Pig liver perfusion and other methods of temporary liver support.

abnormal results for these tests may not bleed and blood transfusion is not entirely free from risk. Hence no transfusion is given to correct the defects unless certain positive indications are present-such as daily deterioration in test results; damage to blood vessels; and if bleeding has occurred. The amount and type of transfusion fluid to be used follows the generally accepted principles for the management of a haemorrhagic diathesis. Calculated amounts are given and the tests repeated to ensure their efficiency. Deficiency of factor V is usually added to deficiencies of the more stable factors, II, VII, IX, and X, which are dependent on vitamin K for their synthesis, and hence fresh frozen plasma is used rather than stored blood or plasma. Platelet concentrates may be required. For patients who are bleeding freshly collected whole blood or fresh frozen plasma with red cell concentrates can be used. Intravenous infusion of heparin, starting at 2,000 units every six hours, is begun whenever transfusion is indicated, in an attempt to reduce the utilization of clotting factors. If the thrombin clotting time exceeds 100 seconds the dose is reduced, for the risk of bleeding due to heparin is then very great. Special attention must also be given to the management of the renal failure, for this creates an additional reason for the bleeding which is so often the immediate cause of death in these patients.