Trombocitopenia induzida por heparina e necrose cutânea por varfarina: relato de caso

Abstract

This paper describes a case of heparin-induced thrombocytopenia complicated by warfarininduced skin necrosis in a 74-year old female patient hospitalized with diagnoses of a hip fracture, deep vein thrombosis and pulmonary thromboembolism. Warfarin-induced skin necrosis is a rare complication of anticoagulant therapy, with high morbidity and mortality that may be associated with heparin-induced thrombocytopenia. Keywords: Heparin; Necrosis; Thrombocytopenia; Warfarin Resumo: É relatado um caso de trombocitopenia induzida por heparina complicada, com necrose cutânea induzida por varfarina em paciente de 74 anos, sexo feminino, internada com diagnóstico de fratura do colo do fêmur, trombose venosa profunda e tromboembolismo pulmonar. A necrose cutânea induzida por varfarina é uma complicação rara da terapia anticoagulante, com alta morbidade e mortalidade, que pode estar associada à trombocitopenia induzida por heparina.

Deep Vein Thrombosis, Ecythyma Gangrenosum and Heparin-Induced Thrombocytopenia Occurring in a Man with a Heterozygous Factor V Leiden Mutation

“…7 Warfarin necrosis has also been reported in patients receiving heparin. 8–10 Later occurrence up to 18 months may be associated with discontinuation and re-initiation of warfarin or displacement of albumin-bound warfarin by other drugs. 11 However, this patient had been on warfarin therapy for years and neither of these factors seemed to apply.…”

“…Several reports describe simultaneous FVL mutation and HIT and also the concomitant existence of WISN and HIT. 8–10,15 Some authors speculate that FVL mutations increase the rate at which thrombocytopenia and thrombosis develop in patients with HIT. 14 Warfarin treatment of HIT patients can lead to severe thrombotic complications, including limb gangrene.…”

Warfarin-induced skin necrosis in a patient with protein S deficiency

“…Warfarin-induced cutaneous necrosis is a rare complication of anticoagulant therapy with prevalence between 0.01 and 0.1%, associated to elevated morbimortality. 1 It occurs almost exclusively in patients with venous thrombosis and pulmonary embolism between the 1 st and the 10 th day after initiation of the anticoagulation. It has been associated to the deficiency of protein C and, more rarely, to the deficiency of protein S. 2 …”

“… 3 The clinical picture is usually associated to the administration of high anticoagulant doses, and the patients most susceptible to this complication are those with positive lupus anticoagulant, protein C and S, antithrombin and factor VII deficient. 1 …”

“…Once cutaneous necrosis is diagnosed, treatment with heparin should be initiated, along with vitamin K to restore the levels of proteins C and S. The treatment includes discontinuation of warfarin; however, this procedure has not been changing the outcome. 1 Good results are obtained with the cautious reintroduction of low-dose warfarin associated to anticoagulation with heparin. It is essential to know the background for the continuity of the therapy, with dosage of protein C and S, fibrinogen, fibrin degradation products levels and investigation of causes of vasculitis.…”