Making the diagnosis: Acute kidney injury (AKI) is a sudden fall in renal function and results in retention of uremic toxins and fluid, electrolyte, and acid-base imbalances. Classically AKI has been defined as a sudden (usually less than 1 week) increase in creatinine above the reference range, but because of the importance of obtaining an early diagnosis and the lack of sensitivity of creatinine in detecting a decline in GFR, more stringent criteria have been defined. AKI should be suspected in patients presenting with acute onset lethargy, anorexia, vomiting and diarrhoea regardless of their urine output. Critically ill and post-operative patients are at high risk and should monitored for AKI development. Physical exam findings often include dehydration and renal pain. Uremic halitosis, oral ulceration, hypothermia and bruising may also be present. The diagnosis is made based on an acute increase in creatinine and/or abrupt decline in urine output. Glucosuria (without hyperglycaemia), proteinuria, pyruria, microscopic haematuria and granular casts may be detected in on urinalysis. Further investigations should include a complete blood count, full biochemistry profile, urine culture, abdominal imaging and acid-base measurement (if possible). Other tests for underlying causes such as Leptospirosis, ethylene glycol toxicity and Lyme disease may be indicated.

Managing the patient: Acute kidney injury (AKI) is the rapid loss of kidney function leading to the accumulation of nitrogenous waste. AKI is potentially reversible either by resolution of the injury or by adaptation of the kidney or by both mechanisms. Management of the patient includes: correcting hypoperfusion, to the kidney, closely monitoring fluids ins and outs and adjusting intravenous fluid therapy as required, treating infections, such as pyelonephritis, leptospirosis and Lyme disease and alleviating blockages or repairing ruptures to the urinary tract. The holistic needs of the patient should be met: padded bedding in a warm, clean stress-free environment; time to rest and sleep; recumbency changed every four hours; water should be freely available, fresh and easily accessible; clinical examination at least twice a day; pain scores every four hours or as required; intravenous catheter care; consider a jugular catheter to facilitate fluid therapy and blood sampling; frequent toileting opportunity as likely high rates of fluid therapy. A urinary catheter would allow monitoring of urine output, oral hygiene, patients may develop painful ulcers on their tongue and oral mucosa. Suitable nutrition to meet the patients RER, a feeding tube should be considered.