The role and optimal therapeutic targets for anticoagulation during VV-ECMO are unclear. Previously published studies are limited by retrospective, observational design, small cohorts, and patient heterogeneity. The clinical significance of reported thrombotic complications is largely unknown. This systematic review underscores the need for randomized controlled trials of anticoagulation strategies for patients undergoing VV-ECMO for respiratory failure.

The extracorporeal membrane oxygenation (ECMO) circuit is made of a number of components that have been customized to provide adequate tissue oxygen delivery in patients with severe cardiac and/or respiratory failure for a prolonged period of time (days to weeks). A standard ECMO circuit consists of a mechanical blood pump, gas exchange device, and a heat exchanger all connected together with circuit tubing. ECMO circuits can vary from simple to complex and may include a variety of blood flow and pressure monitors, continuous oxyhemoglobin saturation monitors, circuit access sites and a bridge connecting the venous access and arterial infusion limbs of the circuit. Significant technical advancements have been made in the equipment available for short and long term ECMO applications. Contemporary ECMO circuits have greater biocompatibility and allow for more prolonged cardiopulmonary support time, while minimizing the procedure-related complications of bleeding, thrombosis and other physiologic derangements that were so common with the early application of ECMO. Modern era ECMO circuitry and components are simpler, safer, more compact and can be used across a wide variety of patient sizes from neonates to adults.

We reviewed reported survival and neurological outcomes, and predictors of these outcomes for pediatric cardiac extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR). We searched PubMed from 2000 to April 2011. Cumulative survival after cardiac ECMO in children was 788/1755 (45%); renal dysfunction, dialysis, neurologic complication, lactate, and ECMO duration consistently predicted this outcome, whereas single ventricle and ECPR did not. Neurological outcomes after cardiac ECMO were based on poorly described telephone questions in two studies for 47 patients with 51% significantly impaired and detailed follow-up testing for 42 patients in three studies with mental delay in 38% and mental score >85 (average or above) in 33%. Cumulative survival after ECPR in children was 371/762 (49%); noncardiac disease, renal dysfunction, neurologic complication, and pH on extracorporeal life support consistently predicted this outcome, whereas duration of CPR did not. Neurological outcomes after ECPR were based predominantly on the pediatric cerebral performance category (PCPC) score by chart review, with 161/181 (79%) having PCPC <2. No study reported detailed follow-up testing for survivors of ECPR. Survival outcomes of most cardiac subgroups were similar, except for concerning mortality in cavopulmonary connection patients. Priority areas for study include identification of potentially modifiable predictors of long-term outcomes.