AKI (for the generalist)

Describing recognition and early management of AKI. (More advanced info from Specialist page).

Early Recognition (KDIGO criteria):

AKI 1: creatinine rise from baseline of 1.5x or 26.5 micromol/l, and/or oliguria (urine output <0.5ml/kg/hr for >6hrs)
AKI 2: rise of 2-3x baseline
AKI 3: rise of >3x baseline or >354 micromol/l, or need for RRT

Consider potential causes
  • Sepsis
  • Hypoperfusion
    • Cardiac/liver failure
    • Haemorrhage
    • Dehydration
  • Drugs or Contrast
  • Obstruction
  • Renal disease
    • e.g rhabdomyolysis, glomerulonephritis, interstitial nephritis, myeloma


1. Correct hypovolaemia

  • Use small fluid boluses (250ml) of crystalloid initially (see fluid therapy)
  • Regularly reassess JVP, peripheral perfusion, BP, urine output

2. Address hypotension

  • If persistent once euvolaemic, consider CVP monitoring +/- vasopressors (HDU/ ITU?)

3. Manage hyperkalaemia

  • Hyperkalaemia protocol

4. Review drugs

  • Stop any drugs which may contribute
  • Stop antihypertensives if BP low
  • Review all drug dosages in renal impairment

5. Urinary tract ultrasound

  • Consider if clinical suspicion of obstruction/abnormal renal tract


Required actions

1. Senior review
2. Updated renal function
3. Check historic renal function
4. Fluid balance assessment
5. Drug chart review
6. Urine dip (+/- protein:creatinine ratio)
7. Check acid/base (TCO2 /H+/pH)
8. Consider urinary tract ultrasound

Consider specialist (nephrology) referral if:
  • Clinical suspicion of intrinsic renal disease (even if mild AKI)
    • Proteinuria +/- haematuria
    • Absence of clear precipitant of AKI
    • Symptoms/signs suggestive of systemic disease
    • e.g. rash, arthropathy, pulmonary infiltrates
  • Progressive renal impairment
  • Renal transplant
  • Refractory pulmonary oedema
  • Refractory hyperkalaemia (> 6.5 mmol/L)
  • (Refractory acidosis (H+> 60 nmol/L; pH<7.2))
  • (Background CKD 4/5)

AKI outcomes

AKI is a smoke alarm! It is associated with:

  • Longer hospital stay
  • Increased mortality

But most patients don’t die of renal failure. They die from their underlying condition.
And remember that too much fluid is a bad prognostic feature in AKI.

Further info

Fluid therapy – our page on the principles and practice.
AKI (specialist) – also has pointers to other sources of info, including for patients

Acknowledgements: Ailish Nimmo was the main author for this page, which was created in November 2017. Date last modified shown in footer.