Hematological and biochemical studies in calves living over 100 days with the polymethylmethacrylate total artificial heart TNS Brno II.

A polymethylmethacrylate total artificial heart (kinetic components made of polyetherurethane) of TNS Brno II type was implanted into seven calves (2-5 months of age) surviving for the average of 152.4 +/- 19.1 days after the implantation. During the entire post-operative period the animals received oral warfarin-sodium, acetylsalicylic acid, dipyridamole and alpha-tocopherol. Blood was taken for biochemical and hematological examinations twice a week from the jugular vein. During the experiments there were decreases in the number of red blood cells, hematocrit and hemoglobin levels. Plasma free hemoglobin and serum enzymes (alkaline phosphatase, AST, ALT, LDH) increased. Coagulation tests were abnormal because anticoagulation therapy was used. There were minimal changes in the number of white blood cells and platelets, fibrinogen, blood pH, blood glucose, serum electrolytes, bilirubin (total and direct), creatinine, blood urea, and lactate. Possible reasons for observed changes include the gradual rise in the central venous pressure and damaged function of the liver parenchyma. Other factors playing a possible role in inducing changes in laboratory findings are also discussed.