5. AKI

Question 1

What is an acute kidney injury?

Answer 1

Decreased kidney function occurring over hours-days. There are different aetiologies and the cause may be multifactorial

Question 2

What are the classifications for an AKI

Answer 2

. Creatinine. Urine output

Stage 1 1.5-2x baseline. <0.5ml/kg/h (<12h)
Stage 2. 2-3x baseline. <0.5ml/kg/h (>12h)
Stage 3 >3x baseline. <0.3ml/kg/h >24h or Anuria

Question 3

What are the commonest causes of an AKI?

Answer 3

Sepsis
Major surgery
Cardiogenic shock
Other hypovalemia
Drugs
Hepatorenal syndrome
Obstruction

Question 4

What is used to classify the causes of an AKI?

Answer 4

Pre-renal- reduced perfusion
Renal- intrinsic renal release
Post-renal- obstruction to urine

Question 5

If someone has an AKI, what are the immediate steps of management?

Answer 5

Life threatening? (NEWS, P. oedema, k>6.5mmol)

ABCDE examination (treat hypovolaemia)

Monitor (fluids, potassium, obs, lactate, daily creatinine)

Investigate- urine dip, uss, LFT’s, platelets, intrinsic kidney disease

Support- treat sepsis, stop drugs, gastroprotection, avoid radiological contrast

Question 6

When do the renal consultants become involved for an AKI?

Answer 6

AKI- not responding to treatment
AKI with complications
Stage 3 AKI
AKI with difficult fluid balance
AKI due to intrinsic renal disease
AKI with hypertension

Question 7

Broadly how do you treat the levels of an AKI?

Answer 7

Pre renal- correct volume depletion and/or renal perfusion

Renal- refer for likely biopsy and specialist treatment of intrinsic renal disease

Post renal- catheter, nephrostomy, urological intervention

Question 8

How do you asses hydration?

Answer 8

Urine loss
Blood pressure
Skin turgour
Mouth dryness
JVP
Pulse

Question 9

What crystalloids can be given in resuscitation fluids?

Answer 9

Saline- Unbuffered, May cause increased chloride

Hartmann’s
Ringers lactate
Plasma-lyte- all buffered but contain potassium so watch for hyperkaelemia

Question 10

What are the signs of hyperkalaemia?

Answer 10

Tall tented T waves, increased PR interval on ECG

Over 6.5mmol on the venous blood gas

Question 11

How do you treat hyperkaelemia?

Answer 11

10ml of calcium chloride IV over 5-10min

Intravenous insulin in 25g glucose

Salbutamol in high doses, be careful in ischemic heart disease

K removal- renal replacement therapy

Question 12

What are the indications for renal replacement therapies?

Answer 12

Fluid overload unresponsive to medical treatment
Severe/prolonged acidosis
Recurrent/persistant hyperkalaemia
Uraemia e.g. pericarditis, encephalitis