Anaesthesia
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Randomized Controlled Trial Comparative Study
Inhalation induction using sevoflurane in children: the single-breath vital capacity technique compared to the tidal volume technique*.
The single-breath vital capacity technique is suitable for inhalation induction of anaesthesia, using sevoflurane in children aged > 5 years. The purpose of this randomised trial was to compare the single breath vital capacity technique with the conventional tidal volume technique. Seventy- three ASA 1 or 2 children were instructed during the pre-operative visit in the vital capacity technique. ⋯ The time to loss of the eyelash reflex was found to be reduced in the vital capacity group compared to the tidal volume group. The time to central myosis, to achieve bispectral index values 60 and 40, haemodynamic changes, respiratory events and side-effect incidences were similar in both groups. However, we found that the vital capacity technique was preferred by the children to the tidal volume technique.
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Randomized Controlled Trial Comparative Study
Surgical vs wire-guided cricothyroidotomy: a randomised crossover study of cuffed and uncuffed tracheal tube insertion.
Using an airway mannequin and artificial lung model, we compared surgical cricothyroidotomy with a 6.0-mm cuffed Portex tracheostomy tube with wire-guided cricothyroidotomy using a 5.0-mm cuffed Melker or 6.0-mm uncuffed Melker tube. The trial was carried out by 27 anaesthetists using a randomised, crossover design. Surgical cricothyroidotomy proved significantly faster (mean (SD) time to first breath 44.3 (12.5) s for Portex surgical, 87.2 (21.6) s for cuffed Melker, 87.8 (19.2) s for uncuffed Melker, p < 0.001). ⋯ Fourteen of the participants preferred the wire-guided system. We conclude that, in this model, a cuffed device is preferable when cricothyroidotomy is needed. In addition, the surgical method is quicker than a wire-guided approach.
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Randomized Controlled Trial
High concentration potassium permanganate eliminates protein and particle contamination of the reusable Classic laryngeal mask airway.
In this three-stage study, we test the hypothesis that supplementary cleaning with potassium permanganate > or =4 mg.l(-1) eliminates protein and particle contamination from the reusable Classic laryngeal mask airway. The first stage involved supplementary cleaning of 70 1 x 1 cm segments from deliberately contaminated laryngeal mask airways using potassium permanganate at 0, 2, 4, 8, 16, 32 and 64 mg.l(-1) and testing for protein staining. This showed that the lowest concentration required to eliminate protein contamination was 8 mg.l(-1). ⋯ The third stage involved scanning electron microscopic examination of 1 x 1 cm segments from three laryngeal mask airways used in the control group, three from the potassium permanganate group, plus three brand new laryngeal mask airways. The mean density of > or =1 mum surface particles was lower in the potassium permanganate 8 mg.l(-1) than the control group (21 vs. 121 .cm(-2), p < 0.0001) and was similar to brand new laryngeal mask airways (24 .cm(-2)). We conclude that supplementary cleaning with potassium permanganate 8 mg.l(-1) eliminates protein deposits from reusable laryngeal mask airways and reduces particle contamination to similar levels to brand new laryngeal mask airways.
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Randomized Controlled Trial
Perivascular axillary brachial plexus block and patient positioning: the influence of a lateral, head-down position.
The aim of this study was to examine the effect of a 20 degrees Trendelenburg position on the blockade of nerves that exit the brachial plexus proximally in patients undergoing single-injection axillary brachial plexus block. After a pilot study of eight cadavers suggested that a head-down and lateral position would encourage the proximal spread of local anaesthetic, 72 patients undergoing elective surgery were divided into two equal groups: a Supine group and a Modified Position group (lateral position, 20 degrees head-down tilt). ⋯ Sensory and motor blockade evaluation showed that there was a significantly higher proportion of axillary nerve (76% vs. 0%, p < 0.001), thoracodorsal nerve (86% vs. 0%, p < 0.001) and subscapular nerve (89% vs. 0%, p < 0.001) blockade in the Modified Position group. Sensory block of the radial nerve was also improved by the modified position (100% vs. 86%, p < 0.05).