Summary
Background.Heparin-induced thrombocytopenia (HIT), an immune-mediated response to heparin administration, is characterized by a reduction in platelet count by 50 percent or platelet counts below 70-100 G l^-1. In addition, HIT may be complicated by thrombosis. We describe a case of HIT that developed in a multiple trauma patient who received enoxaparin.
Case report. A 62-yr-old male patient received 40 mg enoxaparin for three days after multiple trauma (head trauma and multiple limb fractures). On the third day after the injury, the patient reported sudden dyspnea, the chest x-ray revealing diffuse shadows. The dose of enoxaparin was increased. Four days later, the patient suddenly collapsed and developed a full clinical picture of pulmonary embolism. The platelet count initially decreased to 75 G l^-1 and after two days, further decreased to 14 G l^-1. Tests revealed the presence of heparin-dependent antibodies, and a diagnosis of HIT was made. The enoxaparin was stopped and replaced with acenocumarol, however this was complicated by severe bleeding around the right femoral fracture and thrombosis of the femoral and iliac veins. An antithrombotic filter was implanted into the inferior vena cava. The subsequent course was uneventful and the patient recovered completely.
Discussion and conclusion. HIT, following LMWH administration is a rare but serious complication of antithrombotic prophylaxis. It is difficult to diagnose, nevertheless it should be suspected in any case of thrombocytopenia occurring in patients receiving both fractioned and unfractioned heparins. In the case described, the withdrawal of antithrombotic treatment was not possible, and since acenocumarol resulted in serious bleeding, the only solution was to implant a filter into the vena cava.