The Curative Effect And Analysis Of Thromboprophylaxis With Low-molecular-weight Heparin

Background and Objective:In recent years,low-molecular-weight heparin(LMWH) has been widely used in the direction of the prophylaxis and treatment of venous thromboembolism.For its many merits ,LMWH has taken the place of unfractionated heparin (UFH ) as the main anticoagulant.Now there is an agreement of using the plasma anti-FXa activity to evaluate the value of LMWH.The anti-Xa levels at 4h after subcutaneous administration of a dose (peak levels) which varied between 0.5-1.0U/ml are most suitable for therapy.But in practice,doctors also find deep vein thrombosis(DVT) even pulmonary thromboembolism(PTE) happened in patients who are accepting the prophylaxis treatment of LMWH,which may do harm to the lives of patients.So in order to guide the application of LMWH in thromboprophylaxis,we design this experiment.Methods:we chose 20 patients who were treated with unilateral total hip replacement in the department of orthopaedics of the first affiliated hospital of DaLian Medical University from October to December in 2007 by a series of severe standards.Eight were male and twelve were female.They aged between 25-88 years,average 61.7 years and weighted between 54-88kg,average 65.8kg.These patients were injected subcutaneouly with LMWH 2500U differently at preoperative 12h,postoperative 12h and at 9 o'clock daily from the first day after operation.The anti-FXa activity in plasma was monitered when they were hospitalized and at 4h after injection LMWH on day 1 and 3.To observe (1)Is there any difference in the plasma anti-FXa activity after thromboprophylaxis with LMWH 2500U.(2)Does the plasma anti-FX activity at 4h after injection achieve to optimal levels 0.5-1.0U/ml.(3)The relationship between the anti-FXa activity and weight.Results:(1)There was significant increasement in the anti-FXa activity of thromboprophylaxis with LMWH 2500U,but the plasma anti-FXa activity after injection at 4h on day 1 and 3 didn't achieve to the optimal levels 0.5-1.0U/ml.(2)There was no relationship between the anti-FXa activity and weight by drawing scatterplot.Conclusions:(1)The maximal plasma anti-FXa activity of thromboprophylaxis with LMWH 2500U didn't achieve to the optimal levels 0.5-1.0U/ml.We suggested to increase the dose ,such as administration of LMWH 5000U once daily.(2)There was no relationship between the anti-FXa activity and weight.For general patients,we can use a fixed amount of heparin.