AIPPG 2003 Dental MCQ Answer 16

The Correct Answer is D

With advances in medicine, dentists are faced with managing patients with complex medical histories. Frequently, patients on anticoagulation therapy present to the dental office. These patients can be of significant intra-operative and post operative bleeding risk when procedures such as dental extractions, periodontal surgery, biopsies, and even block local anesthesia, are required.

• Management is dependent on the type of procedure being performed, lab test results and type of medication the patient is taking.
  
• Aspirin or Plavix® therapy can be discontinued 7 days prior to surgery which should result in better hemostasis. These drugs can then be restarted safely 48 to 72 hours post-operatively.
  
• For patients taking Coumadin®, proper lab tests should be done and a consult to the physician may be required depending on lab results, medical condition, type of surgery being performed and the possible need for drug dosage reduction.
  
• Studies have shown that extractions can be done in patients with an INR of 2.5 to 3.5 safely, however the higher the INR, the more the need for hemostatic measures. Jeske found that the literature does not support the routine withdrawal of anticoaugulation therapy.
  
• Dentists should be prepared for bleeding that exceeds normal and may have to provide hemostatic measures.
  
• Giglio suggested that single tooth extractions or minimally invasive procedures such as crown lengthening where minimal bleeding is expected, are indicated if the INR is less then 4. In procedures where moderate bleeding is expected, such as block or gingival grafts, an INR of less then 3 is necessary.
  
• Little and Falace’s review of the literature, recommends that surgery may be performed with an INR of 2.0 to 3.0. For INR values of 3.0 to 3.5, it is recommended that the dosage of anticoagulant be altered depending on bleeding expected during the surgical procedure. Surgery should be delayed for values of 3.5 until the INR is within the therapeutic range of 2.0 to 3.5.
  

The physician and dentist should identify the reason the patient is receiving anticoagulation therapy, assess the potential risk versus benefit of altering the drug’s regimen, know the laboratory tests used to assess anticoagulation levels, be familiar with local methods of obtaining hemostasis both interoperatively and postoperatively, be familiar with the potential complications associated with prolonged or uncontrolled bleeding, and consult the patient’s prescribing physician to discuss the type of dental care and investigate the need to alter the anticoagulant regimen. The test that traditionally has been used to test for the anticoagulation level produced by Warfarin therapy is PT. However, because laboratory values varied considerably depending on the type of thromboplastin used in the assay, the World Health Organization introduced the INR 20 years ago. The INR mathematically corrects the PT test results for the quality of the thromboplastin used. Patients who are receiving anticoagulation therapy should have INR values in the range of 2.5-3.5. A patient with normal coagulation parameters would exhibit an INR of 1.0. Scientifically, one would have to have a patient’s INR to make judgment before safely altering an oral anticoagulant dosage recommendation.