Statistical investigation of correlations between serum potassium levels and electrocardiographic findings in patients on intermittent hemodialysis therapy.

SUMMARY Simultaneous determinations of serum potassium and sodium, blood pH, blood pressure, and 12-lead electrocardiograms were obtained in hyperkalemic patients with chronic renal failure. Statistical investigation of the data showed a high correlation between serum potassium levels and ventricular repolarization abnormalities. "Mean intracellular potassium concentration" derived from total body potassium and total body water values was not accurate enough to show significant correlations to ECG changes and did not improve on the already significant correlations with serum potassium levels. Equations are presented which would permit the estimation of serum potassium levels (in a narrow range) from electrocardiographic findings in patients with chronic renal failure and suspected hyperkalemia. Additional Indexing Words: Electrolytes Chronic renal failure Hyperkalemia T HE NUMBER of patients with chronic renal failure who are maintained by intermittent hemodialysis therapy is increasing. Frequency and duration of this treatment are usually determined on clinical grounds and on the basis of serum creatinine and potassium levels. The physician responsible for this type of patient is forced to compromise between the need for frequent blood tests to ensure the safety of the procedure and Dialysis requirements Heart the considerable expense and inconvenience these tests cause the patient. In animal experiments, potassium infusionl or dialysis against potassium-free dialysate2 has caused the gradual development of certain electrocardiographic patterns with progressive deviation of the potassium level from normal. However, there have been no similar studies on man and no attempts have been made to evaluate these alleged correlations by statistical means in a prospective study. Recent investigations of potassium metabolism in patients with chronic renal disease offered the opportunity to obtain a large number of electrocardiographic tracings on patients with normal and with increased serum potassium levels. The results of analysis of these tracings are the subject of this paper.