Anaesthesia
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Randomized Controlled Trial Clinical Trial
Factors affecting neostigmine reversal of vecuronium block during sevoflurane anaesthesia.
We examined the influence of the concentration of sevoflurane and the degree of muscle block at the time of reversal on the activity of neostigmine. Ninety ASA 1-2 patients were anaesthetised with 0.2, 0.7 or 1.2 MAC of sevoflurane (30 patients each) in 66% nitrous oxide in oxygen. The electromyographic (EMG) response of the adductor digiti minimi was monitored at 20-s intervals after train-of-four stimulation of the ulnar nerve. ⋯ Higher endtidal concentrations (p < 0.0001) and more pronounced block at the time of reversal (p < 0.0001) were associated with a delayed recovery in the train-of-four ratio. In addition, the train-of-four ratio 15 min after neostigmine administration was more dependent on the sevoflurane concentration than on the degree of block present (p < 0.0001). These results confirm that neostigmine (40 micrograms.kg-1) can reverse vecuronium-induced but not sevoflurane-induced neuromuscular block.
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In 10 cases of unexpected difficult tracheal intubation using the Macintosh laryngoscope blade, the larynx could not be seen. In each case, a good view was achieved using the Miller blade lateral to the tongue, which enabled tracheal intubation under direct vision. The results achieved using narrow, low-profile straight laryngoscope blades with this technique are reviewed. ⋯ Paraglossal straight blade laryngoscopy may have an advantage over use of the Macintosh technique when intubation proves unexpectedly difficult. It is perhaps time to question standard teaching about the role of the curved blade in such patients or, more particularly, whether the technique of laryngoscopy as currently taught is optimal. The paraglossal straight blade technique needs to be practised in routine intubation before it can be used with confidence in difficult cases.
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Reports and guidelines concerning intensive care practice have been issued recently. However, the introduction of such centrally issued recommendations may be difficult because of marked heterogeneity between intensive care units. ⋯ There were significant differences in the distribution of patients' ages, severities of illness, diagnoses, durations of admission and outcomes. Such heterogeneity may make multicentre trials more difficult to conduct and create problems when uniform measures designed to improve intensive care services are being planned.
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The aim of the study was to evaluate leakage of liquid past the low-pressure cuffs of tracheal tubes. Ten samples of each of nine different types of tubes were tested in a PVC mock trachea, using intracuff pressures of 20, 30, 40 and 50 cmH2O. ⋯ In the most efficient tube, all the cuffs were leak-proof (leakage < 5 ml in 5 min) at 40 cmH2O and in the second best type the cuffs were leak-proof at 50 cmH2O. The leakage of fluid past the tracheal tube remains an unresolved problem with low-pressure cuffs.