in the adult surgical patient has been partially due to the need for therapeutic anticoagulation to maintain the bypass circuit. There are an increasing number of surgical patients being treated with “high-flow, no-heparin” ECLS to improve survival.⁶

Survival after initiation of ECMO is closely correlated with the indication for which ECLS was initiated.⁷ The prognosis is related to baseline functional status, medical comorbidities, operative history, and the duration of ECLS.^8,9 These and other factors (e.g., body habitus, multiorgan failure, neurologic status, or terminal conditions) may influence outcomes prior to cannulation. The Emergency Physician should anticipate the goals of therapy. Will ECLS be used as a bridge to treatment (e.g., percutaneous intervention for coronary disease), as a bridge to recovery (e.g., severe ARDS), or as a bridge to transplant? These concepts are occasionally not mutually exclusive and are accomplished jointly. ECLS may be contraindicated if the underlying problem is not reversible with the help of ECMO.

Approach cannulation for ECLS in the Emergency Department cautiously. ECLS should only be performed by Emergency Physicians with experience in its initiation, maintenance, and discontinuation.⁷ Multiple organizations offer training courses in ECMO cannulation and management. The Emergency Physician can sterilely place central venous and arterial lines while waiting for the Cardiothoracic Surgeon to arrive for cannulation (Chapters 63 and 72).^10,11 The Emergency Physician can initiate and perform ECMO for the patient in cardiac arrest.^10-13 It is up to individual hospitals to maintain up-to-date records for purposes of tracking outcomes and Emergency Physician credentialing.

Guidelines for the development of an ECMO program are beyond on the scope of this chapter but can be found through the Extracorporeal Life Support Organization (ELSO) website.¹⁴ An ECMO ...