HIT
HIT is relatively rare, but can occur even after receiving the smallest dose of heparin - Sean Murnan MD and Richard Slama MD
HWN Suggests
Heparin Induced Thrombocytopenia
Although the use of heparin is relatively common in the ED, rarely we encounter this complication. In contrast to other conditions caused by enhanced consumption, impaired production, or destruction of platelets, which lead to bleeding complications, immune-mediated heparin-induced thrombocytopenia (HIT) does not induce bleeding but rather results in a paradoxical prothrombotic state. Thromboembolic complications develop in approximately 50% of patients with confirmed HIT. Venous thrombosis of the large vessels of the lower limbs and pulmonary embolism are the most frequent complications, followed by peripheral arterial thrombosis and then stroke; myocardial infarction is uncommon.
Featured
Heparin-Induced Thrombocytopenia (HIT) Review
Some experts have proposed a classification of heparin-induced thrombocytopenia into two types, the life-threatening syndrome being "type II" and the benign being "type I." This scheme may be ill-advised as it encourages conflation and confusion between two profoundly different clinical syndromes, one of which can be lethal. For the remainder of this review, HIT refers to the potentially life-threatening thrombogenic complication of heparin exposure.
HITTS
Not all patients who have heparin antibodies develop platelet activation and clinically relevant HIT
Articles of Interest
Heparin Induced Thrombocytopenia (HIT): An ED-Focused Review of the Literature
The 4T Score is meant to capture the MAJOR clinical features of HIT (thrombocytopenia, thrombosis, etc.) and the likelihood that these findings are due to a temporal relationship with heparin administration.6 A 4T Score ≥ 4 should prompt hematology consultation for consideration of evaluation and therapy.
Heparin-induced Thrombocytopenia: Pathophysiology, Diagnosis and Management
Heparin-induced thrombocytopenia (HIT), even rare, is a life-threatening, immune-mediated complication of heparin exposure. It is considered the most severe non-bleeding adverse reaction of heparin treatment and one of the most important adverse drug reactions.
Resources
4Ts Score for Heparin-Induced Thrombocytopenia
Differentiates patients with HIT from those with other causes of thrombocytopenia.
Critical Care Project
Incidence higher with UFH than with LMWH use.
