The effect of the correction of metabolic acidosis on nitrogen and potassium balance of patients with chronic renal failure.

Nitrogen and potassium balance studies were conducted in six nondialyzed uremic patients. Each patient was investigated before and after supplementation with sodium bicarbonate and sodium chloride. Every period of the study lasted longer than 1 wk. Each patient had the same calorie and protein intake during the whole study. Urea nitrogen appearance was correlated with protein intake for the assessment of the compliance of patients with their diets. There was a significant decrease of blood urea nitrogen (p = 0.014) of 36% during bicarbonate supplementation and both metabolic balance studies improved significantly (p = 0.0005 and 0.0096). However, there was no significant improvement during sodium chloride administration indicating that the effect of bicarbonate was the result of the correction of metabolic acidosis and not of the expansion of the extracellular volume.