The management of anticoagulated patients requiring dental extraction: a cross-sectional survey of oral and maxillofacial surgeons and hematologists

To cite this article: Lim W, Wang M, Crowther M, Douketis J. The management of anticoagulatedpatients requiring dental extraction: a crosssectional survey of oral and maxillofacial surgeons and hematologists. J Thromb Haemost 2007; 5: 2157–9. The management of patients receiving long-term oral anticoagulationwho require dental extractionis based on an assessment of risks: the risk of procedure-related bleeding if anticoagulantsare continued measured against the thromboembolic risk if anticoagulantsare stopped. Before the introduction of the International Normalized Ratio (INR) and standardization of the anticoagulantrange for most indications, studies suggested that there was increased bleeding if coumarins were continued in patients undergoing dental procedures [1]. More recent studies assessing bleeding among anticoagulatedpatients as compared to patients who stopped warfarin or as compared to non- anticoagulatedpatients demonstrated no increase in bleeding among the anticoagulatedpatients [2–5]. There are currently no guidelines detailing anticoagulantmanagement or optimal INR level in patients receiving warfarin who undergo dental extraction. Consensus guidelines from the American College of Chest Physicians provide a Grade 2B recommendation that anticoagulanttherapy be continued and tranexamic acidor e- aminocaproic acidmouthwash be used if there is concern regarding local bleeding [6]. Despite this recommendation, anticoagulantsare routinely discontinued; in a 1996 survey, 56% of physicians indicated that they discontinued anticoagulantsroutinely in patients undergoing a single dental extraction[7]. Using a cross-sectional survey design, we compared how oral and maxillofacial surgeons (OMS) and hematologistsmanage warfarin in patients requiring dental extraction, to assess perceived risks of thrombosis and bleeding between these two groups of clinicians and to examine the rationale for warfarin discontinuation despite the literature recommendations. The survey was mailed in November 2005 to practicing OMS and hematologistsin Ontario, Canada. Survey recipients were identified using provincial membership registries (Royal College of Dental Surgeonsof Ontario and the College of Physicians and Surgeons of Ontario). Membership in these associations is mandatory for all actively practicing OMS and hematologists. The survey consisted of two parts: (i) management of warfarin (how warfarin was discontinued and reinitiated); and (ii) assessment of perceived thrombotic and bleeding risks [using short descriptions of hypothetical patients with low, moderate and high thrombotic and bleeding risks, we asked respondents to rate the risk of thrombosis or bleeding using a visual analog scale from 1 to 10 (lowest to highest risk)]. The survey was pretested by a hematologistand general dentist to ensure face validityand accuracy. Data were collected on paper surveys and entered into an EXCEL database. Because the respondents may not have answered all of the questions in the survey, proportions were calculated on the basis of the total number of respondents for any particular question. To compare the perceived thrombotic and bleeding risks, the mean score for each scenario was calculated for OMS and hematologists, and compared by unpaired t-tests using SPSS, version 12.0 (SPSS 15.0 for Windows; SPSS Inc., Chicago, IL, USA). We mailed 291 surveys to 168 OMS and 123 hematologistsin November 2005. In total, 137 (47%) surveys were returned; 82 (48.8%) eligible OMS and 55 (44.7%) eligible hematologistsresponded. The responding OMS were mostly communitybased (75.6%) with a mean of 24 years (range: 1–48 years) in clinical practise. The hematologistswere mainly from academic or combined academic and community practise (76.4%) with a mean of 13 years (range: 1–38 years) in clinical practise. The warfarin management for the two groups is presented in Table 1. Warfarin is discontinued at least 50% of the time by 70% of hematologistsfor a mean of 4.4 days prior to dental extractionaiming for an INR no higher than 2.5, with 72% using bridging anticoagulationprior to the procedure. Warfarin is discontinued at least 50% of the time by 37% of the OMS for a mean of 3.2 days prior to the procedure aiming for an INR no higher than 3.0, with 41% using bridging anticoagulation. The mean visual analog scores for the thrombotic and bleeding scenarios are shown in the latter half of Table 1. In all thrombotic scenarios, with the exception of the highest thrombotic risk, OMS consistently rated thrombotic risk higher than did hematologists(P < 0.001). In contrast, the OMS rated bleeding risk lower than did hematologists, but this was only significant for patients at the highest bleeding risk. In scenarios combining both thrombotic and bleeding risks,