Coagulation Testing Coagulation Testing David Ray Velez, MD Table of Contents Conventional LabsThrombelastogram (TEG) Conventional Labs Bleeding TimeTest: A Small Incision is Made in a Standardized Fashion and Time is Recorded Until Bleeding StopsEvaluates: Platelet Function (Adhesion and Aggregation)Not Effected by Coagulation Factor DisordersNormal Time: 1-9 MinutesProthrombin Time (PT)Test: Thromboplastin is Added to Plasma and Time is Recorded Until Clot FormsEvaluates: Extrinsic and Common Coagulation Pathway FunctionFactors II, V, VII, and XThe Best Test for Synthetic Liver FunctionNormal Time: 10-12 SecondsPartial Thromboplastin Time (PTT)Test: Calcium and Activated Substances (Kaolin and Cephalin) are Added to Plasma and Time is Recorded Until Clot FormsEvaluates: Intrinsic and Common Coagulation Pathway FunctionAll Factors Except VII and XIIIGoal for Anticoagulation: 60-100 SecondsNormal Time: 30-45 SecondsInternational Normalized Ratio (INR)A Calculated Value from Prothrombin Time (PT)Evaluates: Extrinsic and Common Coagulation Pathway FunctionNormal INR: 1.0Goal for Anticoagulation: 2.0-3.0May Be Higher for Prosthetic Heart ValvesActivated Clotting Time (ACT)Bedside Test Measuring Time to Clot Formation After Activation by Kaolin or CeliteUsed to Monitor Intraoperative Coagulation Function During Cases Using High Doses of HeparinMay Be Obtained Every 20-30 Minutes During the CaseNormal Time: 70-120 SecondsTherapeutic Goals:Dialysis: 160-180 SecondsVascular Surgery: > 150-200 SecondsCABG: 480-600 SecondsSame as R Time in TEG Thrombelastogram (TEG) Thrombelastogram (TEG)*See Thrombelastogram (TEG)