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Securing an airway enables the oxygenation and ventilation of the lungs and is a potentially life-saving medical procedure. Adverse and critical events are common during airway management, particularly in neonates and infants. The multifactorial reasons for this include patient-dependent, user-dependent and also external factors. The recently published joint ESAIC/BJA international guidelines on airway management in neonates and infants are summarized with a focus on the clinical application. The original publication of the guidelines focussed on naming formal recommendations based on systematically documented evidence, whereas this summary focusses particularly on the practicability of their implementation., (© 2024. The Author(s).)

It is necessary to discuss the sometimes competing goals of sufficient critical care capacity, maintenance of regular patient care, protection of medical staff, interruption of infectious chains within the general public and individual aspects of patient care in anesthesia and the operating room in times of the SARS CoV-2 pandemic, given the uncertainty of many data on which decisions need to be based. Basic hygiene remains the cornerstone of infection prevention especially when resources are sparse and SARS-CoV-2 specific additional measures need to be taken according to a risk analysis taking the dynamic of the pandemic as well as local factors into account., Competing Interests: SSS ist Mitgesellschafter der BZH-Beteiligungs GbR und erhält Autorenhonorare von den Verlagen Springer, Thieme und Kohlhammer., (Georg Thieme Verlag KG Stuttgart · New York.)

Whereas only a few years ago the only expectation of skilful anesthesia was an undisturbed execution of surgical procedures, today this has changed to a perioperative responsibility in which all physicians involved in the treatment process try to optimize the existing circumstances and risks of the patient before, during and after surgery. Thus, the tasks for the anesthesiologist have been mainly extended to a rapid recovery strategy with as few side effects as possible, such as nausea and vomiting or postoperative cognitive deficits (POCD). The establishment of evident structures and the introduction of suitable perioperative procedures with the goal of maintaining homeostasis, adequate opioid-sparing pain treatment and rapid postoperative convalescence determine the anesthesiological fast-track concept.

Because of new surgical techniques, advanced monitoring modalities and improvements in perioperative care, perioperative mortality and morbidity have been significantly reduced in the last decades; however, patients still suffer from high perioperative mortality and morbidity, especially those with pre-existing cardiovascular diseases. Not only perioperative myocardial infarction but also myocardial injury after non-cardiac surgery, which presents without clinical symptoms, is associated with an adverse outcome. Patients at risk require particular interdisciplinary attention throughout the perioperative phase. The premedication visit is of particular importance. In addition to a thorough patient medical history and physical assessment, the perioperative handling of the patient's pre-existing medication and possible necessity for further preoperative tests should be verified. If necessary and where possible, optimization of the patient's state of health can be planned together with other disciplines. It is the anesthesiologist's responsibility to optimally guide and support patients with pre-existing cardiovascular diseases through the entire surgical procedure. This review summarizes perioperative interventions that have an influence on patient mortality and morbidity and evaluates the underlying evidence. This covers the perioperative handling of cardioprotective medication, choice of the anesthetic regimen, blood pressure management and transfusion regimens. Furthermore, this review highlights recent findings, e.g. perioperative reloading with statins and short-term preoperative initiation of beta blockers. The pros and cons of thoracic epidural anesthesia in patients with an elevated cardiovascular risk are discussed. Not only intraoperative hypotension should be of concern to anesthesiologists but also postoperative hypotension can have a deleterious impact on the outcome. This is relevant in the time period when a significant proportion of patients have already left the monitoring ward. The recently published recommendations by the World Health Organization concerning perioperative hyperoxia might not be beneficial for patients with an elevated cardiovascular risk. Finally, the treatment options for perioperative cardiovascular events are explained and an algorithm for handling of patients with perioperative myocardial injury without clinical ischemic symptoms is suggested (myocardial injury after non-cardiac surgery).

Background: Video-assisted patient education (VaPE) has in the past been a subject of many studies. Compared to conventional methods, most authors reported a better transfer of information, some found increased patient satisfaction and a time-sparing effect. There was no increase in anxiety caused by VaPE. Some authors even found a reduction of anxiety levels before anesthesia. All publications to date have focused on the patient's point of view. There have been no reports on how anesthetists as users assess VaPE., Methods: In this study 22 anesthesia departments using VaPE were contacted. A total of 122 anesthetists were sent questionnaires of which 81 (66%) were completed and returned. The anesthetists were first questioned about the characteristics of the workplace, the frequency of preanesthesia patient contacts, the content of the videos, the technique of video presentation and their own professional experience. After this the anesthetists were asked to assess five statements concerning: usefulness of VaPE, economy of time, transfer of knowledge, induction of anxiety and influence on the quality of the consent interview. In each category there were 4 choices: fully agree, partly agree, partly disagree and fully disagree. The first two choices were evaluated as positive and the second two as negative answers. The anesthetists were also asked to state the most valued characteristics of VaPE. Out of eight given options they were to select the most favored three. A final question was whether in their opinion VaPE could be recommended to non-users., Results: Of the anesthetists 97.5% stated that disclosure interviews predominantly took place in the preoperative anesthetic clinic and 73% performed 15 or more patient interviews per day. Videos about general anesthesia were applied by 70%, about non-obstetric regional anesthesia by 56% and about obstetric epidural anesthesia by 59%. The videos were presented to groups of patients via large screens by 27%, individually with CD players or tablet computers by 51% or with both methods (22%). Of the anesthetists 69% had 5 years or more professional experience, 97.5% found VaPE useful for patients education, 92.5% observed a time-saving effect for the following interview and 96% stated that after watching the video patients were better informed. An increase of anxiety caused by VaPE was noted by 46% whereas 54% found no such effect. As to the quality of interview 50% reported an advantage in focusing on the patient's individual risk profile and the other 50% reported no advantage. The ranking of the main advantages was 1) better patient information, 2) time-saving effect, 3) helpful for patient education, followed by 4) increased patient satisfaction, 5) better understanding of anesthesiology, 6) individualization of the interview and 7) helpful in questions of legal liability. The answer option "no advantage" was not chosen at all. Of the participants 82.5% would recommend VaPE unconditionally (fully agree), 17.5% would give a conditional recommendation to colleagues and no one would not recommend VaPE., Conclusion: This survey among anesthetists confirmed most results obtained from patient-based studies: medical users attributed to VaPE a better information transfer and a time-sparing effect. Furthermore, users regarded VaPE as helpful for the preanesthesia interview. As compared to the patient-based results, however, many anesthetists seem to overrate the anxiety, caused by disclosure videos. From the users' point of view, VaPE is a highly appreciated method for patient education which can be recommended to colleagues.

Epigenetics, i.e. an altered reading of the genome without altering the genes themselves is a growing scientific field. A distinction is made between changes in the DNA by modification of the histones and non-coding RNA that alter the messenger (m)RNAs. Epigenetic modifications can be triggered by personal circumstances or other external factors and therefore influence the occurrence of diseases. Epigenetics are therefore of particular interest to anesthesiologists, pain specialists and intensive care physicians, as anesthetic drugs may have a long-term influence on protein transcription leading for example to alterations in neurocognition after anesthesia, chronification of postoperative pain and immune response in sepsis. Non-coding microRNAs known to be altered in a variety of perioperatively relevant diseases e. g. heart infarct, might serve as prognostic factors of perioperative outcome. Moreover, there are ways to influence epigenetic changes through life style and certain medications. In this review article, examples of anesthesia, intensive care and pain medicine-relevant diseases and the influence of epigenetics on them are presented.

The application of intraoperative neurophysiological monitoring (IONM) is gaining more and more importance in daily clinical practice. The use of IONM allows the localization of neural structures and to control functioning of the peripheral and central nervous systems in anesthetized patients. This enables surgeons to identify and to protect neural structures and cerebral areas. The use of IONM also enables anesthesiologists to adjust anesthesia and cardiopulmonary therapy to the individual needs of the patient. Thereby, it may be possible to reduce the incidence of postoperative delirium and the incidence of postoperative cognitive deficits. To exploit the full potential anesthesiologists and surgeons must be able to use the methods of IONM safely and understand the results; therefore, basic knowledge of the technology, options and limitations of IONM is necessary. It is also important to be aware of the influence of anesthetics on the methods of IONM. Total intravenous anesthesia (TIVA) is the anesthetic method of choice, because it has only minimal influence on IONM methods. It is important to avoid bolus injections of hypnotics to achieve stable blood concentrations. Long- acting neuromuscular blocking agents should be avoided, because they disturb the signals of electromyography and motor-evoked potentials. By using IONM anesthesiologists and surgeons can identify changes in the function of the peripheral and central nervous system prior to irreversible damage.

Anesthesiological challenges during craniotomy result from the anatomically related low compensatory capacity of the intracranial space in response to increased volume and the low ischemic tolerance of brain tissue. The anesthetic agents used should therefore not increase the intracranial volume and improve the ischemic tolerance. An acute life-threatening increase of intracranial pressure can be temporarily treated by hyperventilation until measures, such as osmotherapy and infusion of intravenous anesthetics become effective. During an operation the homeostatic parameters including blood volume, blood pressure, partial pressure of carbon dioxide and oxygen in blood, plasma glucose concentration and core body temperature have to be closely monitored and kept normal (6 Ns). Optimal implementation of anesthesia necessitates a detailed knowledge of the surgical approach and potential complications. Postoperatively, patients should be extubated as soon as possible to closely monitor cognitive function so that potential deterioration can be detected.

Less invasive bronchoscopic techniques for lung-volume-reduction have almost replaced surgical resections. Tracheobronchial obstructions and - to a certain degree - even bronchial tumors can be treated bronchoscopically. However all these procedures show specific risks anesthesiologists have to consider., (© Georg Thieme Verlag Stuttgart · New York.)

Background: The anesthesia premedication consultation is an obligatory procedure prior to any upcoming surgery. It is the anesthesiologist's responsibility to collect all necessary information regarding the patient's medical condition to decide on the appropriate narcosis and to ensure that the patient comprehends the anesthesia procedure and its effects., Aim: Information needs of patients regarding anesthesia are often not adequately fulfilled. This study was carried out to develop a structured questionnaire containing questions that patients may wish to ask the anesthesiologist (question prompt list anesthesiology QPL-A) to support information transfer from the anesthesiologist to the patient in the premedication consultation. The questionnaire should measure the information needs of the patient regarding different aspects of the anesthesia process with good psychometric qualities., Material and Methods: Based on a literature review and interviews with experts a list of anesthesia-related questions was developed and distributed to patients receiving premedication consultation at the University Medical Center in Mainz, Germany (n = 202). In addition, patients were also asked to complete the state trait operation anxiety inventory (STOA)., Results: Using principal component analysis and subsequent varimax rotation (declaration of total variance 68 %), four reliable information needs scales were extrapolated: (1) anesthesia procedure and effects (QPL-A-E, α = 0.92), (2) anesthesia safety (QPL-A-S, α = 0.86), (3) advice concerning preanesthesia behavior (QPL-A-B, α = 0.85) and (4) anesthetists actions (QPL-A-A, α = 0.79). In order to obtain sufficient information regarding the QPL-A-S, the procedure itself and its effects (QPL-A-E) were found to be of greatest importance for the patients and behavioral changes (QPL-A-B), e. g. stopping smoking, were judged to be less important by the patients. Women scored higher on the QPL-A-E (U-test p ≤ 0.001) and QPL-A-A (U-test p ≤ 0.05) than men. Elderly patients (≥ 70) showed significantly more interest in safety information (QPL-A-S) than younger patients (≤ 39, U-test p ≤ 0.05). All scales showed a significant positive correlation with STOA trait anxiety (r = 0.29-0.50) but only the QPL-A-E and the QPL-A-S scales were associated with STOA state anxiety (QPL-A-E: affective r = 30, cognitive r = 0.36, both p ≤ 0.001; QPL-A-S: affective r = 19, p ≤ 0.05, cognitive r = 0.23, p ≤ 0.01). Self-assessed knowledge on narcosis correlated only weakly with the QPL-A-E (r = 0.21 p ≤ 0.01) but not with the other information areas. Information needs were not associated with the education level of the patient, American Society of Anesthesiologists (ASA) classification and malignancy of the disease. Most of the participants (77 %) evaluated the QPL-A to be very or fairly helpful for the expression of their information needs., Conclusion: The QPL-A is a useful tool for meeting the subjective information needs of patients which could improve the patient orientation of the anesthesia premedication consultation.

Independent from the mode of mechanical ventilation, particularly a quick termination of mechanical ventilation is essential for the weaning progress. Respirator-associated complications need to be early detected and treated. Thus it is important to know correspondent pathomechanisms as they have a crucial influence on the weaning process.To facilitate a holistic treatment approach for patients in prolonged weaning, a tight junction of intensive care within specialized units seems mandatory., (© Georg Thieme Verlag Stuttgart · New York.)

In February 2013 the Committee of the American Society of Anesthesiologists (ASA) Task Force published the amended version of the "Practice guidelines for management of the difficult airway" which replace the recommendations from 2003. The amended version re-evaluated the recommendations from 2003 in 2011, evaluated recently published studies and recommendations and included them in the new practice guidelines. In particular, new technical developments, such as the recently established video-assisted intubation procedure were taken into consideration. Despite the many publications in the field of airway management the evidence resulting from the data obtained from recent publications is so low that the new information does not necessitate any amendments to the existing guidelines. In short, the current guidelines basically correspond to the previous version published 10 years ago but are, however, more than twice as extensive. This article summarizes and comments on the cornerstones of the guidelines.

Background: In the context of regional anesthesia procedures adverse events rarely occur but are predominantly systemic intoxication due to local anesthetics (0.01-0.035 %), nerve injuries (0.01-1.7 %) and infections (0-3.2 %)., Materials and Methods: In a level 1 trauma centre data from all continuous peripheral nerve blocks (cPNB) were prospectively acquired over a period of 8 years (2002-2009) in an observational study (n = 10,549). The acquisition of data was carried out in an intranet-based data bank which was accessible for 24 h on every anesthesia workstation. The collected data included type of block, catheter duration and accompanying complications. This study was carried out with special respect to infectious complications (inflammation and infection)., Results: In the years 2002-2004 unexpectedly high rates of infectious complications were observed in 3,491 cPNBs with 146 inflammations (4.2 %) and 112 infections (3.2 %). Based on these alarming findings the existing hygiene regime was revised. The innovations were incorporated into the "Hygiene recommendations for the initiation and continued care of regional anaesthetic procedures" of the German Society for Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, DGAI). A major change was the extension of skin disinfection to a spray-and-scrub combined procedure lasting 10 min. The introduction of this care bundle was carried out in 2005. Among 7,053 cPNBs that were conducted between 2005 and 2009 inflammation occurred in only 183 procedures (2.6 %) and infection in 61 procedures (0.9 %). This reduction was highly significant in both categories (p < 0.001). The risk factors catheter duration and catheter localization statistically remained unchanged during the observational period, Conclusion: Using a real-time computer-based tool for data capture makes a veritable detection of adverse events possible. Such a tool also has the power to monitor the effects of changes in clinical procedures (SOP). In this case it was possible to verify the successful introduction of an extended hygiene care bundle. The new regime significantly decreased the rate of infections in cPNB.

Injuries remain the leading cause of death in children and young adults. Management of multiple trauma patients has improved in recent years by quality initiatives (trauma network, S3 guideline "Polytrauma"). On this basis, strong links with preclinical management, structured treatment algorithms, training standards (ATLS®), clear diagnostic rules and an established risk- and quality management are the important factors of a modern emergency room trauma care. We describe the organizational components that lead to successful management of trauma in hospital., (© Georg Thieme Verlag Stuttgart · New York.)

Air travel has become a natural part of modern life. Both the environment, they take place in and the physical changes humans are exposed to must not be underestimated. Changes of pressure and volume of gases in higher altitudes induce specific physiological reactions, whereas limitations to compensate need to be acknowledged. It is the artificial environment of the aircraft cabin that allows travel in usual flight levels. Nevertheless, mild hypoxia and its sequeale have to be considered., (© Georg Thieme Verlag Stuttgart · New York.)

Preanesthesia visits are highly complex communicative events with legally demanded participation of the patients. The contribution describes the logical communicative course of this communication type as well as the communicative tasks of the participants. It is shown that physicians in fact offer opportunities for patients' questions but combine them with initiatives for the completion of the interaction; formulations of such offerings are also discouraging patients' questions. Initiative questions of patients during the conversation otherwise indicate where patients are in need for questions., (© Georg Thieme Verlag Stuttgart · New York.)

The vast majority of anaesthetists considers application of cricoid pressure for reasons of patient safety an integral part of rapid sequence induction. Cricoid pressure is applied with the idea that it will prevent regurgitation of gastric content into the pharynx, thereby reducing the incidence of pulmonary aspiration. This review describes the background of the introduction of cricoid pressure into clinical practice, analyzes published data concerning clinical relevance of perioperative pulmonary aspiration and efficacy of cricoid pressure in reducing it, discusses problems associated with its use, assesses knowledge and technical performance of cricoid pressure and presents various recent recommendations regarding application of cricoid pressure. The combination of complete lack of evidence for the efficacy of cricoid pressure in preventing pulmonary aspiration and numerous reports of clinically relevant interference with airway management during its use, seriously question the rationale of recommending the general use of cricoid pressure during rapid sequence induction.

The increase in intra-abdominal pressure may be followed by a renal, gut, respiratory and cardial dysfunction and an increase in intra-cranial pressure. The review focuses risk factors and pathophysiological consequences of intra-abdominal hypertension and of abdominal compartment syndrome. Patients with intra-abdominal hypertension and abdominal compartment syndrome are critical ill and need special anesthesiological care due to risk of pulmonary aspiration, hemodynamic disturbances and difficult mechanical ventilation.

Patients with an acute abdomen present with marked deterioration in physiological and pathophysiological conditions, which make general anesthesia to a challenging but also potentially dangerous procedure. A broad and fundamental knowledge of the pathophysiologically involved mechanisms of cardiovascular functions during anesthesia and appropriate anesthesiological approach are crucial for a successful peri-operative management. The anesthesiologist's goal is to perform adequate anesthesia while maintaining cardiovascular stability. Monitoring and management of acid-base-status as well as cardiovascular functions are required to maintain sufficient tissue oxygenation during anesthesia. The postoperative anesthesiological management may also crucially influence the further course and therefore should be considered in the anesthesiological planning. Finally, adequate pain management in all these patients is an important and not to underestimate part in the treatment. This article gives an overview on the major aspects in the different fields in the anesthesiological management of patients with an acute abdomen.

Preventing patient harm is one of the main tasks for the field of anesthesiology from early on. With the introduction of the national German incident reporting system PaSOS, which is hosted by the German anesthesia society, anesthesiology is again leading the field of patient safety. Important elements, success factors and background information for the introduction of successful incident reporting systems in an organization are given. Examples by and from PaSOS are given.

Within recent years patient safety has become increasingly important. Within US hospitals more than 98.000 deaths have been reported annually due to medical errors, more than 80 % due to preventable mistakes. To improve patient safety it is therefore important to develop training tools, which center on the complexity of preventable mistakes, analyze underlying factors and eventually train to deal with them. Since the Berlin Simulation training was founded in 1997 it focused on the internationally accepted "global approach" based on three phases of briefing, simulation and debriefing. It concentrates on the reasons of preventable mistakes and their interaction. Problem solving strategies and the application of NTS ( planing, management, teamwork and communication) and TS (sound scientific knowledge and abilities) are practiced under the supervision of experienced trainers. The goal is to provide insight into the cascades of error and terminate them, to ultimately increase patient safety and provider satisfaction.

Ultrasound-guided anaesthesia of peripheral nerves is a new challenge for anaesthesiologists. The number of ultrasound users in this field has increased over the last 10 years because of improved high frequency ultrasound technology and increased mobility of machines. There have been many publications on blocking procedures but many questions still remain unanswered on the practical aspects of ultrasound-guided techniques. Basic knowledge in ultrasound technology and image characteristics and a defined approach to blocking procedures to ensure sterile working conditions are necessary to guarantee optimal safety of patients. Furthermore economic questions and the implementation of a standardised education program are very important.

Various sonographic techniques that are implemented in transesophageal echocardiography (TEE) for cardiovascular monitoring, allow for an extensive cardiac structure and function analysis. Major priority is assigned to the judgement on myocardial contractility, ventricular filling end ejection, valvular morphology and structure, as well as diagnosis of the ascending and descending aorta. Correct interpretation of the imaged structures increases diagnostic safety, but is built on high requirements on the investigator. On these grounds, this article aims to inform you on the clinical applications of TEE.

In anaesthetic practise ultrasound can facilitate cannulation of veins and arteries not only in adults but also in children. It is the main advantage and safety feature of this technique, that the targeted vessels and the surrounding anatomical structures are visualized and that the needle is advanced under continuous observation. Moreover, its systematic use can reduce the rate of unsuccessful cannulation attempts, which can be caused by anatomical variations or thrombi, occluding the targeted vessel. Ultrasound guided vascular cannulation can decrease complication rates and might improve patients safety e.g. by avoiding puncture of the carotid artery. However, in order to pass on these potential benefits to the patient and justify the increased expenses related to the purchasing of preferably portable ultrasound systems, it is mandatory to offer an appropriate ultrasound training programs for physicians using this technique.

Ultrasound is an emerging new imaging and guiding technique for diagnostic or therapeutic interventional pain procedures. Advantages are the real time monitoring of the targeted structures, the placement of the instruments and the visualization of local anaesthetic spread without exposing patients and personal to radiation. Pain specialists need a large anatomical knowledge and training to use the new method safely and distinctively. The increasing published data available and the personal experience of the authors suggest a potential usefulness in interventional pain therapy, but also limitations.

The requirement for intraoperative blood salvage (IBS) in cancer surgery stems from the high transfusion rate, the unfavourable effects of an anaemia, and the impact of transfusion risks like immunomodulation in tumor patients. The advantages of IBS are availability, the low waste rate, and the excellent quality of this autologous, unstored blood. The only effective elimination of the risk of tumor cell dissemination after retransfusion of wound blood is achieved by blood irradiation. The combination of the established methods of IBS and blood irradiation is practical, and allows a very efficient saving of blood. For Jehovah's witnesses it may open the possibility for tumor surgery. From an anaesthesiological point of view it is part of the therapy, but any context that puts it compatible to medicolegal regulations is welcome. For him as the one responsible for the therapy of intraoperative blood loss it represents the safest and best blood for an optimal hemotherapy in tumor patients. In addition, first data indicate a better outcome of these patients.

The current practice of regional anaesthesia in German-speaking countries was investigated in a survey. The second part of the trilogy presents data about its use, success rates, and techniques. In 2002 questionnaires were mailed to 750 randomly selected departments of anaesthesia of which 384 hospitals participated. Peripheral regional anaesthesia is used above all in traumatology and orthopaedics, 45% of the hospitals with paediatric surgery never used neuroaxial blocks. The residents achieved mean success rates of 69.7+/-11.8% for supraclavicular plexus block to 85.5+/-9.0% for spinal anaesthesia, the specialists in anaesthesia 79.2+/-11.3% (supraclavicular plexus block) to 91.0+/-6.8% (spinal anaesthesia). Standards for basic techniques, recording of success rates, and for quality assurance of peripheral nerve blocks should be worked out to improve the application of peripheral regional anaesthesia procedures. In neuroaxial anaesthesia satisfying success rates were reached in German-speaking countries. In paediatric anaesthesia its use still has many opponents.

This survey analyses the history of 100 years of Draeger Medical Technology. Between 1889 and 1902 a number of inventions on the field of pressure gas technology allowed to solve application problems, which until then proved major obstacles to the safe and efficient use of compressed gases such as oxygen, nitrous oxide or carbon dioxide for medical and industrial purposes. A special significance is to be awarded here to pressure reducing valves, but also reliable manometers, nozzles and valves for pressure tanks were not generally available until then. These were first successfully and on a really significant scale introduced into international medical and non-medical pressure-gas technology by Draeger Inc. (Luebeck/Germany), and proved particularly successful in anaesthesia and rescue-devices (e. g. in the "Roth-Draeger Anaesthesia Apparatus" (1902). Consequently, starting in 1902, Draeger Inc. increasingly put an emphasis on developing medical and rescue technology and -- by doing so -- gained an important influence on the history of the implementation of modern oxygen therapy and of inhalative anaesthesia. A survey of the historically most important Draeger-Developments is provided.

Artificial neural networks (ANN) are constructed to simulate processes of the central nervous system of higher creatures. An ANN consists of a set of processing units (nodes) which simulate neurons and are interconnected via a set of "weights" (analogous to synaptic connections in the nervous system) in a way which allows signals to travel through the network in parallel. The nodes (neurons) are simple computing elements. They accumulate input from other neurons by means of a weighted sum. If a certain threshold is reached the neuron sends information to all other connected neurons otherwise it remains quiescent. One major difference compared with traditional statistical or rule-based systems is the learning aptitude of an ANN. At the very beginning of a training process an ANN contains no explicit information. Then a large number of cases with a known outcome are presented to the system and the weights of the inter-neuronal connections are changed by a training algorithm designed to minimise the total error of the system. A trained network has extracted rules that are represented by the matrix of the weights between the neurons. This feature is called generalisation and allows the ANN to predict cases that have never been presented to the system before. Artificial neural networks have shown to be useful predicting various events. Especially complex, non-linear, and time depending relationships can be modelled and forecasted. Furthermore an ANN can be used when the influencing variables on a certain event are not exactly known as it is the case in financial or weather forecasts. This article aims to give a short overview on the function of ANN and their previous use and possible future applications in anaesthesia, intensive care, and emergency medicine.

Whenever evidence-based medicine (EbM) is mentioned among physicians, it evokes many different and contradictory reactions. On the one hand a lot of physicians have heard of this concept, but may hardly associate anything with it. On the other hand most of the physicians seem to be skeptical rather than in favour of evidence-based medicine. They seem to be concerned about restrictions in daily clinical decision-making or negative implications for the relationship between patient and physician. In this article we would like to deal with the question whether evidence-based medicine is useful for clinicians and which chances are provided for both the physicians and the patients by using it. First, the methodology and aims of evidence-based medicine are introduced. Second, by using an example of clinical anaesthesiology, we discuss the six formal steps for implementing this method. Third, important points which help to assess clinical studies are mentioned. In conclusion we would like to point out that evidence-based medicine is no entirely new concept of medicine but aims to highlight a solid and conscientious scientific basis of clinical decision-making. Thus, evidence-based medicine may act as a methodological strategy helping to clear the proceedings of decision-making and improve the provision of medical care to patients. Furthermore, it may guarantee a rapid transfer of knowledge from outcome-related research to patient care.

Portable digital assistants (PDAs) may be of value to the anaesthesiologist as development in medical care is moving towards "bedside computing". Many different portable computers are currently available and it is now possible for the physician to carry a mobile computer with him all the time. It is data base, reference book, patient tracking help, date planner, computer, book, magazine, calculator and much more in one mobile device. With the help of a PDA, information that is required for our work may be available at all times and everywhere at the point of care within seconds. In this overview the possibilities for the use of PDAs in anaesthesia and intensive care medicine are discussed. Developments in other countries, possibilities in use but also problems such as data security and network technology are evaluated.

Anaesthesia today is a cross-over of all medical sub-specialities, based on a stable scientific fundament and a high margin of safety. Anaesthetic techniques are sophisticated and enable a differentiated treatment of pre-, intra- and post-operative medical demands. The physician-patient-relationship and the patients' satisfaction are main aspects of peri-operative care by anaesthetists even in the area of conflict by economic pressure. Nonetheless, the credit to anaesthetists given by physicians and also by the general public is inadequate resulting in difficulties to recruit a sufficient percentage of the decreasing number of aspiring physicians. This could be prevented by an improved medical school and training. Anaesthesiologists in science address either fundamental questions as to mechanisms of anaesthesia and epidemiological aspects of peri-operative medicine.

Anaesthesia-related risk has been significantly reduced within the last decade. Nevertheless the risk and the possibility of dying or suffering permanent damage still exist. To improve patient safety, risk assessment and analysis must lead to the development of preventive strategies. For this purpose anaesthesia can rely on the concepts of other "high reliability" organisations such as aviation or nuclear power plants. Analyses of critical incidents in the different fields confirm that next to technical problems human factors account for most of the preventable mishaps. Human factors are responsible for individual mistakes as well as for organisational errors. Therefore besides traditional concepts of risk reduction (e.g. guidelines) new strategies (e.g. full-scale simulation) must be applied to minimise the negative impact of human factors on patient safety. Risk management has to consider technical, organisational and human factors to implement a higher standard of patient safety.

Preoxygenation is a simple technique to expand the time under planned apnea till the patient is endangered by hypoxia. In this study, we analysed how preoxygenation is used by anaesthesiologists in clinical routine and how this method is tolerated by the patients. One hundred and twenty-one anaesthesiologists of 4 hospitals were interviewed anonymously about training level, rank, indication for preoxygenation and techniques of preoxygenation, as well as their estimation of the patients' discomfort during preoxygenation. Data on 100 patients about oxygen-mask-tolerance were acquired by an anonymous questionnaire from a standard quality control inquiry. We received back 76 of the 121 questionnaires of anaesthesiologists (63 %). Fifty-nine percent of the anaesthesiologists (45/76) preoxygenated in clinical routine. With increasing training time and higher ranks, less anaesthesiologists preoxygenated routinely: junior residents: 80 %; senior residents: 68 %; consultants: 60 %; assistant medical directors: 48 %.80 % of the anaesthesiologists (61/76) used imperfect techniques for preoxygenation (e. g. oxygen-flow < 8 l/min). At the time of preoperative evaluation, the patients estimated the discomfort during preoxygenation on a continuous scale (1 to 10) as 2 (median; 1 - 7: 95 % confidence interval). Postoperatively, the patients mentioned no discomfort: 1 (1 - 1). The anaesthesiologists overestimated their patients' discomfort significantly with 5 (3 - 7) (p < 0.001).In conclusion, preoxygenation, a simple safety procedure, is not routinely used by many anaesthesiologists and imperfect methods are often employed. A possible reason for the anaesthesiologists' reluctance to preoxygenate is an overestimation of the patients' discomfort, though the patients tolerate preoxygenation very well.

Objective: We examined the new NasOral-System (NOS; Logomed, Germany), which is designed for a fasten and more complete denitrogenization when compared to the use of a contemporary face-mask. The patient inhales oxygen via a nose mask and exhales via mouthpiece. Nose mask and mouthpiece have built-in one-way valves, resulting in an unidirectional gas flow (nasal-oral)., Methods: With approval of the local ethic committee, pre-oxygenation with both the NOS and a face mask (Laerdal) was studied in 50 adult patients. Midazolam 3.75-7.5 mg p.os was given for premedication. The NOS was studied in two different ways: the nose mask fastened by rubberband and with the nose mask held by hand. Prior to induction every patient received every system in a randomised manner. Semi-closed-anaesthetic circle-systems with a fresh-gas-flow of 10 litres/min were used. The FEO2 over 5 min of pre-oxygenation were recorded (AS-3, Datex). Speed and degree of the denitrogenization was documented by an external digital data-acquisition system. Practicability of the systems regarding the anaesthesists (n = 27) and patient comfort were evaluated by means of a standardized postoperative questionnaire., Results: The hand-held NOS is definitely more effective and reliable than both the NOS fastened by rubber-band and the classical face mask: 80% of the hand-held NOS were able to achieve a FEO2 of > or = 0.8 compared to only 36% of the NOS fixed by rubber-band, face mask: 48%. FEO2 of > or = 0.8 was achieved with 52% of the hand-held NOS in 90 s, a time we consider practical for daily routine, whereas only 10% of the NOS fixed by rubberband and 14% of the face masks accomplished this threshold. A cooperative patient is an important condition when using the NOS: a strong premedication effect, absence of dentures, and patients who can not inspire via nose and expire via mouth involve impairment of the positive effects of the NOS. 21% of the anaesthesists felt disturbed by the NOS. 72% do not believe, that induction of anaesthesia will become more safe with the NOS. For 8 patients, breathing with the NOS was disagreeable (face-mask: 3 patients), 15 were disturbed by the nose part/mouth piece (face-mask: no patient)., Conclusion: An acceptable FEO2 of > or = 0.8 can be achieved only without leakage of both the NOS and the face-mask. Therefore, routine FEO2-monitoring seems highly desirable. Efficiency of the hand-held NOS is much better than with the NOS fastened by rubberband or the face mask. However, even the hand-held NOS cannot guarantee for optimal denitrogenization. Practicability in daily use was poor, because a test of airway patency by manual ventilation prior to relaxation/intubation is not possible with the NOS. Using the device as a help in apnoic oxygenation seems useful.