A pilot in distress

Acute kidney injury in patients with chronic renal failure is a common scenario in clinical practice. In many cases, the cause is obvious, as in urinary tract infection, dehydration, use of non-steroidal anti-inflammatory drugs or recent therapeutic manipulation of the renin–angiotensin– aldosterone system. In some cases, however, the acute element can be more difficult to identify or remain elusive even after commencing dialysis. We present the case of a 77-year-old retired small-aircraft pilot with chronic renal failure, who returned from holidays with an acute, substantial and entirely unexplained deterioration in renal function. It was a tortuous journey, until we finally deciphered the underlying cause and avoided imminent dialysis. We discuss the presumed underlying mechanism and implications for the management of acute kidney injury in patients with pre-existing chronic renal failure.