Effect of Magnesium on Serum Potassoum Concentration and Arrhythmia in Hyperkalemia

Kim, Eun Sung; Choi, Jong Ho; Choi, Joo Young

Abstract

The effects of magnesium sulfate treatment on the serum level of blood potassium which was induced by continuous infusion of KCl solution were evaluated in rabbits anesthetized with urethane. Pretreatment group were prepared with intravenously injection of 30 mg/kg of magnesium dissolved in 5 ml normal saline for 10 rninutes. Control group were administered 5 ml normal saline only. After these pretreatments, KCl (3 mEq/kg/hr) was infused continuously until the appearance of lethal arrhythmia in both groups. Venous blood samples were withdrawn without any treatment, immediately after pretreatment, and 50 minutes after the start of KC1 infusion for determination of serum potassium and magnesium level in both groups. In addition, electrocardiograms were monitored continuously throughout the experiment in both groups; The results were as follows: 1) Serum magnesium level were increased significantly in magnesium treated group, but potassium level showed no statistical difference in both groups. However, in magnesium treated group serum potassium level showed less elevation at 50 minutes after infusion of KCl compaired to control group. 2) P wave amplitude, QRS interval and T wave amplitude showed no difference in both groups before and after magnesium pretreatment. However, 30 minutes after continuous infusion of KCl solution, findings of hyperkalemia appeared to be significant in control group but no change in magnesium treated group. Although hyperkalemic findings were developed 50 minutes after KCl infusion in both groups, those in magnesium treated group were observed to a lesser extent. 3) Time span, from start of KCl infusion to the onset of lethal arrhythmia were measured up to 98+/-30.3 minutes in magnesium treated group and 70+/-20.5 minutes in control group. These results suggest that pretreatment with magnesium in hyperkalemic animals retarded the elevation of serum potassium concentration, attenuated the changes of electrocardiographic findings, and delayed the onset time of lethal arrhythmia.