Heparin/dihydroergotamine for venous thrombosis prophylaxis: comparison of low-dose heparin and low molecular weight heparin in hip surgery.

In a prospective, double-blind controlled study we have compared the prophylactic efficacy against deep vein thrombosis of low-dose heparin + dihydroergotamine (A), low molecular weight heparin + dihydroergotamine (B) and placebo (C). A total of three hundred and fifty-six patients undergoing total hip replacement were randomized into three groups and 316 patients were analysed. All thrombi were verified by ascending phlebography. One-third of the patients developed deep vein thrombosis in group A and B, differing significantly from group C. The operative blood loss in group B was higher than that in groups A and C. However, the number of patients transfused and their transfusion requirements did not differ. Severe bleeding occurred in one patient in each group. No deaths were registered during the study. Our study indicates that prophylactic treatment against postoperative deep vein thrombosis with low molecular weight heparin + dihydroergotamine once daily is as effective and safe as conventional low-dose heparin + dihydroergotamine twice daily in patients undergoing total hip replacement. The once-daily regimen has the advantage of better patient acceptance and less nursing time.