Haemolytic Uraemic Syndrome

Question 1

What is haemolytic uraemic syndrome.

Answer 1

A combination of haemolysis with red cell fragments, thrombocytopenia and acute renal failure.

Question 2

What causes haemolytic uraemic syndrome.

Answer 2

Often post-infection.

Classically after pathogenic E.coli O157 (90%).

Question 3

What are the general signs of haemolytic uraemic syndrome. (3)

Answer 3

Fever (if due to infection).
Malaise.
Lethargy.
Myopathy.

Question 4

What are the genitourinary sings of haemolytic uraemic syndrome. (3)

Answer 4

Oligouria.
Polyuria.
Nocturia.

Question 5

What are the dermatological signs of haemolytic uraemic syndrome. (3)

Answer 5

Pruritus.
Rashes.
Purpura.

Question 6

What are the cardiovascular signs of haemolytic uraemic syndrome. (4)

Answer 6

Raised BP.
Palpitations.
Pericarditis.
Oedema.

Question 7

What are the GI signs of haemolytic ureamic syndrome. (3)

Answer 7

Nausea. 
Vomiting.
Diarrhoea. 
Abdominal pain.  
Hiccough.

Question 8

What are the respiratory signs of haemolytic ureamic syndrome. (2)

Answer 8

Pulmonary oedema.

Kussmal’s respiration.

Question 9

What are the CNS signs of haemolytic uraemic syndrome. (3)

Answer 9

Fits.
Peripheral neuropathy.
Encephalopathy.

Question 10

What is haemolytic ureamic syndrome characterised by.

Answer 10

Microangiopathic haemolytic anaemia (MAHA).

Question 11

What is MAHA.

Answer 11

Microangiopathic haemolytic anaemia.

Involves intravascular haemolysis and red cell fragmentation.

Question 12

How does MAHA contribute to the development of haemolytic ureamic syndrome.

Answer 12

Endothelial damage triggers thrombosis, platelet consumption and fibrin strand deposition, mainly in the renal microvasculature.
The strands cause mechanical destruction of passing RBCs.

Question 13

What results from MAHA. (2)

Answer 13

Thrombocytopenia.

AKI.

Question 14

Give a summary of the clinical signs of haemolytic ureamic syndrome. (3)

Answer 14

AKI symptoms.
Diarrhoea.
Abdominal pain.

Question 15

What is seen on a blood film from a patient with haemolytic uraemic syndrome.

Answer 15

Schistocytes.

Question 16

What is seen on a urine dip stick of a patient with haemolytic uraemic syndrome. (2)

Answer 16

Haematuria/proteinuria.

Question 17

What is seen on a blood test of a patient with haemolytic uraemic syndrome. (3)

Answer 17

Low platelets.
Los Hb.
Clotting tests are normal.

Question 18

How is haemolytic ureamic syndrome usually caused. (2)

Answer 18

E.coli O157 infection.

Usually affects children after eating undercooked contaminated meat.

Question 19

What is the mortality rate for haemolytic ureamic syndrome.

Answer 19

3-5%.

Question 20

What distinguished haemolytic ureamic syndrome from DIC on blood tests.

Answer 20

In haemolytic ureamic syndrome the clotting tests are all normal.

Question 21

What is the non-infective cause of haemolytic uraemic syndrome. (2)

Answer 21

Due to a deficiency of complement factor H or complement factor I.
Also called atypical haemolytic uraemic syndrome.

Question 22

What can sporadic cases of haemolytic ureamic syndrome be associated with. (7)

Answer 22

Pregnancy. 
SLE. 
Scleroderma. 
Malignant hypertension. 
Metastatic cancer. 
HIV infection. 
Various drugs (contraceptive pill, ciclosporin, tacrolimus, chemotherapuetic agents).