Heparin-induced thrombocytopenia
From WikiLectures
Heparin-induced thrombocytopenia (HIT) is a complication of heparin or LMWH therapy, characterized by a decrease in the number of platelets by 50% of the initial value. We distinguish two forms of HIT:
- HIT I is a less severe form with a decrease in platelets in the first days after starting therapy, which is corrected spontaneously. It is usually asymptomatic.
- HIT II' is formed by the formation of IgG complexes with platelet factor 4 (PF4), which leads to the elimination of platelets and their simultaneous activation. It appears 5-10 days after starting treatment and is often accompanied by thrombosis. It is necessary to immediately discontinue heparin and replace it with pentasaccharide or lepirudin due to the hypercoagulable state.[1]