Traumatic Haemolysis after Heart Valve Replacement: a Comparison of Haematological Investigations

Summary: Thirty-three patients whc had had prosthetic valves inserted in the preceding four years were investigated to estimate the value of various laboratory tests in the assessment of traumatic red cell destruction. A combination of the findings of an elevation in serum lactic acid dehydrogenase (LDH) and a fall in serum haptoglobir levels, was found to be a reliable and accurate pointer to the presence of red cell damage. This study indicates that the commonly used parameters of an increased reticulocyte count, a rise it serum bilirubin levels, the presence ol methaemalbumin (positive Schumm's test) and fragmented red cells in the peripheral blood, although very valuable in more severe cases, are not sufficiently accurate to be used as indicators ol minor degrees of red cell damage. Milc and clinically insignificant red cell destruction is very common in patients with artificial valves and only one case of the thirty-three studied showed no laboratory evidence of traumatic haemolysis.