Optimal dosing of bemiparin as prophylaxis against venous thromboembolism in surgery for cancer: an audit of practice.

AIMS: Low-molecular-weight heparins are drugs of first choice for thromboprophylaxis in cancer surgery. We sought to determine the optimal use of bemiparin in cancer surgery in standard clinical practice.

PATIENTS AND METHODS: A retrospective, multicentre audit on the use of bemiparin in patients undergoing cancer surgery and given prophylaxis with bemiparin was undertaken. Surgeons' assessment of venous thromboembolic (VTE) risk (moderate or high) was compared to the criteria of current Consensus Guidelines for VTE management. We assessed the incidence of documented symptomatic VTE, bleeding events, thrombocytopenia, deaths and total events related to VTE or bemiparin prophylaxis (i.e. bleeding, thrombocytopenia). The potential economic impact of postoperative vs. preoperative bemiparin was also analysed.

RESULTS: Clinical records from 197 patients from 5 Spanish centres were checked. Prophylaxis was started postoperatively in 45 patients (22.8%). According to the surgeons' criteria, 73 (37.1%) patients were at high VTE risk and received bemiparin 3500 IU/d. However, according to the criteria of current Guidelines, 189 (95.9%) patients were at high risk of VTE (heterogeneity P-value<0.0001). Three (1.5%) patients, all of them receiving bemiparin 2500 IU/d, developed a symptomatic confirmed VTE. There were 4 major and 5 minor bleeding events during bemiparin prophylaxis. A lower incidence of bleeding (2.2% vs. 5.3%; P=0.48) and total events (2.2% vs. 9.9%; P=0.11) was seen with bemiparin started postoperatively as compared to preoperative bemiparin. Bleeding rates did not significantly differ between patients given low or high bemiparin prophylactic doses (4.0% vs. 5.5%; P=0.72). Two patients died due to cardio-respiratory failure and sepsis, respectively. Postoperative bemiparin provided net cost savings of 909 euro per patient compared to preoperative start of prophylaxis due to shorter hospital stays (9 vs. 11 days) and lower incidence of complications in the postoperative bemiparin group.

CONCLUSIONS: Many cancer patients are still poorly assessed for risk of VTE. Bemiparin 3500 IU/d is associated with a lower incidence of VTE without significant increase in complications as compared with bemiparin 2500 IU/d. Postoperative bemiparin prophylaxis seems to be as effective and safer than preoperative start of prophylaxis. Further prospective clinical studies are needed to fully address this issue.