Articles: general-anesthesia.
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Several methods have been developed to quantify central anaesthetic effects and monitor awareness during general anaesthesia. The most important of these are the PRST score, calculated from changes in blood pressure, heart rate, sweating, and tear production, the isolated forearm technique, where the patient is allowed to move during surgery, the processed electroencephalogram (EEG) and the derived parameters median frequency (MF) and spectral-edge frequency (SEF), and mid-latency auditory evoked potentials (MLAEP). In clinical practice, the application of individual doses of anaesthetics is generally guided by autonomic vegetative clinical signs such as changes in blood pressure, heart rate, sweating, and tear production, quantified as the PRST score. ⋯ MLAEP are suppressed in a dose-dependent fashion by many general anaesthetics and correlate with wakefulness, awareness, and explicit and implicit memory during anaesthesia and seem to be a promising method of monitoring awareness during anaesthesia. Nevertheless, future studies will have to determine threshold values for the different MLAEP parameters for intraoperative awareness and explicit and implicit recall of intraoperatively presented information for the different commonly used anaesthetics. Only then will it be possible to determine the usefulness of the method in clinical practice.
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Sleep apnoea syndrome (SAS) is a relatively common, potentially fatal, disorder. Patients with SAS exhibit repetitive, often prolonged episodes of apnoea during sleep, with serious nocturnal and diurnal physiologic derangements. Several anecdotal reports and clinical studies have documented anaesthetic-related occurrence of fatal and near-fatal respiratory complications in these patients. The purpose of this article is to outline the potential problems encountered in anaesthetic management of adult SAS patients, and to suggest a practical approach for anaesthesia both for incidental and specific procedures. ⋯ Perioperative risks attending SAS patients emphasize the importance of their detection, perioperative evaluation and planning.
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Cardioversion is a minor procedure requiring sedation and analgesia. However, it is often performed out-of-hours in remote sites by inexperienced anaesthetists. An understanding is required both of the pathophysiology underlying cardiac arrhythmias and of the technical side of defibrillation equipment, including electrical safety. ⋯ The anaesthetic agent chosen for patients undergoing cardioversion must provide analgesia and sedation, cause the least cardiovascular compromise possible and still enable rapid recovery. Propofol may be the closest anaesthetic agent to this ideal currently available, although careful titration of any agent chosen is also important. Cardioversion may be performed as an emergency, including in the pregnant patient, providing safe anaesthetic practice is followed.
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Although most anaesthetic textbooks cite dental injury as a complication of endotracheal intubation few studies have examined the extent and nature of the problem. Such damage however, formed the basis for one-third of all confirmed or potential anaesthetic claims notified to the Medical Protection Society between 1977 and 1986. This article seeks to explore the extent of the problem, outline predisposing factors, summarise current prophylactic measures and make recommendations to reduce the overall incidence. ⋯ Where he/she considers there to be a higher than average risk of dental damage occurring during intubation a more specialised examination should be conducted by a dental surgeon. It may, where appropriate, be possible for remedial dental treatment to be carried out and customised mouth guards to be constructed prior to the operation. Obviously such recommendations have certain financial implications and would have to be subject to controlled cost-benefit analysis before their widespread application.