Anaesthesia
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We studied the effects of adding 50% nitrous oxide to propofol anaesthesia administered by target-controlled infusion on middle cerebral artery flow velocity and autoregulatory indices derived from transient hyperaemic response tests. Nine healthy (ASA 1) adult patients scheduled to undergo elective surgery were recruited. A standardised anaesthetic comprising alfentanil 10 microg x kg(-1), propofol via a target-controlled infusion pump and vecuronium 0.1 mg x kg(-1) was used. ⋯ Propofol caused a significant decrease in MCA flow velocity and a significant increase in the strength of autoregulation. The addition of nitrous oxide had no significant effect on MCA flow velocity or cerebral autoregulation. These results suggest that addition of 50% nitrous oxide does not influence propofol-induced changes in cerebral haemodynamics.
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Randomized Controlled Trial Clinical Trial
Glycopyrronium and hypotension following combined spinal-epidural anaesthesia for elective Caesarean section in women with relative bradycardia.
The ability of glycopyrronium to reduce the severity of hypotension following subarachnoid block in parturients with a relative bradycardia was evaluated in a double-blind randomised controlled study. Women with a resting heart rate of < or = 80 beat x min(-1) presenting for elective Caesarean section were randomly allocated to receive either glycopyrronium 2 microg x kg(-1) or normal saline intravenously once positioned for combined spinal-epidural anaesthesia. ⋯ Using a sequential analysis technique, analysis after the first 20 subjects indicated the study should be stopped, with no difference in ephedrine requirements or hypotension between the groups. We conclude that pretreatment with glycopyrronium 2 microg x kg(-1) is no more effective than 6 mg ephedrine in preventing hypotension following subarachnoid block in parturients with relatively low resting heart rates.
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Randomized Controlled Trial Comparative Study Clinical Trial
Sevoflurane vs. isoflurane: a clinical comparison in day surgery.
Discharge times after ambulatory surgery are determined by postoperative complications and in particular by the presence and severity of nausea and vomiting. Sevoflurane has become a popular agent for day-case surgery despite little evidence of clear advantages over current alternatives. We compared this agent with isoflurane in day-case patients undergoing knee arthroscopy in order to quantify the incidence of complications associated with each agent. ⋯ There was a significantly higher incidence of complications in the sevoflurane group. These included the presence of nausea and vomiting, and cardiovascular and respiratory complications. We found nothing to commend the routine use of sevoflurane rather than isoflurane in the context of day case anaesthesia.
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Clinical Trial Controlled Clinical Trial
Does sevoflurane inhibit serum cholinesterase in children?
Serum cholinesterase activity was measured at induction, and following anaesthesia in 41 children aged between 4 and 30 months. The median exposure to sevoflurane was 273%.min. ⋯ The only change in cholinesterase activity detected was related to heamodilution. We conclude that plasma fluoride concentration following sevoflurane administration [13.8 (4.2) microm x l(-1)] is too low to exert an inhibiting effect on in vivo cholinesterase activity and that the previously reported decrease in mivacurium requirements during sevoflurane anaesthesia is unlikely to be due to inhibition by fluoride ions.