Prevention of postoperative thromboembolisms in general surgery by the combination of heparin and dihydroergotamine.

The effect and the degree of safety of administering a fixed combination of 5000 IU of heparin + 0.5 mg dihydroergotamine (HDHE s.c. per every 12 hours) as opposed to 5000 IU of heparin (LDH s.c. every 8 hours) was assessed in a prospective randomized study on 86 patients having undergone major abdominal operation. Postoperatively a deep vein thrombosis was detected by the radiofibrinogen test in 10% of the 40 patients of the HDHE group and in 13% of 46 of the LDH group. Four patients died. At autopsy neither fatal nor a contributing pulmonary embolism was found. 'Non-lethal' pulmonary embolism diagnosed by lung perfusion scintigraphy and by chest X-rays, developed in 2 patients treated with LDH and in one treated with HDHE. Two-thirds of the dose of heparin were identically effective in prevention of venous thromboembolisms than the whole dose if heparin was combined with DHE. The decrease of the heparin dose significantly reduced the number of wound haematomas and of suffusion due to injection.