Which of the following conditions has an increased risk for developing hyperkalemia?

Appeared in: KPSC Staff Nurse - 2016

Explanation

End-stage renal disease (ESRD) is a very common cause of hyperkalemia.
In ESRD, the kidneys lose their ability to excrete potassium effectively due to a severely reduced glomerular filtration rate (GFR).
Since the kidneys are responsible for eliminating about 90% of the body's potassium, this failure of excretion leads to the accumulation of potassium in the blood (hyperkalemia).

Option A: Crohn's disease, an inflammatory bowel disease, typically causes hypokalemia (low potassium), not hyperkalemia.
Option B: Cushing's disease is associated with hypokalemia (low potassium).
Option C: While some patients with Chronic Heart Failure (CHF) can develop hyperkalemia (e.g., from medications like ACE inhibitors or poor renal perfusion), it is not as direct or certain a cause as ESRD. Many CHF patients develop hypokalemia due to treatment with loop or thiazide diuretics.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Hyperkalemia as background academic context rather than a clinical decision trigger.
Nurses must closely monitor serum potassium levels in patients with any stage of chronic kidney disease, especially ESRD.
Patient education is critical, focusing on a low-potassium diet. Patients should be taught to avoid or limit high-potassium foods like bananas, oranges, potatoes, and tomatoes.
Recognizing the signs of hyperkalemia, particularly ECG changes like peaked T-waves and widened QRS complexes, is a crucial nursing skill for preventing cardiac arrest.

How to Approach the Question

First, define the key term in the question: 'hyperkalemia' means an elevated level of potassium in the blood (serum K+ greater than 5.0 mEq/L).
Next, analyze the pathophysiology of each option in relation to potassium balance.
Consider Crohn's disease: It's an inflammatory bowel disease that causes diarrhea, which leads to potassium loss. This causes hypokalemia. Eliminate this option.
Consider Cushing's disease: It involves excess cortisol, which increases potassium excretion by the kidneys. This also causes hypokalemia. Eliminate this option.
Evaluate the remaining two options: Chronic heart failure (CHF) and End-stage renal disease (ESRD).
In CHF, the effect on potassium is variable. Diuretics cause potassium loss, while other drugs (ACE inhibitors) or poor kidney perfusion can cause potassium retention. In ESRD, the kidneys definitively fail to excrete potassium. Therefore, ESRD presents the most direct and highest risk for hyperkalemia.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 1 pp. 400-402, 399-401

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 149-151

Practise the full KPSC Staff Nurse - 2016

Attempt every question from this paper in a timed mock, then review the full solution for each one.