AKI

Question 1

What are the parameters for AKI defined as?

Answer 1

Increased serum creatinine above or equal to 26.5umol/L within 48 hours
Increased serum creatinine above 1.5 times the baseline amount within 7 days
Decreased urine output of less than 0.5ml/kg/h for 6 hours.

Question 2

In terms of the serum Cr criteria, what is AKI stage 3 classified as?

Answer 2

Increased Cr above 354umol/L with an acute rise of 44 in 24 hours or less.

Or

3x increased serum Cr from baseline (irrespective of the stage at time of initiation)

Question 3

What are the most common causes of AKI worldwide?

Answer 3

Dehydration and hypotension

Question 4

In terms of impaired renal autoregulation as a cause for pre-renal AKI, what are the 2 mechanisms it could occur by?

Answer 4

Preglomerular vasoconstriction
(NSAIDs, Sepsis)
Post-glomerular vasodilatation
(ACEi/ AIIR antagonists)

Question 5

In terms of reduced effective arterial blood volume as a cause for pre-renal AKI, what could be the more specific causes?

Answer 5

Hypovolemia
Systemic vasodilation
(Sepsis, cirrhosis and anaphylaxis)
Cardiac failure

Question 6

Name some exogenous nephrotoxins

Answer 6

Endotoxins
X ray contrast
Drugs - NSAIDs, ABx (aminoglycosides), antifreeze (ethylene glycol), statins, cisplatin.

Question 7

What are the key things that need to be corrected in AKI?

Answer 7

Volume overload
Hyperkalemia
Acidosis

Question 8

How would you manage the hyperkalemia?

Answer 8

Low K diet
Calcium gluconate 
Furosemide
Dextrose + insulin 
B2 agonists
Resins 
Stopping dietary K 
Sodium bicarbonate

Question 9

What are some indications for dialysis in AKI?

Answer 9

High K+ post treatment
Metabolic acidosis 
Fluid overload after diuretic usage 
Signs of uraemia 
Presence of dialysable nephrotoxins

Question 10

What are the four broad causes of intra-renal AKI?

Answer 10

Small-vessel disease
Glomerular disease
ATN
Acute interstitial nephritis

Question 11

Give some causes of obstruction in post-renal AKI

Answer 11

BPH 
Kidney stones
Bladder stones
Bladder, ureter or prostate cancer 
Catheter insertion

Question 12

When should USS be performed when investigating AKI?

Answer 12

Within 24 hour of presentation if obstruction is suspected or if the cause in unclear.

Question 13

What are some indications for dialysis in the setting of AKI?

Answer 13

High K+ after treatment
Metabolic acidosis 
Fluid overload refractory to diuretics
Uraemia signs 
Presence of dialysable nephrotoxins