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
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.