Low-molecular-weight heparin and unfractionated heparin in prophylaxis against deep vein thrombosis in critically ill patients undergoing major surgery

Abstract

The objective of the present study was to compare the efficacy and safety of low-dose unfractionated heparin (UFH) and a low-molecular-weight heparin (LMWH) as prophylaxis against venous thromboembolism in critically ill surgical patients undergoing major surgery. This was a randomized prospective study in which critically ill patients scheduled to undergo major elective surgery were allocated to receive subcutaneously either LMWH once daily and a placebo injection containing sterile 0.9% normal saline or 5000 IU UFH twice daily subcutaneously. Each patient was evaluated postoperatively clinically and confirmed by Doppler study for development of deep vein thrombosis (DVT). One hundred and fifty-six patients completed the protocol. There was similar efficacy of UFH as compared with LMWH in the prophylaxis of DVT. There was also no statistically significant difference in the incidence of major complications in the heparin group as compared with the LMWH group. However, minor hemorrhagic complications such as wound hematoma and surgical site bleeding were significantly more in the heparin group as compared with the LMWH group. Both UFH 5000 units subcutaneously twice daily and LMWH 40 mg once daily provide highly effective and well tolerated prophylaxis for critically ill surgical patients. Considering the advantage of once-daily dosing, a wider adoption of prophylaxis with LMWH may be justified on the basis of patient acceptability and saving of nursing time.

Low-molecular-weight heparin and intermittent pneumatic compression for thromboprophylaxis in critical patients

“…The observation that the risk of VTE increases as the number of risk factors increases should be taken into account when assessing risk levels and considering thromboprophylaxis (24). The American College of Chest Physicians and the American Society of Colon and Rectal Surgeons have recommended that every hospital should formulate a risk stratification approach to categorize trauma patients in terms of thromboembolic risk (25).…”

“…LMWH is among the most significant recent developments in prophylaxis against DVT (24). The anticoagulatory effects of LMWH have been well characterized and function by reducing the activity of coagulation factor XIIa and thrombin (35).…”

“…It was observed that there was a statistical significance between the three prophylaxis groups and the control group, which indicated the efficacy of those treatments. ICP may exert its antithrombotic effect by stimulating fibrinolytic activity and increasing venous blood flow velocity, while LMWH is well characterized and functions by accelerating the inhibitory effect of antithrombin on factors XIIa, XIa, Xa and IXa and thrombin (24), whether the IPC and LMWH treatments produced a significant difference in efficacy was of no importance. However, by combining ICP and LMWH treatments, an improved response may be achieved as each treatment functions via an independent mechanism.…”

“…However, this protocol was necessary as certain patients exhibited heparin contraindications or pulmonary edema and were unable to receive certain treatments. Secondly, it remains unclear whether an improved benefit/risk ratio of prophylaxis of thromboembolic events versus risk of bleeding complications may be established for LMWH (24). LMWH-induced thrombocytopenia has been reported in clinical therapy (37).…”

Preventing Venous Thromboembolism in Adults

“…The results demonstrated that both LDUH and LMWH prevent DVT, and the incidence of DVT did not differ significantly between LDUH and LMWH. [16][17][18] Data from an RCT and the metaanalysis, however, showed that LMWH is superior to LDUH in the prevention of pulmonary embolism. 17,18 In another meta-analysis comparing LDUH and LMWH in acutely ill medical patients, LMWH was superior to LDUH in preventing DVT but no difference was found in the incidence of pulmonary embolism.…”