Der Anaesthesist
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Perioperative myocardial damage occurs with a high incidence depending on the operative procedure and the patients examined and is considered to be among the most relevant risk factors for increased perioperative morbidity and mortality in patients undergoing non-cardiac surgery. The pathophysiology of myocardial damage in the perioperative period is still not well understood. Both ischemia with and without acute coronary occlusion and non-ischemic stimuli can put a substantial strain on the heart in the perioperative period. ⋯ This is probably due to a considerable difference in phenotype and pathophysiology between perioperative and non-perioperative myocardial infarctions. As a result of this unexplained etiology of perioperative myocardial infarction it remains an open question whether the contemporary diagnostic and therapeutic recommendations for the acute coronary syndrome can be extrapolated to the perioperative situation. The present review reflects the current state of knowledge and presents an optional approach to the diagnosis and therapy of perioperative myocardial injury.
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Since its commercial introduction in 1996, target-controlled infusion (TCI) has become an established technique for administration of intravenous anaesthetics. Modern TCI systems, however, are characterized by an increasing number of additional options and features, such as the choice between different pharmacokinetic models and modes of application, which may confuse the less experienced user. This review describes the differences between pharmacokinetic models, modes of application and the effect of covariates as well as the consequences for dosing. The aim is to explicate for the user of modern TCI systems the underlying scientific concepts and the relevance for clinical practice.
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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.
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The management of general anaesthesia in patients with neuromuscular disorders remains challenging. The underlying causes and clinical presentations of these rare heterogeneous diseases are highly variable and the only common feature is usually skeletal muscle weakness. ⋯ Neuromuscular monitoring can be complicated because of disease-induced alterations in neurophysiology; however, continuous monitoring of the neuromuscular blockade should be realized to accurately determine the recovery from the blockade. These patients very often have an increased risk for postoperative pulmonary complications, which increases further if a residual neuromuscular blockade is present.
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During cardiopulmonary resuscitation (CPR) with a chest compression rate of 60-100/min the time for secure undisturbed ventilation in the chest decompression phase is only 0.3-0.5 s and it is unclear which tidal volumes could be delivered in such a short time. ⋯ Ventilation windows of 0.25, 0.3, and 0.5 s were too short to provide adequate tidal volumes in a simulated non-intubated cardiac arrest patient. In a simulated intubated cardiac arrest patient, ventilation windows of at least 0.5 s were necessary to provide adequate tidal volumes.