978-1-4612-7557-2 Book PrintPDF - Springer978-1-4612-2484-6/1.pdfCardiopulmonary bypass : ... These chapters describe the components of the heart-lung machine (oxygenators, ... will

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.

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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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viii Foreword

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

ix

x Preface

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

xi

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

xv

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