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Renal CCRN Practice Questions

10 free CCRN-style renal practice questions with full rationales. Perfect for last-minute review or rapid drilling on high-yield concepts.

Question Index

  1. Q1: A patient has oliguria, BUN 45, Cr 2.1, BUN:Cr ratio of 21:1, FENa 0.5%, and uri…
  2. Q2: Which electrolyte abnormality is the HALLMARK of refeeding syndrome?
  3. Q3: Indications for emergent dialysis include all EXCEPT:
  4. Q4: The FIRST intervention for severe hyperkalemia with ECG changes is:
  5. Q5: Muddy brown casts on urinalysis are MOST consistent with:
  6. Q6: When correcting hyponatremia, the maximum rate of sodium correction should be:
  7. Q7: CRRT (Continuous Renal Replacement Therapy) is preferred over intermittent hemod…
  8. Q8: Chvostek and Trousseau signs indicate:
  9. Q9: Post-obstructive diuresis occurs after relieving urinary obstruction. The nurse …
  10. Q10: Urine Specific Gravity 1.001 vs 1.030. What do these readings indicate?
Question 1

A patient has oliguria, BUN 45, Cr 2.1, BUN:Cr ratio of 21:1, FENa 0.5%, and urine Na of 8. This is MOST consistent with:

  1. Acute tubular necrosis
  2. Pre-renal azotemia
  3. Post-renal obstruction
  4. Acute interstitial nephritis

Correct Answer: B. Pre-renal azotemia

Rationale: This is classic pre-renal AKI: BUN:Cr >20:1, FENa <1%, Urine Na <20. The kidneys are responding appropriately to decreased perfusion by retaining sodium and water. In ATN, FENa would be >2% and urine Na >40 due to tubular damage. Treatment focuses on restoring renal perfusion.
Question 2

Which electrolyte abnormality is the HALLMARK of refeeding syndrome?

  1. Hyponatremia
  2. Hypophosphatemia
  3. Hyperkalemia
  4. Hypercalcemia

Correct Answer: B. Hypophosphatemia

Rationale: Hypophosphatemia is the hallmark of refeeding syndrome. When malnourished patients are refed, insulin surge drives phosphorus (along with potassium and magnesium) intracellularly. Severe hypophosphatemia can cause respiratory failure, cardiac arrhythmias, and death. Prevention: slow refeeding, thiamine before feeding, monitor and replace electrolytes.
Question 3

Indications for emergent dialysis include all EXCEPT:

  1. Refractory hyperkalemia
  2. Severe metabolic acidosis
  3. Uremic pericarditis
  4. BUN of 60 mg/dL

Correct Answer: D. BUN of 60 mg/dL

Rationale: The mnemonic AEIOU covers urgent dialysis indications: Acidosis (refractory), Electrolytes (hyperkalemia), Intoxication (dialyzable toxins), Overload (fluid), Uremia (symptomatic - encephalopathy, pericarditis, bleeding). An elevated BUN alone, without symptoms, is not an emergent indication. Clinical symptoms matter more than absolute numbers.
Question 4

The FIRST intervention for severe hyperkalemia with ECG changes is:

  1. IV insulin with glucose
  2. IV calcium gluconate
  3. Albuterol nebulizer
  4. Kayexalate

Correct Answer: B. IV calcium gluconate

Rationale: IV calcium gluconate is the FIRST intervention because it stabilizes the cardiac membrane without changing potassium levels. This protects against fatal arrhythmias while other treatments work. Then give insulin/glucose and albuterol (shift K intracellularly), followed by kayexalate or dialysis (actually remove K from body).
Question 5

Muddy brown casts on urinalysis are MOST consistent with:

  1. Pre-renal azotemia
  2. Acute tubular necrosis
  3. Glomerulonephritis
  4. Urinary tract infection

Correct Answer: B. Acute tubular necrosis

Rationale: Muddy brown granular casts are the hallmark finding of Acute Tubular Necrosis (ATN). They consist of sloughed tubular epithelial cells. RBC casts suggest glomerulonephritis. WBC casts suggest pyelonephritis or interstitial nephritis. Pre-renal AKI typically has bland urine sediment.
Question 6

When correcting hyponatremia, the maximum rate of sodium correction should be:

  1. 1-2 mEq/L per hour
  2. 4-6 mEq/L per 24 hours
  3. 8-10 mEq/L per 24 hours
  4. 15-20 mEq/L per 24 hours

Correct Answer: C. 8-10 mEq/L per 24 hours

Rationale: Maximum sodium correction is 8-10 mEq/L per 24 hours to avoid osmotic demyelination syndrome (ODS). Rapid correction causes brain cells to shrink as water shifts out, damaging myelin. ODS causes quadriplegia, pseudobulbar palsy, and can be fatal. "Low and slow" is the mantra for chronic hyponatremia correction.
Question 7

CRRT (Continuous Renal Replacement Therapy) is preferred over intermittent hemodialysis in which patient population?

  1. Stable outpatients
  2. Patients with chronic kidney disease
  3. Hemodynamically unstable ICU patients
  4. Patients with adequate IV access

Correct Answer: C. Hemodynamically unstable ICU patients

Rationale: CRRT is preferred for hemodynamically unstable ICU patients because it removes fluid and solutes gradually over 24 hours, causing less cardiovascular stress than intermittent HD. Intermittent HD removes large volumes rapidly, which can cause hypotension in unstable patients. CRRT modes include CVVH, CVVHD, and CVVHDF.
Question 8

Chvostek and Trousseau signs indicate:

  1. Hypercalcemia
  2. Hypocalcemia
  3. Hypermagnesemia
  4. Hypokalemia

Correct Answer: B. Hypocalcemia

Rationale: Chvostek sign (facial twitching with tapping) and Trousseau sign (carpopedal spasm with BP cuff inflation) indicate hypocalcemia. Low calcium causes increased neuromuscular excitability. Other signs include tetany, laryngospasm, and prolonged QT. Treatment is IV calcium gluconate for symptomatic patients.
Question 9

Post-obstructive diuresis occurs after relieving urinary obstruction. The nurse should monitor for:

  1. Fluid overload and hypertension
  2. Hypovolemia and electrolyte imbalances
  3. Oliguria and rising creatinine
  4. Pulmonary edema

Correct Answer: B. Hypovolemia and electrolyte imbalances

Rationale: Post-obstructive diuresis can produce massive urine output (up to several liters/day) leading to hypovolemia and electrolyte disturbances (hyponatremia, hypokalemia). Monitor I&O closely, replace fluids appropriately (usually 0.5x output), and check electrolytes frequently. This typically resolves in 24-48 hours.
Question 10

Urine Specific Gravity 1.001 vs 1.030. What do these readings indicate?

  1. 1.001 = SIADH; 1.030 = Diabetes Insipidus
  2. 1.001 = Diabetes Insipidus; 1.030 = SIADH
  3. Both indicate Diabetes Insipidus
  4. Both indicate SIADH

Correct Answer: B. 1.001 = Diabetes Insipidus; 1.030 = SIADH

Rationale: DI is "Dry Inside" (dumping dilute urine). SIADH is "Soaked Inside" (holding water, concentrated urine).

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