Group of hereditary or acquired disorders that are characterized by:

-        thrombocytopenia

-         microangiopathic anemia (schistocytes)

-        impairment of certain target organs.

Some hereditary forms are revealed at the occasion of an intercurrent event such as infection, surgery or pregnancy (HELLP).

We can distinguish:

• thrombotic thrombocytopenic purpura: which very rarely compromises the kidney

-        hereditary: ADAMTS13 deficiency, a protease that reduced von Willebrand factor multimers (Upshaw-Shulman syndrome). Treatment: administration of plasma

-        acquired: production of autoantibodies that inhibit the action of ADAMTS13. Treatment: plasmapheresis

• hemolytic uremic syndrome : where acute renal failure and hypertension are on the frontline

-        activation of the alternative cascade of complement due to a deficiency in factor H (many mutations) either inherited or acquired (10%). Treatment:  anti-complement agent (eculizumab for example for the treatment of atypical hemolytic uremic syndrome) (see this topic)

-        verotoxin of the E Coli O157:H7 (typical hemolytic-uremic syndrome): dialysis, optimization volemia

-        immune reaction to a drug: quinine, quetiapine, gemcitabine

-        toxic reaction to a drug: some immunosuppressive drugs or chemotherapeutic agents

-        metabolic defect: cobalamin C deficiency: treatment; vit B12 supplementation

-        abnormal hemostasis: genetic abnormalities of thrombomodulin or plasminogen

Anesthetic implications:

depending on the cause and the clinical picture

References:

•        George JN, Nester CM. 
  Syndromes of thrombotic microangiopathy. 
  NEJM 2014; 371: 654-66.

Updated: September 2018