Agreement between the thromboelastography reaction time parameter using fresh and citrated whole blood during extracorporeal membrane oxygenation with Teg®5000 and Teg®6s

Abstract

Purpose We aimed at assessing the correlation between TEG reaction time (TEG-R) in citrated and fresh blood samples with TEG5000 and TEG 6S during heparin administration in patients with and without ECMO support. Materials and Methods Paired TEG5000 (fresh and citrated whole blood, kaolin and kaolin-heparinase) and TEG6S (citrated whole blood) samples were obtained, together with standard coagulation laboratory tests. Bland-Altman analysis and Lin's concordance correlation coefficient were used to assess agreement. Results Thirteen consecutive ECMO patients and eight consecutive non-ECMO patients were enrolled and TEG was performed for a total of 84 paired samples. ECMO patients received 19.2 (12.6-25.8) U/kg/h of heparin. Five of the non-ECMO patients did not receive heparin, two of them received a very low prophylactic dose (1.6 and 2.9 IU/kg/h, respectively), and one of them 13.1 U/kg/h of heparin. Using TEG®5000, TEG-R was 21.0 (−23.4; 65.5) min longer on fresh compared to citrated blood in patients receiving heparin while only 1.58 (−5.5; 8.7) min longer in patients not-receiving heparin. These differences were reverted by heparinase. Conclusions Using citrated-recalcified blood to perform TEG might lead to underestimation of the effect of heparin.