METABOLIC ALKALOSIS OUT, BUT METABOLIC-AC IDOSIS IN

Our purpose in writing this article is to emphasize the acid-base cons equences and total body imbalances which follow the selective depletio n of HCl. The initial body balance is an equimolar deficit of chloride and gain of bicarbonate. Within a short period of time, body balance changes; the net deficits are closer to equimolar losses of potassium and chloride. Since the loss of potassium occurred without the simulta neous loss of existing body anions (chloride or phosphate), this negat ive balance of potassium is accompanied by an equimolar gain of hydrog en ions. Thus when the negative balance is that of KCl, acid-base bala nce is present but there is a surplus of bicarbonate in the extracellu lar fluid (ECF) together with an equal surplus of hydrogen ions in ano ther compartment (the intra-cellular fluid (ICF)). Moreover, if the EC F volume is contracted, a more severe degree of acidosis of the ICF ma y occur due to a higher PCO2 in venous blood. Given the acid-base bala nce and a deficit of KCl, one should not view this disorder as being ' 'corrected'' by saline at any time other than in the acute phase befor e a large potassium deficit occurs. Sodium chloride should be restrict ed to repair a deficit of sodium chloride. The emphasis on therapy is obviously to replace the deficit of KCl.