Which type of solution would be used to treat dehydration?

• A. Hypotonic solution
• B. Hypertonic solution
• C. Isotonic solution
• D. Colloidal solution

Answer: (C)

The use of an isotonic solution to treat dehydration is based on the principle that it closely matches the osmolarity of the body's fluids. When someone is dehydrated, the goal of treatment is to restore fluid balance without causing further shifts in fluid status between the intravascular and extracellular compartments.

Isotonic solutions, such as normal saline or lactated Ringer's solution, have the same osmotic pressure as blood plasma, which allows for effective rehydration. They can help to replace lost fluids and electrolytes without causing cells to swell or shrink, maintaining homeostasis.

In contrast, hypotonic solutions contain a lower concentration of solutes compared to the body's fluids and can cause cells to swell as water moves into them. Hypertonic solutions, on the other hand, have a higher concentration of solutes and can draw water out of cells, which is not beneficial in the case of dehydration. Colloidal solutions, while useful for expanding blood volume, do not specifically address the need for fluid replacement and electrolyte repletion in dehydration.