Potassium supplementation, diet vs pills: a randomized trial in postoperative cardiac surgery patients.

Background: Cardiac surgery patients are commonly treated with diuretics, which can result in hypokalemia requiring potassium supplementation.

Objective: Our objective was to determine whether cardiac surgery patients receiving therapy with potassium-wasting diuretics can safely and beneficially maintain serum potassium levels by eating potassium-rich foods.

Design: A prospectively randomized trial of diet vs medication supplementation of potassium was undertaken. Patients who were to undergo cardiac surgery and who would be receiving therapy with oral furosemide postoperatively were eligible for the study. Forty-eight patients were enrolled in the trial, and 38 patients completed the study. Patients received either potassium-rich foods (diet) or potassium chloride pills (medication).

Results: There was no significant difference in mean (+/- SD) serum potassium concentrations between groups preoperatively (4.25 +/- 0.30 vs 4.29 +/- 0.33 mEq/L, respectively), on postoperative day 3 (4.23 +/- 0.40 vs 4.27 +/- 0.40 mEq/L, respectively), or postoperative day 4 (4.23 +/- 0.48 vs 4.24 +/- 0.33 mEq/L, respectively) for the diet and medication groups. Length of stay was significantly lower in the diet group (5.0 +/- 0.9 vs 6.3 +/- 2.2 days, respectively). When asked their preferences for method of supplementation, 79% of patients preferred the diet method.

Conclusions: Cardiac surgery patients receiving therapy with diuretics can maintain serum potassium levels at clinically adequate concentrations by eating potassium-rich foods. Length of stay was significantly reduced. This method of potassium supplementation demonstrates the potential for reduced costs and increased patient satisfaction.