24th June 2024

Causes of AKI

A basic way of categorising AKI is based on whether the underlying pathology is pre-renal, renal or post-renal. Pre- and post-renal are the most common causes, while renal causes tend to be the most complex.

Pre-Renal

• Absolute decrease in effective blood volume: haemorrhage or volume depletion
• Relative decrease in effective blood volume: cardiac failure, sepsis, decompensated liver disease
• Arterial stenosis or occlusion of renal artery
• Vasomotor: secondary to drugs such as non-steroidal anti-inflammatories, ACE-inhibitors or angiotensin receptor blockers

Intrinsic Renal

• Vasculitic: this may be due to vasculitis, thrombotic microangiopathies or malignant hypertension
• Acute glomerulonephritis
• Acute interstitial nephritis which may be drug associated
• Acute tubular necrosis. This may be ischaemic, secondary to drugs, as well as contrast agents. It may also be secondary to haemoglobinuria, myoglobinuria, myeloma casts or Intratubular crystals Post-Renal
• Bladder outlet obstruction
• Bilateral ureteral obstruction