Pediatric CCRN Exam Pediatric CCRN Renal 1 — Questions and Answers
Question 1: According to KDIGO criteria, which urine output threshold defines oliguria and indicates acute kidney injury (AKI) in a pediatric patient?
- < 0.3 mL/kg/hr for 6 hours
- < 0.5 mL/kg/hr for 6 hours (Correct answer)
- < 1 mL/kg/hr for 4 hours
- < 2 mL/kg/hr for 8 hours
Correct answer: < 0.5 mL/kg/hr for 6 hours
KDIGO criteria define oliguria as urine output < 0.5 mL/kg/hr for 6 or more consecutive hours, which is a diagnostic criterion for AKI staging.
Question 2: A 4-year-old presents with bloody diarrhea, thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury. What is the most likely diagnosis?
- Nephrotic syndrome
- Henoch-Schönlein purpura
- Hemolytic uremic syndrome (Correct answer)
- Acute glomerulonephritis
Correct answer: Hemolytic uremic syndrome
The classic triad of microangiopathic hemolytic anemia, thrombocytopenia, and AKI following bloody diarrhea is the hallmark presentation of hemolytic uremic syndrome (HUS).
Question 3: Which is the FIRST-LINE treatment for life-threatening hyperkalemia (K+ > 6.5 mEq/L with ECG changes) in a pediatric patient?
- Sodium bicarbonate IV
- Calcium gluconate IV (Correct answer)
- Sodium polystyrene sulfonate (Kayexalate)
- Furosemide IV
Correct answer: Calcium gluconate IV
Calcium gluconate is administered first in life-threatening hyperkalemia because it immediately stabilizes the cardiac membrane, reducing the risk of fatal arrhythmias.
Question 4: A 7-year-old with nephrotic syndrome has periorbital edema and a serum albumin of 1.5 g/dL. What is the PRIMARY pathophysiology of edema in nephrotic syndrome?
- Increased hydrostatic pressure
- Decreased plasma oncotic pressure (Correct answer)
- Lymphatic obstruction
- Sodium retention from SIADH
Correct answer: Decreased plasma oncotic pressure
Massive proteinuria leads to hypoalbuminemia, which reduces plasma oncotic pressure and allows fluid to leak into the interstitial space, causing edema.
Question 5: What is the correct maintenance fluid requirement for a 20 kg child using the Holliday-Segar method?
- 1,200 mL/day
- 1,400 mL/day
- 1,500 mL/day (Correct answer)
- 1,600 mL/day
Correct answer: 1,500 mL/day
Using the 100-50-20 rule: 100 mL/kg × 10 kg = 1,000 mL + 50 mL/kg × 10 kg = 500 mL, totaling 1,500 mL/day.
Question 6: In continuous renal replacement therapy (CRRT), which modality removes solutes through BOTH convection and diffusion?
- Continuous venovenous hemofiltration (CVVH)
- Continuous venovenous hemodialysis (CVVHD)
- Continuous venovenous hemodiafiltration (CVVHDF) (Correct answer)
- Slow continuous ultrafiltration (SCUF)
Correct answer: Continuous venovenous hemodiafiltration (CVVHDF)
CVVHDF combines convection (via ultrafiltration/hemofiltration) and diffusion (via dialysate), maximizing solute clearance across all molecular sizes.
Question 7: A child with AKI has a serum sodium of 122 mEq/L and is actively seizing. What is the most appropriate immediate intervention?
- Normal saline at maintenance rate
- 3% hypertonic saline bolus (Correct answer)
- Free water restriction only
- Furosemide with normal saline
Correct answer: 3% hypertonic saline bolus
Symptomatic severe hyponatremia with seizures requires urgent correction using 3% hypertonic saline to raise serum sodium by 1–2 mEq/L/hr until symptoms resolve.
Pediatric CCRN Exam Pediatric CCRN Renal 1
According to KDIGO criteria, which urine output threshold defines oliguria and indicates acute kidney injury (AKI) in a pediatric patient?