Question

Intravenous (IV) fluids are employed for preserving fluid equilibrium, replenishing lost fluids, and addressing electrolyte irregularities. Solutions such as 0.9% sodium chloride, known as "Normal Saline," and "Lactated Ringers," which are isotonic to human blood, are commonly used. If a patient receives IV fluids with distilled water instead of "normal saline," the provided diagram depicts three potential results. Which of the following best explains the results if the red blood cells were viewed under a microscope?

A) Shriveled red blood cells would be present because water will travel across the plasma membrane into the surrounding hypotonic IV solution

B) Normal red blood cells would be present because sodium pumps in the plasma membrane would excrete sodium ions from the cells to create a more hypotonic cellular environment.

C) Normal red blood cells would be present because IV fluids and red blood cells are in equilibrium with each other

D) Swollen and bursting red blood cells would be present because water would travel from the hypotonic IV solution into the red blood cells.

Answer 1

Hint: Consider the concept of osmosis and how it affects the movement of water across cell membranes.

Complete step-by-step Answer: Osmosis is a fundamental concept in biology that describes the movement of water molecules across a semipermeable membrane. Semipermeable membranes are membranes that allow certain molecules to pass through while blocking others. The plasma membrane of red blood cells is a semipermeable membrane that allows water to pass through but not solutes, such as sodium and chloride ions.

When red blood cells are placed in a solution with a different water concentration than their cytoplasm, water will move across the plasma membrane by osmosis. If the solution is hypotonic, meaning it has a lower solute concentration than the cytoplasm, water will move into the cells. If the solution is hypertonic, meaning it has a higher solute concentration than the cytoplasm, water will move out of the cells.

In the case of distilled water, which is a hypotonic solution with no solutes, water will rapidly move into the red blood cells. This influx of water will cause the cells to swell and eventually burst. This process is called hemolysis. Hemolysis can lead to several serious health problems, including anemia, kidney failure, and even death.

Therefore, it is important to use isotonic solutions, such as normal saline or Lactated Ringer's, when administering IV fluids. Isotonic solutions have the same solute concentration as blood plasma, so water will not move into or out of red blood cells. This will prevent hemolysis and ensure that the patient's red blood cells remain healthy.

Hence the correct answer is Option D

Note: When administering IV fluids, it is crucial to consider the solute concentration of the solution to prevent hemolysis, the rupture of red blood cells. Distilled water, being a hypotonic solution, has a lower solute concentration than the blood plasma, leading to water influx and cell rupture. Normal saline and Lactated Ringer's are isotonic solutions, maintaining the same solute concentration as blood plasma, preventing water movement and preserving red blood cell integrity.