Anaesthesia
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Randomized Controlled Trial Comparative Study
Perineural versus intravenous dexamethasone as adjuncts to local anaesthetic brachial plexus block for shoulder surgery.
This randomised, double-blind, placebo-controlled study compared the effect of perineural with intravenous dexamethasone, both administered concomitantly with interscalene brachial plexus block for shoulder surgery. Patients received 8 mg dexamethasone mixed with ropivacaine in the block injection (n = 42), 8 mg dexamethasone intravenously at the time of the block (n = 37), or intravenous saline (n = 41) at the time of the block. Perineural and intravenous dexamethasone resulted in prolonged mean (SD) duration of block to 16.9 (5.2) h and 18.2 (6.4) h, respectively, compared with 13.8 (3.8) h for saline (p = 0.001). ⋯ Dexamethasone via either route reduced anti-emetic use (p = 0.046). There was no effect on patient satisfaction. These results suggest that both perineural and intravenous dexamethasone are useful adjuncts to ropivacaine interscalene block, with the intravenous route preferred as this avoids the possibility of neural toxicity of dexamethasone.
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Randomized Controlled Trial
Optimum dose of neostigmine to reverse shallow neuromuscular blockade with rocuronium and cisatracurium.
We examined the use of neostigmine for reversing shallow (defined as train-of-four ratio of 0.5), cisatracurium- and rocuronium-induced neuromuscular block in 112 patients, by use of 0 μg.kg(-1) , 10 μg.kg(-1) , 20 μg.kg(-1) or 40 μg.kg(-1) dose of neostigmine for reversal. The times from neostigmine administration to train-of-four ratios of 0.7, 0.9 and 1.0 were evaluated. ⋯ The recovery time from a train-of-four ratio of 0.5-1.0 did not differ between cisatracurium and rocuronium, and was significantly shortened by the administration of neostigmine. We conclude that a neostigmine dose of 40 μg.kg(-1) was the most effective at reducing recovery time after neuromuscular blockade.
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We retrospectively analysed 30-day mortality and duration of intubation for 8016 children ventilated for three or more days, sedated with midazolam (n = 7716) or propofol (n = 300). We matched the propensity scores of 263 pairs of children. The propensity-matched 30-day mortality (95% CI) was similar: 17/263 (6.5%) with midazolam vs. 24/263 (9.1%) with propofol, p = 0.26. Weaning from mechanical ventilation of children sedated with midazolam was slower than weaning of children sedated with propofol, subhazard ratio (95% CI) 1.43 (1.18-1.73), p < 0.001.
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Multicenter Study
The effect of two cognitive aid designs on team functioning during intra-operative anaphylaxis emergencies: a multi-centre simulation study.
This multi-centre repeated measures study was undertaken to determine how contrasting designs of cognitive aids affect team performance during simulated intra-operative anaphylaxis crises. A total of 24 teams consisting of a consultant anaesthetist, an anaesthetic trainee and anaesthetic assistant managed three simulated intra-operative anaphylaxis emergencies. Each team was assigned at random to a counterbalanced order of: no cognitive aid; a linear cognitive aid; and a branched cognitive aid, and scored for team functioning. ⋯ Aggregate scores were higher with the linear compared with the branched aid design (p = 0.03). Cognitive aids improve co-ordination of the team's activities and support team members to verbalise their actions. A linear design of cognitive aid improves team functioning more than a branched design.
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Randomized Controlled Trial
The effect of age and increasing head-up tilt on pre-oxygenation times in children: a randomised exploratory study.
We conducted a randomised exploratory trial in children aged between one and sixteen years old to establish the time to achieve an end-tidal oxygen fraction ≥ 0.9 in three different positions: supine, and 30 and 45° head up. We recruited 120 children analysed in two age groups: 1-8 years and 9-16 years. The median (IQR [range]) time to reach the end point was 80 (59-114 [41-295]) s in the younger group and 150 (107-211 [44-405]) s in the older group, regardless of position (p = 0.0001). ⋯ Only two patients in the older age group could not reach the end point, due to poorly fitting facemasks. We conclude that pre-oxygenation can therefore be achieved effectively in most children, and that tilting children head up by 30 or 45° does not significantly reduce the time taken to achieve an end-tidal oxygen fraction of ≥ 0.9. The recommended period for pre-oxygenation in both groups should remain at 3 min but it should be noted that this may be insufficient for many older patients.