Which among the following is an example of crystalloids?

RRB Nsg. Superintendent-20 July 2019 (Shift-3rd)

Pharmacology

Easy

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-3rd)

Explanation

Ringer lactate is a classic example of an isotonic crystalloid solution.
Crystalloids are solutions containing small molecules (water, electrolytes, sugar) that can pass easily from the bloodstream into the body's tissues.
Ringer lactate's composition of electrolytes (sodium, potassium, calcium, chloride) and lactate (a buffer) is similar to blood plasma, making it ideal for fluid resuscitation and correcting electrolyte imbalances.

Option A: Red Blood Cells (RBCs) are cellular components of blood, not a solution. They are considered a blood product, which is a type of colloid, used to increase oxygen-carrying capacity.
Option B: White Blood Cells (WBCs) are part of the immune system and are not administered as a type of intravenous fluid for hydration or volume expansion.
Option C: Plasma is the liquid component of blood that contains large protein molecules, primarily albumin. This makes it a natural colloid, not a crystalloid. Colloids remain in the vascular space to expand volume.

Visual 1: Diagram: Fluid distribution of Crystalloids vs. Colloids. This visual would show how crystalloid solutions distribute throughout the extracellular fluid (both intravascular and interstitial spaces), while colloids are largely confined to the intravascular space, helping to explain their different clinical uses.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of Intravenous Fluids: Crystalloids as background academic context rather than a clinical decision trigger.
Nurses must understand the difference between crystalloids and colloids to ensure correct fluid administration based on the patient's specific condition, such as dehydration, shock, or electrolyte imbalance.
A key nursing intervention when administering crystalloids is to monitor for signs of fluid overload, such as crackles in the lungs, shortness of breath, and peripheral edema. This is because crystalloids can easily shift from the blood vessels into the surrounding tissues.
What if? If the patient was in hypovolemic shock due to hemorrhage, the initial treatment would be rapid infusion of crystalloids (like Ringer lactate) to restore volume, but this would be quickly followed by blood products (RBCs and plasma) to restore oxygen-carrying capacity and clotting factors.

How to Approach the Question

First, identify the key term in the question: 'crystalloids'.
Define 'crystalloid' in the context of IV fluids. A crystalloid is a solution of small molecules (like salt or sugar) in water that can pass through a semipermeable membrane.
Evaluate each option based on this definition.
Option A (RBC) and B (WBC) are blood cells, not solutions. Eliminate them.
Option C (Plasma) is the liquid part of blood, rich in large protein molecules (albumin), which makes it a colloid. Eliminate it.
Option D (Ringer lactate) is a solution of water and electrolytes, which are small molecules. This fits the definition of a crystalloid. Therefore, this is the correct answer.

Concept Tested & Keywords

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