Significance of ionized calcium during liver transplantation

In liver transplant patients low plasma protein, acid base abnormalities and high citrate concentrations in the blood affects the binding of ionized calcium. In the present study plasma ionized calcium as well as serum total plasma calcium were measured in ten patients undergoing liver transplantation because of end-stage liver failure. During the operation, ionized calcium fell to as low as 0.46 mmol/l although calcium chloride was administered frequently at doses of 10 mg/kg. Serum total calcium concentration values did not fall but rose well above normal at the end of the operation. The measuring of total serum calcium may thus be dangerously misleading in patients undergoing liver transplantation.