Question

A not very well-studied A&P student heard about a phenomenon called water intoxication and thought it sounded fun so she decided to try it. She consumed a large amount of water in a short time (Don’t try this—water intoxication is often fatal.). Instead of feeling drunk, she felt nauseated, developed a severe headache, began to get confused, and then became unconscious. Her much more prepared A&P student roommate quickly realized the problem and called an ambulance. When the roommate told the Emergency Department doctor what had happened, the doctor quickly began administering IV (intravenous) fluids.
a. hypotonic IV fluid
b. hypertonic IV fluid
c. isotonic IV fluid

Answer 1

Answer:

The correct answer is B.

Explanation:

The student is suffering from water poisoning. When this happen, extracellular fluid increases, but with very few solutes (sodium for example), in comparison to intracellular fluid. To balance this, the cells swell (because free solute water goes from extracellular to intracellular compartment, this is called osmosis). This cell swelling is the main reason of the symptoms, in this case: nausea, severe headache, confusion and unconsciousness.

To counteract the swelling, hypertonic IV fluid may be administered. The reason is also osmosis: if the intravascular compartment has more solutes than the extravascular, solute free water will go from the extravascular to the intravascular, resolving the swelling.

Diuretics, such as furosemide, may also be administered for the same reason.