Prophylaxis of postoperative thromboembolic complications with low-dose heparin. An analysis of different administration intervals.

The literature on low-dose heparin thrombosis prophylaxis has been reviewed to evaluate differences in effect and bleeding complications between heparin administered at twelve- and eight-hour intervals. The more frequent administration gives a slightly greater reduction of the overall frequency of thrombosis but is not more effective in reducing extensive thrombi or fatal pulmonary emboli. Moreover, it causes more haemorrage, which is why it is concluded that the twelve-hourly interval must be recommended.