Acute Kidney Injury Flashcards
Hyperuricemia, apart from being associated with a history of gout, is also associated with these cancers
Lymphomas/ALL
Bad cancers with high cell turnover
Three definition criteria of acute kidney injury
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
Octreotide and midodrine are drugs used in this type of acute kidney injury
Hepatorenal syndrome
Octreotide = vasoconstrictor
Midodrine = ionotrope
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
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
How to prevent and treat hyperuricemia in patients undergoing chemotherapy
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)
Most common form of acute kidney injury and the corresponding BUN:Cr ratio
Pre-renal azotemia (low renal perfusion)
High BUN:Cr >20
Most convenient imaging method to differentiate acute from chronic renal disease
Renal ultrasound
(normal size in acute, shrunken in chronic)
Fractional excretion of sodium in the following causes of acute kidney injury:
- Pre-renal
- Intrinsic
- Post-renal
Pre-renal - <1%
Intrinsic - 1-4%
Post-renal - >4%
Urine output levels for anuria and oliguria
Anuria = <50 mL/day
Oliguria = <400 mL/day
Three causes of post-renal acute kidney injury
Obstructions:
BPH - most common cause in adults
Bladder stone
Bilateral ureter obstruction
Treatment for hemolytic uremic syndrome
Plasma exchange
Which casts are present in urinalysis with a patient who has prerenal acute kidney injury
Hyaline and granular casts
(hyaline casts are not pathognomonic for anything)
Five medications (three are groups) that can cause acute kidney injury
Aminoglycosides (cause ATN)
Amphotericin B
NSAIDs
Cisplatin
ACE inhibitors (if patient had pre-existing bilateral renal artery stenosis)
EKG changes in hyperkalemia
Peaked T-waves
Prolonged PR interval
Widened QRS
Community acquired acute kidney injury most commonly presents in the elderly. What symptoms might an old person with acute kidney injury present with?
Altered mental status
Seizures
History of muscle trauma from falling (rhabdomyolysis)
Expected response to fluid repletion (fluid challenge) in both pre-renal acute kidney injury and acute kidney injury caused by acute tubular necrosis
Pre-renal - fluid corrects hypotension, Cr returns to baseline after 1-3 days
ATN - AKI persists despite added fluids
Hepatorenal syndrome resembles prerenal azotemia but can be differentiated with this test
Fluid challenge
Hepatorenal syndrome does not improve with fluids
Prerenal would improve with fluids
The most common acute kidney injury type in pregnancy
HELLP (Hemolysis, Elevated Liver enzymes, Low Platelets)
(Preeclampsia is important though too)
In a patient with acute kidney injury, crystals are seen on urine microscopy. Your next step to find the cause might be …
Imaging (KUB or US) to look for stone causing post-renal blockage
Breathing type associated with metabolic acidosis
Kussmaul breathing
(deep and rapid)
Most common cause of death in patients with acute kidney injury
Hyperkalemia
The breakdown of muscle (rhabdomyolysis) can lead to muscle pain/weakness and dark-brown urine. What is the most important treatment for these patients?
Hydrate to flush out the waste products
Use normal saline or D5W
Indications for dialysis
Severe hyperkalemia and/or uncontrolled acidosis
Fluid overload unresponsive to fluid restriction and/or diuretics
Pericardial friction rub, asterixis, mental changes, seizures
Three causes of intrinsic acute kidney injury and which one is most common?
Acute tubular necrosis - most common
Acute glomerulonephritis
Acute interstitial nephritis
Why is radiocontrast damaging to the kidneys and how to prevent damage?
Radiocontrast constricts vessels, toxic to tubule cells
Prevent with IV fluid before/after contrast
Treatments (2) for a patient who drank ethylene glycol (antifreeze)
Aggressive IV sodium bicarbonate or fomepizole (Antizol)
Hemodialysis
Serum creatinine and urine output criteria for each of the three KDIGO stages for acute kidney injury
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
Ingestion of this household item produces a high anion gap metabolic acidosis, calcium oxalate crystals in the urine and acute kidney injury
Ethylene glycol (antifreeze)
Describe the expected urinalysis findings in a patient with acute interstitial nephritis
WBC casts/clumps but no bacteria (sterile pyuria)
Protein present also
