Michael C. Lewis

Isoflurane/nitrous oxide anesthesia induces increases in NMDA receptor subunit NR2B protein expression in the aged rat brain.

Postoperative cognitive dysfunction, POCD, afflicts a large number of elderly surgical patients following surgery with general anesthesia. Mechanisms of POCD remain unclear. N-methyl-D-aspartate (NMDA) receptors, critical in learning and memory, that display protein expression changes with age are modulated by inhalation anesthetics. The aim of this study was to identify protein expression changes in NMDA receptor subunits and downstream signaling pathways in aged rats that demonstrated anesthesia-induced spatial learning impairments. Three-month-old and 18-month-old male Fischer 344 rats were randomly assigned to receive 1.8% isoflurane/70% nitrous oxide (N(2)O) anesthesia for 4h or no anesthesia. Spatial learning was assessed at 2weeks and 3months post-anesthesia in Morris water maze. Hippocampal and cortical protein lysates of 18-month-old rats were immunoblotted for activated caspase 3, NMDA receptor subunits, and extracellular-signal regulated kinase (ERK) 1/2. In a separate experiment, Ro 25-6981 (0.5mg/kg dose) was administered by I.P. injection before anesthesia to 18-month-old rats. Immunoblotting of NR2B was performed on hippocampal protein lysates. At 3months post-anesthesia, rats treated with anesthesia at 18-months-old demonstrated spatial learning impairment corresponding to acute and long-term increases in NR2B protein expression and a reduction in phospho-ERK1/2 in the hippocampus and cortex. Ro 25-6981 pretreatment attenuated the increase in acute NR2B protein expression. Our findings suggest a role for disruption of NMDA receptor mediated signaling pathways in the hippocampus and cortex of rats treated with isoflurane/ N(2)O anesthesia at 18-months-old, leading to spatial learning deficits in these animals. A potential therapeutic intervention for anesthesia associated cognitive deficits is discussed.

Unique Aspects of the Elderly Surgical Population: An Anesthesiologist’s Perspective

Increasing life expectancies paired with age-related comorbidities have resulted in the continued growth of the elderly surgical population. In this group, age-associated changes and decreased physiological reserve impede the body’s ability to maintain homeostasis during times of physiological stress, with a subsequent decrease in physiological reserve. This can lead to age-related physiological and cognitive dysfunction resulting in perioperative complications. Changes in the cardiovascular, pulmonary, nervous, hepatorenal, endocrine, skin, and soft tissue systems are discussed as they are connected to the perioperative experience. Alterations affect both the pharmacodynamics and pharmacokinetics of administered drugs. Elderly patients with coexisting diseases are at a greater risk for polypharmacy that can further complicate anesthetic management. Consequently, the importance of conducting a focused preoperative evaluation and identifying potential risk factors is strongly emphasized. Efforts to maintain intraoperative normothermia have been shown to be of great importance. Procedures to maintain stable body temperature throughout the perioperative period are presented. The choice of anesthetic technique, in regard to a regional versus general anesthetic approach, is debated widely in the literature. The type of anesthesia to be administered should be assessed on a case-by-case basis, with special consideration given to the health status of the patient, the type of operation being conducted, and the expertise of the anesthesiologist. Specifically addressed in this article are age-related cognitive issues such as postoperative cognitive dysfunction and postoperative delirium. Strategies are suggested for avoiding these pitfalls.

Gender-Specific Differences in the Central Nervous System’s Response to Anesthesia

Males and females are physiologically distinct in their responses to various anesthetic agents. The brain and central nervous system (CNS), the main target of anesthesia, are sexually dimorphic from birth and continue to differentiate throughout life. Accordingly, gender has a substantial impact on the influence of various anesthetic agents in the brain and CNS. Given the vast differences in the male and female CNS, it is surprising to find that females are often excluded from basic and clinical research studies of anesthesia. In animal research, males are typically studied to avoid the complication of breeding, pregnancy, and hormonal changes in females. In clinical studies, females are also excluded for the variations that occur in the reproductive cycle. Being that approximately half of the surgical population is female, the exclusion of females in anesthesia-related research studies leaves a huge knowledge gap in the literature. In this review, we examine the reported sex-specific differences in the central nervous system’s response to anesthesia. Furthermore, we suggest that anesthesia researchers perform experiments on both sexes to further evaluate such differences. We believe a key goal of research studying the interaction of the brain and anesthesia should include the search for knowledge of sex-specific mechanisms that will improve anesthetic care and management in both sexes.

Onset time for sevoflurane/nitrous oxide induction in adults is prolonged with increasing age.

Inhaled induction of anesthesia is occasionally used in adults. Using a modified vital capacity sevoflurane/nitrous oxide (N2O) inhaled induction, we evaluated the effect of increasing age on the onset time of anesthesia. Twenty patients, aged 26-65 yr, performed a vital capacity breath followed by regular tidal breathing from an anesthesia circuit primed with sevoflurane 8%/N2O/O2. The following values were recorded: time to loss of eyelash reflex (LOER); time to bispectral index ≤60 (BIS ≤60); expired fraction of sevoflurane at the time of induction, LOER and BIS ≤60. The mean times and 95% confidence intervals to LOER and BIS ≤60 were 54 s (37-70 s) and 175 s (143-207 s), respectively, and were significantly prolonged by aging (r = 0.65; P = 0.002). Times to LOER and BIS ≤60, predicted from the regression line, were 3.9 and 2 times longer in a 60-yr-old than in a 30-yr-old patient. The expired fraction of sevoflurane measured at time to LOER and BIS ≤60 decreases with increase in age. We conclude that inhaled induction with sevoflurane/N2O is dramatically prolonged with increased age.

Trauma in the elderly: considerations for anesthetic management.

The volume of geriatric trauma patients is expected to increase significantly in coming years. Recognition of severe injuries may be delayed because they are less likely to mount classic symptoms of hemodynamic instability. Head injuries of any severity may place geriatric patients at increased risk of mortality, but there are currently no geriatric-specific treatment recommendations that differ from usual adult guidelines. Our understanding of best practices in geriatric trauma and anesthesia care continues to expand, as it does in all other areas of medicine.

Aging Demographics and Anesthesia

Over the last century, life expectancy in the USA has increased dramatically. Only 100 years ago, it was common for people to die prior to their 50th birthday. The average age of the US population increased by as much as 14 years between 1900 and 1940. Of children born today, 95 % will exceed 50 years of age with many living well into their 80s.

Core clinical competencies in anesthesiology: A case-based approach

The goal of this book is to prepare anesthesiology residents for their specialty examinations in the United States. The Accreditation Council for Graduate Medical Education (ACGME) is the body responsible for the accreditation of postgraduate medical training programs in the United States. The examinations evaluate residents on six core competencies of a competent physician as listed by the ACGME, namely, patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice. The ACGME competencies are similar to the CanMEDS competencies used in Canada and other countries, specifically, medical expert, manager, collaborator, communicator, professional, scholar, and health advocate. The authors begin their book by providing a didactic and concise description of the six core ACGME competencies in medicine as a whole, followed by a short description within the context of anesthesiology. The book includes 77 clinical cases, and the authors advance either some or all of the six core ACGME competencies related to each specific case. The cases are gathered into six sections (Parts 1 to 6) according to the institutions of the contributing authors, many of whom are anesthesiology residents. The choice of gathering cases into sections according to the affiliation of the authors may be somewhat surprising, since, in my view, it would have been more logical to group the cases according to their main core competencies or even their main clinical focus. Each case study begins with a catchy title and continues with a case description written in a ‘‘humorous’’ and colloquial style. Whereas this style can be engaging and entertaining, the reader may often perceive this approach as being unusual at best, especially in this book which aims to advocate clinical core competencies, including professionalism. For example, Case 10 ‘‘Flame on!’’, a case regarding a conscious patient with 100% burns, starts with ‘‘A smell like barbeque fills the entire emergency room. ‘Funny,’ you think, ‘no one told me there was a picnic.’ You note that the smell is coming from the trauma bay...’’. Under the competency ‘‘Patient care’’ and the subcategory ‘‘Perform competently all medical and invasive procedures considered essential for the area of practice’’, the authors write, ‘‘As long as I didn’t stick the morphine syringe into the mattress by mistake, I was performing competently.’’ This style may appear to be counterproductive to teaching the core competencies that are being discussed. The hidden curriculum includes learning which is not visible and explicit in an educational program. For example, when medical students participate in an anesthesiology rotation, they learn technical skills, such as drug administration and tracheal intubation, and they also learn about professional relationships with other healthcare providers and the sociology of anesthesiologists, learning points which are often not explicit in their curriculum. I am concerned about the contribution this book, with its sarcastic style, may have on the hidden curriculum, i.e., in shaping the professional identity of residents and potentially contributing to cynical attitudes instead of encouraging compassion and empathy toward the patient. In each case, the description of the clinical core competencies is clear and well structured with a repetitive format to assist trainees in preparing for their examinations. The amount of redundancy is one drawback which is potentially irritating for the reader; in addition, this 472 page paperback book is rather large (9.6 9 7.4 9 1.1 inches and 1.9 pounds). The interest in this book lies within S. Boet, MD (&) The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada e-mail: sboet@toh.on.ca

Core Clinical Competencies in Anesthesiology: – Contributions from Johns Hopkins Medical Institutions under Deborah A. Schwengel

The goal of this book is to prepare anesthesiology residents for their specialty examinations in the United States. The Accreditation Council for Graduate Medical Education (ACGME) is the body responsible for the accreditation of postgraduate medical training programs in the United States. The examinations evaluate residents on six core competencies of a competent physician as listed by the ACGME, namely, patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice. The ACGME competencies are similar to the CanMEDS competencies used in Canada and other countries, specifically, medical expert, manager, collaborator, communicator, professional, scholar, and health advocate. The authors begin their book by providing a didactic and concise description of the six core ACGME competencies in medicine as a whole, followed by a short description within the context of anesthesiology. The book includes 77 clinical cases, and the authors advance either some or all of the six core ACGME competencies related to each specific case. The cases are gathered into six sections (Parts 1 to 6) according to the institutions of the contributing authors, many of whom are anesthesiology residents. The choice of gathering cases into sections according to the affiliation of the authors may be somewhat surprising, since, in my view, it would have been more logical to group the cases according to their main core competencies or even their main clinical focus. Each case study begins with a catchy title and continues with a case description written in a ‘‘humorous’’ and colloquial style. Whereas this style can be engaging and entertaining, the reader may often perceive this approach as being unusual at best, especially in this book which aims to advocate clinical core competencies, including professionalism. For example, Case 10 ‘‘Flame on!’’, a case regarding a conscious patient with 100% burns, starts with ‘‘A smell like barbeque fills the entire emergency room. ‘Funny,’ you think, ‘no one told me there was a picnic.’ You note that the smell is coming from the trauma bay...’’. Under the competency ‘‘Patient care’’ and the subcategory ‘‘Perform competently all medical and invasive procedures considered essential for the area of practice’’, the authors write, ‘‘As long as I didn’t stick the morphine syringe into the mattress by mistake, I was performing competently.’’ This style may appear to be counterproductive to teaching the core competencies that are being discussed. The hidden curriculum includes learning which is not visible and explicit in an educational program. For example, when medical students participate in an anesthesiology rotation, they learn technical skills, such as drug administration and tracheal intubation, and they also learn about professional relationships with other healthcare providers and the sociology of anesthesiologists, learning points which are often not explicit in their curriculum. I am concerned about the contribution this book, with its sarcastic style, may have on the hidden curriculum, i.e., in shaping the professional identity of residents and potentially contributing to cynical attitudes instead of encouraging compassion and empathy toward the patient. In each case, the description of the clinical core competencies is clear and well structured with a repetitive format to assist trainees in preparing for their examinations. The amount of redundancy is one drawback which is potentially irritating for the reader; in addition, this 472 page paperback book is rather large (9.6 9 7.4 9 1.1 inches and 1.9 pounds). The interest in this book lies within S. Boet, MD (&) The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada e-mail: sboet@toh.on.ca

Core Clinical Competencies in Anesthesiology: Contributions from Stony Brook University Medical Center under Christopher J. Gallagher

The goal of this book is to prepare anesthesiology residents for their specialty examinations in the United States. The Accreditation Council for Graduate Medical Education (ACGME) is the body responsible for the accreditation of postgraduate medical training programs in the United States. The examinations evaluate residents on six core competencies of a competent physician as listed by the ACGME, namely, patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice. The ACGME competencies are similar to the CanMEDS competencies used in Canada and other countries, specifically, medical expert, manager, collaborator, communicator, professional, scholar, and health advocate. The authors begin their book by providing a didactic and concise description of the six core ACGME competencies in medicine as a whole, followed by a short description within the context of anesthesiology. The book includes 77 clinical cases, and the authors advance either some or all of the six core ACGME competencies related to each specific case. The cases are gathered into six sections (Parts 1 to 6) according to the institutions of the contributing authors, many of whom are anesthesiology residents. The choice of gathering cases into sections according to the affiliation of the authors may be somewhat surprising, since, in my view, it would have been more logical to group the cases according to their main core competencies or even their main clinical focus. Each case study begins with a catchy title and continues with a case description written in a ‘‘humorous’’ and colloquial style. Whereas this style can be engaging and entertaining, the reader may often perceive this approach as being unusual at best, especially in this book which aims to advocate clinical core competencies, including professionalism. For example, Case 10 ‘‘Flame on!’’, a case regarding a conscious patient with 100% burns, starts with ‘‘A smell like barbeque fills the entire emergency room. ‘Funny,’ you think, ‘no one told me there was a picnic.’ You note that the smell is coming from the trauma bay...’’. Under the competency ‘‘Patient care’’ and the subcategory ‘‘Perform competently all medical and invasive procedures considered essential for the area of practice’’, the authors write, ‘‘As long as I didn’t stick the morphine syringe into the mattress by mistake, I was performing competently.’’ This style may appear to be counterproductive to teaching the core competencies that are being discussed. The hidden curriculum includes learning which is not visible and explicit in an educational program. For example, when medical students participate in an anesthesiology rotation, they learn technical skills, such as drug administration and tracheal intubation, and they also learn about professional relationships with other healthcare providers and the sociology of anesthesiologists, learning points which are often not explicit in their curriculum. I am concerned about the contribution this book, with its sarcastic style, may have on the hidden curriculum, i.e., in shaping the professional identity of residents and potentially contributing to cynical attitudes instead of encouraging compassion and empathy toward the patient. In each case, the description of the clinical core competencies is clear and well structured with a repetitive format to assist trainees in preparing for their examinations. The amount of redundancy is one drawback which is potentially irritating for the reader; in addition, this 472 page paperback book is rather large (9.6 9 7.4 9 1.1 inches and 1.9 pounds). The interest in this book lies within S. Boet, MD (&) The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada e-mail: sboet@toh.on.ca

Core Clinical Competencies in Anesthesiology: Frontmatter

The goal of this book is to prepare anesthesiology residents for their specialty examinations in the United States. The Accreditation Council for Graduate Medical Education (ACGME) is the body responsible for the accreditation of postgraduate medical training programs in the United States. The examinations evaluate residents on six core competencies of a competent physician as listed by the ACGME, namely, patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice. The ACGME competencies are similar to the CanMEDS competencies used in Canada and other countries, specifically, medical expert, manager, collaborator, communicator, professional, scholar, and health advocate. The authors begin their book by providing a didactic and concise description of the six core ACGME competencies in medicine as a whole, followed by a short description within the context of anesthesiology. The book includes 77 clinical cases, and the authors advance either some or all of the six core ACGME competencies related to each specific case. The cases are gathered into six sections (Parts 1 to 6) according to the institutions of the contributing authors, many of whom are anesthesiology residents. The choice of gathering cases into sections according to the affiliation of the authors may be somewhat surprising, since, in my view, it would have been more logical to group the cases according to their main core competencies or even their main clinical focus. Each case study begins with a catchy title and continues with a case description written in a ‘‘humorous’’ and colloquial style. Whereas this style can be engaging and entertaining, the reader may often perceive this approach as being unusual at best, especially in this book which aims to advocate clinical core competencies, including professionalism. For example, Case 10 ‘‘Flame on!’’, a case regarding a conscious patient with 100% burns, starts with ‘‘A smell like barbeque fills the entire emergency room. ‘Funny,’ you think, ‘no one told me there was a picnic.’ You note that the smell is coming from the trauma bay...’’. Under the competency ‘‘Patient care’’ and the subcategory ‘‘Perform competently all medical and invasive procedures considered essential for the area of practice’’, the authors write, ‘‘As long as I didn’t stick the morphine syringe into the mattress by mistake, I was performing competently.’’ This style may appear to be counterproductive to teaching the core competencies that are being discussed. The hidden curriculum includes learning which is not visible and explicit in an educational program. For example, when medical students participate in an anesthesiology rotation, they learn technical skills, such as drug administration and tracheal intubation, and they also learn about professional relationships with other healthcare providers and the sociology of anesthesiologists, learning points which are often not explicit in their curriculum. I am concerned about the contribution this book, with its sarcastic style, may have on the hidden curriculum, i.e., in shaping the professional identity of residents and potentially contributing to cynical attitudes instead of encouraging compassion and empathy toward the patient. In each case, the description of the clinical core competencies is clear and well structured with a repetitive format to assist trainees in preparing for their examinations. The amount of redundancy is one drawback which is potentially irritating for the reader; in addition, this 472 page paperback book is rather large (9.6 9 7.4 9 1.1 inches and 1.9 pounds). The interest in this book lies within S. Boet, MD (&) The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada e-mail: sboet@toh.on.ca