Objectives: Prothrombin complex concentrates have been used to correct dilutional coagulopathy, but many preparations contain anticoagulants, such as heparin, to counteract their prothrombotic effects. These anticoagulants can interfere with haemostatic assays. The aim of this study was to monitor two different prothrombin complex concentrates for the treatment of albumin dilution in vitro, using rotational thromboelastometry with or without the heparin-antagonising agent protamine.
Methods: Citrated blood from 10 healthy volunteers was, in vitro, diluted 1:1 with 5% albumin and then corrected with a four-factor prothrombin complex concentrate with heparin anticoagulant (Confidex®) corresponding to a clinical dose of 43 IU/kg. Blood samples were tested with or without protamine. An activated prothrombin complex concentrate (APCC) (FEIBA®) without heparin in doses of 50 IU/kg and 100 IU/kg was also tested. Thromboelastometry was performed after recalcification.
Results: Albumin dilution significantly affected all thromboelastometry parameters. The four-factor PCC had an additional anticoagulant effect when added to the albumin-diluted blood; it was partially corrected by protamine for all parameters except maximum clot firmness. The APCC significantly improved all parameters, with over-correction of clotting time but only partial correction of maximum clot firmness.
Conclusions: The anticoagulant content of many prothrombin complex concentrates needs to be considered when performing in vitro testing. A heparin-free APCC better corrected an in vitro albumin-induced dilutional coagulopathy than a four-factor PCC, despite of blocking heparin with protamine.
Keywords: Point-of-Care testing; albumin protein; coagulation factors; coagulation testing; human; prothrombin complex concentrates; thromboelastography.