Extracorporeal Membrane Oxygenation in Acute Hypoxic Respiratory Failure

Abstract

The development of the membrane oxygenator for the use in open heart surgery in the late 1960s was a major advance in cardiopulmonary bypass technology. Compared with the previous generation of bubble oxygenators, these devices were much less destructive of blood components and extended the safe period for cardiopulmonary bypass. It was a matter of time therefore before this technology migrated from the operating room to the ICU to support patients dying of hypoxemia who could not be ventilated. In 1970, Baffes used extracorporeal support in children with congenital heart disease after open heart surgery (Baffes et al. 1970). The first successful use of a membrane oxygenator to support a patient with acute hypoxic respiratory failure (AHRF) was published in 1972 using the Bramson lung (Hill et al. 1972). Following the publication of further case series (Gille and Bagniewski 1976), an NIH-sponsored randomized trial was set up in 1975 to compare the use of veno-venous (V-V) ECMO in ARDS with what was then standard-of-care positive-pressure ventilation (Zapol et al. 1979). The entry criteria were modest by today’s standards (FiO₂ 0.6, PEEP ≥6 cmH₂O for 2 h or more). Ninety patients were randomized, but the disappointing survival of 10 % in both arms of this study led to ECMO being largely abandoned as a treatment for AHRF in adults in North America. Bartlett, who was a lead investigator in the trial, then pioneered the use of ECMO in neonatal respiratory failure and published the first case series of 45 patients from the University of Michigan in 1982 with a 50 % survival (Bartlett et al. 1982). He set up the Extracorporeal Life Support Organization (ELSO), and the Registry now contains a database of over 30,000 patients where ECMO has been used for either pulmonary or cardiac support. Over 25,000 neonates with AHRF have been treated with an overall survival of 80 %. Beginning in the late 1980s, an increasing number of pediatric patients outside the newborn period with respiratory failure unresponsive to conventional treatments have had ECMO used as a rescue therapy. Reports from the Registry show data on over 3,000 patients with an overall survival of 60 % (ELSO Registry 2010).