Isotonic solutions

Definition

Isotonic solutions have the same osmolarity as blood plasma, meaning they do not cause fluid shifts between compartments. They are commonly used to maintain or restore fluid volume without altering electrolyte balance.

5 Must Know Facts For Your Next Test

1. Isotonic solutions include normal saline (0.9% NaCl) and lactated Ringer's solution.
2. They are often administered for hydration in patients experiencing fluid loss due to surgery, dehydration, or shock.
3. Because they do not alter cell size, isotonic solutions are ideal for patients with intravascular dehydration.
4. Inappropriate use of isotonic solutions can lead to fluid overload, especially in patients with heart failure or renal impairment.
5. They serve as the primary choice for initial resuscitation in trauma or septic shock cases.

Review Questions

• What are two common examples of isotonic solutions?
• Why are isotonic solutions preferred for initial resuscitation in trauma patients?
• What is a potential risk of using isotonic solutions in patients with renal impairment?

Related terms

Hypertonic Solutions:

Solutions with higher osmolarity than blood plasma, causing cells to shrink by drawing water out.

Hypotonic Solutions:

Solutions with lower osmolarity than blood plasma, causing cells to swell by drawing water in.

Osmolarity:

A measure of solute concentration defined as the number of osmoles of solute per liter of solution.