Background: Patients undergoing elective Lower limb arthroplasty are at increased risk of deep vein thrombosis (DVT). On reviewing the literature, there is a lack of evidence about the best time to administer anticoagulants post-operatively - recommended between 6 and 12 hours. In addition the recent American College of Chest Physicians guidelines recommends that postoperative DVT prophylaxis is given for a minimum of 10 days.
The principal aim of this audit was to assess the timing and duration of thromboprophylaxis post-arthroplasty in our unit.
Methods: Data was collected prospectively. We recorded the timing of the first post operative dose of Fragmin following closure of the wound along with duration of treatment. 5 months of data were analysed; changes were suggested and implemented. This included 2 post operative Fragmin ward rounds. The first at 6pm for patients undergoing surgery in morning and a second at 10pm for those in the afternoon. All patients now receive prophylaxis for 10 days. If they were discharged before 10 days they were sent home on Fragmin. A further analysis was carried out six months later for a further five months.
Results: Initial Audit – 330 patients – primary hip or knee replacement
The timing from finishing surgery to receiving Fragmin ranged from 0:31 to 8:37. 11% received Fragmin less than 2 hours post operatively, 12% 2–4 hours post operatively, 27% 4–6 hours and 49% 6–8 hours
The Duration of prophylaxis ranged from 3 to 32 days. 54% received prophylaxis for less than 7 days.
Second Audit – 337 patients – primary hip or knee replacements
The delay from completing surgery to receiving Fragmin ranged from 2:05 to 9:38. Now only 2% received Fragmin less than 4 hours post operatively. Only 51%, however received Fragmin 6–10 hours post op.
All patients received Fragmin for a minimum of 10 days in the second audit
Discussion: The initial audit highlighted potentially dangerous practice in our venous throboprophylaxis regime. Changes were instituted.
The new protocol for post-operative Fragmin administration had little impact on the percentage of patients receiving Fragmin within 6 hours of surgery. The results, however, show that only 8 of these patients received anti-coagulation within 4 hours, a definite improvement on the initial audit.
Following the changes to Fragmin continuation at discharge, inpatient stay is now not an indicator of duration of Fragmin therapy. All patients now receive 10 days of Fragmin, either as inpatients or in the community.
Conclusion: The change in protocol has reduced the number of patients receiving anti-coagulation less than 4 hours after surgery. However there are still a significant number of patients who receive Fragmin under the recommended 6 hours post-operative.
