CT scan is non-contrast; however, there is:

right-sided retroperitoneal blood evident

an abdominal aortic aneurysm

It is important to remember that the commonest cause of the ‘classic’ presentation of renal colic amongst patients presenting to have a post-mortem is ruptured abdominal aortic aneurysm.

This patient needs an emergency AAA repair.

Biochemistry demonstrates acute renal failure with a reduced urea-to-creatinine ratio.

The likely diagnosis is rhabomyolysis in this clinical context.

Features suggestive of this diagnosis are:

increased urea and creatinine with a reduced urea-to-creatinine ratio

hyperphosphataemia, hypocalcaemia, hyperkalaemia

metabolic acidosis

increased CK (usually to greater than 40,000)

Although not measured here, AST, and LDH are also increased in rhabdomyolysis

Other potential causes:

hypovolaemia from bleeding

renal artery occlusion during operation

use of contrast in pre-operative CT scan (not in this case)

use of nephrotoxic drugs like gentamicin

low cardiac output from peri-operative myocardial infarction

abdominal compartment syndrome