Pediatric CCRN Exam Pediatric CCRN Renal 2 — Questions and Answers
Question 1: When calculating percent fluid overload in a PICU patient, which formula is correct?
- (Current weight − admission weight) / current weight × 100
- (Current weight − admission weight) / admission weight × 100 (Correct answer)
- (Fluid in − fluid out) / body surface area × 100
- (Current weight − dry weight) / ideal body weight × 100
Correct answer: (Current weight − admission weight) / admission weight × 100
Percent fluid overload = (current weight − admission weight) / admission weight × 100, using the admission weight as the baseline denominator.
Question 2: A 10-year-old with rhabdomyolysis is at high risk for AKI. Which intervention is MOST important to prevent renal tubular damage?
- Administering nephrotoxic antibiotics prophylactically
- Aggressive IV fluid resuscitation targeting urine output ≥ 3 mL/kg/hr (Correct answer)
- Restricting fluid to prevent fluid overload
- Early initiation of peritoneal dialysis
Correct answer: Aggressive IV fluid resuscitation targeting urine output ≥ 3 mL/kg/hr
Aggressive IV hydration dilutes myoglobin and maintains high urine output, flushing nephrotoxic myoglobin from renal tubules before it can cause tubular necrosis.
Question 3: Which electrolyte profile is the hallmark of tumor lysis syndrome in pediatric oncology patients?
- Hypocalcemia, hyperphosphatemia, hyperkalemia, and hyperuricemia (Correct answer)
- Hypercalcemia, hypophosphatemia, hypokalemia, and hypouricemia
- Hypernatremia, hypochloremia, and hypomagnesemia
- Hypocalcemia, hypokalemia, and hyponatremia
Correct answer: Hypocalcemia, hyperphosphatemia, hyperkalemia, and hyperuricemia
Tumor lysis syndrome results from rapid cell death releasing intracellular contents, causing hyperkalemia, hyperphosphatemia, hyperuricemia, and secondary hypocalcemia.
Question 4: Which laboratory finding would BEST suggest a pre-renal cause (rather than intrinsic renal) of AKI in a child?
- FeNa > 2%, urine sodium > 40 mEq/L
- FeNa < 1%, urine sodium < 20 mEq/L (Correct answer)
- BUN:creatinine ratio < 10
- Urine specific gravity < 1.010
Correct answer: FeNa < 1%, urine sodium < 20 mEq/L
In pre-renal AKI, intact tubular function allows the kidney to avidly retain sodium (urine Na < 20 mEq/L) and concentrate urine (FeNa < 1%) in response to decreased perfusion.
Question 5: A pediatric patient develops sudden headache, nausea, vomiting, and altered mental status during hemodialysis. What complication is most likely?
- Air embolism
- Dialysis disequilibrium syndrome (Correct answer)
- Dialysis-associated hypercalcemia
- Dialyzer membrane reaction
Correct answer: Dialysis disequilibrium syndrome
Dialysis disequilibrium syndrome results from rapid osmolality shifts causing cerebral edema, occurring most often in new or high-BUN patients undergoing their first dialysis sessions.
Question 6: Which acid-base disturbance progression is most commonly observed as chronic kidney disease (CKD) advances in children?
- Respiratory alkalosis progressing to metabolic alkalosis
- Metabolic alkalosis throughout all stages
- Non-anion gap metabolic acidosis progressing to elevated anion gap metabolic acidosis (Correct answer)
- Respiratory acidosis progressing to metabolic acidosis
Correct answer: Non-anion gap metabolic acidosis progressing to elevated anion gap metabolic acidosis
Early CKD causes non-anion gap metabolic acidosis from bicarbonate wasting; as GFR falls further, uremic acid retention elevates the anion gap.
Question 7: Which mode of renal replacement therapy provides the GREATEST hemodynamic stability for critically ill pediatric patients?
- Intermittent hemodialysis (IHD)
- Sustained low-efficiency dialysis (SLED)
- Peritoneal dialysis
- Continuous venovenous hemofiltration (CVVH) (Correct answer)
Correct answer: Continuous venovenous hemofiltration (CVVH)
CVVH removes fluid and solutes slowly and continuously, avoiding the rapid osmolality and volume shifts of intermittent dialysis that can cause hemodynamic instability.
Pediatric CCRN Exam Pediatric CCRN Renal 2
When calculating percent fluid overload in a PICU patient, which formula is correct?