A 51-year-old obese woman who had just undergone a second osteotomy for arthrosis of the hip joint was given unfractionated heparin, 7,500 IU subcutaneously three times daily, as thrombosis prophylaxis. Signs of fulminant pulmonary embolism occurred on the 16th postoperative day with a platelet count of 33,000/microliters. Suspected heparin-induced thrombocytopenia and thrombosis (HITT) was confirmed by platelet tests. When heparin had been discontinued immunoglobulin G was administered, seven times 5 g intravenously, in view of the immunological genesis of HITT. In addition thrombolysis treatment with streptokinase combined with phenprocoumon was undertaken, until satisfactory anticoagulation was achieved after 4 days. Platelet count rose to 136,000/microliters within 20 hours of the first immunoglobulin dose. Complete clinical normality was restored, scintigraphy showed no perfusion deficit in the lungs.

A deep-vein thrombosis developed in a 71-year-old patient on the eleventh day of heparin treatment (25,000 U intravenously over 24 hours) given because of a nontransmural anterior-wall infarct. Subsequently there occurred a unilateral and then bilateral thrombotic occlusion of the femoral arteries and thrombosis of the infrarenal artery with occlusion of the right renal artery which necessitated operative thrombectomy. Platelet count, initially 370,000/microliters, fell to 34,000/microliters. No source of emboli was found either echocardiographically or by thoracic and abdominal computed tomography. After heparin administration had been discontinued on the 15th day, platelet count quickly returned to normal. Rapidly progressing demarcation necessitated amputation of both legs. The patient died on the 23rd hospital day. The reported findings indicate a heparin-induced thrombosis-thrombocytopenia syndrome.