NORCET 9 Mains - 2025: Which of the following conditions can cause hyperphosphatemia?& x20;

NORCET 9 Mains - 2025

Medical & Surgical Nursing

Easy

Appeared in: NORCET 9 Mains - 2025

Explanation

Calcium and phosphate have a reciprocal or inverse relationship in the body.
When serum calcium levels decrease (hypocalcaemia), serum phosphate levels tend to increase (hyperphosphatemia).
This relationship is most evident in conditions like chronic kidney disease, where impaired phosphate excretion leads to high phosphate levels, which in turn lowers calcium levels.
Another key example is hypoparathyroidism, where the lack of parathyroid hormone (PTH) causes both decreased phosphate excretion (hyperphosphatemia) and decreased calcium levels (hypocalcaemia).

Option B: Hypokalaemia (low potassium) does not have a direct regulatory relationship with phosphate levels. While severe electrolyte disturbances can be complex, it is not a primary cause of hyperphosphatemia.
Option C: Hypercalcemia (high calcium) is associated with hypophosphatemia (low phosphate), not hyperphosphatemia, due to their inverse relationship. For example, in primary hyperparathyroidism, high PTH levels increase calcium but also increase renal phosphate excretion, lowering phosphate levels.
Option D: While severe hyperglycemia, as seen in diabetic ketoacidosis (DKA), can cause a temporary shift of phosphate from the intracellular to the extracellular space, leading to transient hyperphosphatemia, it is not a primary or sustained cause. In fact, upon treatment of DKA with insulin, profound hypophosphatemia can occur as phosphate shifts back into the cells.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Electrolyte Imbalances: Causes of Hyperphosphatemia as background academic context rather than a clinical decision trigger.
Nurses must closely monitor calcium and phosphate levels in patients with chronic kidney disease, as hyperphosphatemia is a common and serious complication that can lead to bone disease and cardiovascular calcification.
Recognizing the signs of hypocalcemia (e.g., tetany, Chvostek's sign, Trousseau's sign) is crucial in a patient with known hyperphosphatemia, as the symptoms are often due to the low calcium.
Patient education for those with CKD includes dietary restrictions on high-phosphate foods (like dairy, nuts, and dark sodas) and adherence to phosphate binder medications.

How to Approach the Question

First, identify the core concept of the question, which is the cause of hyperphosphatemia (high phosphate).
Recall the fundamental relationships between major electrolytes. The most important one here is the inverse relationship between calcium and phosphate.
Evaluate each option based on this principle: If calcium goes down, phosphate goes up. Therefore, hypocalcaemia is linked to hyperphosphatemia.
Consider the other options: Hypercalcemia would be linked to low phosphate (hypophosphatemia).
Eliminate options that have no direct regulatory link (Hypokalaemia) or only a transient effect (Hyperglycaemia).
Confirm the answer by thinking of clinical examples like chronic kidney disease or hypoparathyroidism, where hypocalcemia and hyperphosphatemia coexist.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 2 p. 1169-1171

E6 Medicine Davidson Principles Practice 24e p. 389-391