European journal of anaesthesiology
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Comparative Study
In-vitro contracture testing for susceptibility to malignant hyperthermia: can halothane be replaced?
Malignant hyperthermia is a potentially lethal inherited hypermetabolic syndrome that develops in susceptible individuals following administration of depolarising neuromuscular relaxants or volatile anaesthetics. Genetic analysis can only confirm a diagnosis of malignant hyperthermia in about 70%, and in the remainder an in-vitro contracture test, with halothane and caffeine, on muscle obtained from open muscle biopsy is required to establish the diagnosis. As the licence for clinical use of halothane expired in 2005, its continuing availability is in doubt. More modern volatile anaesthetics such as enflurane, isoflurane, desflurane and sevoflurane are less potent triggers of malignant hyperthermia in humans and pigs. The aim of this study was to investigate whether these agents can be considered possible substitutes for halothane in a modified in-vitro contracture test. ⋯ Halothane was the strongest discriminator for malignant hyperthermia in the in-vitro contracture tests. It remains the ideal substance for diagnostic testing and cannot simply be replaced by other agents in this test.
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Comparative Study Clinical Trial
Effect of sex and pregnancy on the potency of intrathecal bupivacaine: determination of ED₅₀ for motor block with the up-down sequential allocation method.
The up-down sequential allocation model has been adapted to estimate the relative potency ratios for analgesia and motor block of the most commonly used epidural and intrathecal local anaesthetics. The aim of this study was to establish the median effective doses (ED50) for motor block with intrathecal bupivacaine and to estimate the ED50 ratios of these in male, female and pregnant patients. ⋯ We have demonstrated a hierarchy of potencies for motor block with intrathecal bupivacaine for men, women and pregnant women suggesting possible relevant differences owing to the effects of both sex and pregnancy.
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Randomized Controlled Trial Comparative Study
Comparison of the effects of low-flow and high-flow inhalational anaesthesia with nitrous oxide and desflurane on mucociliary activity and pulmonary function tests.
The aim of this study was to investigate the effects of inhalational anaesthesia using low and high gas flow rates of nitrous oxide and desflurane on mucociliary clearance and pulmonary function. ⋯ Respiratory function and mucociliary clearance are better preserved in a low-flow anaesthesia technique than in high-flow anaesthesia with nitrous oxide and desflurane. Therefore, a low-flow anaesthesia technique with nitrous oxide and desflurane may provide an important clinical advantage because it provides appropriately heated and humidified gases to the tracheobronchial tree.