Plasma magnesium during human liver transplantation.

Patients with severe liver disease and accompanying malnutrition may exhibit electrolyte disturbances including the magnesium balance. In 18 patients plasma magnesium (p-Mg) was determined at the start of the liver transplantation and during the anhepatic and reperfusion phases of the operation. The blood loss was 6.9 (2.5-8.8) 1 (median and range) and the cumulative transfusion volume was 10.2 (5.0-17.2) 1 of which 5.9 (2.5-14.2) 1 was with fresh frozen plasma. p-Mg was 0.72 (0.58-0.88) mmol.l-1 and it did not change significantly during the operation. Thus, in 4 patients it was at or below the lower reference value of 0.67 mmol.l-1. In 11 patients it changed less than 0.05 mmol.l-1, while in 4 patients the concentration was rose, and in 3 patients we noted a fall in each of 0.08 mmol.l-1. There was no correlation between p-Mg and the blood loss or the administered volume of fresh frozen plasma. In 10 randomly chosen fresh frozen plasma units, the p-Mg was 0.64 (0.61-0.71) mmol.l-1. These observations do not support a need for close monitoring or substitution of magnesium during human liver transplantation. On the other hand, the finding of a low value in 4 of 18 patients suggests that plasma magnesium should be monitored and eventually corrected while the patient is on the waiting list.