Intraoperative single-dose heparin prophylaxis against deep-vein thrombosis.

This randomized prospective study examines the efficacy of intravenously administered heparin as prophylaxis against deep-vein thrombosis, detected isotopically with iodine 125, in 37 patients scheduled to undergo major abdominal procedures. Twenty patients were given 5000 units of sodium heparin on opening the abdominal cavity, while 17 patients who did not receive heparin acted as controls. The effect of heparin was reversed at the end of the operative procedure by protamine. Three control patients had deep-vein thrombosis postoperatively but only one heparin-treated patient did. Complications in the treated group included excessive blood loss intraoperatively in one patient and an incisional hernia postoperatively in another. Although the results are not statistically significant, this study suggests that a single dose of heparin given intravenously during operation is a safe and effective means of prophylaxis against deep-vein thrombosis in patients who undergo general surgical procedures. Studies are now being carried out to determine the optimal dose of heparin, time of administration and duration of anticoagulation.