Acute Care Nurse Practitioner Acute Kidney Injury and Renal Replacement Therapy 1 — Questions and Answers
Question 1: According to KDIGO criteria, which finding defines Stage 1 AKI?
- Creatinine increase ≥0.3 mg/dL within 48 hours (Correct answer)
- Creatinine increase ≥2× baseline
- Urine output <0.3 mL/kg/hr for >24 hours
- GFR decrease >50%
Correct answer: Creatinine increase ≥0.3 mg/dL within 48 hours
KDIGO Stage 1 AKI = serum creatinine rise ≥0.3 mg/dL within 48 hours OR ≥1.5× baseline within 7 days OR UO <0.5 mL/kg/hr for >6 hours.
Question 2: Which of the following is the MOST common cause of AKI in the ICU?
- Glomerulonephritis
- Urinary obstruction
- Sepsis-associated AKI (Correct answer)
- Contrast nephropathy
Correct answer: Sepsis-associated AKI
Sepsis is the most common cause of AKI in critically ill patients, accounting for nearly 50% of ICU AKI cases.
Question 3: Which urinalysis finding MOST suggests intrinsic renal AKI (acute tubular necrosis)?
- Hyaline casts
- Muddy brown granular casts (Correct answer)
- RBC casts
- WBC casts with eosinophils
Correct answer: Muddy brown granular casts
Muddy brown granular casts are pathognomonic of acute tubular necrosis (ATN), the most common intrinsic renal cause of AKI.
Question 4: In pre-renal AKI, which urine chemistry finding is expected?
- FeNa <1%, urine osmolality >500 mOsm/kg (Correct answer)
- FeNa >2%, urine osmolality <350 mOsm/kg
- FeNa <1%, urine osmolality <300 mOsm/kg
- FeNa >3%, urine sodium <20 mEq/L
Correct answer: FeNa <1%, urine osmolality >500 mOsm/kg
Pre-renal AKI shows FeNa <1% (kidney avidly retains sodium) and concentrated urine >500 mOsm/kg (intact tubular function).
Question 5: Which nephrotoxic agent is MOST commonly implicated in ICU-acquired AKI?
- Loop diuretics
- Aminoglycosides (Correct answer)
- ACE inhibitors
- Beta-blockers
Correct answer: Aminoglycosides
Aminoglycosides cause direct proximal tubular toxicity and are among the most common nephrotoxic agents in ICU patients.
Question 6: An ACNP wants to contrast-enhance a CT scan in a patient with eGFR 28 mL/min. Which is the MOST evidence-based preventive strategy?
- Pre-treat with N-acetylcysteine
- Ensure adequate IV hydration with isotonic saline before/after (Correct answer)
- Use high-osmolar contrast media
- Administer furosemide pre-procedure
Correct answer: Ensure adequate IV hydration with isotonic saline before/after
IV isotonic saline hydration before and after contrast administration is the only consistently evidence-based preventive strategy for contrast-induced nephropathy.
Acute Care Nurse Practitioner Acute Kidney Injury and Renal Replacement Therapy 1
According to KDIGO criteria, which finding defines Stage 1 AKI?