International normalized ratio (INR) values in patients receiving oral vitamin K antagonists and undergoing oral surgery : a clinical audit

Introduction: Dental extractions can be safely carried out on patients under vitamin K antagonists (VKAs) therapy, without stopping or changing the dosage, but the international normalized ratio (INR) needs to be monitored on the day of the intervention, showing adequate rates before proceeding. Objectives: This study aims at evaluating INR values, measured before oral surgery procedures, to assess the rate of patients, under VKAs therapy, outside the therapeutic range. Materials and methods: A clinical audit was carried out involving patients under VKAs, who needed minor oral surgery procedures, over a period of 18 months. The patient was instructed to not modify or suspend VKAs prior to the intervention. Before surgery, each patient fulfilled a questionnaire on dietary and oral hygiene habits, and a blood sample was collected for INR assessment (cut-off value for surgical procedure ≤3.5). Results: One hundred twenty-two patients were enrolled: 69 (56.6%) had an INR value within the established therapeutic range, 53 (43.4%) were out of range. No intra- or postsurgical major bleeding was recorded. Conclusions: INR, measured on the same day of oral surgery, has the potential to prevent bleeding complications by the identification of those patients out of range, who may require adjusting the drug therapeutic dosage.