Patients who are euvolemic, hemodynamically stable but unable to take adequate fluid by oral or enteral route need maintenance intravenous (IV) fluids to replace anticipated insensible (such as respiration, perspiration, and stools) and sensible (such as urine) losses [1].

The goal of maintenance IV fluid is to replace the ongoing daily physiologic losses such as urine, feces, and sweat, maintain normal water and electrolyte balance and provide adequate calories to avoid starvation ketosis [1, 2].

Ideal maintenance IV fluid should provide adequate water and electrolytes to preserve the extracellular volume and ensure proper tissue perfusion without causing volume depletion, fluid overload, or electrolyte disturbances, along with supplementation for optimal calories [1].

Sodium concentration of maintenance IV fluids is a crucial but debatable issue discussed in many studies, which needs special consideration because of its two common and potentially harmful effects, hyponatremia [3, 4] and volume overload [5, 6].

The concepts of appropriate sodium concentration of maintenance IV fluids in adults are changing like a pendulum shift.

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