[Prevention of venous thromboembolism in surgery]

Incidence of postoperative deep venous thrombosis extends from 7% (transurethral prostatectomy) to more than 50% (hip surgery) depending on the magnitude of trauma and due to the corresponding surgical procedure. Although more common with higher age, younger patients suffer from postoperative thromboembolic complications as well. This insight leads to the conclusion that all immobilized adult patients or those needing an operation are to receive thromboembolic prophylaxis should there be no contraindication. As 50% of all postoperative thromboses develop sometime during the operative procedure, thromboembolic prophylaxis has to be effective intraoperatively as well. The first dose must therefore be preoperative. Duration of prophylaxis depends on the ambulation of the individual patient and should be maintained for at least seven days. Physiotherapeutic measures and drug therapy should complement each other. Low molecular heparins have been very successful lately. Their effect on thrombosis in visceral surgery has been equal when compared with unfractioned heparin whereas the effect in hip surgery compared to unfractioned heparin has been even more promising. Due to the longer half-life of low molecular heparin when compared with unfractioned heparin and its better bioavailability, one dose of low molecular heparin a day is sufficient. This is certainly a benefit for the patient and the nursing staff. To our current knowledge the tendency toward bleeding does not differ basically if low molecular heparins or standard heparin is being used. In patients with spinal anaesthesia, as with low molecular heparins, the first dose has to be administered preoperatively. Different ways of application are possible.