Der Anaesthesist
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Propofol is known to possess direct antiemetic effects. Its use for induction and maintenance of anaesthesia has been shown to be associated with a lower incidence of postoperative nausea and vomiting (PONV) when compared to any other anaesthetic drug or technique. ⋯ The possible effects of propofol on the cerebral cortex, its interactions with the dopaminergic and the serotoninergic systems are evaluated by the known clinical and basic science results. Finally, the advantages and disadvantages of using propofol to decrease the incidence of PONV in clinical practice are discussed.
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Sevoflurane, like all currently used volatile anaesthetics, is degraded by carbon dioxide absorbents. The most significant degradant is a haloalkene known trivially as "compound A". Compound A is nephrotoxic in rats and, at higher doses, in nonhuman primates, causing proximal tubular necrosis. ⋯ There have been no case reports of compound A-associated renal injuryin humans. In volunteers, one study found changes in experimental but not conventional renal markers, while other investigations show no significant changes in either standard or experimental markers. The mechanism of compound A nephrotoxicity in rats appears to involve metabolism to glutathione and cysteine conjugates, and their subsequent renal uptake and metabolism by pathways that are different in rats and humans.
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The cardiovascular effects of sevoflurane are similar to those of isoflurane with some minor exceptions. In contrast to isoflurane and particularly to desflurane, sevoflurane has not been associated with increases in heart rate in healthy volunteers and in patients. ⋯ In several multi-center studies of patients with coronary artery disease or at high risk for coronary artery disease receiving either sevoflurane or isoflurane for either cardiac or non-cardiac surgery, the incidence of myocardial ischemia and infarction did not differ between treatment groups. In both human and animal models, sevoflurane preserves cerebral blood flow and reduces cerebral metabolic rate, much like isoflurane.
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The total costs for a department of anaesthesia amount to a fraction of the total hospital budget that is proportional to the overall number of hospital departments; this means anaesthetic departments are in general not cost drivers. In the analysis of perioperative costs, anaesthesia accounts for about 10-15% of the total costs for the complete hospital stay, the exact proportion depending on the type of surgery. In the analysis of costs for the intraoperative period alone anaesthesia personnel contributes about 20%, and material costs about 10% of the total costs, while inhalational agents account for less than 1%. ⋯ The question of whether these effects and side effects translate into cost differences between agents depends largely on local factors, e.g., patient case mix, staffing, policy of discharge from the postanaesthetic care unit, and many others. We conclude that volatile anaesthetics account for only a minor portion of the budgets in the anaesthesia department and the hospital overall. The higher market price for the new agents that result in higher costs per MAC-hour may be compensated for by the economic impact of the fewer side effects and the shorter postanaesthesia stay in the hospital.
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Sevoflurane degrades in CO2 absorbents to produce compound A, which may have hepatotoxic potential in humans. Several recent studies in human volunteers have been performed to evaluate this potential. Three studies have evaluated sevoflurane administered to volunteers using a 3% concentration for 8 h duration at approximately 2 L/min flow rate. ⋯ No significant excretion of protein, glucose or renal enzymes was observed. Application of these results to clinical practice must be interpreted in light of the experimental nature of the anesthetic administration. Although some controversy remains, these data, combined with results of recent studies in surgical patients, suggest that renal function following modest duration low-flow sevoflurane anesthesia is similar to that following isoflurane anesthesia.