Prediction of the mediastinal drainage after coronary artery bypass surgery.

Using multiple correlation and linear regression approaches, we investigated the association between the amount of mediastinal drainage for the first 24 postoperative hours and clinical variables as well as multiple haematological tests performed at three time points: before anaesthesia induction, 10 minutes after protamine administration and just after skin closure, on 46 patients undergoing primary coronary artery bypass grafting. Three models from the three times were then developed to predict mediastinal drainage. The number of internal mammary grafts, the total number of grafts and plasma fibrinogen concentration were useful predictors of mediastinal drainage at all three times. The platelet count taken only after skin closure was found to provide additional predictive information. Each regression model explained approximately 60% of the variation in postoperative mediastinal drainage. The information obtained from these predictive models is useful in defining high-risk populations.

Patterns of coagulopathy during liver transplantation: experience with the first 75 cases using thrombelastography.

Using both conventional laboratory clotting profile and thrombelastography, coagulation status was monitored intraoperatively during liver transplantation in the first 75 cases performed at the Austin Hospital between June 1988 and October 1992. Superimposed on a baseline coagulopathy due to liver disease is a specific pattern of coagulation disturbance which occurs during a liver transplant. Fibrinolysis occurs in the anhepatic stage, worsens with early reperfusion and then spontaneously resolves. In addition reperfusion is associated with a transient clotting defect. If blood loss is excessive, coagulopathy due to massive transfusion may compound the situation. Thrombelastography is a measurement technique allowing rapid on-site assessment of functional clotting status. It is particularly useful in liver transplant surgery. In combination with clinical bleeding assessment it facilitates selective use of component therapy (fresh frozen plasma, platelets and cryoprecipitate) and specific drug treatment only when it is appropriate. It also acts as a liver function test, being especially useful in assessing the graft after reperfusion.

Blood loss and transfusion requirements in liver transplantation: experience with the first 75 cases.

The blood loss data and transfusion requirements including blood bank, salvaged washed red cells, fresh frozen plasma and cryoprecipitate were analysed for the first 75 cases of liver transplantation performed at the Austin Hospital between June 1988 and October 1992. The mean blood loss was 8.8 litres (standard deviation 14.1) with a median value of 4.0 litres. Blood product use expressed as mean number of units (SD) was bank red blood cells 7.1 (12.7), washed red blood cells 3.9 (5.9), fresh frozen plasma 7.1 (9.1), platelets 5.1 (7.4), and cryoprecipitate 1.7 (5.1). These results demonstrate that liver transplantation can be performed without imposing excessive demands on blood transfusion services. Management should include surgical techniques to minimize bleeding and use of autologous transfusion. Use of component therapy (FFP, platelets and cryoprecipitate) should not be empirical. It should be selective on the basis of clinical bleeding assessment and guided by results of the laboratory coagulation profile and changes in thrombelastographic (TEG) parameters.