635 SODIUM BALANCE IN THE INFANT ILEOSTOMATE

Abstract

Sodium balance was assessed in infant ileostomates to learn if a sodium intake of approximately double the normal infant's requirement would be adequate to protect the infant against anticipated ileal Na losses. Six infants were studied just prior to ileostomy closure, at 3½-11 months of age. During the three-day balance study infants were maintained on 3/4 strength Pregestamil with total Na intake adjusted to 6 mEq/kg/day. Ileal excreta contained 80-119 mEq Na/1000g stool (4-30 mEq Na/day). Mean urine Na was 8±6 (S.D.) mEq/day and mean net sodium balance was +7±5 mEq/day. Mean plasma renin was 8.8±9.6 ng/ml/hr (normal 6.3±3.9) and mean plasma aldosterone was 82±37 ng/100 ml (normal 60±35). Sodium balance was again assessed in three of these infants 1 wk. following reanastomosis when sodium intake was 3 mEq/kg/day. Mean fecal sodium excretion was 2.2 mEq/day (p <0.05 compared to the ileostomy balance period. Urinary sodium excretion was 4±4 mEq/day. Mean net sodium balance +5±3 mEq/day was similar to the ileostomy balance data but renin 2.9±1.2 ng/ml/hr aldosterone 49±17 ng/100 ml were decreased. Conclusion: six mEq Na/kg/day probably provides less than optimal sodium intake for the infant ileostomate resulting in increased serum aldosterone and avid sodium retention. One wk. after reanastomosis colonic absorption of sodium is sufficient to reduce the sodium needs of the infant.