A Doctor ordered to administer a hypotonic intravenous solution to a client. A prudent nursing officer knows that which of the following is an example of hypotonic fluid?

1. A

   0.45% NS

2. B

   RL

3. C

   0.90% NS

4. D

   DNS

Appeared in: PGIMER Chandigarh NO - 2015

Explanation

• Hypotonic solutions have a lower solute concentration than blood and other body fluids.
• 45% NS (half-normal saline) has an osmolality of about 154 mOsm/L, which is significantly lower than the normal plasma osmolality (around 275-295 mOsm/L).
• This lower concentration causes fluid to shift via osmosis from the intravascular space into the intracellular space, rehydrating the cells.
• It is commonly used to treat conditions like hypernatremia (high sodium) and cellular dehydration.

Why Other Options Were Wrong

• Option B: Ringer's Lactate (RL) is an isotonic solution, with an osmolality of approximately 273 mOsm/L, which is similar to the body's plasma. It does not cause a significant fluid shift into the cells.
• Option C: 90% NS (Normal Saline) is the standard isotonic solution, with an osmolality of about 308 mOsm/L. It is used to expand intravascular volume and does not cause fluid to shift into cells.
• Option D: DNS (Dextrose 5% in 0.9% Normal Saline) is a hypertonic solution in the bag, with an osmolality of about 562 mOsm/L. It would initially draw fluid out of the cells, which is the opposite effect of a hypotonic solution.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Classification and clinical application of intravenous (IV) fluids based on tonicity to guide bedside assessment, documentation, and the next nursing action.
• Administering the correct type of IV fluid is a critical nursing responsibility. Using a hypotonic solution when it's not indicated can lead to serious complications like cerebral edema.
• Nurses must continuously monitor patients receiving hypotonic fluids for changes in neurological status (e.g., confusion, headache, lethargy), which could signal cerebral swelling.
• Hypotonic solutions are contraindicated in patients at risk for increased intracranial pressure (e.g., head trauma, stroke), extensive burns, or trauma, as they can worsen fluid shifts and edema.

How to Approach the Question

• First, identify the key term in the question: 'hypotonic intravenous solution'. This tells you the question is about the classification of IV fluids.
• Recall the definition of hypotonic: a solution with a lower solute concentration than body fluids, which causes fluid to move into cells.
• Mentally review the common IV fluids and their classifications.
• Evaluate each option: 0.45% NS is half the concentration of isotonic 0.9% NS, making it hypotonic. RL and 0.9% NS are classic isotonic solutions. DNS contains dextrose and normal saline, making it hypertonic.
• Select the option that fits the definition of a hypotonic solution.

Concept Tested & Keywords

• Concept Tested: Classification and clinical application of intravenous (IV) fluids based on tonicity.
• Stem keywords: hypotonic intravenous solution, hypotonic fluid
• Lead-in keywords: example of
• Negative lead-in flag: false

Question ID

QXCrDwkTadVuhS2UyB6D7_

Copy ID

Reference Book

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 68-70

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 142-144