Heparin versus dextran in the prevention of deep vein thrombosis. A multi unit controlled trial
Eight surgical units cooperated in a controlled clinical trial of iv dextran 70 and low dose sc heparin in the prevention of deep vein thrombosis (DVT). Sodium heparin was given sc 2500 units 2 hr before operation and 5000 units twice daily until the 7th postoperative day. The infusions of dextran 70,500 ml, were given at operation and on the first and second postoperative days. Control patients received no specific prophylaxis. DVT was diagnosed by the 125I fibrinogen test in 37% of controls, 25% of dextran patients, and 12% in the heparin group. Heparin was significantly more effective than dextran. The presence of malignant disease was associated with a higher incidence of DVT, but it did not affect the relative efficacy of either agent. There was no significant difference in measured bloodloss between the groups. 8 pulmonary emboli were reported, 4 in controls, 3 in dextran group, and 1 on heparin. All emboli were minor except in 1 control patient who died of massive embolism. The regimen of low dose subcutaneous heparin was more effective than that of iv dextran 70 in preventing DVT.