Anaesthesia
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Randomized Controlled Trial
A randomised controlled trial of dexmedetomidine for suspension laryngoscopy.
We randomly allocated 80 patients to intravenous dexmedetomidine (0.25, 0.5, or 1 μg.kg(-1) ) or placebo 15 min before anaesthetic induction. Dexmedetomidine 0.5 and 1.0 μg.kg(-1) significantly reduced the mean (95% CI) propofol effect-site concentrations by 0.83 (0.63-1.03) μg.ml(-1) , p = 0.001 and 1.29 (1.12-1.46) μg.ml(-1) , p = 0.0003 at intubation, by 1.05 (0.85-1.25 μg.ml(-1) , p = 0.0006 and 1.33 (1.15-1.51) μg.ml(-1) , p = 0.0002 when surgery started, and by 0.59 (0.39-0.79) μg.ml(-1) , p = 0.030 and 0.72 (0.57-0.87) μg.ml(-1) , p = 0.004 on completion of surgery, respectively. ⋯ Bradycardia was treated after dexmedetomidine in six patients: five after 1.0 μg.kg(-1) ; and one after 0.25 μg.kg(-1). Single-dose dexmedetomidine can reduce anaesthetic requirements, with both desirable and undesirable haemodynamic effects.
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Randomized Controlled Trial Comparative Study
Comparison of the single-use Ambu(®) aScope™ 2 vs the conventional fibrescope for tracheal intubation in patients with cervical spine immobilisation by a semirigid collar*.
Fibreoptic intubation remains a key technique for the management of difficult intubation. We randomly compared the second generation single-use Ambu(®) aScope™ 2 videoscope with a standard re-usable flexible intubating fibrescope in 50 tracheal intubations in patients with a difficult airway simulated by a semirigid collar. ⋯ Quality of vision was significantly lower with the aScope 2 (excellent 24 (48%) vs 49 (98%), p = 0.0001; good 22 (44%) vs 1 (2%), p = 0.0001; poor 4 (8%) vs 0, p = 0.12) but with no difference in the subjective ease to intubate (easy score of 31 (62%) vs 38 (76%), p = 0.19; intermediate 12 (24%) vs 7 (14%), p = 0.31; difficult 7 (14%) vs 5 (5%), p = 0.76). The longer times to intubate and the poorer scores for quality of vision do not support the use of the single-use aScope 2 videoscope as an alternative to the re-usable fibrescope.