What is the typical initial fluid choice for dehydration in adults?

• A. Lactated Ringer's solution
• B. Dextrose 5% in water
• C. Albumin
• D. Normal saline (0.9% NaCl)

Answer: (D)

Dehydration with volume loss in adults is treated by rapidly restoring circulating volume using an isotonic crystalloid. Normal saline 0.9% NaCl matches plasma osmolality and stays mainly in the extracellular space, so it quickly expands intravascular volume and improves tissue perfusion without shifting water into cells. It’s widely available and familiar, making it the standard starting fluid for resuscitation in adults with dehydration.

Dextrose solutions provide free water after the glucose is metabolized and don’t sustain intravascular volume, so they’re not ideal for initial resuscitation. Albumin is a colloid used only in specific situations and is more costly with less clear benefit for uncomplicated dehydration. Lactated Ringer’s is another acceptable isotonic option, but normal saline is conventionally chosen as the initial fluid.