Dental OSCE (Objective Structured Clinical Examination) Practice Exam

Which tests are typically performed to monitor Warfarin therapy?

1. PT and INR

2. PTT and INR

3. PT and APTT

4. PTT only

The correct answer is: PT and INR

Monitoring Warfarin therapy is primarily carried out using two specific tests: Prothrombin Time (PT) and International Normalized Ratio (INR). PT measures the time it takes for blood to clot and helps assess the extrinsic pathway of coagulation, which is affected by Warfarin. INR is a standardized way of expressing PT that accounts for variations in different lab testing methods, ensuring that results are consistent regardless of where the test is performed. The need for using both PT and INR arises because they provide crucial information about the anticoagulation status of patients on Warfarin, allowing healthcare providers to adjust dosages appropriately to maintain therapeutic levels and minimize the risk of bleeding or clotting complications. In this context, INR specifically helps to guide the dosing of Warfarin to ensure patients remain within the desired therapeutic range. Other tests such as partial thromboplastin time (PTT) and activated Partial Thromboplastin Time (APTT) are not typically used for monitoring Warfarin therapy as they primarily evaluate different pathways of the coagulation cascade that Warfarin does not significantly influence. This distinction is important for effective management of patients on anticoagulation therapy.