Awareness During AnesthesiaM. M. GhoneimBoston: Butterworth-Heinemann, 2001. ISBN: 0-7506-7201-3. 181 pp. $59.95.
Awareness and memory during anesthesia are problems that continue to bedevil practitioners of anesthesiology. Although relatively rare, and unaccompanied by the high dollar medicolegal consequences of some other mishaps, they nevertheless create a great deal of anxiety among anesthesiologists, possibly because of the lack of means to evaluate and quantify them and because of the profound impact they can have on our patients. In Awareness During Anesthesia, Ghoneim et al. attempt to bring order out of chaos. In this book, the authors explore awareness, as well as learning, during anesthesia, and explicit and implicit memory of intraoperative events.
The book consists of a preface and nine chapters authored by people who have done much of the pioneering work in the field. It is an easily readable presentation of material not covered in detail in standard anesthesia books. Each chapter ends with a “comments,” “conclusions,” or “discussion” section, which summarizes important points and emphasizes any “take home” messages.
The preface and first two chapters by Ghoneim serve as introduction and overview. Included in the first chapter are a brief history of patient awareness and recall, some of the causes and consequences, and a detailed list of strategies for preventing its occurrence, as well as how to deal with such events when they happen.
In the second chapter, Ghoneim explores implicit memory for events during anesthesia (a more insidious and potentially more damaging phenomenon than explicit memory), discussing its manifestation and some of the ingenious study designs researchers have developed to look at it. Different anesthetic techniques and their incidences of recall are also discussed.
The third chapter starts by discussing memory and depth of anesthesia. It goes on to discuss the various modalities for monitoring and measuring depth of anesthesia, from the isolated forearm techniques through tests of autonomic function, to electroencephalogram-based methods like evoked potentials and Bispectral Index monitoring. These various modalities are discussed in more depth in chapters five through seven.
“Learning during sedation, anesthesia and surgery”, the fourth chapter, describes studies attempting to confirm or refute this concept. Andrade concludes that the evidence is “equivocal, with approximately the same number of studies obtaining evidence for learning as failing to do so.” Of interest is the role epinephrine and norepinephrine may have on learning during anesthesia.
A review of the literature on the psychological sequelae of memory during anesthesia, as well as sharing some of his experiences treating such patients, provides detailed descriptions of the impact recall can have on patients months or years after treatment and is enough to make the reviewer look carefully at the way we practice anesthesia. This chapter makes a persuasive argument that significant psychological trauma may exist in the absence of conscious recall.
The last chapter, by Domino and Aitkenhead, delves into the medicolegal consequences of awareness. Much of the data is from the American Society of Anesthesiologists closed claims project. In this fascinating section, demographics and risk factors for malpractice claims are discussed, as well as social and cultural factors that influence them. Other pertinent aspects, such as standard versus substandard care, and type and severity of injury are explored.
Each chapter in this book could stand alone as a comprehensive article. In addition, the authors often cite work done by other authors in this book. Unfortunately, this leads to repetition in some of the articles of techniques, tests, and concepts. That small complaint aside, this book stands as an easy-to-read, quite comprehensive collection of information focusing on this worrisome issue. While explaining the issues involved in trying to solve the problem of awareness and recall, it offers suggestions on avoidance of the same.
This book endeavors to explain the causes, sequelae, and some strategies for avoidance of awareness during anesthesia. These are valuable lessons indeed. In the opinion of this reviewer, familiarity with the material in this book is probably a better safeguard against unwanted awareness than any monitor currently available. This book should be read by everyone who delivers anesthesia, and it will cause most of us to reassess the way we practice our craft.