Anaesthesia
-
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.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Simulated difficult intubation. Comparison of the gum elastic bougie and the stylet.
A randomised study was carried out to compare the efficacy of the gum elastic bougie and the stylet in a simulated difficult intubation. A laryngoscopic assessment, as described by Cormack and Lehane, was made in 100 patients. A Grade 3 view was then simulated. ⋯ In the Stylet First Group (50 patients) the order was reversed. After two attempts the tube was correctly placed in the trachea in 96% of cases in the Bougie First Group compared to only 66% of cases in the Stylet First Group (p < 0.001). We recommend that a gum elastic bougie should be readily available and that anaesthetists should use it in preference to a stylet whenever a good view of the glottis is not immediately available.
-
Randomized Controlled Trial Clinical Trial
Effect of transcutaneous electrical nerve stimulation on onset of axillary plexus block.
We examined the effect of high frequency transcutaneous electrical nerve stimulation on the onset of brachial plexus block. Three groups of patients scheduled for surgery of the hand had a local anaesthetic block performed with 40 ml mepivacaine 1.5% using the axillary approach. ⋯ There were no differences in the onset of block between the groups. Thus, the frequency-dependent action of local anaesthetics could not be demonstrated.
-
Randomized Controlled Trial Comparative Study Clinical Trial
A comparison between the Macintosh and the McCoy laryngoscope blades.
The view of the larynx using the Macintosh laryngoscope and the McCoy levering laryngoscope was assessed in 177 adult patients. The view with the McCoy blade in the neutral position and in the position (neutral or elevated) that gave the 'best' view were recorded. The McCoy blade in the neutral position was associated with a lower incidence of grade 1 views and a higher incidence of grade 2 views than the Macintosh blade. ⋯ In 25 patients, the vocal cords could not be seen with the Macintosh blade; in these patients the view was better with the McCoy blade (the cords were visible) on 14 occasions and worse in one (p = 0.001). We conclude that the McCoy blade in its neutral position does not behave identically to the Macintosh blade. The McCoy blade is a useful aid to difficult intubation but should not replace the Macintosh blade as the first choice laryngoscope.
-
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.