ATI TEAS (Test of Essential Academic Skills) Version 7ScienceMedium
A patient is admitted to the emergency department with severe dehydration. To rapidly rehydrate the patient and ensure fluid moves from the interstitial space back into the blood vessels, which type of intravenous fluid would be most appropriate?
- AHypertonic solution
- BIsotonic solution
- CHypotonic solution
- DDextrose 5% in water (D5W)
Show answer & explanationAnswer & explanation
Correct answer: A. Hypertonic solution
A hypertonic solution has a higher solute concentration than the body's cells. When administered intravenously, it creates an osmotic gradient that draws fluid from the interstitial space and intracellular compartments into the blood vessels, effectively increasing intravascular volume and combating severe dehydration.
Why the other options are wrong
- B. Isotonic solutions expand the extracellular fluid without causing fluid shifts between compartments, suitable for general rehydration but not for drawing fluid from interstitial space into vessels.
- C. Hypotonic solutions would cause fluid to shift out of the blood vessels and into cells, worsening intravascular dehydration.
- D. D5W is isotonic in the bag but becomes hypotonic in the body as dextrose is metabolized, causing fluid to shift into cells.
Hypertonic Solution (IV)
An intravenous fluid with a higher concentration of solutes than the body's cells, causing water to be drawn out of cells and interstitial spaces into the bloodstream.
- Increases intravascular fluid volume.
- Used to treat severe dehydration, cerebral edema, or hyponatremia.
- Requires careful monitoring due to risk of fluid overload or cellular dehydration.
Memory trick: Hyper-Higher, Hypo-Lower, Iso-Same.