Anaesthesia
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Randomized Controlled Trial Clinical Trial
The effect of clonidine on sevoflurane requirements for anaesthesia and hypnosis.
We evaluated the effects of clonidine given orally on sevoflurane requirements for anaesthesia and hypnosis. Patients received either clonidine (5 micrograms.kg-1) by mouth (n = 21) 90 min before surgery or no premedication (n = 21) by random allocation. MAC was calculated using repeated tetanic nerve stimulation with end-tidal sevoflurane concentration increased or decreased by 0.3 vol.% depending on the previous response. ⋯ The mean (SD) MAC in the clonidine-treated patients was 1.53 (0.20)% compared with 1.83 (0.15)% in the control group (p < 0.001). Similarly, MAC awake was reduced in the clonidine group (0.50 (0.08)% compared with 0.60 (0.07)% in the control group) (p < 0.001). We conclude that clonidine 5 micrograms.kg-1 orally administered pre-operatively reduces sevoflurane requirements for anaesthesia and hypnosis.
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Randomized Controlled Trial Comparative Study Clinical Trial
Tracheal intubation conditions after one minute: rocuronium and vecuronium, alone and in combination.
Rocuronium is a recently introduced nondepolarising neuromuscular blocking agent with a rapid onset and intermediate duration of action. Experimental observations have suggested that during onset it acts synergistically with other nondepolarising agents, but that at a steady state the combined action is additive. In order to investigate whether synergism during onset produces a clinical benefit we performed the following study of tracheal intubation conditions. ⋯ The conditions produced in the rocuronium and the mixture groups were similar and both were significantly better than those of vecuronium. Excellent intubation conditions were achieved in 57% of the rocuronium group, 70% of the mixture group and 27% of the vecuronium group. We conclude that a mixture of rocuronium and vecuronium acts synergistically during the early part of their action and a mixture containing one ED95 of both agents provides comparable conditions for tracheal intubation as an equipotent dose of rocuronium.
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Randomized Controlled Trial Clinical Trial
Thoracic epidural analgesia started after cardiopulmonary bypass. Adrenergic, cardiovascular and respiratory sequelae.
The effects of thoracic epidural analgesia started after cardiopulmonary bypass were studied on the subsequent adrenergic, cardiovascular and respiratory responses. Sixteen cardiac surgical patients received either a standardised general anaesthetic (control group) or a standardised general anaesthetic and thoracic epidural analgesia (epidural group). The epidural catheter was sited before surgery and heparinisation. ⋯ Postoperative respiratory function was less impaired in the epidural group, with higher forced expiratory volume in 1 s, forced vital capacity and peak expiratory flow (p < 0.05). Pain scores were also significantly lower in the epidural group (p < 0.05). There were no significant differences in cardiovascular parameters.
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Randomized Controlled Trial Clinical Trial
The effects of single-handed and bimanual cricoid pressure on the view at laryngoscopy.
The effects of two different methods of cricoid pressure on laryngoscopic view were studied in 94 healthy women presenting for routine gynaecological surgery. Laryngoscopy was performed with either single-handed or bimanual cricoid pressure; after grading of the view obtained, the other method was used and second grading performed. Laryngoscopic view was better with the bimanual than with the single-handed technique (p = 0.016). ⋯ Age, weight, Mallampatti score and thyromental distance did not differ between patients in these three groups. Bimanual cricoid pressure should be the initial technique of choice during rapid sequence induction but, in a minority of cases, switching to a single-handed technique may improve the laryngoscopic view. The technique of cricoid pressure which produces the best laryngoscopic view in an individual patient cannot be predicted from the physical features studied.