Insulin decreases the serum potassium concentration during the anhepatic stage of liver transplantation.

BACKGROUND: Severe hyperkalemia is a serious problem during orthotopic liver transplantation. The effectiveness of insulin in decreasing serum potassium concentration during the anhepatic stage of orthotopic liver transplantation was investigated.

METHODS: Forty patients with serum potassium concentrations greater than 4.0 mM/L at the onset of the anhepatic stage were randomized into two groups. Control group patients (n = 20) received no treatment, and treatment group patients (n = 20) received an intravenous bolus of regular insulin (20 u) 10 min into the anhepatic stage, followed by a glucose infusion (500 ml 5% dextrose in water) over 15 min.

RESULTS: In the control group, the potassium concentration did not change, whereas in the treatment group, it decreased from 4.70 +/- 0.54 to 4.18 +/- 0.63 mM/L (mean +/- SD) within 15 min and to 3.57 +/- 0.55 mM/L 60 min after therapy. The potassium concentration was less in the treatment group than in the control group within 30 min of treatment (3.97 +/- 0.52 vs. 4.49 +/- 0.43 mM/L, respectively; P < 0.05). The potassium concentration increased similarly 30 s after graft reperfusion in both groups of patients, but was less in the treatment group (5.91 +/- 1.63 vs. 7.37 +/- 1.67 mM/L, respectively; P < 0.05). The potassium concentration returned to prereperfusion levels within 5 min after graft reperfusion.

CONCLUSIONS: In patients undergoing orthotopic liver transplantation, the administration of insulin rapidly decreases serum potassium concentration, even in the absence of the liver, suggesting an important contribution by extrahepatic tissues in the insulin-stimulated uptake of potassium.