THE EFFECT OF ACUTE RESPIRATORY ACIDOSIS ON THE INTERNAL EQUILIBRIUM OF POTASSIUM 1

Abstract

Studies of the effect of acid-base disorders on K metabolism have not separated changes in the internal equilibrium of K from changes in total body K. In order to study internal equilibrium without changes in total body K the ureters were ligated in control dogs, and in dogs maintained at pH 7 by breathing 30% CO2-70% O2. The mean serum K level in acidotic dogs rose over 4 hours to 3.2 meq/l above the mean serum K level in control dogs. In addition a K load was given intravenously over 2-3 hours to control dogs and dogs with respiratory acidosis, pH 7. The serum K level was maintained in a toxic range for 1 hour or more. Using chloride space calculations it was shown that at normal pH about 72% of retained K entered the cells. In the acidotic dogs virtually none of the K entered the cells. From these and previously published studies the acidosis is assumed to raise and alkalosis to lower the extracellular-intracellular concentration ratio of K. The relation of this hypothesis to the clinical interpretation of the serum K level is discussed.