Bergen, Halmstad, Goteborg and KabiVitrum AB Stockholm, Sweden and Norway. At the Xth Int. Congress on Thrombosis and Haemostasis in San Diego results from a multicenter trial on 432 patients were presented, comparing a low molecular weight heparin (LMWH) fragment (Fragmin, Kabi) once daily with low dose heparin twice daily. Prophylaxis started 2 hours preoperatively. The frequency of postoperative DVT did notdiffer (6.4 % v. 4.3 %) but the onset of thrombosis was delayed in the LMWH group. Haemorrhagic complications occurred significantly more often in the LMWH group (11.6 % v. 4.6 ?o). The results were similar independent whether the analysis was made according to the intention to treat principle or based on patients with correct prophylaxis. On the basis of these data and newer knowledge regarding the pharmacokinetics of LMWH a second prospective randomized double-blind multicenter trial on patients.older than 40 years undergoing elective abdominal surgery was started. The only difference was that the first dose of 5000 ariti-factor Xa units of LMWH was given on the evening before surgery. Only conventional low dose heparin was given 2 h before surgery. The study is designed to include 1000patients, a number which will be obtained during the spring 1987. At the time of abstract deadline 799 patients have been included. The over-all frequency of DVT (fibrinogen uptake test) is 6.8 %, the frequency of haemorrhagic complications 3.6 % and mortality 1.8 % (one fatal pulmonary embolism). These frequencies remained unaltered after inclusion of 336, 576, 655 and 799 patients. Although the code has not been broken yet, it can be concluded that the new regimen with start of prophylaxis the evening before surgery has not altered the frequency of DVT or mortality whereas the frequency of haemorrhagic side effects has decreased considerably.
Failure of low-dose heparin to improve efficacy of peroperative intermittent calf compression in preventing postoperative deep vein thrombosis.
