Evidence-based On-call

Deep vein thrombosis

Therapy

Check platelets after 5 days to exclude heparin-induced thrombocytopenia. ^b

Why?

Heparin-induced thrombocytopenia is uncommon (3% of patients on heparin, <1% on LMWH) ^b but may increase the risk of venous thromboembolism. ^c

Heparin-induced thrombocytopenia increases the risk of venous thromboembolism

Patient	Prognostic Factor	Outcome	CER	OR (95% CI)	NNF+ (95% CI)
on heparin or LMWH ^c	heparin-induced thrombocytopenia not independent	venous thromboembolism at uncertain duration	18%	4.98 (3.75 to 6.62)	1 (1 to 2)