GU - Acute Kindey Injury

Question 1

Defintion

Answer 1

• Increase in serum creatinine by > 26 micromol/l within 48 hours
• Increase in serum creatinine by 50% the baseline, which is known or presumed to have occurred within the last. 7 days
• Acute renal failure with oligouria (<0.5ml/kg/hour) is usually present for 6 hours

Question 2

Aetiology

Answer 2

1. Prerenal (MC in children): Hypovolaemia caused by infections such as gastroenteritis, burns, haemorrhage and nephrotic syndrome
2. Renal: HUS, Vasculitis, renal vein thrombosis, acute tubular necrosis, glomerulonephritis, pyelonephritis
3. Post renal: obstructions such as posterior urethral valves, blocker catheters, kidney stones in ureter or bladder

Question 3

Children at high risk of AKI

Answer 3

• Nephro-urological, cardiac or liver disease
• Malignancy and/or a bone marrow transplant
• Dependance on others for access to fluids
• History of taking medication that may adversely affect renal function
  = ACE-I, e.g. enalaprin,
  = Angiotensin II blockers e.g. Losartan
  = NSAIDS e.g. ibuprofen inc. topical NSAIDs,
  = Aminoglycosides
  = Calcineurin inhibitors e.g. tacrolimus

Question 4

AKI warning scores

Answer 4

AKI stage 1 - creatinine > 1.5 - 1.9 X reference creatinine or ULRI
AKI stage 2 - creatinine > 2 - 2.9 X time reference creatinine or ULRI
AKI stage 3 - creatinine > 3 X reference creatinine or ULRI
+ fall in urine output <0.5mls/kg/hr for 8 hrs

• ULRI = upper limit of the reference interval for age

Question 5

Signs and symptoms

Answer 5

• Hypotensive
• Hypovolaemia
• Oliguria
• Sx of volume overload: pulmonary oedema, peripheral oedema
• Nausea and vomiting
• Palpable bladder

Question 6

Diagnosis

Answer 6

FBC, U+E, Creatinine, bone profile, albumin
Urinalysis (dipstick), MC+S
Urinary tract USS - No identifiable cause for the deterioration or as risk of urinary tract obstruction - with 24 hours

Question 7

Treatment

Answer 7

1. Regular monitoring of circulation and fluid balance
2. Ultrasound scan to identify any obstruction of the urinary tract
3. Stop nephrotoxic medications
4. Treatment depending upon the cause e.g. fluid replacement, assessment of the site
   of obstruction, renal biopsy
5. Dialysis indicated when:
   - Failure of conservative management ,
   - Hyperkalaemia,
   - Severe
   - Hypo/hypernatremia,
   - Multisystem failure,
   - Severe metabolic acidosis