After an appendectomy, what is the appropriate management for a patient with sodium at 129 mmol/L?

The appropriate management for a patient with sodium at 129 mmol/L, indicating hyponatremia, involves careful repletion of sodium, particularly after a surgical procedure such as an appendectomy. In this situation, administering sodium chloride 0.9% intravenous infusion is beneficial because it delivers a solution that effectively restores sodium levels without causing a rapid increase in serum sodium concentration, which could lead to complications like osmotic demyelination syndrome.

The 0.9% sodium chloride solution (normal saline) contains 154 mmol/L of sodium and helps to raise the serum sodium level incrementally and safely. This gradual correction is vital in avoiding potential adverse effects associated with too rapid an increase of sodium levels, emphasizing the need for cautious management of hyponatremia.

Other options, although relevant in different contexts, do not align as closely with the immediate management goal for this particular case of hyponatremia following surgery. For instance, 0.45% sodium chloride, while hypotonic, would not provide sufficient sodium to correct the hyponatremia effectively. Insulin-glucose intravenous infusion is typically used for the management of hyperglycemic episodes and has no direct role in correcting sodium levels. Sodium bicarbonate is rarely indicated in