Variability in Anticoagulation Management of Patients on Extracorporeal Membrane Oxygenation

Abstract

Objective The objective of this study was to determine current practices of anticoagulation in patients on extracorporeal membrane oxygenation (ECMO). Design Internet-based cross-sectional survey distributed between November 2010 – May 2011. Setting Extracorporeal Life Support Organization (ELSO)-registered ECMO centers internationally. Participants ECMO medical directors and coordinators. Interventions None. Measurements and Main Results There were 121 responses from ECMO medical directors and coordinators at 187 ELSO centers with access to the survey. Eight-four of 117 (72%) respondents reported having a written institutional ECMO protocol for both anticoagulation and blood product management at their institution. Sixty-nine of 117 (59%) respondents reported use of tip-to-tip or partially heparin-bonded circuits. Unfractionated heparin was used at all centers; only 8% of respondents indicated use of alternative anticoagulation medications in the 6 months prior to the survey. The preferred method of anticoagulation monitoring was the serial measurement of activated clotting time (ACT), as reported by 97% of respondents. In this survey, 82% of respondents reported antithrombin III (ATIII) testing, 65% reported anti-factor Xa testing, and 43% reported use of thromboelastography during ECMO. Goal ranges for these three tests and interventions triggered by out-of-range values were found to be variable. Conclusions ECMO anticoagulation management policies vary widely by center. The majority of ECMO programs employ ACT as the preferred anticoagulation monitoring tool. The coagulation system is also monitored using more specific markers such as ATIII, anti-factor Xa and thromboelastography by a large number of centers. Future research is needed to elucidate optimal anticoagulation management and improve outcomes.

Catastrophic Left Ventricular Thrombosis Complicating Extra-corporeal Membrane Oxygenation: A Case Report

“…Anticoagulation effect of UFH can be monitored using activated clotting time (ACT), aPTT or antiXa factor levels. The recommended levels of aPTT or ACT are 1.5-2.5 times of baseline values, however specific target values of these parameters for adequate systemic anticoagulation for ECMO patients are not precisely known (Bembea et al, 2013). The desired clinical effect of anticoagulation is also affected by concomitant coagulopathy, thrombocytopenia or hemodilution, which are common in these patients.…”

Mechanical circulatory support: balancing bleeding and clotting in high-risk patients

“…A recent international survey of 187 ELSO centers (67% pediatric, 30% mixed adult, and pediatric and 3% adult only) demonstrated significant variability in practice between centers. 30 Unfractionated heparin (UFH) was used in 100% of ECMO patients. The parenteral direct thrombin inhibitors were available in 53% of centers, but were used rarely (only 8% of centers).…”

“…Testing to monitor antiplatelet therapy in those centers using aspirin or dipyridamole was not discussed. 30 The variability between treatment centers lead to the development of the ELSO anticoagulation management guidelines which are based on expert consensus and review of multiple anticoagulation practices. 28,32 UFH is recommended with a 50-100 unit/kg bolus at cannulation followed by an infusion starting at 7.5-20 units/kg/hr and adjusted based on an ACT of 180 to 220 seconds.…”

“…31 In children, physiologic AT levels are lower than adults, resulting in the administration of AT concentrate by some centers during ECMO, despite the lack of safety and efficacy data. 30,34 Challenges with UFH exist including development of heparin induced thrombocytopenia and an inability to achieve therapeutic anticoagulation. In both clinical scenarios, alternate anticoagulant agents are required.…”

Influence of coagulation parameters by stabilization of fibrinogen

“…Thus, it could be assessed where minimal concentration of coagulation factors would be necessary, so a surface can activate the hemostasis [11]. Conversely, the information could be important for extracorporeal systems, how much volume can be added, without affecting the coagulation and becoming detrimental for the patient [12,13].…”