Heparin-induced thrombocytopenia in a non-heparin-naive patient: a case report.

INTRODUCTION: Administration of low molecular weight heparin (LMWH) is recommended for prophylaxis of venous thromboembolism in patients undergoing hip surgery. In this context, heparin-induced thrombocytopenia (HIT) type II is a complication of rare incidence but sometimes fatal outcome.

CASE DESCRIPTION: A 52-year old obese patient undergoing antithrombotic therapy with Enoxaparin after hip surgery presented with a painful, swollen leg and thrombocytopenia on day eight after surgery. Medical history showed previous administration of Enoxaparin without complications 2 years ago. Further diagnostic investigation supplied evidence of multiple thromboembolic events and concomitant compartment syndrome. Administration of Enoxaparin was stopped immediately and treatment with Argatroban was initiated. Diagnosis of HIT was confirmed according to current guidelines. Despite interventional thrombectomy and fasciotomy, amputation of both lower limbs had to be performed due to ongoing necroses. After a 30-days-stay at the intensive care unit because of sepsis, respiratory and renal failure, clinical condition improved and the patient could be transferred for rehabilitation.

DISCUSSION AND EVALUATION: HIT II is known as complication of administration of LMWH in the perioperative setting. Diagnosis results from clinical findings and platelet count. Argatroban is recommended as an alternative therapeutic anticoagulant in HIT II. Inflammation and surgical trauma are discussed as priming factors to increase risk of HIT II.

CONCLUSIONS: Administration of LMWH may result in HIT II despite prior uneventful drug exposure. Except for immediate diagnosis, only consequent anticoagulation can stop the course of disease. Hence, interdisciplinary awareness is inevitable for early diagnosis and accurate therapy to prevent from a catastrophic clinical course.