Efficacy and safety of two regimens of low molecular weight heparin fragment (Fragmin) in preventing postoperative venous thrombolism.

The efficacy and safety of 2 regimens of Fragmin in preventing postoperative venous thromboembolism was compared on 206 consecutive patients, aged 40 years or more, undergoing major abdominal surgery. Ninety-four patients received a single daily injection of 2,500 U of Fragmin for at least 6 postoperative days (group I), while 112 received 5000 U per day in 2 injections of 2,500 U each (group II). In group I 7.4% of patients and in group II 2.6% of patients developed postoperative deep venous thrombosis (DVT); the difference was not statistically significant (p greater than 0.05). There was no significant difference between the 2 groups in terms of numbers of patients having excessive postoperative blood loss, requiring prophylaxis to be discontinued, or measured postoperative drainage. None of the patients in group I, and 2 out of 112 in group II developed wound haematoma. These findings suggest that a single daily injection of 2,500 U of Fragmin may provide an effective prophylaxis against postoperative venous thromboembolism.