Retrospective Evaluation of Delayed Administration of Fondaparinux in Providing Comparable Safety and Efficacy Outcomes in Patients Undergoing Elective-Arthroplasty Procedures

Purpose To evaluate the selected outcome measures of venous thromboembolic (VTE) events and major bleeding in patients undergoing a major-elective arthroplasty procedure. Comparing fondaparinux initiated 18 to 24 hours after the procedure with alternative regimens recommended by the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy consensus guidelines for prophylaxis of venous thromboembolism. Background The Lehigh Valley Hospital, Cedar Crest campus has three large orthopedic groups providing services at this site. Each group has successfully managed post-surgical bleeding and prophylaxis of VTE occurrences using individually managed anticoagulation regimens. In house monitoring has shown equivalency. Recently, a new agent was FDA-approved that might provide a further reduction in venous embolic events, but potentially at the cost of increased major bleeding. Some data suggest that the ‘timing’ of an anticoagulant's dose may impact both bleeding and thrombotic event rates. However, the exact ‘optimum’ time and regimen to maximize these two divergent outcomes is still elusive. This paper is meant to provide some insight into these issues. Methods The records of all elective major orthopedic procedures involving hip or knee replacement were identified for the period of January 1 to June 30, 2004. Patients (n = 185) receiving fondaparinux 18 to 24 hours after their surgical intervention were compared with all other patients (n = 550) who received any VTE prophylaxis regimen. Electronic chart review was performed by pharmacists to collect preselected outcome data related to these procedures. Patients were evaluated for all cause 30-day readmissions related to bleeding or VTE events and any in- hospital mortality or in-hospital VTE events. Results Of 735 patients, 185 patients received fondaparinux post-operatively in the selected time frame. The remaining 550 patients received either warfarin or enoxaparin. The patients had similar demographic characteristics, and the ratios of procedural events were equivalent. Length of stay (LOS) data were also comparable. Outcome measures as assessed by a 30-day readmission rates for any morbidity, symptomatic venous embolic event, bleeding, or in-hospital VTE event were also statistically equivalent during the analyzed period. No major bleeds were seen in any of the evaluated patients. Conclusions The possibility of using fondaparinux for VTE prophylaxis and initiating therapy at the 18- to 24-hour mark post-operatively appears to provide equivalent levels of safety and efficacy compared to regimens using warfarin or enoxaparin.