As anaesthetic-related maternal mortality reduces in the developed world, alternative indicators of obstetric anaesthetic quality are required. Serious morbidity is difficult to define and quantify, but can be reduced by the provision of effective critical care. Regional anaesthesia, although safer than general anaesthesia, is not without risks. Evidence-based strategies exist to reduce the risks.
Informatics is a broad field encompassing artificial intelligence, cognitive science, computer science, information science, and social science. The goal of this review is to illustrate how Web 2.0 information technologies could be used to improve anesthesia education.
Educators in all specialties of medicine are increasingly studying Web 2.0 technologies to maximize postgraduate medical education of housestaff. These technologies include microblogging, blogs, really simple syndication (RSS) feeds, podcasts, wikis, and social bookmarking and networking. 'Anesthesia 2.0' reflects our expectation that these technologies will foster innovation and interactivity in anesthesia-related web resources which embraces the principles of openness, sharing, and interconnectedness that represent the Web 2.0 movement. Although several recent studies have shown benefits of implementing these systems into medical education, much more investigation is needed.
Although direct practice and observation in the operating room are essential, Web 2.0 technologies hold great promise to innovate anesthesia education and clinical practice such that the resident learner need not be in a classroom for a didactic talk, or even in the operating room to see how an arterial line is properly placed. Thoughtful research to maximize implementation of these technologies should be a priority for development by academic anesthesiology departments. Web 2.0 and advanced informatics resources will be part of physician lifelong learning and clinical practice.
The risk-benefit ratio of using nitrous oxide has been debated for many years. In this article the adverse effects of nitrous oxide on patient well-being, including its role in postoperative nausea and vomiting, its toxic effects and adverse physiological changes are reviewed. Guidelines for the rational use of the drug are suggested.
Remifentanil is still in its infancy in terms of postmarketing development. Its appropriate role in modern anesthesia care is still being defined and reports of novel clinical applications for remifentanil are frequently appearing in the anesthesia literature. This review will focus on selected advances in our understanding of remifentanil pharmacokinetics and pharmacodynamics and on newly proposed clinical applications for remifentanil.
Although enthusiasm of intensivists has been raised during the last 2-3 years due to several successful clinical trials, severe sepsis and septic shock still have an increasing incidence with more or less unchanged mortality. Within the last 12 months, the progress in sepsis research covering definitions, epidemiology, pathophysiology, diagnosis, standard and adjunctive therapy, as well as experimental approaches is encouraging. In this review, state-of-the-art publications of 2003 are presented to elucidate the possible impact on clinical routine.
The rationale for using a new definition based on the PIRO system has been widely acknowledged, although it is not yet applicable in clinical practice. This includes genomic information for stratifying subgroups of patients, and a broader field of laboratory diagnostics due to clinical studies and basic research on the cellular mechanisms of inflammation and organ dysfunction. Early diagnosis is important for a fast implementation of specific therapies, and it has been confirmed that the time until the start of therapy has an impact on patient outcome. Thorough data analysis of successful trials with activated protein C has revealed encouraging details on long-term outcome and subgroup effects. Together with new findings on low-dose hydrocortisone, this stresses the relevance of adjunctive therapy in severe sepsis and septic shock.
Scientific progress in areas of sepsis has been continuing throughout 2003, although the challenges are still enormous. The identification of more specific markers and new therapeutic approaches will hopefully improve the diagnosis, monitoring of therapy, and outcome in the septic patient.
The use of two-dimensional (2D) transesophageal echocardiography (TEE) is nearly universal in cardiac surgical operating rooms around the world. Cardiac anesthesiologists or cardiologists perform these examinations, facilitating significant advancements in surgical techniques by the immediacy and accuracy of intra-operative ultrasound imaging. Three-dimensional (3D) TEE capabilities have been available since the 1990s but penetration has been poor. With the advent of real-time 3D TEE, interest in this technology has increased dramatically. This is a comprehensive review of English language publications in the field from 2007 to 2009.
This review utilized Pubmed databases, with search strategy based on primary key words: 3D echocardiography, transesophageal echocardiography, cardiac surgery, and/or cardiopulmonary bypass. Three major areas of clinical practice are impacted by the findings of these studies: cardiac valve repair and replacement, assessment of ventricular function, and image guidance for percutaneous procedures.
The review resulted in the conclusion that 3D TEE provides unique and dynamic 3D spatial information that cannot be obtained by 2D TEE or fluoroscopy. In addition to technical and process advancements, future studies should address educational value in terms of acceleration of learning curves, and impact on surgical decision making.
Ultrasound-guidance is gaining tremendous popularity. There is growing evidence of value with emphasis on clinical relevance, but can ultrasound-guidance scientifically warrant changing the practice of upper extremity regional? The literature is searched to describe findings where ultrasound may reduce complication rates, reduce block performance times, and improve block efficacy and quality.
Ultrasound examination identified variations in anatomical positioning of C5-C7 roots in approximately half of all patients despite no deleterious effects on block efficacy. Anesthetic volumes in brachial plexus blockade may be reduced without compromise of effectiveness. However, even with reduced volumes injected into the interscalene space, respiratory compromise from effect(s) on the phrenic nerve may result in hemi-diaphragmatic paresis. Ultrasound-guidance may reduce discomfort during axillary block placement compared with neurostimulation or parasthesia. Nerve catheters may be highly effective and provide prolonged analgesia compared with single-shot injections. Infraclavicular catheters result in improved analgesia compared with supraclavicular catheters and multiple injections of local provide no advantage over single-shot infraclavicular blockade. Dexamethasone combined with local may extend analgesia following a single-injection interscalene or supraclavicular block. During interscalene blockade, intraepineurial injections may occur, but incidence of nerve injury remains low. Therefore, debate continues about intraepineurial injections.
Intraepineurial injection requires additional investigation. Conclusions have suggested reducing typical volumes (40 ml) of local with ultrasound-directed upper extremity blockade. Increased use of perineural catheters is being advocated for prolonged analgesia, but risk-to-benefit consequences need to always be considered.
To provide a review of the rationale and evidence supporting three frequently used psychosocial interventions for chronic pain: cognitive-behavioral therapy, operant behavioral therapy and self-hypnosis training. We also review recent work in these areas, with an emphasis on the 2006 publishing year.
Recent clinical trials and laboratory work continue to support the use of cognitive-behavioral therapy and operant behavioral therapy as adjunctive treatments for chronic pain. Notable areas of new research include a novel program of systematic exposure to pain-related fear (such as fear of reinjury) and the adaptation of cognitive-behavioral therapy for special pain groups (e.g. juveniles and those with pain secondary to physical disability). Regarding self-hypnosis training, recent work suggests that hypnosis can provide temporary pain relief to the majority of individuals with chronic pain and that a substantial minority of these patients experience a clinically significant reduction in baseline pain over time.
Cognitive-behavioral therapy and operant behavioral therapy treatments focus on factors that exacerbate or maintain suffering in chronic pain, and should be considered as part of a multidisciplinary treatment paradigm. Self-hypnosis training may also be of benefit, although it appears to be no more (or less) effective than other relaxation strategies that include hypnotic elements.
Swelling is inexorably linked to shock and resuscitation in trauma. In many forms, swelling complicates and interacts with traumatic injury to raise pressures in the abdomen, resulting in intraabdominal hypertension, which may overtly manifest as abdominal compartment syndrome (ACS) driving multiple organ failure. Despite renewed clinical interest in posttraumatic intraabdominal pressure, there remains a chiasm between knowledge of the risks and clinical interventions to mitigate them. This review provides a concise overview of definitions, risk factors, diagnosis and management using an illustrative trauma case.
Intraabdominal pressure commonly increases following trauma, wherein ACS may manifest earlier than generally appreciated and complicate other insults such as shock and hemorrhage. Contemporary resuscitation strategies may exacerbate intraabdominal hypertension, particularly massive crystalloid resuscitation. Although unproven, the recent transition to crystalloid restriction and high plasma resuscitation strategies may influence the prevalence of ACS. Nonetheless, aggressive intraabdominal pressure monitoring should be mandatory in the critically ill. Despite potential nonoperative options, decompressive laparotomy remains the only definitive but often morbid treatment.
ACS results from many dysfunctions acting in concert with each other in self-propagating vicious cycles. Starting with greater awareness, it is imperative that the growing knowledge should be translated into clinical practice.
Recent advances in blunt thoraco-abdominal trauma management include improvements in imaging, particularly in trauma bay ultrasound. Indications for non-operative management have expanded for solid organ and aortic injury. The physiology of abdominal compartment syndrome continues to be defined, with resulting improvements in care.
Since the publication of original work on the transversus abdominis plane (TAP) block, the translation of the research into clinical practice has resulted in some 146 articles being published in peer-reviewed journals. However, there continues to be controversies over the best approach to be used. The introduction of ultrasound should have aided the development of this block, but in fact it has caused more questions to be asked. There are a number of reviews of the block already published, but were they published too early and what is our current understanding of the TAP block and its mechanisms of action?
The TAP block continues to develop. We now understand that the TAP block is a multifaceted block, working with both localized field effects as well as distal effects due to a distant spread of local anesthetic. Recent research would suggest that the location of needle tip placement causes variation in the block characteristics obtained. The more anterior approaches adopted for use since the introduction of ultrasound might be better described as RAFI (regional abdominal field infiltration) blocks.
The TAP block, in all its guises, is an effective analgesic tool, but what is the best approach? Randomized controlled trials comparing the TAP/RAFI blocks to epidural based analgesia are required.
Purpose of review:
The transversus abdominis plane (TAP) block is a relatively new regional anaesthesia technique that has shown analgesic benefit in abdominal and pelvic surgery. There has been recent interest in expanding this regional technique to enhance analgesia following caesarean delivery.
We will discuss the gross anatomy and neuroanatomy relevant to the TAP, contrast studies looking at the spread of solution within the TAP and the clinical analgesia achieved with the TAP block. We will also present the most recent publications on TAP block analgesia for caesarean delivery and compare the TAP block to intrathecal morphine.
The TAP block significantly improves postoperative analgesia and reduces opioid consumption and opioid-related side-effects in women undergoing caesarean delivery who did not receive intrathecal morphine.
The aim of this review is to outline the priorities in the anaesthetic management of the child with facial abnormalities. It presents a practical approach to this, based on the anatomical site of the deformity and degree of mouth opening.
The literature reviewed primarily consists of case reports and series describing anaesthesia in children with relevant syndromes. Also scrutinized is the literature examining the role and effectiveness of recently developed airway management equipment.
This is a challenging area of anaesthetic practice but the use of a structured approach, combined with supraglottic airway devices and fibre-optic and indirect laryngoscopic equipment, has allowed the safe administration of anaesthesia to almost all children with conditions resulting in facial abnormality.
Accurate identification of patients at risk for ventricular arrhythmias is critical to prevent sudden cardiac death. The perioperative period is usually regarded as one of risk for potential triggering conditions. This review focuses on the anaesthesiologic risk of inherited arrhythmias whose aetiology is a mutation in genes encoding cardiac ion channels in the absence of structural heart abnormalities.
Genetic analysis identifies the genes whose expressions generate ion channel and regulating or anchoring subunits; electrophysiology can study the role of each ion current during cardiac fibrillation and develop many tests for risk. There is, however, a great heterogeneity of clinical phenotype and many histological studies detecting structural heart alterations despite negative noninvasive evaluations.
For some ion channel diseases, a therapy has been established; for others, the therapy and risk stratification are still matters of concern, and it is necessary to evaluate the new tools and tests available. For the highly lethal complication of these 'channellopathies', anaesthesia should proceed with caution in the light of the characteristics of each arrhythmia to prevent complications.
The current review discusses the role of coagulation in microcirculatory abnormalities and whether anticoagulants may improve microvascular perfusion.
Microvascular alterations frequently occur in sepsis and ischemia-reperfusion injury. These alterations are due to endothelial dysfunction and interaction of endothelium and circulating cells. Although the activation of coagulation has been extensively shown to occur in these conditions, microthrombosis seems not to be a predominant factor. Nevertheless, the interplay between coagulation, inflammation and the endothelium seems to favor microvascular dysfunction. Several agents with anticoagulant properties, especially activated protein C and antithrombin, improve the diseased microcirculation, but these agents have pleiotropic effects, and it seems unlikely that these beneficial effects are linked to direct inhibition of coagulation. Current evidence does not support the use of pure anticoagulant agents to improve microvascular perfusion.
The activation of coagulation may play an indirect role in microvascular dysfunction, through interplay with endothelium and inflammation.
Tonsillectomy is a very common procedure, but with risks or challenges, both for the surgeon and anesthesiologist. Many places have considerable experience and expertise with this procedure, and a lot of clinical studies are continuously being presented.
Most preoperative aspects are covered, including indications, preoperative risk assessment, premedication, anesthetic induction and maintenance, as well as recovery function and side-effects; such as bleeding, agitation, pain, nausea and sleep apnea. Controversies exist as to ambulatory versus in-patient care, laryngeal mask airway versus endotracheal intubation, use of local anesthetic infiltration and use of glucocorticoids.
Preoperative evaluation should identify increased bleeding risk, potential airway problems, ongoing infection and symptoms of obstructive sleep apnea.Intravenous propofol is most often used for anesthetic induction, although inhalational sevoflurane is a valid alternative. Laryngeal mask airway or endotracheal tube may both be used safely and effectively; the choice will depend upon the routine and experience of the team. Paracetamol and NSAIDs are useful baseline medication for nonopioid multimodal postoperative pain treatment and prophylaxis. Similar with local anesthesia infiltration and dexamethasone medication, although somewhat more disputed. Dexamethasone is also useful for nausea/vomiting prophylaxis, together with ondansetron and also propofol for anesthesia maintenance.
The degradation of volatile anaesthetics by desiccated carbon dioxide absorbents can result in adverse outcomes. Desiccated carbon dioxide absorbent reacting with desflurane can cause potentially life-threatening intraoperative carbon monoxide exposure; the reaction with sevoflurane can cause the formation of several toxic breakdown products, e.g. compound A. Compound A-related renal toxicity in humans is still a matter of controversy.
Anaesthesiologists have a significantly higher frequency of substance abuse by a factor of nearly 3 when compared with other physicians. This is still a current problem that must be reviewed.
Many hypotheses have been formulated to explain why anaesthesiologists appear to be more susceptible to substance abuse than other medical professionals (genetic differences in sensitivity to opioids, stress, the association between chemical dependence and other psychopathology or the second-hand exposure hypothesis). Environmental exposure and sensitization may be an important risk factor in physician addiction. There is a long debate about returning to work for an anaesthetist who has been depending on opioid drugs, and recent debates are discussed. Institutional efforts have been made in many countries and physician health programmes have been developed.
As drug abuse among anaesthesiologists has continued, new studies have been conducted to know the theories about susceptibility. Written substance abuse policies and controls must be taken in place and in all countries.
Chronic pain leads to a reduction in the quality of life for those who suffer it. Due also to high medical costs and lost productivity, chronic pain is a significant burden on society. One contributor to the burden of pain is the fear that medications used in pain management produce dependency, leading to diversion and addiction. Certain medications used in practice, although not abused by the patient, seem to be favored and these are frequently reported to be used recreationally by the nonpatient population. This report identifies medications that most frequently present a problem in pain practices, why they are a problem, and possible alternatives to their use.
Problem medications used in analgesic regimens tend to be those that have rapid onset due to their lipophilic nature or route of administration, short duration, and a sedating or energizing effect. These medications are generally more affordable than alternatives with less abuse potential. These medications are more often covered by insurance and more frequently prescribed. Changes in prescribing habits have resulted in predictable shifts in abuse.
Addiction and diversion of prescription medications is a multidimensional problem. Its multifactorial solution will require efforts at many regulatory levels.
Common definitions for workplace generations are the silent generation (born 1925-1945), the baby boomer generation (1946-1962), generation X (1963-1981), and generation Y (1982-2000). Distinct motivational and value perceptions stereotype generations. This review defines the characteristics of workplace generations today and provides insight into how differences influence the workplace environment.
Senior faculty members are mostly boomers, whereas residents and junior faculty members tend to belong to generation X. Medical students and incoming interns are from generation Y. When compared with boomers, generation X is more savvy with technology, more independent, less loyal to the institution, and seeks balance between work and lifestyle. The 80-h resident working week restriction has reinforced differences between older and younger physicians. Generation Y exhibits traits that are similar to those of generation X. Their increased interest in anesthesiology may reflect, in part, their assumption that it affords better control of lifestyle.
Understanding, improved communication strategies, mentorship, and flexibility in methods employed to achieve common goals are most likely to capture the interest and cooperation of members of generation X and possibly Y. Future studies should test effects of particular interventions on outcome in terms of recruitment and performance milestones.
This review outlines the methodology of a major report into academic strategy recently undertaken by the Royal College of Anaesthetists in the United Kingdom. Analyzing the factors that made the report's conclusions robust and workable provides lessons for other countries or healthcare systems faced with similar problems in academic anesthesia.
The main themes covered by this review include: organization of healthcare and university systems, medical postgraduate training, and funding of research. In the UK, there exists a dual process: clinical service delivery and postgraduate clinical training [which are both the province of the National Health Service (NHS)], and research and undergraduate education (which are both the province of universities). Both NHS and universities are sponsored by the UK government. 'Professors' or 'heads of academic department' in the UK have no automatic responsibility over the activities of the majority of anesthetic consultants in their own hospitals. Anesthesia in the UK has never been a specific unit of assessment in the research granting process, such that anesthetic departments have received little external grant support compared with many other departments such as medicine or cardiology. As a result, anesthetic departments across the UK have either become entrenched as small departments or they have vanished through mergers.
The review's main conclusions are: the creation of a central National Institute for Academic Anaesthesia to coordinate and implement academic strategy and funding; engaging with national pathways for the training of future academics; and suggestions for the future role for anesthetic specialist societies in academic strategy. These initiatives can radically transform the research environment in a positive way.
Resident duty hour limits were implemented in 2003 by the Accreditation Council for Graduate Medical Education to improve resident wellness, increase patient safety and improve the educational environment of American residents. Now that academic anesthesiology departments and medical centers have had more than 3 years of experience under the duty hour rules, it is critical to review the available evidence on the effectiveness of these rules.
The available data clearly support that American residents across specialties perceive an improvement in their educational environment and an increase in their quality of life. It is not clear if the duty hour rules have affected patient safety or the quality of resident education. Faculty have been impacted by these rules, with many feeling their work loads have increased, and hospitals have had to fund additional providers to cover work previously done by residents.
Accreditation Council for Graduate Medical Education duty hour rules are generally being followed by American anesthesiology residency programs. Residents perceive an improvement in their overall wellness, but it remains unclear if there has been an improvement in patient safety or quality of resident education.
Academic departments of anesthesiology have had to adapt a wide variety of clinical and educational work functions to the viewpoints, values and normative expectations of the newer generations of physicians who now present themselves for training as well as for faculty employment. This commentary will elaborate on key points that academic departments must recognize and incorporate into their functional and organizational imperatives in order to remain successful with regard to physician recruitment and retention.
Recognition of differences between newer-generation vs. established physician issues and concerns include differences in: learning style, teaching style, approach to clinical schedules and the concept of life-work balance, academic and personal motivation, desire for control of their work experience, effective productivity incentives, as well as communication style issues and implications thereof. The spectrum of physicians who contribute to the impact of these factors on contemporary academic anesthesiology departments include faculty, nonfaculty staff physicians, residents and medical students.
Academic departments of anesthesiology which can successfully incorporate the changes and most importantly the functional and organizational flexibility needed to respond to the newer generations' worldview and so-called balanced goals will be able to best attract high-caliber housestaff and future faculty.
The aim of this review is to discuss recent developments in vascular access technology and to highlight those that are particularly relevant to the practitioner.
The need for venous access should always be critically assessed in every child, and it is important to use the limited number of suitable veins wisely and to avoid unnecessary attempts. Near-infrared devices make veins visible, but they do not necessarily increase the success rate of peripheral venous puncture. In contrast, ultrasound is now almost universally used for central venous puncture, and it helped to popularize the supraclavicular puncture of the left anonymous vein. The focus has shifted more toward infectious and especially thrombotic complications.
Despite the development of new technical devices, successful venous puncture remains heavily dependent on the skills of the operator.
There is a growing demand for greater efficiency in ambulatory surgery. The patient population is increasingly sick which is also undergoing more advanced and complex surgery. This creates a danger in discharging patients without meeting the criterion of requirement of a responsible adult as an escort to accompany the patient home. The purpose of this review is to examine the most recent findings to determine whether an escort for patient discharge is necessary.
Recent studies have outlined the risks of discharging patients without escort after ambulatory anesthesia. There are three aspects that deter discharge of patients without an escort: medication used in general anesthetics or sedation; regional anesthesia; and surgical factors. All these can affect the cognitive, memory and psychomotor function of the patients, deeming them unable to perform normal daily activities such as driving.
Both clinicians and patients may have underestimated the risks associated with discharging patients without an escort after ambulatory anesthesia. There should be greater awareness of this problem. Patient discharge without an escort after ambulatory surgery under general anesthesia, sedation or premedication can potentially be dangerous and is not recommended.
The publication of To Err is Human by the Institute of Medicine highlighted the increased international concern about patient safety. Each country has developed its own medical adverse event reporting system. In 2007, the Japanese government attempted to establish a new accountability system in medicine, after an obstetrician was arrested for manslaughter. This paper reviews how this accountability system affected Japanese physicians' behavior, and describes different types of medical adverse event reporting systems.
In general, reporting of adverse event systems can be either mandatory or voluntary, with the purpose being either for learning or for accountability. The goal of a newly proposed mandatory accountability system from the Japanese government was to investigate the cause of death in medical cases in order to clarify liability. Reports generated by this system could potentially be cited in civil law suits, administrative sanctions, and criminal prosecutions. After announcement of this new system, Japanese physicians began to act defensively, fearing criminal prosecution. Refusing to see high-risk patients and 'bouncing' (sometimes referred to as 'turfing' or 'dumping') to other hospitals became national phenomena. In addition, medical school graduates began avoiding highly legally vulnerable specialties. Even though this new system is not yet legalized in Japan, at least 153 obstetrics hospitals and 3320 clinics have closed.
The new system of investigating medical adverse events in Japan allows for incident reports to be utilized in court. This has led to widespread fear of prosecution and defensive medicine. The lessons from Japan should be considered when other countries implement nationwide accountability systems.
In this review, we evaluate the current US employment models for healthcare in general and anesthesiologists in particular and the emergence of large, multispecialty physician groups and the forces behind this change to the current anesthesia practice model. We will also examine the present payment method for anesthesiologists and determine how Accountable Care Organizations will affect the future payment models.
Very few anesthesiologists are aware of the changing economic landscape in the specialty, and this review will provide an up-to-date examination of the changes that anesthesiologists may face in the ensuing years. Accountable Care Organizations will have a drastic impact on the ways in which anesthesiologists are reimbursed and will require anesthesiologists to become more involved in perioperative patient care and outcomes.
This is the most critical time in the specialty of anesthesiology from an economic viewpoint, and significant threats and opportunities will arise for anesthesiologists in how they are reimbursed, and how they demonstrate the delivery of quality care to patients.
We examined the advantages and disadvantages of certifying additional subspecialties in anesthesiology from five vantage points - patients, generalist anesthesiologists, subspecialist anesthesiologists, departments of anesthesiology, and society as a whole - in order to recommend a course of action.
The published literature does not provide conclusive data on the relative benefits or costs of subspecialization in anesthesiology. Currently, only critical care medicine and pain medicine are recognized officially as subspecialties of anesthesiology. Pediatric anesthesia and cardiothoracic anesthesia have accredited fellowships, and a fellowship accreditation application is under review for obstetric anesthesia.
Based on our examination, from the five perspectives given above, we recommend that training in all subspecialties of anesthesiology be encouraged. Official fellowship accreditation and subspecialty certification, however, should be reserved for subspecialties in which anesthesiologists provide services comparable to those provided by nonanesthesiologist subspecialists, such as critical care medicine and pain medicine.
Placenta accreta is one of the leading causes of peripartum hemorrhage. The goal of this article is to review anesthetic management of parturients with placenta accreta and to examine a modern approach to massive peripartum hemorrhage.
The incidence of placenta accreta is rising in parallel with the increased rate of cesarean delivery. If accreta is diagnosed or suspected preoperatively, anesthetic management can be optimized. Even with the best possible management, the blood loss associated with placenta accreta can resemble that of a major trauma. The use of Damage Control Resuscitation strategies to guide transfusion may improve morbidity and mortality.
Careful planning and close communication are essential between anesthesiology, obstetric, interventional radiology, gynecologic oncology, blood bank, and specialized surgical teams when taking care of a patient with placenta accreta.
Compounds acting at both nicotinic and muscarinic acetylcholine receptors appear to have antinociceptive activity, and acetylcholine release in the spinal cord may be involved in endogenous pain control. The therapeutic potential of most cholinergic agonists or of agents that increase synaptic acetylcholine is limited by side effect liabilities. Recent studies, however, have identified some compounds with improved safety profiles. Multiple subtypes of nicotinic and muscarinic receptors exist, and molecular and pharmacological studies are just beginning to identify which subtypes are involved in the antinociceptive effects of cholinergic receptor activation. Further advances in this area will be necessary to determine if the rational design of subtype selective cholinergic agonists will provide novel analgesic agents.
To provide an overview of acquired coagulopathies that can occur in various perioperative clinical settings. Also described are coagulation disturbances linked to antithrombotic medications and currently available strategies to reverse their antithrombotic effects in situations of severe hemorrhage.
Recent studies highlight the link between low fibrinogen and decreased fibrin polymerization in the development of acquired coagulopathy. Particularly, fibrin(ogen) deficits are observable after cardiopulmonary bypass in cardiac surgery, on arrival at the emergency room in trauma patients, and with ongoing bleeding after child birth. Regarding antithrombotic therapy, although new oral anticoagulants offer the possibility of efficacy and relative safety compared with vitamin K antagonists, reversal of their anticoagulant effect with nonspecific agents, including prothrombin complex concentrate, has provided conflicting results. Specific antidotes, currently being developed, are not yet licensed for clinical use, but initial results are promising.
Targeted hemostatic therapy aims to correct coagulopathies in specific clinical settings, and reduce the need for allogeneic transfusions, thus preventing massive transfusion and its deleterious outcomes. Although there are specific guidelines for reversing anticoagulation in patients treated with antiplatelet agents or warfarin, there is currently little evidence to advocate comprehensive recommendations to treat drug-induced coagulopathy associated with new oral anticoagulants.
Changing attitudes toward global health are affecting medical education programs at all levels in the USA and abroad. This review describes some of these changes, and how these affect the educational aspects of US global health programs and anesthesia training in developing countries.
Interest in global health has surged in the past decade, and support for programs has increased in medical schools, university hospitals and from the US government. Recognition of the surgical burden of disease as a global public health problem has been slow but is also increasing. Anesthesia involvement in building healthcare education infrastructure and workforce in low-resource countries is needed and important, and benefits can be had on both sides of the border.
The past 5 years have brought a new global focus on workforce development and education in anesthesia. Programs need to be supported by all stakeholders and monitored for safety, quality and outcomes.
With the increasing use of antiplatelet drug treatment, complications resulting from its interference with invasive procedures (surgery or regional anaesthesia) have become an everyday challenge to the surgical team. The purpose of this review is to examine the most recent findings and integrate them into the ambulatory surgery setting.
Recent studies have outlined the risks of withholding antiplatelet drug treatment, but it is now generally considered to be preferable to withhold treatment than to maintain it. The role of low molecular weight heparins or short-life NSAIDs as bridge drugs is now discussed and their usefulness challenged.
Most ambulatory surgical procedures present low bleeding risk. The current attitude in this setting is to maintain aspirin therapy and possible antiplatelet drug inhibitors throughout the perioperative period. High-risk patients proposed for high-risk surgery should not be treated as outpatients.
To address lung recruitment according to pressure/volume curves, along with regional recruitment versus hyperinflation evidence from computed tomography and electrical impedance tomography.
Cyclical tidal volume recruitment of atelectatic lung regions causes acute lung injury, as do large breaths during pneumonectomy. Using the lower inflection point on the static pressure/volume inflation curve plus 2 cmH2O as a positive end-expiratory pressure setting limits hyperinflation in acute lung injury, but may not provide enough positive end-expiratory pressure to avoid cyclical recruitment/derecruitment injury in more severe acute lung injury regions. Both computed tomography and electrical impedance tomography can help titrate positive end-expiratory pressure in these regions, thereby assuring an 'open lung' ventilatory pattern. Regional pressure/volume curves show that adequate positive end-expiratory pressure for severe acute lung injury regions may not be reliably determined from whole lung pressure/volume curves. Balancing positive end-expiratory pressure requires both arterial PO2 and PCO2 values to determine at what level hyperinflated regions become seriously underperfused (develop very high ventilation-perfusion ratios), adding to the hypercarbia from increased deadspace.
Positive end-expiratory pressure levels must be high enough to minimize recruitment/derecruitment cycling. Balancing recruitment versus overdistension may require thoracic tomography, to assure sufficient improvement in oxygenation while limiting hypercarbia.
Formal Monod-Wyman-Changeux allosteric mechanisms have proven valuable in framing research on the mechanism of etomidate action on its major molecular targets, γ-aminobutyric acid type A (GABAA) receptors. However, the mathematical formalism of these mechanisms makes them difficult to comprehend.
We illustrate how allosteric models represent shifting equilibria between various functional receptor states (closed versus open) and how co-agonism can be readily understood as simply addition of gating energy associated with occupation of distinct agonist sites. We use these models to illustrate how the functional effects of a point mutation, α1M236W, in GABAA receptors can be translated into an allosteric model phenotype.
Allosteric co-agonism provides a robust framework for design and interpretation of structure-function experiments aimed at understanding where and how etomidate affects its GABAA receptor target molecules.
Opioid administration is a mainstay of anesthetic practice both for treating acute perioperative pain and for chronic pain syndromes. Growing pharmacogenetic data make it evident that many opiate-related phenomena are influenced by genetics. Genetic variation may significantly affect opiate absorption, distribution, metabolism, excretion and toxicity. We provide a current review of opiate pharmacogenetics.
Gene association studies should ideally be conducted in highly phenotyped populations of homogenous ethnic admixture with identified associations adjusted for patient demographics, risk factors and medications. Patients' phenotype responses to opiates are the result of a complex interplay between genetic and environmental variables. Although most pharmacogenetic studies to date have assessed the association between individual single nucleotide polymorphisms that exist within selected single gene regions (e.g. opioid receptor mu-1, catechol-O-methyltransferase, cytochrome P450 2D6) and opiate effects, more recent studies have begun to assess the potential influences of gene-gene interactions.
Knowledge of genetic factors that affect opioid efficacy, metabolism, and side effects have the potential for personalizing both acute and chronic pain management, and for designing more effective opiate pain medications with lower side effect profiles.
When tissue is destroyed, pain arises. Tissue destruction is associated with an inflammatory reaction. This leads to activation of nociceptors. The following review will concentrate on pro-algesic and analgesic mediators, which arise from immune cells or resident cells in the periphery or the circulation during inflammation.
In early inflammation endogenous hyperalgesic mediators are produced, including cytokines, chemokines, nerve growth factor as well as bradykinin, prostaglandins and ATP. Simultaneously, analgesic mediators are secreted: opioid peptides, somatostatin, endocannabinoids and certain cytokines. Inflammation increases the expression of peripheral opioid receptors on sensory nerve terminals and enhances their signal transduction, as well as the amount of opioid peptides in infiltrating immune cells. Interference with the recruitment of opioid-containing immune cells into inflamed tissue by blockade of adhesion molecules or by intrathecal morphine injection reduces endogenous analgesia.
Inflammatory pain is the result of the interplay between pro-algesic and analgesic mediators. To avoid central side effects, future analgesic therapy should be targeted at either selectively blocking novel pro-algesic mediators or at enhancing endogenous peripheral analgesic effects.
To summarize recent in-vitro and in-vivo research on molecular mechanisms of general anesthetics' actions.
Classes of general anesthetics with distinct clinical profiles appear to induce amnesia, hypnosis, and immobility via different molecular targets. Propofol, etomidate, and barbiturates produce profound amnesia and hypnosis, but weak immobility, by enhancing the activity of specific gamma-aminobutyric acid typeA receptors. In contrast, nitrous oxide, xenon, and ketamine produce analgesia, but weak hypnosis and amnesia, by inhibiting glutamate and nicotinic receptors and activating potassium 'leak' channels such as TREK-1. Volatile halogenated anesthetics show little selectivity for molecular targets. They act on all the channels mentioned above, and other targets such as glycine receptors and mediators of neurotransmitter release.
Several clinically distinct 'anesthetic states' are induced by different classes of drugs acting on neuronal circuits via different molecular targets. Understanding the mechanisms underlying the therapeutic and toxic actions of general anesthetics helps us reframe the 'art' of anesthesia into more of a 'science'. These studies also enhance efforts to develop new drugs with improved clinical utility.
Exsanguinating hemorrhage and postshock organ failure account for 35-40% of deaths from trauma, and there is an increasing recognition of the importance of coagulopathy in the evolution of this disease.
Since 1999, case reports, small series, retrospective studies and a few controlled trials have reported the use of recombinant-activated factor VII (rFVIIa) as an adjunct for reversal of coagulopathy in trauma patients, and numerous other publications have examined the use of rFVIIa in related conditions such as traumatic brain injury, hemorrhagic stroke and uncontrolled surgical bleeding.
We present a brief discussion of the mechanism of action of rFVIIa and its role in facilitating hemostasis and a review of the recent medical literature on the use of rFVIIa in trauma patients, including current guidelines and controversies.
Severe bleeding after cardiac surgery is a potential problem that poses major risks and challenges. Severe bleeding after cardiac surgery still occurs despite many pharmacological approaches to decrease bleeding and reduce transfusion requirements. Activated recombinant factor VII may be a therapy that is potentially useful in the management of refractory bleeding after cardiac surgery and in other postoperative bleeding states.
Several small, uncontrolled case series have suggested that activated recombinant factor VII may be useful in the management of some patients with intractable bleeding after cardiopulmonary bypass in both pediatric and adult populations. Blood loss or transfusion requirements have been reported to be substantially reduced in some patients who receive activated recombinant factor VII perioperatively. However, these reports have not established the optimal dosing or ideal timing of the administration of activated recombinant factor VII, or determined the frequency of serious adverse events related to its use.
Current reports summarized in this review suggest that activated recombinant factor VII may be a promising agent in the management of uncontrolled bleeding after cardiopulmonary bypass, but additional randomized, placebo-controlled trials are needed to support this use.
To review the literature regarding the use of recombinant activated factor FVII (rFVIIa) in the treatment of postpartum hemorrhage (PPH).
The previous and recent case reports and case series suggest a potential benefit of rFVIIa in the management of severe PPH refractory to standard treatment. However, the lack of randomized controlled studies limits the value of the available data. rFVIIa cannot work optimally if there is a shortage of the basic components of the coagulation cascade such as fibrinogen. New experimental data suggest that rFVIIa can relocate into the extravascular space and remain functionally active which may prolong its hemostatic effect longer than the short circulatory half-life indicates.
Although some preliminary guidelines have been published, the case reports and case series illustrate that the practice of using rFVIIa in PPH is far from uniform. rFVIIa should usually not be used to compensate for an inadequate transfusion therapy. Therefore, early and effective administration of red blood cells, fresh frozen plasma, fibrinogen concentrate (or cryoprecipitate), and platelets as well as the control of uterine atony are essential before considering administration of rFVIIa in the treatment of PPH.
Excessive bleeding is a common and morbid problem after cardiac surgery. There is no doubt a need for an effective and safe hemostatic agent in order to minimize transfusions and avoid surgical reintervention for hemostasis. Recombinant activated factor VII (rFVIIa) is being used (off-label) increasingly after cardiac surgery to prevent or to control hemorrhage, but its efficacy and safety remain unclear.
Several case reports, case series and registries would tend to support the use of activated recombinant factor VII to control excessive bleeding after cardiac operations. On the contrary, two randomized controlled trials have produced negative results whereas a third has not been published yet. Adverse thrombotic events are reported with increasing frequency.
At present, the generalized use of rFVIIa to prevent or to control excessive bleeding after cardiac surgery cannot be recommended. The decision to administer a potent hemostatic such as rFVIIa outside its recognized prescribing indications should be made with caution by well informed physicians and discussed with the patient. Patients should be informed about knowledge gaps and pertinent risks, which are both important in the case of rFVIIa.
There are several aspects that should be considered when measuring the outcome of ambulatory anaesthesia. Major complications and admission/readmission rate are classical measures. Fast-track eligible, pain, and postoperative nausea and vomiting during the early recovery and time to discharge are commonly reported. There is, however, an increasing interest in quality of recovery in a more protracted perspective taking various aspects of resumption of activities of daily living into account. The aim of the present review is to provide an update around postoperative quality of recovery assessment tools. Resumption of activities of daily living or defined functional capacities back at baseline are measures that provide further insight to the quality of recovery.
There is an increased interest in recovery in a more protracted perspective. The Functional Recovery Index is one simple assessment tool explicitly developed for measuring recovery after ambulatory anaesthesia. The Postoperative Quality of Recovery Scale is a more extensive test developed for measuring the recovery after anaesthesia over time in the postoperative period.
The quality of recovery in a more protracted perspective, resumption of activity of daily living is a measure that needs to be considered in studies of perioperative interventions in ambulatory anaesthesia.
Both patients and care providers are concerned about the adverse events associated with pharmaceutical approaches used in postoperative pain management. Acupuncture and transcutaneous-electrical nerve stimulation (TENS) are complementary treatment techniques and are very popular in the management of a variety of painful conditions. Therefore, their use might help to reduce opioid requirements and decrease the incidence of medication-related adverse events. The aim of this review is to summarize the latest findings on the use of acupuncture and TENS in postoperative pain management.
The number of recent high-quality trials on acupuncture and TENS in postoperative pain is limited. Evidence of efficacy in acupuncture studies is contradictory although some high-quality studies clearly found positive effects. Differences in setting and methodology might explain the variability in the results. Findings of the few recent trials using TENS are consistently positive.
Evidence of efficacy in recent studies on acupuncture and TENS in management of postoperative pain is limited. However, some high-quality studies clearly show positive results for both methodologies. As these techniques cause no harm, their use as adjunct to conventional pharmaceutical approaches could be considered particularly for patients in whom conventional techniques fail and/or are accompanied by severe medication-related adverse events.
Along with a growing awareness of quality in healthcare, has come a focus on postanesthetic morbidities, which still remain challenging in our daily practice of anesthesia. Acupuncture and related techniques (acustimulation) are often suggested to be adequate treatments with low cost and minimal adverse effects. This review focuses on the current evidence and applicability of these techniques for use in ambulatory anesthesia.
Trials exploring the effects of acustimulation may produce ambiguous results and sometimes be difficult to evaluate. Controversies still remain as to the clinical relevance. Recent trials suggest that acustimulation may prevent postoperative pain, nausea and vomiting. There are also promising results for the use of the techniques in reducing preoperative anxiety, postoperative shivering and emergence delirium.
Pharmacological drug treatment may be only partially effective and produce an adverse event. Research suggests that acustimulation may alleviate postoperative morbidities, although the body of evidence of the effect is equivocal. The treatments are easy to perform, and adverse events and costs are minimal. It may be profitable to implement this beneficial treatment to ambulatory patients.
Recent advances in drug delivery technology have provided new means of delivering medications with improved efficacy and safety. This review details developments in drug delivery recently made available or in development with the potential to better deliver analgesia.
Patient-controlled analgesia of intravenous medications was a major advance in drug delivery technology that allowed opioids to be administered more effectively and more safely. Extension of this technology to medications not administered intravenously has further broadened therapeutic options in the treatment of acute pain. Improvements in sustained-release formulations and patient-controlled analgesia modalities that are not catheter-based confer the potential to deliver analgesia less invasively. Receptor-specific antagonists allow opioids to be administered with fewer untoward side effects.
New routes of administration allow familiar medications to be utilized with greater clinical efficacy. Elimination of the need for indwelling catheters may reduce both the frequency of analgesic gaps and catheter-related complications. Physicians need to be familiar with developments in drug delivery technologies to be able to effectively utilize analgesics as part of well designed multimodal regimens to bring effective and well tolerated analgesia to patients with acute pain.