Warfarin discontinuation for dental extraction 'placing patients at risk'

W. LIM, M. WANG, M. CROWTHER, J. DOUKETIS (2007)
The management of anticoagulated patients requiring dental extraction: a cross-sectional survey of oral and maxillofacial surgeons and hematologists
Journal of Thrombosis and Haemostasis 5 (10), 2157–2159.
doi:10.1111/j.1538-7836.2007.02700.x


MedWire News: Warfarin treatment is inappropriately stopped before dental extraction by a significant proportion of hematologists and oral and maxillofacial surgeons (OMS), potentially placing patients at increased risk of thromboembolic complications, conclude Canadian researchers.

An assessment of risks is an essential part of the management of patients receiving long-term oral anticoagulation who require dental extraction, balancing the risk of procedure-related bleeding if anticoagulants are continued against the thromboembolic risk if they are stopped.

Noting that, despite consensus guidelines from the American College of Chest Physicians saying that anticoagulant therapy should be continued, the drugs are routinely discontinued, the researchers sent a survey on attitudes towards warfarin management in patients requiring dental extraction to 168 OMS and 123 hematologists.

In all, 137 surveys were returned, yielding 82 eligible responses from OMS and 55 from hematologists. Of the OMS that responded, 75.6% were community based and had an average of 24 years in clinical practice, while 76.4% of hematologists were from academic or combined academic and community practice and had an average of 13 years in clinical practice.

Among hematologists, 70% of practitioners discontinued warfarin at least 50% of the time for an average of 4.4 days prior to dental extraction, aiming for an international normalized ratio (INR) of no more than 2.5. Bridging anticoagulation prior to the procedure was used by 72% of hematologists.

In comparison, 37% of OMS discontinued warfarin at least 50% of the time for an average of 3.2 days prior to the procedure, aiming for an INR of no more than 3.0. In addition, 41% of OMS used bridging anticoagulation, Wendy Lim and colleagues, from McMaster University in Ontario, write.

OMS were found to consistently rate the thombrotic risk higher than did hematologists in all bleeding scenarios apart from those involving the highest thrombotic risk. OMS rated bleeding risks lower than did hematologists, but only for patients with the highest bleeding risk.

In scenarios that combined both bleeding and thrombotic risks, rates of discontinuation of warfarin was approximately 50% higher in hematologists than in OMS. For patients with high thrombotic risk and low bleeding risk, warfarin was discontinued by 19% of OMS and 35% of hematologists.

The team concludes in the Journal of Thrombosis and Haemostasis: "Increasing education and awareness among hematologists and OMS that dental extraction does not require routine anticoagulant discontinuation is a priority that may minimize patient risk."

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