CSR Electrolyte Management in Renal Disease

Question 1

A hemodialysis patient presents with a pre-dialysis serum potassium of 7.0 mEq/L and ECG changes (peaked T waves, widened QRS). Which food should be IMMEDIATELY eliminated from the diet?

Accepted Answer

Bananas, oranges, potatoes, and tomatoes

Answer

Bananas, oranges, potatoes, and tomatoes are among the highest-potassium foods. At K+ 7.0 mEq/L with ECG changes (life-threatening), eliminating these high-potassium foods immediately is critical, though medical management (IV calcium, insulin/glucose) takes priority.

Question 2

In managing dietary phosphorus in CKD, which type of dietary phosphorus has the LOWEST bioavailability and is therefore least harmful?

Accepted Answer

Organic phosphate from plant sources bound to phytate

Answer

Plant-derived phytate-bound phosphorus has the lowest bioavailability (~20–40%) because humans lack intestinal phytase to cleave phytate. Animal-source phosphorus is 40–60% bioavailable, while inorganic phosphate additives are nearly 100% bioavailable.

Question 3

A peritoneal dialysis patient has persistent hypomagnesemia (Mg 1.4 mEq/L). Which dietary counseling is appropriate?

Accepted Answer

Encourage adequate intake of magnesium-rich foods (nuts, seeds, legumes, whole grains) and consider oral magnesium supplementation after physician review

Answer

PD patients can lose magnesium into dialysate, and dietary restriction of magnesium-rich foods (often also high in potassium/phosphorus) can cause hypomagnesemia. Low magnesium increases risk of cardiac arrhythmias, insulin resistance, and cardiovascular events in CKD.

Question 4

Which clinical condition is MOST associated with hyponatremia in CKD patients and is directly managed through fluid restriction?

Accepted Answer

Dilutional hyponatremia from fluid overload and impaired free water excretion

Answer

In advanced CKD and dialysis patients, impaired free water excretion leads to dilutional hyponatremia when fluid intake exceeds excretory capacity. Fluid restriction (not sodium supplementation) is the primary treatment.

Question 5

The dialysis patient's 'dry weight' is a critical parameter in managing fluid and sodium balance. How is dry weight BEST defined?

Accepted Answer

The lowest weight a patient can tolerate at the end of dialysis without symptoms of hypotension or cramping, representing euvolemic status

Answer

Dry weight (target weight or euvolemic weight) is the post-dialysis weight at which the patient is as close to euvolemia as possible — neither fluid-overloaded nor fluid-depleted — determined clinically by blood pressure, absence of edema, and absence of hypotension/cramping during UF.

(CSR) Board Certified Specialist in Renal Nutrition Practice Test

(CSR) Board Certified Specialist in Renal Nutrition Practice Test

CSR Electrolyte Management in Renal Disease