Anaesthesia
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Randomized Controlled Trial
Self-administered methoxyflurane for procedural analgesia: experience in a tertiary Australasian centre.
Methoxyflurane, an agent formerly used as a volatile anaesthetic but that has strong analgesic properties, will soon become available again in the UK and Europe in the form of a small hand-held inhaler. We describe our experience in the use of inhaled methoxyflurane for procedural analgesia within a large tertiary hospital. In a small pilot crossover study of patients undergoing burns-dressing procedures, self-administered methoxyflurane inhalation was preferred to ketamine-midazolam patient-controlled analgesia by five of eight patients. ⋯ The procedures included change of dressing, minor debridement, colonoscopy and incision-and-drainage of abscess. There was a 97% success rate of methoxyflurane analgesia to facilitate these procedures. Limitations of methoxyflurane include maximal daily and weekly doses, and uncertainty regarding its safety in patients with pre-existing renal disease.
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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.
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In many orthopaedic operating rooms, anaesthesia providers routinely wear lead aprons for protection from radiation, but some studies have questioned whether this is needed. We conducted a systematic review to identify studies that measured the amount of radiation that anaesthetists were exposed to in the orthopaedic operating room. ⋯ Radiation doses at this distance were often at the limits of the sensitivity of the measuring dosimeter. We question the need to wear lead protection for anaesthesia providers who are routinely at 1.5 m or a greater distance from standard fluoroscopy units.
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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.