Thromboprophylaxis with a low molecular weight heparin (tinzaparin) in emergency abdominal surgery. A double-blind multicenter trial

In this prospective randomized double-blind study the thromboprophylactic effect of postoperative low molecular weight heparin (tinzaparin) was compared with placebo in 80 patients undergoing emergency abdominal surgery. The fibrinogen uptake test was used but because of withdrawal of the labelled fibrinogen from the market the calculated number of patients was not reached. However, this is one of the few studies in emergency abdominal surgery we thought it important to report. The frequency of deep vein thrombosis was reduced with prophylaxis from 22% (95% conf. intervall 11-38%) to 8% (2-21%), a risk reduction of 65%, which is however not significant. Together with data from the few previously published studies it can be concluded that patients undergoing emergency abdominal surgery seem to benefit from prophylaxis, which should be instituted either before operation or at latest 24 hours after. The exact prophylactic relation between pre- and post-operative start would, however, require a separate, randomized study