Renal: AKI

Question 1

What is the most common cause of AKI in children?

Answer 1

• haemolytic uraemic syndrome (HUS)

Question 2

Haemolytic Uraemic Syndrome (HUS) is a triad of:

Answer 2

1. Microangiopathic haemolytic anaemia (Coombs’ test negative).
2. Thrombocytopenia.
3. Acute kidney injury (acute renal failure).

glomeruli become clogged with platelets and damaged red blood cells.

Question 3

What causes HUS? What is the classical presenting feature?

Answer 3

• Shiga toxin-producing E. coli (STEC)
• can occur after contact with cattle/farm animals, not cooking minced beef well.
• profuse diarrhoea that turns bloody 1-3 days later.

Question 4

How should suspected HUS be investigated?

Answer 4

• FBC and film (raised WCC and low platelets), fragmented red cells on film, low Hb
• U&E - rise in urea and creatinine
• LDH - high LDH early indicator
• Clotting screen
• Stool sample
• Urinalysis: haematuria or proteinura are early signs

Question 5

How is HUS managed?

Answer 5

• notify local health protection team
• supportive treatment - fluid and electrolyte management, dialysis if needed
• > 80% make full recovery

Question 6

What is AKI?

Answer 6

• an abrupt decrease in kidney function occurring over 7 days or fewer.
• diagnosis of AKI and its staging is based on acute changes in serum creatinine and/or a reduction in urine output (oliguria).

Question 7

What are the causes of AKI? Pre, renal, post?

Answer 7

Question 8

What are the diagnostic criteria for AKI?

Answer 8

• Any of the below criteria:
• rise in serum creatinine >=26 micromol/L within 48hrs
• 50% rise in serum creatinine within last 7 days
• fall in urine output to <0.5ml/kg/hr for more than 6 hours.

Question 9

How is AKI staged?

Answer 9

AKI 1: Cr 1.5x baseline level or rise of 26 micromol/L <48hrs.

AKI 2: Cr 2x baseline level

AKI 3: Cr 3x baseline level or Cr >354 micromol/L

Question 10

When should I arrange urgent admission (same day) for AKI?

Answer 10

• AKI 3
• underlying cause requiring urgent management e.g. urinary tract obstruction, upper UTI
• no clear cause for AKI
• At risk of urinary tract obstruction
• Sepsis
• Hypovolaemia - needing IV fluids and monitoring
• deterioration in clinical condition - need for more frequent monitoring
• suspected complication of AKI - pulmonary oedema, uraemic encephalopathy, pericariditis, severe hyperkalaemia (>=6.5)

Liaise with nephrologist if:
CKD 4/5
? glomerulonephritis, vasculitis, myeloma
hx renal transplant

Question 11

How should AKI be managed in primary care if patient not requiring hospital admission, referral or specialist input?

Answer 11

• manage underlying cause
• urine dip - protein and blood, UTI
• advise on fluid intake
• stop nephrotoxic meds until improved
• regularly monitor U&E
• refer if deteriorate/ not responding
• monitor for 3 years after AKI to check for progression to CKD (even if egfr returns to baseline)
• review meds - check U&E 1-2 weeks after restarting any med