Geriatric Anesthesiology Second Edition Geriatric Anesthesiology Second Edition Jeffrey H. Silverstein G. Alec Rooke J.G. Reves Charles H. McLeskey Editors Jeffrey H. Silverstein, MD G. Alec Rooke, MD, PhD Professor Professor Department of Anesthesiology, Surgery, Department of Anesthesiology and Geriatrics and Adult Development University of Washington and the Veterans Vice Chairman for Research Affairs Puget Sound Health Care System Associate Dean for Research Seattle, WA Mount Sinai School of Medicine and New York, NY, USA Visiting Professor of Anesthesia, Critical Care, and Pain Medicine Harvard Medical School Beth Israel Deaconess Medical Center Boston, MA, USA J.G. Reves, MD Charles H. McLeskey, MD Vice President for Medical Affairs Salt Lake City, UT, USA Dean, College of Medicine Department of Anesthesiology/College of Medicine Medical University of South Carolina Charleston, SC, USA Library of Congress Control Number: 2007926756 ISBN: 978-0-387-72526-0 e-ISBN: 978-0-387-72527-7 Printed on acid-free paper. © 2008 Springer Science+Business Media, LLC. All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, 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 in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identifi ed as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. 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. 9 8 7 6 5 4 3 2 1 springer.com To my Grandparents, Regina and David Silverstein and Blanche and Daniel Klein, MD. Their love and their sufferings provided endless opportunities and insights. I hope, and believe, they would have liked this result. —JHS To my Children, Douglas and Linnea. —GAR To Margaret Cathcart and her late Husband, Dr. John W. Cathcart. —JGR To my Parents, Marion and Hamilton McLeskey, who encouraged care and consideration for our elderly. —CHM Preface to the Second Edition Do not go gentle into that good night, Old age should burn and rave at close of day; Rage, rage against the dying of the light. Dylan Thomas The goal of getting older is to age successfully. Unfortunately, the majority of our older patients will have acquired one or more chronic medical conditions as they age, and, even if a perfectly healthy older patient presents for surgery, that patient’s ability to handle physiologic stress will be diminished, including the stress of surgery. Nearly half of all surgical procedures involve patients older than age 65, and that percentage is likely to increase as the U.S. population ages. Thus, the perioperative care of the older patient represents one of the primary future frontiers of anesthetic practice. Even though perioperative mortality has diminished for the elderly, as well as for the population in general, the growing number of cases spotlights periopera- tive morbidity and mortality as an important issue for patients and health care systems alike. The vision set forward by the fi rst edition (i.e., to apply the growing body of knowledge in this subspecialty area to the everyday practice of anesthesiol- ogy) remains the mission and vision of this second edition. The editors believe that the updated contents of this edition represent an important opportunity to consoli- date and organize the information that has been acquired since 1997 and to apply that knowledge to the current practice of anesthesiology. Part I contains several new chapters on topics that may not always seem to be directly involved with anesthetic care, but are important to the future of medical and anesthesia care. An understanding of the aging process may lead to methods of slowing its progression, or at least of ameliorating some of its consequences, includ- ing the development of chronic disease. Most anesthesiology residency programs provide limited formal teaching of geriatric anesthesia. The editors believe the incorporation of relevant subspecialty material in the anesthesiology curriculum is needed to improve care for this patient population. The realities of reimbursement for services rendered to the older patient, either by Medicare or other payers, warrant the attention of all anesthesiologists who provide care for older patients. Ethics as applied to treatment of the older patient is also addressed. The medical management of this population is often complicated by issues such as patient goals that differ from physician expectations, physician “ageism,” patient cognitive impair- ment, and the physician’s failure to recognize the true risk of surgery and attendant recovery time. The last chapter of Part I reviews current knowledge and suggests research areas where the greatest impact on patient outcomes might be realized. Parts II and III review the physiology of aging and the basic anesthetic manage- ment of the geriatric patient, and Part IV examines selected surgical procedures vii viii Preface to the Second Edition frequently performed in older patients. Not all of these chapters are specifi c to anesthetic management. Geriatric medicine is a broad fi eld with many relevant topics. Wound healing is a perfect example. The reality is that anesthesiologists can likely have a positive impact on patient care by being better able to recognize condi- tions that may compromise skin when other medical professionals may fail to and, as a result, can improve protection of the skin, especially during long operating room cases. In contrast, polypharmacy and drug interactions, major topics in geriatric medicine, have direct relevance to anesthetic management. The cardiac surgery chapter is an example of how age affects outcomes after a specifi c type of surgical procedure. The unusual aspects of anesthetic management for cardiac surgery revolve mostly around the patient’s underlying disease status rather than there being anything specifi c to cardiac anesthesia in the older patient beyond the princi- ples delineated in Parts II and III. For chapters similar to those in the fi rst edition, an effort has been made to update content and incorporate studies that examine outcome. Such work helps us chal- lenge conventional wisdom and sometimes test novel ideas that prove benefi cial. Even the most casual reader of this textbook will recognize huge gaps in our present knowledge. It is not suffi cient, for example, to take an understanding of the physiol- ogy of aging and draw conclusions regarding anesthetic management from that information. Oftentimes, however, we are forced to do just that when making anes- thetic management decisions. The editors hope the future will provide better research and answers that advance the fi eld of geriatric anesthesiology. The editors thank the many authors of this text. In addition to their hard work, they responded to entreaties for revisions and updates with admirable patience and promptness. Their contributions expand our knowledge and will improve the care of elderly patients. Lastly, the editors thank Stacy Hague and Elizabeth Corra from Springer. Without their vision and determination, this book would not exist. Jeffrey H. Silverstein, MD G. Alec Rooke, MD, PhD J.G. Reves, MD Charles H. McLeskey, MD Preface to the First Edition Approximately 14% of the current U.S. population is 65 years of age or older. By the year 2020, it is predicted that 20% or 60,000,000 Americans will reach this mile- stone. Further, if today’s statistics continue unchanged, at least half of these indi- viduals will undergo anesthesia and surgery, likely of increasing complexity, prior to their eventual demise. The geriatric patient population represents a huge and growing challenge for anesthesia providers the world over. My interest in the anesthetic management of geriatric patients was kindled 15 years ago while on the faculty at Bowman Gray. One of our surgeons asked me to anesthetize his healthy 72-year-old father. All went well in the intraoperative and postoperative periods and he was discharged home in the customary time frame. However, my colleague later reported that he had observed subtle psychomotor changes in his father which persisted postoperatively for 7 weeks. It dawned on me that perhaps the geriatric patient is not simply an older adult, but rather, a truly different physiologic entity. What could explain the relatively commonly observed delayed postoperative return of normal mentation in the geriatric surgical patient? It is this and other unanswered questions regarding the anesthetic management of the elderly that stimulated the development of this text. Geriatric Anesthesiology is designed to be a comprehensive text that methodically addresses the aging process while emphasizing important clinical anesthetic consid- erations. The fi rst two sections of the text defi ne the demographics of our aging popu- lation and describe age-related physiologic changes that occur in each major organ system. The third section addresses the multitude of factors that contribute to a safe and successful anesthetic with suggested adjustments in technique that may improve anesthetic management of the elderly. Topics range from preoperative evaluation and risk assessment to the altered effects of various classes of drugs with further discus- sion regarding positioning, thermoregulation, perioperative monitoring, and postop- erative recovery. In addition, issues such as management of pain syndromes, outpatient anesthesia, medicolegal implications, and even special CPR techniques in this age group are considered. The fourth section identifi es the ten most commonly performed surgical procedures in the elderly, and for each, offers recommended anesthetic techniques. The text ends with an intriguing exploration into future research oppor- tunities in the fi eld, including molecular mechanisms of aging. Considerable energy has gone into the creation of this text. I am grateful for the signifi cant efforts made by all the contributing authors and especially appreciate contributions made by the editors from Williams & Wilkins. The text would have been impossible to complete without the encouragement, dogged determina- tion, and professionalism of Ms. Tanya Lazar and Mr. Carroll Cann. Tim Grayson was innovative and supportive during the original design and formulation of this project. ix x Preface to the First Edition I am optimistic that this text will heighten the awareness of the very real clinical differences presented by the geriatric patient population. Perhaps by referring to appropriate sections in this text, anesthesia providers will be armed with a better understanding of the physiologic changes of aging and the recommended consider- ations and modifi cations of anesthetic technique, which we hope will contribute to an ever-improving outcome for the geriatric surgical patient population. Charles H. McLeskey, MD Contents Preface to the Second Edition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Preface to the First Edition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Part I Introduction to Clinical Geriatrics 1 The Practice of Geriatric Anesthesia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Jeffrey H. Silverstein 2 Demographics and Economics of Geriatric Patient Care . . . . . . . . . . . . 15 Maria F. Galati and Roger D. London 3 Theories of Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Stanley Muravchick 4 Ethical Management of the Elderly Patient . . . . . . . . . . . . . . . . . . . . . . . 38 Paul J. Hoehner 5 Teaching Geriatric Anesthesiology to Practitioners, Residents, and Medical Students . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Sheila J. Ellis 6 Research Priorities in Geriatric Anesthesiology . . . . . . . . . . . . . . . . . . . 66 Christopher J. Jankowski and David J. Cook Part II Cardinal Manifestations of Aging and Disease in the Elderly 7 Alterations in Metabolic Functions and Electrolytes . . . . . . . . . . . . . . . 97 Michael C. Lewis 8 Perioperative Thermoregulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Daniel I. Sessler 9 Postoperative Central Nervous System Dysfunction . . . . . . . . . . . . . . . . 123 Deborah J. Culley, Terri G. Monk, and Gregory Crosby 10 Alterations in Circulatory Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Thomas J. Ebert and G. Alec Rooke 11 The Aging Respiratory System: Anesthetic Strategies to Minimize Perioperative Pulmonary Complications . . . . . . . . . . . . . . . . . 149 Rodrigo Cartin-Ceba, Juraj Sprung, Ognjen Gajic, and David O. Warner xi