Certified Registered Nurse Infusion (CRNI) Practice Exam

How does the osmolarity of isotonic solutions affect patient care?

1. Facilitating drug delivery

2. Enhancing body hydration

3. Preventing cellular dehydration

4. Causing tissue irritation

The correct answer is: Preventing cellular dehydration

The osmolarity of isotonic solutions is crucial in patient care, particularly in preventing cellular dehydration. Isotonic solutions have the same osmotic pressure as the cells in the body, meaning they maintain an equilibrium where the concentration of solutes outside the cells is equal to the concentration of solutes inside the cells. This balance helps to ensure that water does not leave the cells excessively, avoiding cellular dehydration which can lead to complications such as organ dysfunction or cell death. In the clinical setting, isotonic solutions are often used in intravenous therapy to replace fluids and maintain hydration without causing shifts in water between the intracellular and extracellular environments. This is particularly important for patients who are unable to drink fluids or who have lost a significant amount of fluid due to illness, surgery, or other medical conditions. Administering isotonic solutions helps maintain the normal function of cells and supports overall patient health. The other choices do have relevance in different contexts, but they do not specifically capture the protective role of isotonic solutions against cellular dehydration in the same direct manner. While facilitating drug delivery and enhancing body hydration are important aspects of medical treatment, the primary significance of isotonic solutions lies in their ability to ensure cellular integrity by preventing dehydration.