Acute Kidney Injury

Question 1

Hyperuricemia, apart from being associated with a history of gout, is also associated with these cancers

Answer 1

Lymphomas/ALL

Bad cancers with high cell turnover

Question 2

Three definition criteria of acute kidney injury

Answer 2

Increase in SCr by 0.3 mg/dL in 48 hours
OR
Increase in SCr to 1.5x baseline in 7 days
OR
Urine volume <0.5mL/kg/hour for six hours

Question 3

Octreotide and midodrine are drugs used in this type of acute kidney injury

Answer 3

Hepatorenal syndrome

Octreotide = vasoconstrictor
Midodrine = ionotrope

Question 4

In acute kidney injury, which type of IV treatment is most appropriate for patients who also have:
1.) Cirrhosis
2.) Heart failure
3.) No CHF or Cirrhosis
4.) AIN or glomerulonephritis

Answer 4

1.) Cirrhosis - IV albumin
2.) Heart failure - IV diuretics
3.) No CHF or Cirrhosis - assess response to IV fluid challenge
4.) AIN or glomerulonephritis - IV steroids

Question 5

How to prevent and treat hyperuricemia in patients undergoing chemotherapy

Answer 5

Prevent: Increase urine output to 3-5L/day and start allopurinol before chemo

Treat: IV sodium bicarbonate to alkalinize urine and acetazolamide (to inhibit resorption of sodium bicarb in proximal tubule so it alkalinizes the urine)

Question 6

Most common form of acute kidney injury and the corresponding BUN:Cr ratio

Answer 6

Pre-renal azotemia (low renal perfusion)

High BUN:Cr >20

Question 7

Most convenient imaging method to differentiate acute from chronic renal disease

Answer 7

Renal ultrasound

(normal size in acute, shrunken in chronic)

Question 8

Fractional excretion of sodium in the following causes of acute kidney injury:
- Pre-renal
- Intrinsic
- Post-renal

Answer 8

Pre-renal - <1%
Intrinsic - 1-4%
Post-renal - >4%

Question 9

Urine output levels for anuria and oliguria

Answer 9

Anuria = <50 mL/day

Oliguria = <400 mL/day

Question 10

Three causes of post-renal acute kidney injury

Answer 10

Obstructions:
BPH - most common cause in adults
Bladder stone
Bilateral ureter obstruction

Question 11

Treatment for hemolytic uremic syndrome

Answer 11

Plasma exchange

Question 12

Which casts are present in urinalysis with a patient who has prerenal acute kidney injury

Answer 12

Hyaline and granular casts

(hyaline casts are not pathognomonic for anything)

Question 13

Five medications (three are groups) that can cause acute kidney injury

Answer 13

Aminoglycosides (cause ATN)

Amphotericin B

NSAIDs

Cisplatin

ACE inhibitors (if patient had pre-existing bilateral renal artery stenosis)

Question 14

EKG changes in hyperkalemia

Answer 14

Peaked T-waves

Prolonged PR interval

Widened QRS

Question 15

Community acquired acute kidney injury most commonly presents in the elderly. What symptoms might an old person with acute kidney injury present with?

Answer 15

Altered mental status

Seizures

History of muscle trauma from falling (rhabdomyolysis)

Question 16

Expected response to fluid repletion (fluid challenge) in both pre-renal acute kidney injury and acute kidney injury caused by acute tubular necrosis

Answer 16

Pre-renal - fluid corrects hypotension, Cr returns to baseline after 1-3 days

ATN - AKI persists despite added fluids

Question 17

Hepatorenal syndrome resembles prerenal azotemia but can be differentiated with this test

Answer 17

Fluid challenge

Hepatorenal syndrome does not improve with fluids

Prerenal would improve with fluids

Question 18

The most common acute kidney injury type in pregnancy

Answer 18

HELLP (Hemolysis, Elevated Liver enzymes, Low Platelets)

(Preeclampsia is important though too)

Question 19

In a patient with acute kidney injury, crystals are seen on urine microscopy. Your next step to find the cause might be …

Answer 19

Imaging (KUB or US) to look for stone causing post-renal blockage

Question 20

Breathing type associated with metabolic acidosis

Answer 20

Kussmaul breathing

(deep and rapid)

Question 21

Most common cause of death in patients with acute kidney injury

Answer 21

Hyperkalemia

Question 22

The breakdown of muscle (rhabdomyolysis) can lead to muscle pain/weakness and dark-brown urine. What is the most important treatment for these patients?

Answer 22

Hydrate to flush out the waste products

Use normal saline or D5W

Question 23

Indications for dialysis

Answer 23

Severe hyperkalemia and/or uncontrolled acidosis

Fluid overload unresponsive to fluid restriction and/or diuretics

Pericardial friction rub, asterixis, mental changes, seizures

Question 24

Three causes of intrinsic acute kidney injury and which one is most common?

Answer 24

Acute tubular necrosis - most common

Acute glomerulonephritis

Acute interstitial nephritis

Question 25

Why is radiocontrast damaging to the kidneys and how to prevent damage?

Answer 25

Radiocontrast constricts vessels, toxic to tubule cells Prevent with IV fluid before/after contrast

Question 26

Treatments (2) for a patient who drank ethylene glycol (antifreeze)

Answer 26

Aggressive IV sodium bicarbonate or fomepizole (Antizol) Hemodialysis

Question 27

Serum creatinine and urine output criteria for each of the three KDIGO stages for acute kidney injury

Answer 27

1.) SCr 1.5-1.9x baseline OR >0.3mg/dL in 48hr Urine <0.5mL/kg/hr for 6-12 hr 2.) SCr 2-2.9x baseline Urine <0.5mL/kg/hr for >12hr 3.) SCr >3x baseline OR >4.0mg/dL OR initiation of dialysis Urine <0.3mL/kg/hr for >24hr OR anuria for >12hr

Question 28

Ingestion of this household item produces a high anion gap metabolic acidosis, calcium oxalate crystals in the urine and acute kidney injury

Answer 28

Ethylene glycol (antifreeze)

Question 29

Describe the expected urinalysis findings in a patient with acute interstitial nephritis

Answer 29

WBC casts/clumps but *no* bacteria (sterile pyuria) Protein present also