AKI – Acute Kidney Injury

AKI is a common issue for patients presenting to the ED and  not only has a significant mortality associated with it but also a massive cost to the NHS. Early recognition and treatment can improve outcomes.


  • Nausea/Vomiting
  • Diarrhoea
  • Dehydration
  • Reduced urine output
  • Confusion/Drowsiness

At Risk Groups

  • >65yrs old
  • PMH: CKD, Liver, Cardiac, Diabetes
  • Unable to maintain hydration
  • Urinary Tract Obstruction
  • Medication: ACEi, ARBs, NSAIDs, Diuretics

We should be looking for AKI by doing U&E on any patient we suspect a potential AKI

KDIGO Staging

STAGECreatinineUrine Output
1>1.5-1.9 x baseline (7-day) OR
26.5 μmol/l increase (48hr)
<0.5ml/kg/hr for 6-12hr
2>2.0-2.9 x baseline
<0.5ml/kg/hr >12hr
3>3.0 x baseline OR
Increase to >354 μmol/l OR
Renal Replacement
<0.3ml/kg/hr >24hr
Anuria >12hr


AKI Stage 3 – Ensure Blood Gas completed
  • Assess fluid status
  • Urea:Creatinine Ratio
    • >100 indicates dehydration (OR UGIB)
    • Remember: Ur is mmol/l and Cr μmol/l so devide Cr by 1000
    • (i.e. Ur 6.5:Cr 180 = 6.5/0.18 = 36.1)
  • IV fluid often required
  • Consider stopping causative drugs
    • ACEi or ARBs, Diuretics, NSAIDs
  • Consider dose reduction
    • opiates, gabapentin and pregabalin
    • metformin, SGLT2/DPP-4 (lizard spit 4 diabetes)
    • antibiotics (eg penicillins, gentamicin, vancomycin, teicoplanin)
    • anticoagulants
    • digoxin
  • Consider need for Catheter (obstruction or monitoring)
    • Avoid if possible (sig, risk of uro-sepsis, which caries a mortality of 10%)
  • Consider Imaging e.g. CTKUB for obstructing stone (normally doneas an inpatient)


  • Common cause of AKI
  • Antibiotics <1hr
  • 500ml fluid bolus
  • Also: Appropriate Cultures, Lactate

Significant Complications

  • Hyperkalaemia
  • Acidosis – may need advice from Leeds nephrology for bicarb
  • Pulmonary Oedema – early senior involvement


Stage 1(without complication)
  • Likely Home
  • Repeat U&E <72hr (via GP)
Stage 2 or 3, Stage 1(with complication)
  • Admission to parent specialty or ICU
  • Consider Referral to Leeds Nephrology – Stage 3 + any of
    • Significant Acidosis (pH<7.15)
    • Hyperkalaemia ([K] >6.0)
    • Uraemic
    • Urgent Dialysis


Must be agreed with nephrology and bed allocated. The following parameters must be achieved unless explicitly agreed with nephrology and appropriate steps taken

  • Haemodynamically stable
  • pH >7.2
  • [K] <6.5 & no ECG changes
  • Lactate <4mmol/l

Reference material

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