Correlation of thromboelastography with standard tests of anticoagulation in paediatric patients receiving extracorporeal life support

Abstract

Children requiring extracorporeal life support (ECLS) are at significant risk for thrombotic and haemorrhagic complications. Thromboelastography (TEG) is increasingly being used to assist in monitoring the coagulation status of critically ill patients. Its role in heparinised children receiving ECLS is unknown.

Methods: A retrospective review of TEG in 27 children (mean age 2 years and 8 months) receiving ECLS in a tertiary paediatric intensive care unit between December 2006 and April 2008. Paired TEG (kaolin and heparinase) analysis was performed on 171 occasions. On all occasions activated partial thromboplastin time (APTT) and platelet count were performed within 4 hours of the TEG (mean 6.5 minutes after TEG). On 158 occasions, the activated clotting time (ACT) was measured simultaneously with TEG.

Results: The TEG (kaolin) sample was not interpretable due to the heparin effect in 89 (52%) samples. There was a weak correlation between TEG (heparinase) variables and APTT, and between TEG and ACT with a stronger correlation between TEG (Maximum amplitude) and platelet count.

Conclusion: TEG monitoring should always include paired samples in heparinised children on ECLS. In this heterogeneous population, weak, and moderate correlations exist between TEG and standard haematological tests. Prospective studies, with simultaneous sampling for TEG and conventional laboratory tests, must be performed in order to establish its absolute utility as a clinical tool in this population.