Chronic haemolysis after Lillehei-Kaster valve replacement. Comparison with the findings after Björk-shiley and Starr-Edwards mitral valve replacement.

Nineteen female and sixteen male patients who have had their heart valves replaced with Lillehei-Kaster valves were investigated for haemolysis four to 18 months after operation. Investigation included serum lactic dehydrogenase, serum haptoglobins, and urine haemosiderin. Red cells survival, using autologous red cells labelled with 51Cr, was measured in 12 patients. No patient showed manifest anaemia. The serum lactic dehydrogenase levels were raised in 66% of the mitral valve patients, 81% of the aortic valve patients, and in all the double valve patients. The serum haptoglobins were decreased in 66% of mitral patients, 68% of aortic valve patients, and in 75% of the double valve patients. All the 12 patients studied had lower than normal red cell survivals. No correlation was found between the incidence of haemolysis and the size of the valve. In isolated mitral valve replacement 66% showed compensated haemolysis compared with 42% in Björk-Shiley valves (p less than 0.05), 85% in Starr-Edwards valves (composite seat) (p less than 0.01), and none in frame-mounted irradiated homografts (previous study) (p less than 0.001).

Plasma factor VIII, variables affecting stability under standard blood bank conditions and correlation with recovery in concentrates.

Some of the variables affecting factor VIII during storage of plasma at 4 C prior to preparing factor VIII concentrates and cryoprecipitates were investigated. No significant difference in factor VIII levels could be demonstrated between whole blood, platelet-rich plasma or plasma depleted of platelets when stored at 4 C. However, in frozen plasma platelets were shown to have a deleterious effect on factor VIII. No significant difference in factor VIII levels was found in whole blood or plasma stored at 4 C for 6 hours as compared with blood or plasma stored for 18 hours (p = greater than 0.1). There was, however, a highly significant difference (p = less than 0.001) between plasma and whole blood stored at 4 C for 4 hours as compared with storage for 18 hours. There was a significant correlation (correlation coefficient 0.714) between factor VIII levels in the starting material and the factor VIII recovered in cryoprecipitates, but in a small pilot study no correlation between factor VIII levels in the starting material and that recovered in freeze-dried concentrates, could be found. There was no significant difference in factor VIII levels between the Group O and Group A donations used in this study (p = greater than 0.1), and no correlation was found between the drop in pH during storage and the factor VIII decay pattern.