Ionized magnesium concentration during liver transplantation, resection of the liver and cardiac surgery

Abstract

In this study we investigated three groups of patients, the first undergoing liver transplantation (n=9), the second resection of the liver (n=7) and the third cardiac surgery (n=10) with regard to changes of ionized and total magnesium concentration during operation.

Liver transplantation: Ionized magnesium concentration decreased from 0.58 mmol/L to 0.34 mmol/L far below the reference interval (0.49–0.72 mmol/L), whereas total magnesium concentration changed only from 0.78 mmol/L to 0.67 mmol/L (reference interval: 0.65–1.05 mmol/L). Citrate concentration increased from 220 μmol/L to 1925 μmol/L (anhepatic stage) because of massive transfusion of blood products. It was inversely correlated to ionized magnesium concentration.

Resection of the liver: There was a decline of ionized magnesium from 0.56 mmol/L to 0.43 mmol/L, which slightly exceeded the decline of total magnesium from 0.74 mmol/L to 0.64 mmol/L. Citrate concentration increased moderately even in cases, when no citrate was administered reflecting reduced hepatic function during operation.

Cardiac surgery: Only in patients, to whom citrate but not magnesium was infused, ionized magnesium concentration fell slightly below the reference interval (0.45 mmol/L). In the other patients, to whom magnesium was administered, ionized magnesium concentration was within the reference interval or exceeded it.

It is concluded that in patients with impaired hepatic function andor high citrate load the monitoring of ionized magnesium concentration is mandatory.

Key Words:

• Citrate
• liver function
• total magnesium
• transfusion