British journal of anaesthesia
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Randomized Controlled Trial
Advance of age decreases the minimum alveolar concentrations of isoflurane and sevoflurane for maintaining bispectral index below 50.
We investigated age-related differences in the minimum alveolar concentration (MAC) of isoflurane and sevoflurane for maintaining bispectral index (BIS) below 50 (MAC(BIS50)). ⋯ Advance in age significantly decreased the concentrations of isoflurane and sevoflurane required to maintain BIS below 50. BIS correctly reflected age-associated decrease of end-tidal concentrations of isoflurane and sevoflurane required for maintaining adequate depth of anaesthesia during resting state.
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Randomized Controlled Trial Comparative Study
Thoracic epidural analgesia in post-thoracotomy patients: comparison of three different concentrations of levobupivacaine and sufentanil.
Relative effects of dosage, volume and concentration of local anaesthetics used for postoperative thoracic epidural analgesia are still under debate. In this randomized, prospective, double-blinded study, we evaluated the incidence of side-effects such as changes in arterial pressure, postoperative nausea, vomiting, and pruritus in patients admitted for thoracic surgery during continuous thoracic epidural infusion using levobupivacaine and sufentanil mixture in three different volumes. ⋯ The same dose of a mixture of levobupivacaine and sufentanil administered in three different volumes and concentrations during continuous thoracic epidural infusion for thoracotomy provided an equal incidence of adverse haemodynamic effects, nausea, vomiting, or pruritus.
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Randomized Controlled Trial
Ketamine has no effect on bispectral index during stable propofol-remifentanil anaesthesia.
Ketamine 0.15-1 mg kg(-1) decreases postoperative morphine consumption, but 0.5 mg kg(-1) is associated with an increase in the bispectral index (BIS) values that can lead to an overdose of hypnotic agents. The purpose of our investigation was to study the effect of ketamine 0.2 mg kg(-1) administered over a 5 min period on the BIS during stable target-controlled infusion (TCI) propofol-remifentanil general anaesthesia. ⋯ Under stable propofol and remifentanil TCI anaesthesia, a slow bolus infusion of ketamine 0.2 mg kg(-1) administered over a 5 min period did not increase the BIS value over the next 15 min.
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Inhaled anaesthetics (IAs) produce multiple dose-dependent behavioural effects including amnesia, hypnosis, and immobility in response to painful stimuli that are mediated by distinct anatomical, cellular, and molecular mechanisms. Amnesia is produced at lower anaesthetic concentrations compared with hypnosis or immobility. Nicotinic acetylcholine receptors (nAChRs) modulate hippocampal neural network correlates of memory and are highly sensitive to IAs. Activation of hippocampal nAChRs stimulates the release of norepinephrine (NE), a neurotransmitter implicated in modulating hippocampal synaptic plasticity. We tested the hypothesis that IAs disrupt hippocampal synaptic mechanisms critical to memory by determining the effects of isoflurane on NE release from hippocampal nerve terminals. ⋯ Inhibition of hippocampal nAChR-dependent NE release by subanaesthetic concentrations of isoflurane supports a role in IA-induced amnesia.
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Smoking and hazardous drinking are common and important risk factors for an increased rate of complications after surgery. The underlying pathophysiological mechanisms include organic dysfunctions that can recover with abstinence. ⋯ However, this intervention must be intensive to obtain sufficient effect on surgical complications. All patients presenting for surgery should be questioned regarding smoking and hazardous drinking, and interventions appropriate for the surgical setting applied.