British journal of anaesthesia
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We present a new pattern of nerve stimulation--double burst stimulation (DBS)--to detect residual neuromuscular block manually. The DBS consists of two short lasting, 50-Hz tetanic stimuli or bursts separated by a 750-ms interval. The response to this pattern of stimulation is two single separated muscle contractions of which the second is less than the first during nondepolarizing neuromuscular blockade. ⋯ The DBS with three impulses in each burst (DBS3,3) was considered to be the most sensitive and the least painful and thus most suitable for clinical use. The degree of fade in TOF and DBS3,3 was almost identical at any level of blockade (correlation coefficient 0.96), and the major post-DBS3,3 effect was a depression of the first twitch in TOF lasting less than 15 s. It is concluded that the DBS is more sensitive than the TOF in manual detection of residual block.
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We have assessed a Venturi driven device for delivering continuous positive airway pressure (CPAP) using a reservoir bag and expiratory valve under conditions of continuous flow and simulated spontaneous breathing. The system performed well and was economical, consuming only 3.5 litre min-1 of fresh gas. One Venturi was partially blocked and performed inadequately, but the function of a second one was close to the manufacturer's specification (inspired oxygen 33%, flow 20 litre min-1 against end-expiratory pressures of 0-1.8 kPa). ⋯ The characteristics of the expiratory valve approached those of a threshold resistor. Small fluctuations in airway pressure occurred at all settings of CPAP and decreased with the increasing compliance of the circuit at higher values of CPAP. The method provided to monitor the airway pressure was inaccurate and overestimated the true pressure by 20% at pressures greater than 1 kPa.
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Randomized Controlled Trial Comparative Study Clinical Trial
Changes in oxygen saturation during inhalation induction of anaesthesia in children.
Changes in oxygen saturation (SaO2) were studied during induction of anaesthesia in 48 healthy children receiving halothane or isoflurane for outpatient dental extractions. Substantial reductions in SaO2 occurred in more than 50% of the children given isoflurane and were associated with the irritant effects of this agent on the airway. SaO2 was largely unaltered during the use of halothane. These findings indicate that the airway complications caused by isoflurane may be associated with decreases in SaO2.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of continuous paravertebral and extradural infusions of bupivacaine for pain relief after thoracotomy.
Pain was controlled in 20 post-thoracotomy patients using a continuous infusion of 0.25% bupivacaine through an extradural or para-vertebral catheter. Both techniques provided good analgesia. Hypotension and urine retention occurred significantly less frequently in the paravertebral than in the extradural group.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of 1.5% enflurane with 1.25% isoflurane in oxygen for caesarean section: avoidance of awareness without nitrous oxide.
We examined the feasibility of administering nearly 100% oxygen throughout the induction-delivery period of general anaesthesia for 113 Caesarean sections. Isoflurane 1.25% was compared with 1.5% enflurane for maintenance of anaesthesia. ⋯ The three main criteria for a satisfactory general anaesthetic technique for Caesarean section were fulfilled, namely no maternal awareness, no undue depression of the fetus and no adverse effect on uterine contractility. Isoflurane and enflurane appear to be suitable anaesthetic agents for facilitating hyperoxygenation during Caesarean section.