Efficacy and safety of 6% hydroxyethyl starch 130/0.4 (Voluven) for perioperative volume replacement in children undergoing cardiac surgery: a propensity-matched analysis.

INTRODUCTION: Six percent hydroxyethyl starch (HES) 130/0.4 is considered an alternative to human albumin (HA) and crystalloids for volume replacement in children undergoing cardiac surgery. In this large propensity-matched analysis, we aimed to assess the efficacy and safety of replacing HA with HES for intraoperative volume therapy in children undergoing cardiac surgery with cardiopulmonary bypass (CPB). METHODS: We retrospectively reviewed our database, including children who underwent cardiac surgery between January 2002 and December 2010. Four percent HA was used until 2005; it was replaced by HES thereafter. Demographic data, intra- and postoperative blood loss and blood component transfusions were recorded, together with the incidence of postoperative complications and mortality. We performed a propensity-matched analysis using 13 possible confounding factors to compare children who received either HES or HA intraoperatively. The primary objectives included the effects of both fluids on intraoperative fluid balance (difference between fluids in and fluids out (efficacy)) and blood loss and exposure to allogeneic blood products (safety). Secondary safety outcomes were mortality and the incidence of postoperative renal dysfunction. RESULTS: Of 1,832 children reviewed, 1,495 were included in the analysis. Intraoperative use of HES was associated with a less positive fluid balance. Perioperative blood loss, volume of red blood cells and fresh frozen plasma administered, as well as the number of children who received transfusions, were also significantly lower in the HES group. No difference was observed regarding the incidence of postoperative renal failure requiring renal replacement therapy or of morbidity and mortality. CONCLUSIONS: These results confirm that the use of HES for volume replacement in children during cardiac surgery with CPB is as safe as HA. In addition, its use might be associated with less fluid accumulation. Further large studies are needed to assess whether the reduction in fluid accumulation could have a significant impact on postoperative morbidity and mortality.

Experimental model of hyperfibrinolysis designed for rotational thromboelastometry in children with congenital heart disease.

We assessed an in-vitro model of hyperfibrinolysis using rotational thromboelastometry (ROTEM) by the addition of increasing concentrations of tissue-type plasminogen activator (t-PA) on whole blood obtained from children undergoing cardiac surgery. We assessed the relevance of this model by repeating the tests in the same population after tranexamic acid (TXA) infusion. In addition, we determined the sensitivity and specificity of ROTEM parameters to detect the different degrees of fibrinolysis. Blood samples obtained from 20 children were analyzed at two predefined timepoints: after induction of anesthesia, before TXA (baseline), and at the end of surgery during TXA infusion (end surgery). At baseline, an extrinsic activation with tissue factor (EXTEM) test was performed without and with increasing concentration of t-PA (102, 255, 512, 1024, 1535, and 2539 units t-PA/ml). At the end of surgery, a second EXTEM test was performed without and with two different t-PA concentrations (1535 and 2539 units t-PA/ml). At baseline, increasing t-PA concentrations in the EXTEM test induced a gradual increase of hyperfibrinolysis characterized by a reduction in clot firmness and stability parameters. In the presence of TXA, t-PA-induced hyperfibrinolysis was completely abolished. Lysis-onset time (LOT) and degree of fibrinolysis measured at 30 min (LI30) best assessed the degree of fibrinolysis. This in-vitro model of t-PA-induced hyperfibrinolysis using the EXTEM test of ROTEM may represent a promising tool to assess hyperfibrinolysis in the pediatric population. In addition, we observed that LOT and LI30 should be considered as the best parameters to detect different degrees of fibrinolysis.