Warfarin reversal: consensus guidelines, on behalf of the Australasian Society of Thrombosis and Haemostasis

Warfarin cessation is non-essential in patients undergoing total knee arthroplasty--a case-control study

BACKGROUND

Warfarinised patients frequently present for total knee arthroplasty (TKA). Current practice of heparin 'bridging' is potentially cumbersome and hazardous. The research question is if cessation of warfarin is necessary for TKA.

METHODS

The study design was a retrospective case-control series of 61 warfarinised patients and 61 control patients undergoing TKA. TKA was performed by the senior author using a medial parapatellar approach without tourniquet. The target perioperative international normalised ratio (INR) for warfarinised patients was 2-2.2. Primary outcomes were changes in haemoglobin, transfusion requirements and complication rates.

RESULTS

There was no statistically significant difference between control and warfarin group in mean perioperative Hb (g/L) (pre-op 140 vs 141, day 0 115 vs 115, day 1 108 vs 111, P = 0.63), transfusion rates (14.75% vs 9.83%, P = 0.58), total complication rate (9.8% vs 9.8%, P = 0.75), demographics, range of motion or length of stay. There was a statistically significant higher use of the re-infusion drain in the warfarinised group (47.5% vs 24.6%, P = 0.014).

CONCLUSION

This study supports the hypothesis that warfarin cessation is non-essential in patients undergoing TKA. This data is applicable to a patient group using re-infusion drains. Limitations of this study are typical of a small non-controlled observational study.

Warfarin management in patients on continuous anticoagulation therapy undergoing total knee replacement

We evaluated the safety and efficacy of total knee replacement in patients receiving continuous warfarin therapy.

We identified 24 consecutive patients receiving long-term warfarin therapy who underwent total knee replacement between 2006 and 2008 and compared them with a group of age- and gender-matched patients not on long-term anticoagulation. Primary observations were changes in haemoglobin, transfusion rates and complications. Secondary observations were fluctuations in the international normalised ratio (INR) and post-operative range of movement.

There was no significant difference between the two groups in pre- or post-operative haemoglobin, incidence of transfusion or incidence of post-operative complications. There were no surgical delays due to a high INR level. The mean change in INR during the peri-operative phase was minimal (mean 0.4; sd 0.7). There was no significant difference in the range of movement between the two groups after day two post-operatively.

Current American College of Chest Physicians guidelines recommend bridging therapy for high-risk patients receiving oral anticoagulation and undergoing major orthopaedic procedures. We have shown that a safe alternative is to continue the steady-state warfarin peri-operatively in patients on long-term anticoagulation requiring total knee replacement.

Discontinuation of perioperative antiplatelet and anticoagulant therapy in stroke patients

Growing evidence suggests that perioperative withdrawal of ASA for secondary stroke prevention increases thromboembolic risk without the associated benefit of decreased bleeding complications. ASA maintenance is acceptable in many procedures, including invasive ones. Many procedures, in particular ophthalmologic, dermatologic, and dental surgeries, also are safe while continuing oral AC. Warfarin has been continued successfully even in some surgeries that have high bleeding risk. When the risk is too high, temporary bridging therapy with LWMH is safe in many populations. Although the exact thromboembolic risks associated with temporary cessation of AP and AC are unknown and likely low, morbidity and mortality associated with thromboembolism are high. Further studies investigating the risks and benefits of maintaining AP and AC during procedures, particularly invasive ones, are needed. Meanwhile, it is critical that physicians understand the risks and benefits of perioperative AP and AC and the variety of procedures in which these agents can be safely continued.