Post on 01-May-2018
Cardiopulmonary Bypass
Christina T. Mora EDITOR
Robert A. Guyton ASSOCIATE EDITORS
Donald C. Finlaysont Richard L. Rigatti
Cardiopulmonary Bypass
Principles and Techniques of Extracorporeal Circulation
With 219 Figures
Springer-Verlag New York Berlin Heidelberg London Paris Tokyo Hong Kong Barcelona Budapest
EDITOR Christina T. Mora, M.D. Department of Anesthesiology Emory University School of Medicine Atlanta, GA 30322 USA
ASSOCIATE EDITORS Robert A. Guyton, M.D. Division of Cardiothoracic Surgery Emory University School of Medicine Atlanta, GA 30322 USA
Donald C. Finlayson, M.D., F.R.C.P.CC.) tDeceased
Richard L. Rigatti, B.S., C.T., C.C.T. Perfusion Services Emory University Hospitals Atlanta, GA 30322 USA
Library of Congress Cataloging-in-Publication Data Cardiopulmonary bypass : principles and techniques of extracorporeal
circulation / [edited by] Christina T. Mora ... let aLl. p. cm.
Includes bibliographical references and index. ISBN-13:978-1-4612-7557-2 I. Cardiopulmonary bypass. 2. Blood - Circulation, Artificial.
I. Mora, Christina T. [DNLM: I. Cardiopulmonary Bypass. 2. Heart, MechanciaL WG 168
C26622 1995] RD598.C3546 1995 617.4'12059-dc20 94-29083
Printed on acid-free paper.
© 1995 Springer-Verlag New York Inc. Softcover reprint of the hardcover 1st edition 1995
All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer-Verlag New York, Inc., 175 Fifth Avenue, New York, NY 10010, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use of general descriptive names, trade names, trademarks, etc., in this publication, even if the former are not especially identified, is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone. While the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.
Production managed by Laura Carlson; manufacturing supervised by Rhea Talbert. Typeset by Bytheway Typesetting Services, Inc., Norwich, NY.
9 8 7 6 5 432 1
ISBN-13:978-1-4612-7557-2 e-ISBN-13:978-1-4612-2484-6 DOl: 10.1007/978-1-4612-2484-6
This work is dedicated to:
My parents, Elizabeth and Jorge, for their faith;
My husband, Dennis Mangano, for his love and patience;
and to our son, Thomas Jorge, for his gift of grace.
Foreword
Medical technology is so deeply indebted to so many scientific creditors that a late-coming analyst cannot easily trace the movements of intellectual capital that bankrolled a successful clinical enterprise. Cardiopulmonary bypass is one of the triumphs of medical technology, both in terms of volume (approaching one million procedures a year worldwide) and cost-effectiveness. If John Gibbon stands out as the tenacious broker who transformed a laboratory curiosity into a tool that surgeons would buy and use, contributions from many others - engineers, physiologists, and internists of all kinds - can also be recognized in the many facets of cardiopulmonary bypass. As its acceptance and use continue to expand, further investments of technology and clinical wisdom are still needed.
The Emory authors of this textbook have benefited from a long-standing local tradition of investigative work, clinical audit, and postgraduate education. Thirty years ago, in the pioneer days of cardiopulmonary bypass, attention was, of necessity, focused on devices and components, and on the degree of physiologic damage that could be tolerated to see the patient through a dangerous procedure. Nowadays, the emphasis is on the patient-or, more precisely, on the clinical impact of any procedure, material, component, or monitoring system that over the years has found its place in the care of cardiac patients.
The mechanics of cardiopulmonary bypass reflect the convergence of the efforts of several device manufacturers on a limited number of blood-contracting materials and gas-exchange and pumping systems, as well as much closer attention to quality control and cost containment. The procedure of cardiopulmonary bypass is reasonably well standardized. Physiology remains the frontier. New technology allows us to question accepted procedures, as exemplified by the advent of continuous-flow centrifugal pumps, warm retrograde cardioplegia, and normothermic body perfusion techniques. Yet innovation must be placed in the perspective of welldocumented earlier experience, with proper attention to second-order effects on all organ systems. The physiologic consequences of cardiopulmonary bypass are much more extensive than was once thought, even though the morbidity of the procedure has been considerably reduced.
A better appreciation of the potential and the limits of cardiopulmonary bypass has allowed its recent application to special patient populations other than candidates for cardiac surgery. Its use as a mechanical or metabolic aid, after many false starts, now appears firmly established, even though the volume of cases in which its use is indicated is still quite small.
All of these issues are addressed in this text, which places innovation in the context of well-established knowledge. As a long-term observer of medical science
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and technology as applied to cardiopulmonary bypass, I congratulate Dr. Mora and her coauthors. I am confident that this textbook will enhance the proficiency of those who study it and will thereby contribute to continuing improvement in the quality of patient care in cardiac surgery.
Pierre M. Galletti, Ph.D., M.D.
Preface
Although the basic concept of extracorporeal circulation is almost 200 years old, the technique of cardiopulmonary bypass (CPB) has been used routinely in surgical procedures for only about 40 years. During the latter part ofthis century, however, the heart-lung machine has enabled the rapid growth of heart surgery, so that, by 1995, over 500,000 cardiac operations using CPB will have been performed in the United States alone.
The last decade has also witnessed an increase in the use of extracorporeal technology in the non-cardiac surgery patient. Cardiologists have brought the bypass circuit to the angioplasty suite; circulatory arrest is being used to facilitate intracranial surgery; and clinical trials to assess an intravenous oxygenator are underway. Although fatalities directly attributable to modern CPB techniques are remarkably few, extracorporeal support of cardiorespiratory function is still associated with multiple pathophysiologic processes and attendant morbidity. But with continued research and acquired knowledge, the adverse events that often accompany these life-saving techniques can be eliminated. With that goal in mind, Cardiopulmonary Bypass has been designed to provide a compendium of the current knowledge regarding the clinical practice, pathophysiology, and future direction of extracorporeal circulation.
The text is presented in seven parts. Part I, authored by a pioneer in the field of extracorporeal technology, recounts the history of the development of CPB. Part II outlines the physiology and pathophysiology of CPB. These chapters discuss both hemostasis and myocardial protection during bypass, and detail the effects of perfusion on the central nervous, respiratory, renal, hepatic, and immune systems and endocrine axis. Parts III and IV focus on the mechanics and conduct of bypass. These chapters describe the components of the heart-lung machine (oxygenators, pumps, heat exchange devices, etc.) and the procedural aspects of perfusion (cannulation, initiation and maintenance of bypass, discontinuation of bypass support, and management of perturbations). CPB in specific patient populations is explored in Parts V and VI. The use of extracorporeal circuits and oxygenators is increasing in non-cardiac surgery (intracranial, thoracic, liver transplantation, and high-risk angioplasty patients) and outside the operating room (ventricular assist devices in bridge-to-transplant patients or patients recovering from myocardial failure; extracorporeal membrane oxygenation in the pediatric and adult patient). Because the conduct of CPB in pediatric, obstetric, and thoracic surgery patients requires special expertise, the care of these patients during perfusion is considered in detail in Part V. Topics of current interest are found in Part VII and include normothermic bypass (Chapter 34) and blood conservation (Chapter 31 ) during cardiac surgery.
The book is intended to serve as a comprehensive text on the subject of CPB
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for surgeons, perfusionists, and anesthesiologists. This somewhat difficult task is accomplished by presenting both basic concepts and detailed knowledge on a given subject in language intended for all readers. A specific chapter may be of greater interest to one group, but every chapter contains essential information. For example, a grasp of basic pharmacokinetic principles (Chapter 4) is necessary to the perfusionist who requires a fundamental understanding of drug disposition during bypass, but who may be less likely to study the effect of bypass on a certain antibiotic. Similarly, the surgeon and anesthesiologist should understand the basic principles of extracorporeal oxygenation (Chapter 10) and heat exchange (Chapter 14), but may not need to know the specific thermal constants of the materials used in heat exchange devices. Several chapters, however - such as Chapter 17, on the discontinuation of bypass support, and Chapter 18, on the management of perturbations - will be vital to all readers. These chapters emphasize the importance of communication among the surgeon, perfusionist, and anesthesiologist during these critical events.
I would like to thank those who provided valuable assistance in the preparation of this text. I have been privileged to work with members of the Emory University School of Medicine, Department of Anesthesiology and the Division of Cardiothoracic Surgery; many of these colleagues gave generously of their time and support. Pierre Galletti, author of Heart Lung Bypass (1962), which served as the inspiration for this work, provided both direction and moral support during the course of this project. J. Devn Cornish kindly allowed me to recruit his expert help in editing many of the chapters on the technical aspects of perfusion, and the text benefited greatly from his contribution.
The day-to-day progress on this text was ensured by my secretary, Louise Evans, and I feel fortunate to have worked with this dedicated and tenacious individual. Helen Fontsere, editor for the Emory Department of Anesthesiology, polished each chapter and provided invaluable help in citing references, obtaining letters of permission, and addressing the myriad of tasks required to make a manuscript publisher-ready. Mary Lopez and Michele Mitchell offered encouragement and administrative support. Members of the Emory Department of Medical Illustration created many of the illustrations and photographs; Patsy Bryan, Nancy Mathews, Benjamin King, Jack Kearse, and Chuck Bogle never grumbled when I requested "one more" revision.
I am grateful to the publishers at Springer-Verlag for their enthusiasm and commitment to this book. Esther Gumpert, Laura Gillan, Andrea Seils, and the production staff contributed their seasoned expertise and ensured an orderly and timely production process.
Finally, I thankfully acknowledge the support of my husband, Dennis Mangano, who weathered the first year of our marriage in San Francisco while I completed this text in Atlanta.
Christina Mora Mangano, M.D.
Contents
Foreword.......................................................................................... vii Pierre M. Galletti
Preface .............................................................................................. ix Christina T. Mora
Contributors............... ..................................................................... xv
Part I. The History of Cardiopulmonary Bypass
1. Cardiopulmonary Bypass: The Historical Foundation, the Future Promise...................................................................... 3 Pierre M. Galletti and Christina T. Mora
Part II. Physiology of Cardiopulmonary Bypass
2. The Myocardium: Physiology and Protection During Cardiac Surgery and Cardiopulmonary Bypass ........................................................ 21 Robert A. Guyton
3. Hypothermia, Cardiac Surgery, and Cardiopulmonary Bypass............... 40 Willis H. Williams, Hakob G. Davtyan, and Milada Drazanova
4. Pharmacokinetics and Pharmacodynamics During Cardiac Surgery and Cardiopulmonary Bypass.............................................................. 55 Richard I. Hall, Brian L. Thomas, and Carl C. Hug, Jr.
5. Hemostasis and Cardiopulmonary Bypass......................................... 88 Markku T. Salmenperii, Jerrold H. Levy, and Laurence A. Harker
6. The Central Nervous System: Responses to Cardiopulmonary Bypass...... 114 Christina T. Mora and John M. Murkin
7. The Respiratory, Renal, and Hepatic Systems: Effects of Cardiac Surgery and Cardiopulmonary Bypass .......... ....... ................ ....... ...... 147 James G. Ramsay
8. The Immunologic System: Perturbations Following Cardiopulmonary Bypass and the Problem of Infection in the Cardiac Surgery Patient........ 169 Bradley L. Bufkin, John P. Gott, Christina T. Mora, and Jerrold H. Levy
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xii Contents
9. The Endocrine System: Effects of Cardiopulmonary Bypass.................. 180 Carolyn F. Bannister and Donald C. Finlayson
Part III. Mechanics and Components of the Heart-Lung Machine
10. Oxygenators for Extracorporeal Circulation ...................................... 199 Philip D. Beckley, David W. Holt, and Richard D. Tallman, Jr.
11. Mechanical Pumps for Extracorporeal Circulation.............................. 220 Christopher R. Trocchio and James O. Sketel
12. Conduits and Filters for Extracorporeal Circulation ............................ 229 Kathy K. Spitzer and Charles T. Walker
13. Assembling and Monitoring the Extracorporeal Circuit ........................ 238 Richard B. Davis, Jeffrey N. Kauffman, Terry L. Cobbs, and Sharon L. Mick
14. Heat Exchange in Extracorporeal Systems ................. ........................ 247 Richard L. Rigatti and Roger Stewart
Part IV. Conduct of Cardiopulmonary Bypass for Cardiac Surgery
15. Aortoatriocaval Cannulation for Cardiopulmonary Bypass ................... 257 Mark W. Connolly
16. Initiation and Maintenance of Cardiopulmonary Bypass....................... 264 James R. Zaidan
17. Discontinuation of Cardiopulmonary Bypass.. ..... ...... ....... ..... ............ 281 Luis G. Michelsen and Jack S. Shane wise
18. Safety and Management of Perturbations During Cardiopulmonary Bypass.............................................................. 298 Scott M. Sadel
Part V(a). Cardiopulmonary Bypass in Special Patient Populations Complete Cardiopulmonary Bypass
19. Pediatric Cardiopulmonary Bypass.................................................. 311 James M. Bailey and William L. Daly
20. Thoracic Aortic Surgery and Cardiopulmonary Bypass........................ 329 Tomas D. Martin
21. Intracranial Surgery with Cardiopulmonary Bypass............................. 340 Brian L. Thomas
22. Emergency Coronary Artery Bypass and Cardiopulmonary Bypass......... 347 Joseph M. Craver
23. Chest Trauma and Emergency Cardiopulmonary Bypass ...................... 353 Panagiotis N. Symbas
24. Pregnancy and Cardiopulmonary Bypass.......................................... 359 Christina T. Mora
Contents
Part V(b). Cardiopulmonary Bypass in Special Patient Populations Partial Cardiopulmonary Bypass
xiii
25. Cardiopulmonary Bypass-Supported Angioplasty............................... 379 Steven K. Macheers
26. Closed Chest Bypass for Liver Transplantation .................................. 389 Linda E. McLean, Scott M. Kreger, and Christina T. Mora
Part VI. Mechanical Assist of the Failing Heart and Lung
27. Ventricular Assist Devices............................................................. 399 Bradley L. Bufkin and Robert A. Guyton
28. Intraaortic Balloon Pump Counterpulsation ...................................... 413 John P. Gott
29. Extracorporeal Membrane Oxygenation for Severe Cardiorespiratory Failure...................................................................................... 433 J. Devn Cornish
30. The Intravascular Oxygenator, IVOX®: Augmentation of Blood-Gas Transfer..................................................................... 450 Robert K. Wenger and JD Mortensen
Part VII. Special Considerations in Cardiopulmonary Bypass
31. Blood Conservation in Cardiac Surgery............................................ 461 James G. Cormack, Robert W. Bolen, and Dirk A. Maisel
32. Religious Objections to Blood Transfusion........................................ 473 Robert B. Lee and Tomas D. Martin
33. Medical-Legal Aspects of Cardiopulmonary Bypass ............................ 481 Tomas D. Martin and Charles R. Hatcher, Jr.
34. Warm-Blood Cardioplegia and Normothermic Cardiopulmonary Bypass ...................................................................................... 484 Robert A. Guyton
Index ............................................................................................. 493
Contributors
JAMES M. BAILEY, M.D., Ph.D., Assistant Professor of Anesthesiology and Pediatrics, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
CAROLYN F. BANNISTER, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
PHILIP D. BECKLEY, Ph.D., Assistant Professor of Circulation Technology, Director, Circulation Technology Division, School of Allied Medical Professions, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
ROBERT W. BOLEN, B.S., C.C.P., Chief Perfusionist, Emory University Hospitals, Atlanta, GA 30322; Clinical Instructor of Circulation Technology, School of Allied Medical Professions, The Ohio State University, Columbus, OH 43210, USA
BRADLEY L. BUFKIN, M.D., Resident, Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
TERRY L. COBBS, B.S., C.C.P., Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
MARK W. CONNOLLY, M.D., Assistant Professor of Surgery (Cardiothoracic), Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
JAMES G. CORMACK, M.D., Assistant Professor of Anaesthesia, Department of Anaesthesia, University of Alberta, Edmonton, Alberta T6G 2B7, Canada
J. DEVN CORNISH, M.D., Associate Professor of Pediatrics, Director, Division of Neonatology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
JOSEPH M. CRAVER, M.D., Professor of Surgery (Cardiothoracic), Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
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xvi Contributors
WILLIAM L. DALY, B.S., C.C.P., Chief Perfusionist, Egleston Children's Hospital, Perfusion Services, Emory University Hospitals, Atlanta, GA 30322; Clinical Instructor of Circulation Technology, School of Allied Medical Professions, The Ohio State University, Columbus, OH 43210, USA
RICHARD B. DAVIS, Ph.D., Assistant Professor of Circulation Technology, Circulation Technology Division, School of Allied Medical Professions, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
HAKOB G. DAVTYAN, M.D., Resident, Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
MILADA DRAZANOVA, M.D., Clinical Research Assistant, Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
DONALD C. FINLAYSON, M.D., F.R.C.P.(C.), Deceased
PIERRE M. GALLETTI, Ph.D., M.D., University Professor and Professor of Medical Science, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
JOHN P. GOTT, M.D., Assistant Professor of Surgery (Cardiothoracic), Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
ROBERT A. GUYTON, M.D., Professor of Surgery (Cardiothoracic), Chief, Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
RICHARD I. HALL, M.D., Associate Professor of Anaesthesiology and Pharmacology, Assistant Professor of Surgery, Department of Anaesthesiology, Dalhousie University; Director, Surgical Intensive Care Unit, Department of Anaesthesiology, Victoria General Hospital, Halifax, Nova Scotia B3H 2Y9, Canada
LAURENCE A. HARKER, M.D., Blomeyer Professor of Medicine, Director, Division of Hematology/Oncology, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
CHARLES R. HATCHER, Jr., M.D., Vice President for Health Affairs and Director, Woodruff Health Sciences Center, Emory University, Atlanta, GA 30322, USA
DAVID W. HOLT, B.S., C.C.T., Clinical Instructor of Circulation Technology, Circulation Technology Division, School of Allied Medical Professions, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
CARL C. HUG, Jr., M.D., Ph.D., Professor of Anesthesiology and Pharmacology, Deputy Chairman for Research, Department of Anesthesiology, Emory University School of Medicine; Director, Cardiothoracic Anesthesia, The Emory Clinic, Atlanta, GA 30322, USA
Contributors xvii
JEFFREY N. KAUFFMAN, B.C., C.C.P., C.C.T., Chief Perfusionist, Crawford Long Hospital of Emory University Hospitals, Atlanta, GA 30322; Clinical Instructor of Circulation Technology, School of Allied Medical Professions, The Ohio State University, Columbus, OH 43210, USA
SCOTT M. KREGER, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
ROBERT B. LEE, M.D., Assistant Professor of Surgery (Cardiothoracic), Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
JERROLD H. LEVY, M.D., Associate Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
STEVEN K. MACHEERS, M.D., Resident, Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
DIRK A. MAISEL, B.S., C.C.P., Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
TOMAS D. MARTIN, M.D., Associate Professor of Surgery, Department of Surgery, University of Florida, College of Medicine; Chief, Adult Cardiovascular Surgery, University of Florida Health Science Center, Gainesville, FL 32610, USA
LINDA E. McLEAN, B.S., C.C.T., C.C.P., Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
LUIS G. MICHELSEN, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
SHARON L. MICK, B.S., C.C.P., Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
CHRISTINA T. MORA, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
JD MORTENSEN, M.D., President, Oxygenator Technology Development, Inc., Salt Lake City, UT 84116, USA
JOHN M. MURKIN, M.D., Professor of Anaesthesia, Department of Anaesthesia, University of Western Ontario, London, Ontario N66 3S5, Canada
JAMES G. RAMSAY, M.D., Associate Professor of Anesthesiology, Director, Critical Care Medicine, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
xviii Contributors
RICHARD L. RIGATTI, B.S., C.T., C.C.T., Director, Perfusion Services, Emory University Hospitals, Atlanta, GA 30322; Clinical Instructor of Circulation Technology, School of Allied Medical Professions, The Ohio State University, Columbus, OH 43210, USA
SCOTT M. SADEL, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
MARKKU T. SALMENPERA, M.D., Associate Professor of Anesthesia, Department of Anesthesia, Helsinki University, FIN-00290 Helsinki, Finland
JACK S. SHANEWISE, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
JAMES O. SKETEL, B.S., C.C.P., Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
KATHY K. SPITZER, B.S., C.C.P., C.C.T., Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
ROGER STEWART, B.S.M.E., P.E., Cardiopulmonary Products, Cobe Laboratories, Arvada, CO 80004, USA
PANAGIOTIS N. SYMBAS, M.D., Professor of Surgery (Cardiothoracic), Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
RICHARD D. TALLMAN, Jr., Ph.D., Associate Professor of Circulation Technology, Circulation Technology Division, School of Allied Medical Professions, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
BRIAN L. THOMAS, M.D., Assistant Professor of Anesthesiology, Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
CHRISTOPHE~R. TROCCHIO, B.S., C.C.P., Perfusion Education Coordinator, Emory University Hospitals, Atlanta, GA 30322; Clinical Instructor of Circulation Technology, School of Allied Medical Professions, The Ohio State University, Columbus, OH 43210, USA
CHARLES T. WALKER, C.C.P., Chief Perfusionist, Veterans Administration Medical Center; Perfusionist, Emory University Hospitals, Atlanta, GA 30322, USA
ROBERT K. WENGER, M.D., Resident, Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
WILLIS H. WILLIAMS, M.D., Professor of Surgery (Cardiothoracic), Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA
JAMES R. ZAIDAN, M.D., Professor of Anesthesiology, Deputy Chairman for Education, Department of Anesthesiology, Emory University School of Medicine; Chief of Anesthesia, Emory University Hospital, Atlanta, GA 30322, USA