Internal Medicine Acute Kidney Injury Questions and Answers

Question 1

A 75-year-old man with heart failure is admitted with decompensation and treated aggressively with intravenous furosemide.
His baseline creatinine was 1.2 mg/dL.
On day 3, his creatinine is 2.5 mg/dL and his urine output is low.
His blood pressure is 105/65 mmHg.
Which set of urine findings is most consistent with pre-renal azotemia from over-diuresis?

Accepted Answer

Urine Sodium < 20 mEq/L, FeNa < 1%, bland sediment

Answer

Urine Sodium > 40 mEq/L, FeNa > 2%, muddy brown casts

Answer

Red blood cell casts, proteinuria > 1 g/day

Answer

White blood cell casts, urine eosinophils > 5%

Question 2

A 45-year-old male is found down after a reported seizure. He is confused with diffuse muscle tenderness. His creatinine is 2.1 mg/dL, and a urine dipstick is strongly positive for blood but microscopic analysis shows 0-2 RBCs/hpf. His creatine kinase (CK) level is 45,000 U/L. What is the most critical initial step in managing his acute kidney injury?

Accepted Answer

Aggressive intravenous fluid resuscitation with isotonic saline

Answer

Administration of sodium bicarbonate to alkalinize the urine

Answer

Urgent hemodialysis

Answer

Administration of N-acetylcysteine

Question 3

A 68-year-old male with a baseline creatinine of 1.8 mg/dL and diabetes mellitus is scheduled for a cardiac catheterization requiring intra-arterial contrast. Which of the following interventions has the strongest evidence for preventing contrast-induced acute kidney injury (CI-AKI)?

Accepted Answer

Intravenous isotonic saline infusion before and after the procedure

Answer

Oral N-acetylcysteine 24 hours before and on the day of the procedure

Answer

Intravenous sodium bicarbonate infusion

Answer

A single dose of intravenous furosemide immediately after the procedure

Question 4

A 58-year-old male with decompensated alcoholic cirrhosis and ascites is hospitalized. His baseline creatinine of 0.9 mg/dL has risen to 2.5 mg/dL over two days. He is not in shock, has not received nephrotoxic drugs, and a renal ultrasound is normal. Urine sodium is < 10 mEq/L. After a 2-day trial of diuretic cessation and volume expansion with 1 g/kg of albumin, his creatinine does not improve. Which of the following is the most appropriate next step in management?

Accepted Answer

Administration of midodrine, octreotide, and continued albumin

Answer

Initiation of broad-spectrum antibiotics for presumed SBP

Answer

Placement of a transjugular intrahepatic portosystemic shunt (TIPS)

Answer

Urgent renal replacement therapy

Question 5

A 62-year-old female with severe acute kidney injury (creatinine 6.8 mg/dL) secondary to sepsis is being managed in the ICU. Which of the following findings is the most urgent indication for initiating renal replacement therapy?

Accepted Answer

Pericardial friction rub on auscultation

Answer

Blood urea nitrogen (BUN) of 110 mg/dL

Answer

Serum potassium of 6.3 mEq/L, refractory to medical therapy

Answer

Serum bicarbonate of 16 mEq/L

Question 6

A 70-year-old male was started on omeprazole and piperacillin-tazobactam one week ago for aspiration pneumonia. He now presents with a new-onset maculopapular rash, a temperature of 38.5°C (101.3°F), and a rise in his serum creatinine from a baseline of 1.1 mg/dL to 3.0 mg/dL. Urinalysis is most likely to show which of the following findings?

Accepted Answer

White blood cell casts and sterile pyuria

Answer

Muddy brown granular casts

Answer

Hyaline casts and a fractional excretion of sodium <1%

Answer

Red blood cell casts and dysmorphic RBCs