RESUMO
Different prevention regimens of venous thromboembolism, by using the low molecular-weight heparin Fraxiparin, were studied in 152 patients who had undergone major orthopedic leg surgery under spinal and general anesthesia. The regimens differed in the time of Fraxiparin administration (before or after surgery). Fraxiparin and spinal anesthesia were found to promote the lower incidence of venous thromboembolism. The preoperative preventive treatment of venous thromboembolism, by using a low molecular-weight heparin in patients undergoing spinal anesthesia is unnecessary because of a high risk of epidural hematomas. If the risk for venous thromboembolism is higher before surgery and remains the same after it, thromboprophylaxis should be prolonged for at least one month.
