No abstract

Disturbance of fibrinogen/fibrin polymerization is the primary problem triggering dilutional coagulopathy during major orthopedic surgery. The magnitude of clot firmness reduction is determined by the type of fluid used, with hydroxyethyl starch showing the most pronounced effects. These undesirable effects of intravascular volume therapy can be reversed by increasing fibrinogen concentration by administering fibrinogen concentrate, even during continuing blood loss and intravascular volume replacement.

Key points † Monitoring whole-blood coagulation using viscoelasticity assays is useful in managing perioperative bleeding. † This observational study compared thromboelastometry [ROTEM w ] assays with standard coagulation tests in 359 children in six age groups. † Age-dependent differences identified in both standard and ROTEM w assays provide important reference ranges for monitoring paediatric surgical patients.Background. The small sample volume needed and the prompt availability of results make viscoelastic methods like rotational thromboelastometry (ROTEM w ) attractive for monitoring coagulation in small children. However, data on reference ranges for ROTEM w parameters in children are scarce.Methods. Four hundred and seven children (ASA I and II) undergoing elective surgery were recruited for this prospective, two-centre, observational study. Subjects were grouped as follows: 0-3, 4 -12, 13 -24 months, 2-5, 6-10, and 11-16 yr. Study objectives were to establish age-dependent reference ranges for ROTEM w assays, analyse age dependence of parameters, and compare ROTEM w data with standard coagulation tests.Results. Data from 359 subjects remained for final analysis. Except for extrinsically activated clot strength and lysis, parameters for ROTEM w assays were significantly different among all age groups. The most striking finding was that subjects aged 0-3 months exhibited accelerated initiation (ExTEM coagulation time: median 48 s, Q1-Q3 38 -65 s; P¼0.001) and propagation of coagulation (a angle: median 78 o , Q1-Q3 69-84 o ; P,0.001) and maximum clot firmness (median 62 mm, Q1-Q3 54-74 mm), although standard plasma coagulation test results were prolonged (prothrombin time: median 13.2 s, Q1-Q3 12.6 -13.6 s; activated partial thromboplastin time: median 42 s, Q1-Q3 40-46 s). Lysis indices of ,85% were observed in nearly one-third of all children without increased bleeding tendency. Platelet count and fibrinogen levels correlated significantly with clot strength, and fibrinogen levels correlated with fibrin polymerization.Conclusions. Reference ranges for ROTEM w assays were determined for all paediatric age groups. These values will be helpful when monitoring paediatric patients and in studies of perioperative coagulation in children.Viscoelastic coagulation tests have gained a renewed interest in the safe management of surgery-or trauma-induced coagulopathy in adult and paediatric patients. 1 -4 Viscoelastic whole-blood analyses, such as thromboelastography (TEG w ) and thromboelastometry (ROTEM w ), reflect initiation and propagation of coagulation, fibrinogen/fibrin -platelet interaction, and clot lysis. In 1997, the ROTEM w device was introduced into clinical routine at our institution. A multicentre study published by Lang and colleagues 5 presented reference ranges for ROTEM w assays for adults aged 17-85 yr. With the exception of some data referring to preterm neonates, newborns, and children exhibiting cardiac failure, reference data are scarce for paediatric patients. 6 -10 The main objective of ...

Administration of fibrinogen concentrate effectively improves fibrinogen polymerization and total clot strength, which were the main underlying problems of dilutional coagulopathy in children undergoing craniosynostosis surgery.