Der Anaesthesist
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Midlatency auditory evoked potentials (MLAEP) are suppressed dose-dependently during anaesthesia with a variety of general anaesthetics. Therefore, MLAEP have been proposed to measure depth of anaesthesia and to indicate intraoperative awareness. Several studies give evidence of a close relationship between MLAEP and motor signs of wakefulness, intraoperative awareness, and explicit and implicit memory functions during general anaesthesia. ⋯ The new volatile anaesthetic sevoflurane leads to a dose-dependent increase in MLAEP peak latencies and a decrease in MLAEP amplitudes. At about 1.5 vol.% end-expiratory sevoflurane concentration, MLAEP are significantly suppressed and Nb latency is in the range of 68-80 ms. Therefore, from the present data and those from the literature, one may expect that sevoflurane at concentrations greater than 1.5 vol.% for general anaesthesia would be able to suppress awareness phenomena such as purposeful movements, auditory perception, intraoperative wakefulness and awareness, memory formation, and explicit and implicit recall of intraoperative events.
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Polymorphonuclear leukocytes (PM-NL) constitute the first line of defence in the protection of the host from invading microorganisms. PMNL also contribute to the removal of cellular debris from necrotic tissues during reparative processes. For these purposes PMNL are armed with highly efficient bactericidal mechanisms which, under certain pathophysiological conditions, can be turned against the host himself. ⋯ The manifestation of ARDS in leukopenic patients, however, indicates the development of this clinical syndrome independently of the presence of PMNL. The ability to differentiate between PMNL-dependent and PMNL-independent pathways in the pathogenesis of this syndrome is not only of theoretical interest but also of therapeutic significance. Since the patient's systemic inflammatory response may vary according to the stage and type of the underlying disease, an exact qualitative and quantitative analysis of PMNL functions may provide the rationale for new anti-inflammatory drug regimens aimed at modifying the host's response without increasing the risk of infection.
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Review Comparative Study
[Nephrotoxicity and fluoride from the viewpoint of the nephrologist].
Fluoride released from methoxyflurane (MOF) during its hepatic and extrahepatic metabolism has been regarded as the major culprit responsible for MOF-induced nephrotoxicity. In the isolated, perfused rat kidney model, admixture of 1500 mumol/l fluoride to the perfusate resulted in tubular and glomerular damage with concomitant anuria. Fluoride administration in Fischer 344 rats in vivo elicited a renal diabetes insipidus-like syndrome that had also been observed in patients after MOF anaesthesia. ⋯ The degree of nephrotoxicity correlates loosely with maximal serum fluoride levels, but can probably be modulated by further factors like intrarenal in situ formation of fluoride, urinary pH and flow, and especially, the presence of other nephrotoxins. This mitigates the importance of maximal fluoride serum levels, especially the 50 mumol threshold, as predictors of clinically relevant nephrotoxicity. To date, no nephrotoxic effects of sevoflurane could be demonstrated.
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Acute respiratory distress syndrome (ARDS) is rare but beset with a high mortality rate. In recent years, however, a trend towards higher survival rates has been observed. High inspiratory oxygen concentrations, large tidal volumes, and high peak inspiratory airway pressures applied during mechanical ventilation have been identified as harmful to the lung and can contribute to the progression of ARDS. ⋯ Should these procedures fail to improve impaired gas exchange, extracorporeal membrane oxygenation is an additional therapeutic option. None of these therapeutic procedures, however, has been tested against traditional standard treatment in a classical randomised controlled trial. The following review focuses on the latest insights into the pathophysiology, diagnosis, and treatment of ARDS.
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The current increase in the cost of health care must be considered as a severe threat to the prehospital emergency services system. Two examples have been selected--the patient with polytrauma and the patient in cardiac arrest--to demonstrate the dilemma between a need for objective data and the requirements of emergency patients. Study results obtained in trauma patients indicating that total prehospital time, including scene time, is correlated to patient outcome have led to the conclusion that at the scene treatment by emergency physicians may be dispensable. ⋯ Politicians require an improvement in the quality of the validation of emergency measures, although the instruments available for the investigation of these measures are known to be obsolete (experimental models, experimental design). Additionally, the financial support of research in emergency medicine suffers from being accourded low priority by public research funds such as the German Research Fund. However, in view of the rapid application of experimental results to daily practice it should be emphasized that patients also support research in emergency medicine via their direct financial contributions to the health insurance companies.