AKI

Question 1

Dx of AKI?

Answer 1

(1. ) Rapid loss of glomerular function over a few days, which leads to retention of urea, ammonia etc
(2. ) Rise in creatinine of ≥ 25 micromol/L in 48 hours
(3. ) Rise in creatinine of ≥ 50% in 7 days
(4. ) Urine output of < 0.5ml/kg/hour for > 6 hours

Question 2

What 4 problems are associated with acute renal failure

Answer 2

(1. ) Uraemia
(2. ) Failure of fluid balance (fluid overload)
(3. ) Failure of electrolyte regulation (hyperkalaemia)
(4. ) Failure to regulate acid-base

Question 3

Causes of AKI

Answer 3

(1. ) Pre-renal:
- inadequate blood supply to kidneys reducing the filtration of blood
- may be due to: Dehydration, Hypotension (shock), Heart failure

(2. ) Renal
- disease in kidney: e.g. glomerulonephritis, Interstitial nephritis, Acute tubular necrosis

(3. ) Post-renal:
- obstructive uropathy causing back-pressure into the kidney and reduced kidney function.
- E.G. Kidney stones, malignancy, enlarged prostate etc

Question 4

RF for AKI

Answer 4

• Hypovalaemia
• Chronic kidney disease
• Heart failure
• Diabetes
• Renal transplant
• > 65y
• Nephrotoxic e.g. NSAIDS and ACEi
• Use of a contrast medium such as during CT scans

Question 5

Ix of AKI

Answer 5

(1. ) Bloods: FBC, UE, ESR etc
(2. ) ABG:hypoxia, acidosis
(3. ) Urine: dip, MCS, UE, CRP
(4. 0 ECG: hyperkalaemia
(5. ) CXR = pulmonary oedema
(6. ) US** = renal size, hydronephritis

Question 6

Mx of AKI

Answer 6

Identify underlying causes

1. Fluid rehydration with IV fluids in pre-renal AKI
2. Stop nephrotoxic medications such as NSAIDS and antihypertensives that reduce the filtration pressure (i.e. ACE inhibitors)
3. Relieve obstruction in a post-renal AKI, for example insert a catheter for a patient in retention from an enlarged prostate