Condition- Haemolytic Uraemic Syndrome

Question 1

Haemolytic uraemic syndrome is defined by a triad of…

Answer 1

• MAHA
• AKI
• Thrombocytopenia

Question 2

HUS overlaps with which other disease?

Answer 2

TTP

Question 3

Describe the pathogenesis of HUS…

Answer 3

1. The toxin activates platelets=> platelet aggregation and activation of the clotting cascade (=>THROMBOCYTOPENIA)
2. Fibrin deposition in small vessels and microthrombi formation (=> MAHA)
3. Damaged RBCs clog up afferent arterioles in the kidneys leading to renal ischaemia (=> AKI)

Question 4

What is the main cause of HUS?

Answer 4

E.Coli infection (the strain prodcuing Shiga Toxin)

Question 5

List some causes of HUS

Answer 5

• Infection:
  
  • E. coli 0157- 90% of cases. Ingestion of undercooked meat. Produce Shiga toxin
  • Shigella
  • Pneumococcal infection
  • HIV
• Drugs- OCP
• SLE, scleroderms
• Other: malignancy, pregnancy

Question 6

What are the 2 categories of haemolytic uraemic syndrome

Answer 6

D+ (with diarrhoea, usually children)
D- (no prodromal illness)

Question 7

List some of the symptoms of HUS

Answer 7

HUS

• Haemolytic Symptoms- jaundice, anaemia
• Urinary Symptoms- oligo/anuria
• Shits- bloody diarrhoea, abdo pains

General

• Malaise
• Fever (<38)
• Nausea

Question 8

A person with E.Coli Infection + HUS starts getting weakness, reduced vision and fits- why?

Answer 8

They have TTP

• TTP and HUS often come hand in hand
• TTP persents with more CNS symptoms

Question 9

List some signs of HUS on physical examination

Answer 9

• MAHA: RBC breakdown => jaundice + aenamia signs
• Thrombocytopaenia => bruising
• AKI => oedema, hypertension

Question 10

Bloods is the first line investigation for HUS- what would you see?

Answer 10

• FBC: normoytic anaemia, high neutrophils, low platelets
• U+Es: High urea, high creatinine, high K+ and low Na+
• Clotting screen= Normal APTT (abnormal in DIC)
• LFTs: High unconjugated bilirubin + high LDH (haemolyisis)

Question 11

Other than bloods which investigations could you conduct on someone with HUS and What would you see?

1. is blood film- what would you see on it?

Answer 11

• Blood film
  
  • Schistocytes- due to MAHA
  • High reticulocytes and spherocytes
• Urinalysis: haematuria
• Stool + Blood culture: MC&S
• ABG: metabolic acidosis