Removal of excess body potassium by hemodialysis

Potassium has been removed acutely from nephrectomized potassium-loaded dogs by hemodialysis while other electrolyte concentrations were maintained constant. Potassium extraction occurred in a rapid phase with a decrease of plasma potassium concentration and in a second phase of continued extraction with no change of plasma potassium concentration. Hypopotassemia and electrocardiographic changes of hypopotassemia appeared while the dogs remained in net positive potassium balance. P wave amplitude showed a tendency to decrease following loading of potassium and increased following removal of potassium from the dogs. The change of P wave amplitude following loading of potassium showed significant multiple correlation with plasma and myocardium potassium concentrations, and with the ratio of myocardium/plasma potassium concentration alone, but not with either plasma or with myocardium potassium concentration alone.