Hypernatremia is commonly detected in patients with?

SCTIMST Staff Nurse - 2015 (Set-B)

Medical & Surgical Nursing

Medium

Appeared in: SCTIMST Staff Nurse - 2015 (Set-B)

Explanation

Hypernatremia is defined as a serum sodium level greater than 145 mEq/L, primarily caused by a water deficit.
Fever increases the body's metabolic rate and core temperature.
To cool down, the body increases insensible water loss through sweating (perspiration) and rapid breathing (tachypnea).
This loss of free water leads to hemoconcentration, where the remaining sodium in the blood becomes more concentrated, resulting in hypernatremia.

Option A: Corticosteroids promote the retention of both sodium and water, which typically leads to fluid volume excess (hypervolemia), not the relative water deficit that causes hypernatremia.
Option C: Diarrhea causes loss of both fluid and electrolytes (including sodium). Therefore, it is a more common cause of hyponatremia (low sodium) or isotonic dehydration.
Option D: Digoxin does not directly affect sodium levels. Its primary electrolyte interaction is with potassium; low potassium levels (hypokalemia) significantly increase the risk of digoxin toxicity.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology and causes of hypernatremia as background academic context rather than a clinical decision trigger.
Nurses must closely monitor the hydration status of febrile patients, encouraging fluid intake and tracking intake and output to prevent dehydration and subsequent hypernatremia.
In older adults, the thirst mechanism may be impaired, increasing their risk for dehydration and hypernatremia when they have a fever. Proactive fluid management is crucial.
What if? If a febrile patient also has vomiting and diarrhea and is replacing losses with only plain water, they would be at high risk for developing hyponatremia, not hypernatremia, due to the loss of sodium that is not being replaced.

How to Approach the Question

First, understand the question's core concept: it asks for a common cause of hypernatremia.
Recall the definition of hypernatremia: an elevated serum sodium level (greater than 145 mEq/L), which is most often caused by a deficit of water relative to sodium.
Analyze each option's effect on fluid and electrolyte balance.
Evaluate 'fever': Fever causes sweating and rapid breathing, leading to pure water loss and concentrating the blood's sodium. This is a direct cause.
Evaluate 'steroids': Recall that corticosteroids cause sodium AND water retention, not a relative water loss.
Evaluate 'diarrhea': Recognize that diarrhea involves loss of both water and sodium, making hyponatremia a common outcome.

Concept Tested & Keywords

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