1.
Effect of Tranexamic Acid on Coagulation and Fibrin Clot Properties in Children Undergoing Craniofacial Surgery
Fenger-Eriksen C, Lindholm AD, Krogh L, Hell T, Berger M, Hermann M, Fries D, Juul N, Rasmussen M, Hvas AM
Thrombosis and haemostasis. 2020
Abstract
OBJECTIVE Craniosynostosis surgery in small children is very often associated with a high blood loss. Tranexamic acid (TXA) reduces blood loss during this procedure, although the potential underlying coagulopathy in these children is not known in detail. Objective was to determine the nature of any coagulopathy found during and after craniosynostosis surgery and to characterize the effect of TXA on fibrin clot formation, clot strength, and fibrinolysis. MATERIALS AND METHODS Thirty children received either TXA (bolus dose of 10 mg/kg followed by 8 hours continuous infusion of 3 mg/kg/h) or placebo. Dynamic whole blood clot formation assessed by thromboelastometry, platelet count, dynamic thrombin generation/thrombin-antithrombin, clot lysis assay, and fibrinogen/factor XIII (FXIII) levels were measured. Additionally, clot structure was investigated by real-time live confocal microscopy and topical data analysis. RESULTS Increased ability of thrombin generation was observed together with a tendency toward shortened activated partial thromboplastin time and clotting time. Postoperative maximum clot firmness was higher among children receiving TXA. FXIII decreased significantly during surgery in both groups.Resistance toward tissue plasminogen activator-induced fibrinolysis was higher in children that received TXA, as evidenced by topical data analysis and by a significant longer lysis time. Fibrinogen levels were higher in the TXA group at 24 hours. CONCLUSION A significant coagulopathy mainly characterized by changes in clot stability and not parameters of thrombin generation was reported. Tranexamic acid improved clot strength and reduced fibrinolysis, thereby avoiding reduction in fibrinogen levels.
2.
Reduced perioperative blood loss in children undergoing craniosynostosis surgery using prolonged tranexamic acid infusion: a randomised trial
Fenger-Eriksen C, D'Amore Lindholm A, Norholt SE, von Oettingen G, Tarpgaard M, Krogh L, Juul N, Hvas AM, Rasmussen M
British journal of anaesthesia. 2019
Abstract
BACKGROUND Tranexamic acid (TXA) reduces intraoperative blood loss and transfusion during paediatric craniosynostosis surgery. Additional reduction of postoperative blood loss may further reduce exposure to allogeneic blood products. We studied the effect of combined intra- and postoperative TXA treatment on postoperative blood loss in children. METHODS Thirty children admitted for craniosynostosis surgery were randomised to combined intra- and postoperative TXA treatment or placebo. The primary endpoint was postoperative blood loss. Secondary endpoints included total blood loss, transfusion requirements, and clot stability evaluated by tissue plasminogen activator-stimulated clot lysis assay. RESULTS TXA reduced postoperative blood loss by 18 ml kg(-1) (95% confidence interval 8.9) and total blood loss from a mean of (standard deviation [SD]; 20) ml kg(-1) to 28 (14) ml kg(-1) (P<0.001). Intraoperative red blood cell (RBC) and fresh frozen plasma (FFP) transfusions were reduced in the treatment group from RBC 14.0 (5.2) ml kg(-1) to 8.2 (5.1) ml kg(-1) (P=0.01) and from FFP 13.0 (6.3) ml kg(-1) to 7.8 (5.9) ml kg(-1) (P=0.03). Postoperative RBC transfusion median was 5 (inter-quartile range [IQR] 0-6) ml kg(-1) in the placebo group and 0 (0-5.7) ml kg(-1) in the TXA group. Resistance to lysis was higher in the treatment group (P<0.001). CONCLUSIONS Combined intra- and postoperative tranexamic acid treatment reduced postoperative and overall blood loss and transfusion requirements. Improved clot stability represents a possible mechanism for blood loss reduction.