Hemolytic-Uremic Syndrome

Question 1

What is hemolytic-uremic syndrom (HUS)? It has 3 components.

Answer 1

An acute syndrome, characterized by microangiopathic hemolytic anemia, thrombocytopenia, and severe renal failure.

Question 2

What is the pathophysiology behind HUS?

Answer 2

Genetic/chronic disease of complement-mediated thrombotic microangiopathy. Thought that thrombin generation and inhibition of fibrinolysis lead to renal arteriolar and capillary microthrombi.

Question 3

What is the main cause of HUS in children? What are some of the other causes?

Answer 3

E. coli type 0157:H7 leading cause of HUS. Other causes: drugs, GI bacteria (salmonella, shigella, yersinia), HIV associated thrombotic microangiopathy, pneumococcal infection.

Question 4

What are clinical presentations of HUS?

Answer 4

Diarrhea precedes HUS (blood 75% of time), abdominal pain, fever, vomiting, somnolence, seize, hepatomegaly and abnormal LFTs, anuria or oliguria

Question 5

Results of blood test and stool cultures for HUS?

Answer 5

CBC- Hgb

Question 6

Treatment for HUS?

Answer 6

Largely supportive. Blood transfusions for severe anemia, electrolyte and fluid management, platelet transfusion only for pts w/ sig. bleeding or invasive surgery, PLEX w/ IMA for pts w/ severe CNS involvement, Acute needs- HTN/ seizure control, Chronic- dialysis for anuric or oliguric RF

Question 7

Causes of mortality in HUS?

Answer 7

Adults with HUS have worse prognosis than children. Causes of mortality: proteinuria, renal insufficiency, HTN.

Question 8

What causes hemorrhagic and necrotic colitis? What are some of the symptoms?

Answer 8

Shigella toxin. Symptoms include diarrhea, dysentery, hemorrhagic colitis, hemolytic uremic syndrome.