Grade	Serum creatinine criteria	Urine output criteria
1	Increase ≥ 26 μmol/L within 48hrs or increase  ≥1.5 to 1.9 times reference creatinine	<0.5 mL/kg/hr for > 6 consecutive hrs
2	Increase ≥ 2 to 2.9 times reference creatinine	<0.5 mL/kg/ hr for > 12 hrs

 

Acute Kidney Injury (AKI) is most frequently caused by ischaemia, sepsis or nephrotoxic insults to the kidney. In patients with hospital-acquired AKI the cause is frequently multi-factorial in patients with multiple risk factors*.

Acute kidney injury is common in hospitalised patients and also has a poor prognosis with the mortality ranging from 10%-80% dependent upon the patient population studied. If renal replacement therapy is required the mortality rate rises further to as high as 80%.

 

Overview of Management

 

1. Identify and aggressively treat infections as per hospital antibiotics guidelines

2. If pre-renal AKI without fluid overload administer intravenous fluids, omit nephrotoxic drugs: NSAIDs, anti-HTN drugs, ACEi, AT2 receptor blockers, Furosemide, Spironolactone, Gentamicin, adjust doses and drug levels where appropriate

3. Identify and treat acute complications (hyperkalaemia, acidosis, pulmonary oedema)

4. Physiological surveillance / EWS should be performed for all patients with AKI to identify early signs of physiological deterioration which may require escalation in the level of care

5. Monitor urine output / fluid balance status

6. Patients identified as being at risk of contrast-induced AKI, should have careful assessment of volume status and receive pre-procedure volume expansion with intravenous fluids when appropriate

7. Arrange urgent renal ultrasound to exclude obstruction within 24 hours of admission

8. Perform urine dipstick: if positive for blood and protein contact on-call renal team

9. Arrange repeat renal bloods

 

Risk factors for developing AKI include:

 

• Age > 75 yrs
• Chronic kidney disease (CKD, eGFR < 60 mls/min/1.73m2)
• Cardiac failure
• Atherosclerotic peripheral vascular disease
• Liver disease
• Diabetes mellitus
• Nephrotoxic medication
• Hypovolaemia
• Sepsis