Acute Kidney Injury (AKI)

Question 1

What is the current definition of acute kidney injury?

Answer 1

Increases in serum creatinine by > 26.5 umol/l within 48hrs or >1.5umol/l within the 7 days prior
Urine volume is more than 0.5 ml/kg/h for 5 hrs

Question 2

What are the stages of AKI?

Answer 2

AKI 1, 2 and 3
Stage 3 is 3 x baseline serum creatinine and <0.3 ml/kg/h for more than 24hrs or anuria for more than 12hrs

Question 3

What is the incidence of AKI?

Answer 3

One in five people admitted to hospital each year as an emergency have an AKI

Question 4

What are the immediate dangerous consequences of AKI?

Answer 4

Acidosis
Electrolyte imbalance
Intoxication TOXINS
Overload
Uraemic complications
AEIOU

Question 5

What are the short and long term outcomes of AKI?

Answer 5

Short term - death, dialysis and length of stay
Long term - death, CKD, dialysis and CKD related CV events

Question 6

What increases mortality?

Answer 6

Small rises in creatinine

Question 7

In the long term, what is the risk of death?

Answer 7

Over 10 years is increased by 2 fold with AKI
If eGFR on discharge is less than 60 then 1.5x

Question 8

What is normal baseline for creatinine?

Answer 8

80umol/l
Too late to act if creatinine is over 400
Even 120 will cause significant kidney injury

Question 9

What are the pre-renal causes of AKI?

Answer 9

Cardiac failure, haemorrhage, sepsis, vomiting and diarrhoea

Question 10

What are the post-renal causes of AKI?

Answer 10

Tumours, prostate disease and stones
(obstruction)

Question 11

What are the intrinsic causes of AKI?

Answer 11

Glomerulonephritis, vasculitis, radiocontrast, myeloma, rhabdomyolysis and rugs (NSAIDs and gentamicin)

Question 12

What are AKI risk events?

Answer 12

Sepsis, toxins, hypotension, hypovolaemia (haemorrhage, vomiting, and diarrhoea), and major surgery

Question 13

What is the STOP AKI prevention care bundle?

Answer 13

Sepsis - screen and treat promptly
Toxins - avoid (gentamicin, NSAIDs and IV iodinated contrast)
Optimise - BP and volume status
Prevent harm - daily U+Es, fluid balance and med review

Question 14

What is suggested if sepsis is suspected?

Answer 14

Blood cultures, urine output monitoring, fluids, antibiotics, lactate level and oxygen saturation monitoring

Question 15

What is the medicine sick day rules?

Answer 15

When you are unwell with vomiting or diarrhoea, fever, sweats and shaking then STOP medicines - ACE inhibitors, ARBs, NSAIDs, diuretics and metformin
Restart when well

Question 16

How is AKI diagnosed?

Answer 16

Increase in creatinine - >26/5 in 48hrs or >1.5 within 7 days
Reduced urine output - <0.5ml/kg/hr for 6hrs or <300mls in 12 hrs

Question 17

What could be caused by AKI - volume status?

Answer 17

Hypovolaemia - give boluses of fluid IV
Euvolemic - give maintenance fluid
Hypervolemia - senior review

Question 18

What investigations and assessments are needed in AKI?

Answer 18

History, examination, drugs, insults, renal function, urine dipstick, FBC, USS, blood gas, and blood tests

Question 19

What can be included in history?

Answer 19

Past medical history, FH, drug exposure, pre/post renal factors, uraemic symptoms and timing of symptoms - SOB, urine output and vomiting

Question 20

What is included in blood tests?

Answer 20

U+Es, bicarb, LFTs, bone and FBC
Clotting

Question 21

What is included in AKI review?

Answer 21

Bloods
Ultrasound
Medicines
Plan for fluid maintenance - fluid balance chart and daily weights

Question 22

What is included in AKI follow up?

Answer 22

Record
Repeat bloods - check if renal function has returned to baseline and if not then think other diagnosis
Treatment and medication review - do they need to restart diuretics, antihypertensive or other meds

Question 23

What are the potential indications for RRT?

Answer 23

Acidosis, electrolyte imbalance (hyperkalaemia), intoxication (lithium), overload and uraemic complications

Question 24

How does an ECG look when patient has hyperkalaemia?

Answer 24

Peaked T waves - usually earliest sign
Tall tented T waves
P waves widen and flatten, PR segment lengthens and P waves eventually disappear

Question 25

What are later changes to an ECG with hyperkalaemia?

Answer 25

Prolonged QRS interval with bizarre QRS morphology
High grade AV block
Any kind of conduction block
Sinus bradycardia or slow AF
Then cardiac arrest - asystole, VF or PEA

Question 26

What is the treatment for hyperkalaemia?

Answer 26

Stabilise myocardium - calcium gluconate
Shift K intracellularly - salbutamol or insulin-dextrose
Remove - diuresis, dialysis and anion exchange resins