Silver nitrate dressings of burns may cause?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Pharmacology

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Explanation

Silver nitrate 0.5% solution is hypotonic, meaning it has a lower solute concentration than the body's cells and tissues.
Due to the principle of osmosis, this hypotonic solution pulls electrolytes—primarily sodium (Na+), potassium (K+), and chloride (Cl-)—from the wound bed into the saturated dressing.
This continuous loss of electrolytes from the body leads to systemic depletion, resulting in conditions like hyponatremia (low sodium) and hypokalemia (low potassium).

Option A: Abnormalities in blood gases, specifically metabolic acidosis, are a characteristic side effect of Mafenide acetate (Sulfamylon), not silver nitrate.
Option B: An abnormal blood count, specifically transient leukopenia (a drop in white blood cells), is a known side effect of Silver sulfadiazine (Silvadene).
Option D: While severe burns can lead to dehydration and acute kidney injury, causing an increased blood urea nitrogen (BUN), this is a complication of the burn injury itself, not a direct side effect of the silver nitrate solution.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Side effects of topical agents used in burn management as background academic context rather than a clinical decision trigger.
The primary nursing responsibility when using silver nitrate dressings is the diligent monitoring of serum electrolyte levels and assessing for signs of imbalance, such as muscle weakness or cardiac dysrhythmias.
Nurses must ensure dressings remain saturated with the 0.5% solution. If the dressings dry out, the solution becomes concentrated (hypertonic), which can damage healing tissue and worsen fluid shifts.
Silver nitrate causes a characteristic black staining of skin, linens, and surfaces. Nurses should take precautions to protect the environment and educate the patient and family about this harmless but permanent staining.

How to Approach the Question

First, identify the key components of the question: the drug ('Silver nitrate dressings') and the outcome ('may cause').
This is a factual recall question from pharmacology, specifically focusing on burn care.
Recall the primary characteristic of the 0.5% silver nitrate solution used for burns: it is a hypotonic solution.
Apply the physiological principle of osmosis. A hypotonic solution applied to a wound will draw solutes (electrolytes) from the tissue into the dressing.
Evaluate the options based on this mechanism. 'Depletion of sodium and potassium' is a direct result of this electrolyte-leaching effect.
To confirm, mentally differentiate this from the side effects of other common burn agents. Mafenide acetate is linked to acidosis (blood gases), and silver sulfadiazine is linked to leukopenia (blood count), reinforcing that electrolyte depletion is specific to silver nitrate.

Concept Tested & Keywords

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 695-697, 696-698