Management of patients on warfarin by general dental practitioners in South West Wales: continuing the audit cycle

Abstract

To ascertain the current management protocols of patients on warfarin by general dental practitioners (GDPs) in South West Wales and to compare these findings with current guidelines and the results from a previous audit published in 2003. A questionnaire similar to that used in the first audit was sent to 447 GDPs in South West Wales. In addition, questions were included on factors which might affect international normalised ratio (INR), the timing of pre-operative INR assessment and the risk of bleeding associated with implant surgery. GDPs' details were derived from the online GDC database of registered dental practitioners. Registered specialists and GDPs who practised only orthodontics were excluded. Of the 447 questionnaires distributed, 332 (74%) were returned. Eight percent (n = 26) of the respondents did not treat patients on warfarin. Two hundred and forty-seven respondents (74%) considered implant placement as a procedure with high risk of bleeding, with inferior dental block, sub-gingival restorations and sub-gingival debridement receiving a lower response (45%, 28% and 12%, respectively). When planning a high risk procedure, 206 respondents (63%) indicated they would seek advice from a cardiologist or general medical practitioner; none of the respondents would advise the patient to reduce their warfarin dose, while 1% indicated they would ask the patient to stop taking warfarin without seeking any medical opinion. A total of 278 respondents (84%) stated they would check the INR before treatment and of these, 214 (65%) indicated they would do so within 24 hours of treatment and 60 (18%) within 48 hours. Ten respondents said they would not normally check INR. One hundred and twelve respondents (34%) considered 2.5 as the safe upper INR limit for performing high risk procedures, 21 (6%) considered an INR of between 1 and 2 as the safe limit, 99 (30%) considered and INR of 3 as safe, 36 (10%) considered 3.5 as safe and 36 (10%) considered an INR of 4 as safe. Finally, 286 respondents (86%) considered drug interactions and 236 (71%) considered alcohol as significant influencing factors on INR. The findings demonstrate a broad change in practice towards the new recommendations produced in 2001 but also highlight that further education and support may be necessary, as well as greater consistency in published guidelines.