Anaesthesia
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Comparative Study Clinical Trial Controlled Clinical Trial
The effect of introducing fibreoptic bronchoscopes on gas flow in laryngeal masks and tracheal tubes.
The laryngeal mask airway, reinforced laryngeal mask airway and tracheal tube were studied to determine (1) flow resistance during simulated inspiration and (2) the maximum size of fibreoptic scope which can be passed down the lumen at clinically useful ventilatory settings. In addition, the flow resistance imposed by the mask aperature bars was quantified. ⋯ Removal of the mask aperture bars resulted in a mean decrease in flow resistance of 3.6%. Our data have shown that the laryngeal mask airway can accommodate a larger fibrescope than either the reinforced laryngeal mask airway or tracheal tube at clinically useful ventilatory settings and that the current recommendations for maximum size of fibrescope should be revised.
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Randomized Controlled Trial Comparative Study Clinical Trial
Neuromuscular and cardiovascular advantages of combinations of mivacurium and rocuronium over either drug alone.
We investigated isobolic mixtures of mivacurium and rocuronium to determine if the combination offered any advantages over either drug alone. We used five dose regimens to achieve ED95 x 2: [(1.5 x ED95 mivacurium) + (0.5 x ED95 rocuronium); (1 x ED95 mivacurium) + (1 x ED95 rocuronium); (0.5 x ED95 mivacurium) + (1.5 x ED95 rocuronium); (2 x ED95 mivacurium); (2 x ED95 rocuronium)]. We studied onset time, duration of block, recovery of block, arterial blood pressure and heart rate. ⋯ Onset time was shortest in the rocuronium alone group and was significantly faster in all the rocuronium treated groups compared to mivacurium alone (p < 0.001). Arterial blood pressure and heart rate decreased transiently in the mivacurium alone group but not in the other groups. These results demonstrate increased cardiovascular stability and more rapid onset of block with combinations of mivacurium and rocuronium without significant prolongation of the block.
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Randomized Controlled Trial Clinical Trial
The effect of epidural opioids on maternal oxygenation during labour and delivery.
The effects of epidural fentanyl on the incidence of maternal hypoxaemia during labour and on neonatal welfare were examined. Women were randomly allocated to receive one of two epidural infusions, bupivacaine 0.125% alone or bupivacaine 0.0625% with 2.5 micrograms.ml-1 fentanyl, and maternal arterial oxygen saturation was monitored continuously until delivery. ⋯ Similarly, the incidence of desaturation to SpO2 < or = 90% was greater in the fentanyl group than in controls (p = 0.02). There was no correlation between maternal oxygenation or plasma fentanyl concentration and neonatal welfare as measured by umbilical arterial and venous blood gas and acid base status, Apgar score and Neurologic and Adaptive Capacity Score.
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Comparative Study Clinical Trial Controlled Clinical Trial
A comparison of the forces exerted during laryngoscopy. The Macintosh versus the McCoy blade.
The forces exerted at laryngoscopy with the McCoy and Macintosh blades have been compared in 40 patients. The variables measured were the duration of laryngoscopy, the three maximally-applied forces and the mean force. ⋯ It is concluded that the use of the McCoy blade results in significantly less force being applied during laryngoscopy. This may be the reason for the reduction in the stress response reported previously with the use of the McCoy blade.