Question

Sally goes to the emergency room (ER) seeking treatment for mild dehydration. The ER nurse mistakenly gives Sally an IV bag of solution that is very hypotonic to normal cells. Which of the following statements about the release of vasopressin reflects what would occur as a result of this mistake?

A.) There is no effect on vasopressin release.
B.) There is increased release of vasopressin.
C.) There is not enough information to tell.
D.) There is decreased release of vasopressin.

Answer 1

The administration of a hypotonic IV solution would decrease blood osmolarity, leading to a decreased release of vasopressin as the body would not need to conserve water.

Step-by-step explanation:

If Sally is given a hypotonic IV solution, the concentration of solutes in her blood plasma would decrease, leading to a lower osmolarity compared to her body cells. As a result, water would enter her cells to establish osmotic balance, and this may cause the cells to swell. In response to the decreasing osmolarity of her blood, her body would decrease the release of vasopressin (ADH), because there is less need to conserve water through reabsorption in the kidneys. Vasopressin is released in response to high blood osmolarity (as occurs in dehydration), which means that in this scenario of lower osmolarity due to a hypotonic solution, the trigger for vasopressin release is diminished.