Heparin-induced thrombocytopenia (HIT)
Last updated: Friday, 06, August, 2010
|Key Information||Appropriate Tests|
Thrombocytopenia occurring during the course of heparin therapy.
HIT is less common with low molecular weight heparins than with standard unfractionated heparin, but may occur.
|HIT type I|
Mild thrombocytopenia (>100 x 109/L), which is not progressive and is not associated with extension of thrombosis.
Monitor clinical status and platelet count.
|HIT type II|
Moderate to severe thrombocytopenia (<100 x 109/L) which may be progressive and associated with extension of thrombosis and/or thrombosis at other sites (arterial and/or venous). Consult pathologist.
FBC; heparin-dependent platelet antibodies, including assessment of cross-reactivity of the patient's antibody with low molecular weight heparins and heparinoids. Heparin must be ceased if the diagnosis of type II HIT is established. Subsequent heparin therapy is contraindicated.