acute kidney injury

Question 1

what does AKI stand for?

Answer 1

acute kidney injury

Question 2

what is the definition of acute kidney injury?

Answer 2

increase in serum creatinine:

• by 26.5umol/L or more within 48 hours or
• to >1.5x baseline, which is known or presumed to have occurred within the prior 7 days or
• urine volume <0.5ml/kg/h for 6 hours

Question 3

how many stages of acute kidney injury are there?

Answer 3

3

Question 4

what does the immediately dangerous consequences of AKI depend on?

Answer 4

causes

• acidosis
• electrolyte imbalance
• intoxication toxins
• overload
• uraemic complications

Question 5

what can the causes of AKI be classified into?

Answer 5

pre-renal

intrinsic (renal)

post-renal

Question 6

what are the normal functions of the kidneys?

Answer 6

• body fluid homeostasis
• electrolyte homeostasis
• acid/base homeostasis
• regulation of vascular tone
• excretory function
• endocrine function

Question 7

what are possible bad short term and intermediate/long term complications of AKI?

Answer 7

short term (in hospital): death, dialysis, length of stay

intermediate/long term (post-discharge): death, CKD, dialysis, CKD related CV elements

Question 8

how does mortality change with the stage of AKI?

Answer 8

mortality increases with stage

Question 9

what are pre-renal causes of AKI?

Answer 9

cardiac failure

haemorrhage

sepsis

vomiting and diarrhoea

Question 10

what are renal causes of AKI?

Answer 10

glomerulonephritis

vasculitis

radiocontrast

myeloma

rhabdomyolysis

drugs (NSAIDs, gentamicin)

Question 11

what are post renal causes of AKI?

Answer 11

tumours

prostate disease

stones

Question 12

how is AKI prevented?

Answer 12

by identifying patients who are at risk

(presence of risk event or risk factor)

Question 13

what are examples of AKI risk events?

Answer 13

sepsis (pneumonia, cellulitis, UTI)

toxins (x-ray contrast, NSAIDs, gentamicin, herbal medicine)

hypotension

hypovolaemia (haemorrhage, vomiting, diarrhoea)

major surgery

Question 14

what are some risk factors for AKI?

Answer 14

• age > 75
• previous AKI
• ♡ failure
• liver disease
• chronic kidney disease
• DM
• vascular disease
• cognitive impairment

Question 15

What is the protocol when identifying patients at risk of AKI?

Answer 15

In presence of risk event or factor consider:

• treat sepsis if present
• avoid toxins
• optimise BP and volume status
• prevent harm

Question 16

Much of AKI is avoidable, how can it be prevented?

Answer 16

• Avoid dehydration
• Avoid nephrotoxic drugs
• Review clinical status in those at risk and act on findings

Question 17

What are medicine “sick day rules”?

Answer 17

When you have vomiting or diarrhoea (unless only minor) or fever, sweats and shaking you stop taking certain medications

Restart medications when well (24-48 hours after eating and drinking normally)

Question 18

When should medicines be restarted after “sick day” rules?

Answer 18

• Restart medications when are well (after 24-48 hours of eating and drinking normally)

Question 19

What are exampls of medications that should be stopped on “sick days”?

Answer 19

• ACE inhibitors
• ARBs
• NSAIDs
• Diuretics
• Metformin

Question 20

What investigations should be done for AKI?

Answer 20

• Renal function
• Urine dipstick
• FBC
• USS
• Blood gas
• Specific blood tests if indicated

Question 21

What parts of the history are important for AKI?

Answer 21

Question 22

What parts of the examination are important for AKI?

Answer 22

Question 23

What does RRT stand for?

Answer 23

Renal replacement therapy

Question 24

What are potential indications for renal replacement therapy (RRT)?

Answer 24

• Dependant on cause to an extend of at least in the first few hours
  
  • Acidosis
  • Electrolyte imbalance
  • Intoxication toxins
  • Overload
  • Uraemic complications

Question 25

What electrolyte imbalance can occur in AKI that can have serious consequences?

Answer 25

Hyperkalaemia

Question 26

What are ECG changes present in hyperkalaemia?

Answer 26

• Peaked T waves (usually earliest sign of hyperkalaemia)
• P wave widens and flattens
• PR segment lengthens
• P waves eventually disappear
• Prolonged QRS interval with bizarre QRS morphology
• High-grade AV block with slow junctional and ventricular escape rhythms
• Any kind of conduction block (bundle branch blocks, fascicular blocks)
• Sinus bradycardia or slow AF
• Development of sine wave appearance
• Can cause cardiac arrest
  
  • Asystole
  • Ventricular fibrillation
  • PEA with bizarre, wide complex rhythm

Question 27

What is usually the earliest sign of hyperkalaemia?

Answer 27

Peaked T-waves

Question 28

What is the treatment of hyperkalaemia?

Answer 28

• Stabilise (myocardium)
  
  • Calcium gluconate
• Shift (K⁺ intracellularly)
  
  • Salbutamol
  • Insulin-dextrose
• Remove
  
  • Diuresis
  • Dialysis
  • Anion exchange resins

Question 29

What medicine can be used to stabilise the myocardium in hyperkalaemia?

Answer 29

Calcium gluconate

Question 30

What medication can be used to shift K intracellular in hyperkalaemia?

Answer 30

• Salbutamol
• Insulin-dextrose

Question 31

What can be done to remove K from the body in hyperkalaemia?

Answer 31

• Diuresis
• Dialysis
• Anion exchange resins

Question 32

What kind of cardiac arrest can hyperkalaemia cause?

Answer 32

• Can cause cardiac arrest
  
  • Asystole
  • Ventricular fibrillation
  • PEA with bizarre, wide complex rhythm

Question 33

How does the T wave change in hyperkalaemia?

Answer 33

Peaked T waves

Question 34

How does the P wave change in hyperkalaemia?

Answer 34

Widens and flattens at first

Eventually completely disapears

Question 35

How does the PR segment change in hyperkalaemia?

Answer 35

Lengthens

Question 36

How does the QRS complex change in hyperkalaemia?