CLINICAL PRACTICE GUIDELINES The Society of Thoracic Surgeons, The Society of Cardiovascular Anesthesiologists, and The American Society of ExtraCorporeal Technology: Clinical Practice Guidelines* Anticoagulation During Cardiopulmonary Bypass Linda Shore-Lesserson, MD, Robert A. Baker, PhD, CCP, Victor A. Ferraris, MD, PhD, Philip E. Greilich, MD, David Fitzgerald, MPH, CCP, Philip Roman, MD, MPH, and John W. Hammon, MD Department of Anesthesiology, Zucker School of Medicine at Hofstra Northwell, Hempstead, New York; Cardiac Surgery Research and Perfusion, Flinders University and Flinders Medical Center, Adelaide, South Australia, Australia; Division of Cardiovascular and Thoracic Surgery, University of Kentucky, Lexington, Kentucky; Department of Anesthesiology and Pain Management, University of Texas-Southwestern Medical Center, Dallas, Texas; Division of Cardiovascular Perfusion, Medical University of South Carolina, Charleston, South Carolina; Department of Anesthesiology, Saint Anthony Hospital, Lakewood, Colorado; and Department of Cardiothoracic Surgery, Wake Forest University School of Medicine, Winston-Salem, North Carolina Despite more than a half century of safe cardiopulmo- nary bypass (CPB), the evidence base surrounding the conduct of anticoagulation therapy for CPB has not been organized into a succinct guideline. For this and other reasons, there is enormous practice variability relating to the use and dosing of heparin, monitoring heparin anti- coagulation, reversal of anticoagulation, and the use of alternative anticoagulants. To address this and other gaps, The Society of Thoracic Surgeons, the Society of Cardio- vascular Anesthesiologists, and the American Society of Extracorporeal Technology developed an Evidence Based Workgroup. This was a group of interdisciplinary pro- fessionals gathered to summarize the evidence and create practice recommendations for various aspects of CPB. To date, anticoagulation practices in CPB have not been standardized in accordance with the evidence base. 