Der Anaesthesist
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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
[Effects of sevoflurane on the area of the liver and spleen].
Recently, there has been increased interest in the preservation of hepatic function during anaesthesia and surgery. In common with other halogenated volatile anaesthetics, sevoflurane causes dose-related cardiovascular depression, which suggests that the blood flow of various organ systems is affected. ⋯ The effort should be encouraged to study this new volatile anaesthetic in human subjects; if a parallel to isoflurane can be drawn, the impact of both substances on the hepatic circulation should be quite small. In Germany, the introduction of sevoflurane into clinical practice should be a reason to proceed with clinical investigations of this type.
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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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Review Comparative Study
[Fluoride-induced nephrotoxicity: factor fiction?].
In the 1960s, the widespread use of the inhalational anaesthetic methoxyflurane was associated with a significant occurrence of postoperative renal dysfunction. This was attributed to hepatic biotransformation of methoxyflurane and subsequent release of inorganic fluoride ions into the circulation. Based upon the clinical experience with methoxyflurane, serum fluoride concentrations exceeding 50 mumol/l were considered to be nephrotoxic. ⋯ New insights into the intrarenal metabolisation of volatile anaesthetics may well explain the absence of nephrotoxicity after sevoflurane. The threshold for fluoride nephrotoxicity of 50 mumol/l, still given in many medical text-books, can no longer be applied as an indicator of nephrotoxicity after isoflurane, enflurane or sevoflurane. Therefore, the elevated serum fluoride concentrations consistently recorded following anaesthesia with sevoflurane are devoid of clinical significance.
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Sevoflurane may be an interesting substance for paediatric anaesthesia due to its combination of a very low blood-gas partition coefficient and non-pungency. This review discusses the status of sevoflurane in paediatric anaesthesia on the basis of studies published so far. The blood-gas partition coefficient of sevoflurane in children is 0.66, and hence markedly lower than those of isoflurane (1.25) and halothane (2.26) [15]. ⋯ The incidence of postoperative nausea and vomiting after sevoflurane anaesthesia is comparable to that after halothane (Table 2). Sevoflurane may be a user-friendly alternative to halothane and is more preferred by children than halothane [32]. The status of sevoflurane in paediatric anaesthesia will depend on several factors: its own benefit/risk-ratio, a possible re-evaluation of the known risks of halothane and the financial limitations of the hospitals.