Dose:  2 to 3 mEq/kg/Day PO
            (To correct symptomatic hyponatremia, see comments)

Comments:  Oral sodium chloride is used to provide sodium to infants who are at risk for or who have developed hyponatremia (serum Na⁺ < 130 mEq/l). The most common causes of the hyponatremia are due to diuretic therapy in infants with fluid retention or BPD. In VLBW infants, several studies have shown improved growth following supplementation with sodium chloride during the first several weeks of life. The amounts ranged from 1.5 to 3.0 mEq/kg/day [Holliday. Requirements for Sodium Chloride and Potassium and Their Interrelation with Water Requirements. In Tsang and Nichols (eds) Nutrition during Infancy. St. Louis: C.V. Mosby Company 1988; page 169].

Symptomatic hyponatremia (usually due to SIADH acutely or due to chronic diuretic therapy) is usually treated using 3% sodium chloride. This limits the amount of free water given to the infant. The amount of sodium can be ascertained from the following formula:
mEq Na⁺ = wgt (kg) x 0.66 x (desired [Na⁺] - actual [Na⁺]).
The goal of therapy is to increase the serum sodium above 125 mEq/liter, a point at which symptoms are unlikely. An infusion of 3% sodium chloride (513 mEq/L) using 8 ml/kg over 2 or more hours should raise the serum sodium concentration by 5 mEq/L (Karlowicz and Adelman: Acute Renal Failure. In Sptizer, A. Intensive Care of the Fetus and Newborn. Mosby-Year Book, Inc., St. Louis, p. 1063,  1996.) 

Toxicity: Excessive sodium administration may cause hypernatremia.

Preparation:  
PO: Sodium chloride (4 mEq/ml) is available from pharmacy in a 1 ml unit dose syringe. Refrigerate. Expiration date noted on syringe.

IV: Sodium chloride (0.9%) is available from pharmacy in 10 ml vial.  Sodium chloride 3% (513 mEq Na/L) is available in a 500 ml bottle. Both are stable for 24 hours after opening.

See formulas used to double check the concentration of sodium in the IVFs.

Compatibility: Compatible with TPN and filter. Also compatible with D2.5W, D5W, D10W, dextrose and saline solutions, dextrose and LR solutions, LR, 0.45% NS, and normal saline. It is incompatible with amphotericin and has equivocal compatibility with diazepam, imipenem-cilastatin, oxacillin, phenytoin, and trimethoprim-sulfamethoxazole .