Perioperative Management Of Surgical Patients Research Articles

DEXMEDETOMIDINE: A VERSATILE, MULTITASKING ANESTHETIC AGENT FOR PERIOPERATIVE MANAGEMENT, A NARRATIVE REVIEW

Dexmedetomidine stands out as a versatile anesthetic agent with a unique combination of sedative, analgesic, and sympatholytic properties, making it highly suitable for various perioperative applications. Its ability to provide arousable sedation, reduce opioid requirements, and maintain hemodynamic stability offers significant advantages in the perioperative management of surgical patients, particularly those with cardiovascular risks or a history of opioid use. The neuroprotective potential of dexmedetomidine further broadens its clinical applicability, especially in neurosurgical and trauma settings. While generally well-tolerated, its use necessitates careful monitoring to mitigate side effects such as bradycardia and hypotension, particularly in patients with hepatic impairment. The availability of atipamezole as an antidote enhances the safety profile of dexmedetomidine, allowing for rapid and effective reversal of its sedative and cardiovascular effects. Given the comprehensive benefits and the evolving evidence supporting its use, dexmedetomidine represents a valuable addition to the anesthesiologists toolkit, warranting its continued exploration and integration into perioperative care protocols.

Perioperative management of sarcopenia in patients undergoing major surgeries in Singapore: a modified Delphi consensus.

Ageing population is a worldwide phenomenon with correspondingly higher proportion of older patients being treated in the hospital setting. Sarcopenia, which increases with age, has serious negative implications on health, hospitalisation, and overall postoperative recovery. There is no mutual consensus on perioperative management of sarcopenia in surgical patients in Singapore. The purpose of this study is to create greater clarity pertaining to the recognition of sarcopenia, the application of assessment criteria of sarcopenia and perioperative management of surgical patients in Singapore. A modified Delphi consensus consisting of a panel of experts from Singapore forming a multidisciplinary team, including surgeons, geriatricians, anesthesiologists, physiotherapists, and dieticians. Eight recommendations were proposed by the steering committee. Literature search from MEDLINE, Embase, and Scopus for articles up till June 2023 were performed to support recommendation statements. The expert panel voted on agreement to recommendation statements and graded the level of evidence supporting each statement through surveys to achieve consensus, set at 85% a priori. The panellists underwent two rounds of anonymized, independent voting before reaching consensus for all eight statements. After the first round, seven statements reached consensus, including the corresponding grading for level of evidence. The statement which did not achieve consensus was revised with supporting literature and after the second round of survey, all eight statements and level of evidence reached consensus, completing the Delphi process. These eight statements covered themes to (1) encourage the identification of sarcopenia, (2) guide preoperative, and (3) postoperative management of sarcopenia. With the varying approaches in perioperative management, poor understanding of and identification of sarcopenia can result in suboptimal management of sarcopenia in surgical patients. Given the abundance of evidence linking beneficial impact on recovery and postoperative complications with prudent management of sarcopenia, it is imperative and urgent to achieve awareness and consensus.

Comparison of logistic regression and machine learning methods for predicting postoperative delirium in elderly patients: A retrospective study.

To compare the performance of logistic regression and machine learning methods in predicting postoperative delirium (POD) in elderly patients. This was a retrospective study of perioperative medical data from patients undergoing non-cardiac and non-neurology surgery over 65 years old from January 2014 to August 2019. Forty-six perioperative variables were used to predict POD. A traditional logistic regression and five machine learning models (Random Forest, GBM, AdaBoost, XGBoost, and a stacking ensemble model) were compared by the area under the receiver operating characteristic curve (AUC-ROC), sensitivity, specificity, and precision. In total, 29,756 patients were enrolled, and the incidence of POD was 3.22% after variable screening. AUCs were 0.783 (0.765-0.8) for the logistic regression method, 0.78 for random forest, 0.76 for GBM, 0.74 for AdaBoost, 0.73 for XGBoost, and 0.77 for the stacking ensemble model. The respective sensitivities for the 6 aforementioned models were 74.2%, 72.2%, 76.8%, 63.6%, 71.6%, and 67.4%. The respective specificities for the 6 aforementioned models were 70.7%, 99.8%, 96.5%, 98.8%, 96.5%, and 96.1%. The respective precision values for the 6 aforementioned models were 7.8%, 52.3%, 55.6%, 57%, 54.5%, and 56.4%. The optimal application of the logistic regression model could provide quick and convenient POD risk identification to help improve the perioperative management of surgical patients because of its better sensitivity, fewer variables, and easier interpretability than the machine learning model.

Managing a perioperative medicine program.

Perioperative medicine is now a well-recognized albeit still evolving, interdisciplinary subspecialty, which encompasses a wide array of equally invested stakeholders and equally important contributors. The practice of perioperative medicine is fundamentally and optimally a collaborative effort, which aims to provide a comprehensive framework encompassing all aspects of the patient's surgical journey. Moving from a conceptual model of perioperative medicine to an operational perioperative medicine program and clinic requires a methodical management approach. This comprehensive management approach considers a variety of factors, such as defining the mission of a perioperative medicine program, expanding the role of the anesthesiologist and internal medicine hospitalist, recognizing the role of the advanced practice provider, stratifying perioperative management of surgical patients, developing and implementing a program, undertaking a clinical proof-of-concept pilot of a program, scaling up and building out a program, maximizing the electronic health record, leveraging telemedicine and virtual health, and providing adjunctive services.

PLACE OF MODERN REGIONAL ANESTHESIA TECHNIQUES IN THE PERIOPERATIVE PERIOD. ADVANTAGES OF LONG-TERM EPIDURAL ANALGESIA WITH ROPIVACAINE

The article deals with the use of modern regional analgesia techniques in the perioperative period. A review of the literature was also conducted, which includes issues of pain control in patients in the perioperative period, characteristics of pain in surgical patients, features of pain relief methods, and certain aspects of the characteristics of local anesthetics. Based on the review of the literature, it can be concluded that neuraxial anesthesia, as well as blockade of peripheral nerves and plexuses have become an integral part of the modern clinical practice of an anesthesiologist. Due to a number of advantages, various methods of local and regional anesthesia are gaining acceptance, and the use of extended catheter techniques for central and peripheral blockades is now recognized as a standard technique in the perioperative management of surgical patients. In modern regional anesthesia and analgesia, both in outpatient settings and in surgical hospitals, the effectiveness and safety of local anesthetics are of fundamental importance

Postoperative delirium prediction using machine learning models and preoperative electronic health record data

BackgroundAccurate, pragmatic risk stratification for postoperative delirium (POD) is necessary to target preventative resources toward high-risk patients. Machine learning (ML) offers a novel approach to leveraging electronic health record (EHR) data for POD prediction. We sought to develop and internally validate a ML-derived POD risk prediction model using preoperative risk features, and to compare its performance to models developed with traditional logistic regression.MethodsThis was a retrospective analysis of preoperative EHR data from 24,885 adults undergoing a procedure requiring anesthesia care, recovering in the main post-anesthesia care unit, and staying in the hospital at least overnight between December 2016 and December 2019 at either of two hospitals in a tertiary care health system. One hundred fifteen preoperative risk features including demographics, comorbidities, nursing assessments, surgery type, and other preoperative EHR data were used to predict postoperative delirium (POD), defined as any instance of Nursing Delirium Screening Scale ≥2 or positive Confusion Assessment Method for the Intensive Care Unit within the first 7 postoperative days. Two ML models (Neural Network and XGBoost), two traditional logistic regression models (“clinician-guided” and “ML hybrid”), and a previously described delirium risk stratification tool (AWOL-S) were evaluated using the area under the receiver operating characteristic curve (AUC-ROC), sensitivity, specificity, positive likelihood ratio, and positive predictive value. Model calibration was assessed with a calibration curve. Patients with no POD assessments charted or at least 20% of input variables missing were excluded.ResultsPOD incidence was 5.3%. The AUC-ROC for Neural Net was 0.841 [95% CI 0. 816–0.863] and for XGBoost was 0.851 [95% CI 0.827–0.874], which was significantly better than the clinician-guided (AUC-ROC 0.763 [0.734–0.793], p < 0.001) and ML hybrid (AUC-ROC 0.824 [0.800–0.849], p < 0.001) regression models and AWOL-S (AUC-ROC 0.762 [95% CI 0.713–0.812], p < 0.001). Neural Net, XGBoost, and ML hybrid models demonstrated excellent calibration, while calibration of the clinician-guided and AWOL-S models was moderate; they tended to overestimate delirium risk in those already at highest risk.ConclusionUsing pragmatically collected EHR data, two ML models predicted POD in a broad perioperative population with high discrimination. Optimal application of the models would provide automated, real-time delirium risk stratification to improve perioperative management of surgical patients at risk for POD.

The new SUMPOT to predict postoperative complications using an Artificial Neural Network

An accurate assessment of preoperative risk may improve use of hospital resources and reduce morbidity and mortality in high-risk surgical patients. This study aims at implementing an automated surgical risk calculator based on Artificial Neural Network technology to identify patients at risk for postoperative complications. We developed the new SUMPOT based on risk factors previously used in other scoring systems and tested it in a cohort of 560 surgical patients undergoing elective or emergency procedures and subsequently admitted to intensive care units, high-dependency units or standard wards. The whole dataset was divided into a training set, to train the predictive model, and a testing set, to assess generalization performance. The effectiveness of the Artificial Neural Network is a measure of the accuracy in detecting those patients who will develop postoperative complications. A total of 560 surgical patients entered the analysis. Among them, 77 patients (13.7%) suffered from one or more postoperative complications (PoCs), while 483 patients (86.3%) did not. The trained Artificial Neural Network returned an average classification accuracy of 90% in the testing set. Specifically, classification accuracy was 90.2% in the control group (46 patients out of 51 were correctly classified) and 88.9% in the PoC group (8 patients out of 9 were correctly classified). The Artificial Neural Network showed good performance in predicting presence/absence of postoperative complications, suggesting its potential value for perioperative management of surgical patients. Further clinical studies are required to confirm its applicability in routine clinical practice.

Is enhancing recovery after pancreatic cancer surgery even possible?-a narrative review.

This narrative review traces the evolutionary journey of ERAS® with emphasis on challenges specific to pancreatic cancer. This article will also attempt to explore the barriers to routine ERAS® implementation and offers possible solutions to increasing its uptake and compliance rates. Enhanced Recovery After Surgery (ERAS®) represents a paradigm shift in the perioperative management of surgical patients using a multi-modality approach each of which is based on best available evidence. ERAS® has come a long way since its inception and can now be regarded as one of the promising ways forward in the perioperative management of patients undergoing pancreatic surgery. We identified 37 studies on the impact of ERAS® in pancreatic surgery, published over the last 2 decades. Implementation of ERAS® helped in shortening the length of stay without an increase in hospital re-admissions, morbidity, or mortality. Compliance to ERAS® is relatively low following pancreatic surgery, with a reported median compliance of 52%. Elderly patients or those with higher BMI, higher ASA scores, hypoalbuminemia, cardiac comorbidities or longer operative duration are more prone for deviations. ERAS pathways have been successful in achieving their intended outcomes, despite low compliance. Complementing existing ERAS® pathways with prehabilitation measures, risk-stratified clinical pathways and the accessibility to step-down care facilities following discharge may facilitate its wider utilisation.

Perioperative Assessment of High-Risk Abdominal Surgery: A Case Study.

Objectives• To outline the key components of a pre-operative cardiac risk assessment.• To review the major guidelines utilized to assess patients’ surgical risks.• To discuss the perioperative management of surgical patients to prevent cardiac and pulmonary complications.• To review the utility of biomarkers in the pre- and post-operative period.

Preoperative and Postoperative Resting Energy Expenditure of Patients Undergoing Major Abdominal Operations.

Nutrition therapy plays a major role in the perioperative management of surgical patients. Understanding energy metabolism and correctly establishing the adequate energy needs is a crucial step to provide optimal nutrition care. The aim of this study was to assess the resting energy expenditure (REE) after major abdominal procedures and its associated factors. This was a prospective observational study conducted at a single center. REEs of patients admitted for gastrointestinal surgical procedures were measured by indirect calorimetry 24 hours prior to the procedure and reassessed at least once within the fifth postoperative day. Substrate oxidation was calculated according to the Frayn equation. Nutrition status was evaluated using subjective global assessment. There were no significant changes in the REEs throughout the study period; however, there was a decrease in the respiratory quotient during the postoperative period, as well as a decrease in carbohydrate oxidation and an increase in lipid oxidation. Only 33.3% of the patients presented a postoperative increase in REE > 10%. Those patients presented higher blood-monocyte levels. Postoperative REE is not increased in most of the patients. In patients who had increased REE, associated factors included higher levels of monocytes.

Fostering patient safety through health policy innovation: A case study of implementation of the WHO Surgical Checklist in the UK.

The need to seek innovative solutions to the delivery of safe, cost effective healthcare has never been so pressing. Against a backdrop of austere financial circumstances, the focus must be on reducing unnecessary expenditure on patients that come to harm during the course of their treatment. This article uses the World Health Organization (WHO) Surgical Safety Checklist and its implementation as an example of effecting cultural change within an established western healthcare system. By embedding a safety culture within the perioperative management of surgical patients the incidence of adverse outcomes and harm can be reduced, rationalising the cost of delivering healthcare and improving the efficiency of healthcare systems. An understanding of health policy as a vehicle to induce cultural change throughout a healthcare organisation is essential if new safety innovations are to be effectively implemented.

Glucocorticoid-Induced Adrenal Insufficiency: A Study of the Incidence in Hospital Patients and A Review of Peri-Operative Management

Glucocorticoid (GC) pharmacotherapy is an effective treatment for a range of diseases, but exposure can suppress the hypothalamic-pituitary-adrenal axis, leading to glucocorticoid-induced adrenal insufficiency (GC-AI) in some patients. However, the incidence of diagnosed GC-AI and the associated health burden, including the incidence of adrenal crises (ACs), are unknown. Although GC-AI treatment is based on well-established principles, there are no agreed protocols regarding the peri-operative management of exposed patients. The aims of this study were to assess the incidence of diagnosed GC-AI in hospital patients and review current approaches to peri-operative management of surgical patients with GC exposure. An analysis of hospital admission data concerning adult patients diagnosed with GC-AI and a review of published recommendations for peri-operative GC cover. Between 2001 and 2013, admission with a diagnosis of GC-AI in New South Wales, Australia was rare (annual average of 22.5 admissions/year) and ACs were even more rare (n = 3). Almost two-thirds (64.4%, n = 188) of the patients with diagnosed GC-AI were aged between 50 and 79 years and 45.2% (n = 132) had a comorbid infection. The current approach to peri-operative management of patients with GC exposure appears to be influenced by both the absence of clear guidelines and historic practices. This results in the exposure of some patients to supraphysiologic doses of GCs during the peri-operative period. Hospital admission with a diagnosis of GC-AI (with or without an AC) is very rare. Clear guidelines on peri-operative GC cover are necessary to avoid overreplacement with supraphysiologic doses in susceptible patients. AC = adrenal crisis; ACTH = adrenocorticotropic hormone; AI = adrenal insufficiency; CI = confidence interval; GC = glucocorticoid; GC-AI = glucocorticoid-induced adrenal insufficiency; HPA = hypothalamic-pituitary-adrenal; OR = odds ratio.

Perioperative management of the patient with diabetes requiring emergency surgery

Perioperative management of the patient with diabetes requiring emergency surgery

Focused cardiac and lung ultrasonography: implications and applicability in the perioperative period.

Focused ultrasonography in anesthesia (FUSA) can be a procedural and diagnostic tool, as well as potentially a tool for monitoring, and can facilitate the perioperative management of surgical patients. Its utilization is proposed within the anesthesiologist and/or intensivist scope of practice. However, there are significant barriers to more generalized use, but evidence continues to evolve that might one day make this practice a standard of care in the perioperative period. Currently, the most widely used applications of FUSA include the guidance and characterization of perioperative shock (acute cor pulmonale, left ventricular dysfunction, cardiac tamponade, and hypovolemia) and acute respiratory failure (pneumothorax, acute pulmonary edema, large pleural effusion, major atelectasis, and consolidation). Increased diagnostic accuracy of all of these clinical conditions makes FUSA valuable in the perioperative period. Furthermore, FUSA can be applied to other anesthesiology fields, such as airway management and evaluation of gastric content in surgical emergencies.

Use of Nefopam in Perioperative Pain Management; Keeping Nefopam in between.

Without mentioning chronic pain, acute postoperative pain has been regarded as a matter of great concern to patients as well as physicians. The 'Pain as the Fifth Vital Sign' initiative may have helped make its control of primary importance in the perioperative management of surgical patients [1]. Extensive literature has demonstrated the benefits of effective postoperative pain control including improved surgical outcome, reduced hospital stays and decreased development of new chronic pain conditions [2,3,4]. However, the main analgesics for acute pain, opioids, may be associated with several side effects such as somnolence, confusion, urinary retention, ileus, respiratory depression, and death in case of misuse or overuse. Therefore, multimodal analgesia combining opioid and non-opioid analgesics is preferred for postoperative pain management [5]. Nefopam has been used for acute moderate pain since the mid-1970s as a centrally acting non-opioid analgesic. It was found to have several analgesic mechanisms including inhibition of monoamine uptake resulting in an increase of the inhibitory tone of the serotonergic and norepinephrine descending pathway, and reduced glutaminergic transmission by decreasing the activation of postsynaptic glutamatergic receptors. Owing to the multiple analgesic mechanisms of nefopam, animal and clinical researches were performed to examine the analgesic interaction with other drugs including opioids. Several reports were also published in the Korean Journal of Pain regarding its mechanism and drug interaction, proposing the use of nefopam for multimodal analgesia for postoperative pain [6,7,8]. In addition to its analgesic effect, it also reduces postoperative shivering, making it favorable for perioperative use. Given that postoperative pain is acute nociceptive, inflammatory and even neuropathic in nature, the multimodal analgesic technique could be more effective and suitable for postoperative pain management. Some studies revealed the potential of nefopam as an analgesic for neuropathic pain [9,10,11]. As already reported, the preoperative administration of gabapentin and pregabalin decreased opioid consumption in a setting of postoperative pain. Therefore, it appears that pre- or intraoperative administration of nefopam could be a plausible approach for preventing postoperative shivering and reducing opioid consumption [12]. Despite the above mentioned properties favoring nefopam for perioperative use, adverse effects such as confusion and tachycardia have been well noted. Furthermore, unexpected side effects including neuropsychiatric (related with abuse), cutaneous, or anaphylactic reactions have been reported [13,14]. Therefore, extensive use of nefopam in the perioperative period should wait until further research establishes the safety of the intraoperative use of nefopam, defines the analgesic mechanisms, and provides good quality strategies for nefopam in the multimodal analgesic approach. Also, it should be kept in mind that for whatever reason nefopam is not available in the United States.

Perioperative Surgical Home and the Integral Role of Pain Medicine.

Many criticisms surround the current management of the surgical experience. These include the fragmented nature of care delivered perioperatively with multiple transitions, the high costs of many common procedures, and the sometimes disappointing outcomes given the monetary and human investments made in surgical care ⇓. Modeled in some ways after the concept of the patient-centered medical home, the American society of anesthesiologists has articulated a definition of the perioperative surgical home (PSH) as “a patient-centered and physician-led multidisciplinary and team-based system of coordinated care that guides the patient throughout the entire surgical experience” ⇓. Though, we do not yet fully understand the potential benefits of the PSH model, a recent review suggests that the quality of care is often improved, and costs are reduced ⇓. At the core of the PSH concept is the notion that various groups of health care specialists should work together to provide optimal care. Complementary to that notion, and particularly relevant to reducing fragmented treatment as well as improving the patient's experience, is the recognition that the seamless longitudinal management of specific aspects of care may facilitate optimal outcomes. Pain management in the immediate postoperative period is already one of the better developed components of the PSH, and one on which further expansion of the model can be based ⇓. As our understanding of factors predisposing patients to excessive acute postoperative pain, persistent postoperative pain, poor functional outcomes, and the prolonged use of opioids grows, so too will our ability to contribute to the perioperative management of surgical patients. Figure ⇓ displays a roadmap of key goals for comprehensive pain management in the perioperative setting. Figure 1 A roadmap of pain management in perioperative pain care. In this model pain management issues are addressed at several points in the PSH process. The goals …

Intravenous lipids in adult surgical patients.

Parenteral nutrition is considered an essential element of the perioperative management of surgical patients. It is recommended in patients who require nutritional therapy but in whom the enteral route is contraindicated, not recommended or non-feasible. The new generation of lipid emulsions (LEs) based on olive and fish oils are safe and may improve clinical outcome in surgical patients. The increased provision of n-3 polyunsaturated fatty acids in fish oil-containing LEs seems to be associated with fewer infectious complications and shorter ICU and hospital stays following major abdominal surgery. Increased provision of olive oil in the absence of fish oil may also exert beneficial effects, but a clear conclusion on this is limited due to the low number of available studies. Hence, at the moment, the evidence supports the use of n-3-polyunsaturated fatty acid-enriched LEs as a part of the parenteral nutrition regimen for selected groups of patients, such as those with major surgical trauma or those undergoing extended resections or liver transplantation.

Fast-track surgery: A new concept of perioperative management of surgical patients

In the past few decades, surgery has advanced greatly because of an improved understanding of perioperative pathophysiology, development of minimally invasive operative techniques and advanced anaesthetic techniques. Fewer operations are requiring extended periods of hospital stay and a growing number of procedures are performed on an ambulatory basis. The pressure on medical systems is continuously growing as a result of economic constraints, increasing numbers of patients undergoing surgical procedures and greater patient autonomy. Patient awareness is steadily increasing along with their participation in their own care, leading to expectations of a higher standard of care. This has led to the development of a new concept of fast-track surgery.

Transfusion therapy in the peri-operative period.

Transfusion therapy in the peri-operative period.

Stoelting's Anesthesia and Co-Existing Disease

A comprehensive understanding of the pathophysiology of coexisting diseases is essential for the perioperative management of patients undergoing surgery and anesthesia. The Anesthesia and Co-Existing Disease text is in its fifth edition and provides the practitioner with a good reference source regarding the pathology of common and uncommon disease states and their relevance to the anesthesiologist. The new edition of this multi-authored text was edited by Drs. Hines and Marschall. It retains the purpose of the original publication by Dr. Stoelting, while also reflecting the advancements in medical knowledge of these subjects since the last edition of the book was published in 2002. The contributions of multiple experts enrich the substance of the text. The uniform structure of the chapters has aided the editors in achieving consistency in the writing style. The updated edition also reflects the advances in medical knowledge and contemporary management principles. Each chapter commences with bullet-format outline, focusing the attention of the reader on the topics that are addressed, and concludes with highlighted key points, emphasizing the important educational points. The addition of color highlighting contributes to the functionality of the text as a source for review of relevant information. Abundant, well-designed illustrations, figures, graphs, and tables supplement the text and enhance the didactic value of the book. The chapters of the book reflect the organ system approach to the organization of the disease entities. Although common disorders have a more prominent place in the text and are presented in greater detail, the uncommon conditions are also discussed and important features are emphasized. The organization of the chapter content in the new edition has resulted in relocation of some topics to a different chapter reflecting the current understanding of the pathophysiology and management of these disease states. Some level of detail has been omitted in the discussion on bacterial endocarditis and prophylaxis recommendations, neurologic syndromes, anesthetic considerations in sleep apnea, and understanding of the strong ion difference in acid-base disorders. In addition, there are fewer references in this edition. The leading chapter of the book is dedicated to ischemic heart disease, underscoring the significance of this entity to the practice of anesthesia. The comprehensive discussions of the pathophysiology of this disease, the risk stratification approach, and perioperative care issues present an admirable synthesis of the contemporary principles of management of ischemic heart disease. The chapter on systemic and pulmonary hypertension contains an excellent overview of the hypertension syndromes in both circulatory beds and highlights the effect of pulmonary hypertension on the administration of anesthesia. The vascular disease chapter incorporates diseases affecting the blood vessels, as well as thromboembolic phenomena. The chapter on heart failure contains an in-depth discussion of the pathophysiology of the types of heart failure and cardiomyopathy and their management in the perioperative period. A consolidated, comprehensive chapter on respiratory diseases includes discussions on the pathology and anesthetic implications of upper respiratory tract infection, obstructive and restrictive lung diseases, pulmonary embolism, and lung transplantation. The discussion on acute respiratory failure provides an excellent review of this entity and highlights the contemporary management principles of the disorder. However, the rationale for placing that discussion under the topic of diagnostic procedures rather than as a stand-alone topic is uncertain. The disorders of the nervous system are organized into 3 subchapters, including diseases of the brain, the spinal cord, and the peripheral and the autonomic nervous system, reflecting the link between anatomic and functional correlation and clinical impact. The discussions on obesity and other nutritional disorders contain an abundance of tables and diagrams that provide an excellent overview and highlight various issues, including obesity-related cardiomyopathy, medication dosing in obesity, inborn errors of metabolism, and cardiopulmonary changes in obesity and pregnancy. The final chapters are dedicated to special patient populations such as obstetric, pediatric, and geriatric patients and emphasize the particular challenges that these patient populations present in the perioperative period. The printed text is accompanied by an online feature that provides easy access to the book from any electronic portal and the ability to rapidly locate key information. The references are linked to their abstracts on MEDLINE (Medical Literature Analysis and Retrieval System Online), facilitating the acquisition of a deeper understanding on the topics of interest. Anesthesia and Co-Existing Diseases is a unique and valuable reference text that provides anesthesia practitioners with essential expertise on the pathology of coexisting diseases and their implications for the perioperative management of surgical patients. Clinicians at all levels of their professional development, from students and residents to experienced anesthesia providers, will find this book a valuable addition to their anesthesia library. John E. Ellis, MD Department of Anesthesiology and Critical Care University of Pennsylvania Philadelphia, Pennsylvania [email protected]com Zdravka Zafirova, MD Department of Anesthesia and Critical Care University of Chicago Chicago, Illinois