Acute tubular necrosis

Question 1

What is it?

Answer 1

Acute tubular necrosis is damage and death (necrosis) of the epithelial cells of the renal tubules. It is the most common cause of acute kidney injury. Damage to the kidney cells occurs due to ischaemia or toxins. The epithelial cells have the ability to regenerate making acute tubular necrosis reversible. It usually takes 7-21 days to recover.

Question 2

Causes

Answer 2

Ischaemia can occur secondary to hypoperfusion in:

Shock
Sepsis
Dehydration

Direct damage from toxins can occur due to:

Radiology contrast dye
Gentamycin
NSAIDs

Question 3

Urinalysis

Answer 3

“Muddy brown casts” found on urinalysis is a pathognomonic finding specific to acute tubular necrosis. There can also be renal tubular epithelial cells in the urine.

Question 4

Management

Answer 4

Treatment is the same as with other causes of an acute kidney injury:

Supportive management
IV fluids
Stop nephrotoxic medications
Treat complications