Quantitative treatment of the hyponatremia of cirrhosis

Background. Hyponatremia represents a frequent complication of liver cirrhosis, associated with adverse events and death. It is caused either by excessive water retention or solute depletion, or a combination of both. Aims. To determine the cause of hyponatremia clinically and to examine the usefulness of quantitative calculations of water excess and Na deficit to guide treatment. Methods. We studied 23 patients with liver cirrhosis and PNa ≤ 131 meq/L to determine the cause of hyponatremia and results of quantitative treatment. Results. The most frequent cause of hyponatremia was diuretic-induced Na depletion, which occurred in 14 out of 23 instances, while four patients had water excess. Hyponatremia was corrected after a quantitative estimate of the Na deficit or relative water excess by algebraic formulas. The former was quantitatively replenished as 3% NaCl, the latter was excreted with the technique of furosemide-induced diuresis and re-infusion of solute, but not water, losses. After quantitative replacement, there was a significant correlation (R = 0.98, P < 0.001) between the Na concentration predicted mathematically and that actually measured. Conclusions. The hyponatremia of cirrhosis is frequently caused by diuretics. Its treatment can be effectively guided with the aid of quantitative estimates of Na deficit and/or water excess in all instances, although the methods of correction described are indicated in severe clinical conditions.