SummaryThe pharmacokinetics and tolerability of factor XIII (FXIII) from plasma were compared with those of FXIII from placenta in a randomised, double-blind, crossover study involving 13 patients with congenital FXIII deficiency. Both FXIII activity and FXIII antigen were monitored. No difference was seen in the mean half-lives of the two preparations (9.3 days and 9.1 days for plasma and placenta FXIII activity, respectively). Response was similar for both preparations, but was slightly greater for FXIII from plasma.Similar results were found for recovery (65% vs 60%). The area under the data completed by extrapolation was significantly higher for FXIII from plasma. No differences between preparations in terms of efficacy or tolerability were observed. It can be concluded that treatment with FXIII concentrate from plasma is as efficient as with FXIII concentrate from placenta in terms of recovery and half-life. Both preparations were equivalent in terms of safety during the observation period. With the administration of monthly injections of approximately 30 U/kg serious bleeding events were prevented and no other serious adverse events occurred.

The main haemostasis changes observed in a screening study performed in 40 patients who underwent an open heart surgery with extracorporeal circulation (ECC) are: a significant drop in platelet count from the onset of the ECC to the third postoperative day, a decrease of platelet retention and aggregation during ECC with an 8-day persistently increased heparin-neutralizing activity in plasma but not in serum, a moderate decrease of plasma factors I, II, VII-X, X and XIII and a more important drop in factor V which disappears 24 h after ECC, a transitory increase of fibrinolysis during ECC and the lack of FDP elevation in the serum. These disorders require a very good neutralization of the heparin used during ECC. The ratio protamine/heparin can be established by a titration clotting time test. Protamine chloride seems to be more efficacious and to act more quickly than protamine sulfate for the neutralization. An overload in protamine can enhance the hemostatic, biological and clinical disorders. The preventive administration of platelet concentrate immediately after the heparin neutralization contributes to reduce the bleeding disorders related to the quantitative and qualitative platelet defects.

SummaryIn an experimental study in the rabbit, the modifications of some haemostasis parameters (platelet count, platelet retention and aggregation, platelet factors 3 and 4, platelet and plasma plasmin inhibiting activities, fibrinogen and other plasma factor levels, FDP), and histological findings are compared in both the normal animal and the animal with disseminated intravascular coagulation (DIC) induced by thrombin perfusion after administration of fibrinolytic inhibitors (plasminogen antiactivators and proteinase inhibitors).In the normal animal, the administration of fibrinolytic inhibitors is followed by haemostatic changes similar to those found in thrombophilic states. The modifications are more pronounced with plasminogen antiactivators than with proteinase inhibitors.In the animal with DIC, the administration of fibrinolytic inhibitors enhances the haemostatic and the biological disorders produced by thrombin perfusion. The effect of the plasminogen antiactivators is even more evident.The preventive administration of heparin reduces or abolishes the biological and histological disorders induced by thrombin; its beneficial effect is considerably reduced when thrombin is combined with fibrinolytic inhibitors.The administration of acetylsalicylic acid appears to be ineffective for the prevention of haemostatic and histological changes induced by thrombin perfusion.

No abstract

The main haemostasis changes observed in a screening study performed in 40 patients who underwent an open heart surgery with extracorporeal circulation (ECC) are: a significant drop in platelet count from the onset of the ECC to the third postoperative day, a decrease of platelet retention and aggregation during ECC with an 8-day persistently increased heparin-neutralizing activity in plasma but not in serum, a moderate decrease of plasma factors I, II, VII-X, X and XIII and a more important drop in factor V which disappears 24 h after ECC, a transitory increase of fibrinolysis during ECC and the lack of FDP elevation in the serum. These disorders require a very good neutralization of the heparin used during ECC. The ratio protamine/heparin can be established by a titration clotting time test. Protamine chloride seems to be more efficacious and to act more quickly than protamine sulfate for the neutralization. An overload in protamine can enhance the hemostatic, biological and clinical disorders. The preventive administration of platelet concentrate immediately after the heparin neutralization contributes to reduce the bleeding disorders related to the quantitative and qualitative platelet defects.