[Hemostasis and antifibrinolytic therapy in major pediatric surgery]

More than 30 years ago the pioneering work of Andrew and co-workers showed that the coagulation system of children is different than from adult. They have introduced the term of "developmental hemostasis" to describe this phenomenon. They were able to show that the concentration of coagulation factors and inhibitors are age-dependent and therefore reference limits from adult practice cannot be transferred to children one to one. Numerous studies showed that the perioperative loss of blood, and thus the use of homologous blood could be limited by administering antifibrinolytic substances such as aprotinin. Other antifibrinolytics acting substances like Epsilon-aminocaproic acid (EACA) or tranexamic acid (TXA) tended to be misfits in routine clinical practice. In 2006, the publication of a retrospective study carried out by Mangano et al, in which considerable safety concerns were expressed with regard to aprotinin led to a significant rethinking of its clinical use. Two years later the results of the BART (Blood Conservation using antifibrinolytics in a Randomized Trial) study confirmed that there was an increased postoperative mortality associated with the use of aprotinin compared to TXA and EACA. In a few adult studies so far tranexamic acid was found to be comparably as effective as aprotinin. Although TXA is a long known drug available on the market for more than 50 years, the studies connecting factors of indication, dosage regimen and safety are limited especially in children and infants. This article highlights the differences in the coagulation system in children compared to adult as well as indication, dosage regimens and possible side effects of antifibrinolytic agents in children.