Anaesthesia
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Randomized Controlled Trial Clinical Trial
Pressure support ventilation during isoflurane anaesthesia.
We have studied the respiratory effects of 5 and 10 cmH2O pressure support ventilation during anaesthesia with 1.5% end-tidal concentration of isoflurane in nine healthy, spontaneously breathing, adult patients. Some of the patients demonstrated an irregular respiratory pattern with periods of apnoea and we therefore went on to study a further seven patients with a continuous 500 s recording of airflow. Pressure support ventilation augmented mean (SD) tidal volume from 212 (56) ml to 360 (88) ml at 5 cmH2O and to 509 (108) ml at 10 cmH2O (n = 16, p < 0.05). ⋯ Mean (SD) inspiratory work of breathing decreased from 1.77 (0.70) J. min-1 to 0.31 (0.36) J.min-1 at 5 cmH2O and 0.16 (0.26) J.min-1 at 10 cmH2O pressure support ventilation (n = 9, p < 0.05). Analysis of the respiratory rhythm in the second group of seven patients revealed an oscillating respiratory pattern in four patients at 5 cmH2O and six of the seven patients at 10 cmH2O pressure support ventilation. The metabolic advantage of the decreased work of breathing during pressure support ventilation during anaesthesia is unlikely to balance the disadvantage of an oscillating respiratory rhythm.
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Randomized Controlled Trial Clinical Trial
SCOTI--a new device for identification of tracheal intubation.
A new lightweight device for the detection of placement of a tracheal tube in the trachea or oesophagus is described. The device utilises a sonic technique detecting resonating frequencies in an open (trachea) or closed (oesophagus) structure. Evaluation of the device in a clinical environment is described and it has been shown to be capable of verifying the correct placement of the tracheal tube in the trachea in 98% of patients studied. Further evaluation of this intubating aid appears justified.
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Randomized Controlled Trial Clinical Trial
The neuromuscular blocking effects of vecuronium during sevoflurane, halothane and balanced anaesthesia in children.
Forty-five children aged 5-12 years were randomly allocated to receive 1.0 MAC of sevoflurane or halothane, or balanced anaesthesia with propofol and alfentanil. The ulnar nerve was stimulated every 20 s supramaximally with a train-of-four pattern and adductor pollicis electromyography was recorded. A cumulative log-probit dose-response curve of vecuronium was established. ⋯ Effective doses of vecuronium were lowest in the sevoflurane group and greatest during balanced anaesthesia; for 50% neuromuscular blockade these were 13.3% micrograms.kg-1, 21.8 micrograms.kg-1 and 36.6 micrograms.kg-1 during sevoflurane, halothane and balanced anaesthesia, respectively, p < 0.05. Recovery of neuromuscular function was slower during sevoflurane than during halothane or balanced anaesthesia. Sevoflurane potentiated vecuronium more than halothane; when compared to balanced anaesthesia the dose requirements of vecuronium were reduced by approximately 60% and 40%, respectively.
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Randomized Controlled Trial Comparative Study Clinical Trial
Anaesthesia and adverse effects after intrathecal pethidine hydrochloride for urological surgery.
Anaesthesia, postoperative analgesia and the incidence of adverse effects after intrathecal pethidine hydrochloride 0.50 mg.kg-1 and 0.75 mg.kg-1 were assessed and compared with a conventional technique using isobaric bupivacaine 13.75 mg in patients undergoing transurethral resection of the prostate gland. Sensory and motor block were significantly shorter with both pethidine regimens than with bupivacaine (p < 0.001). Although sensory and motor block were shorter after pethidine 0.50 mg.kg-1 than after pethidine 0.75 mg.kg-1 the difference in duration was clinically insignificant. ⋯ Pruritus was seen only in patients receiving pethidine. Intra-operative sedation occurred more often in patients receiving both pethidine 0.50 mg.kg-1 and 0.75 mg.kg-1 compared with patients receiving bupivacaine (p < 0.04). Both pethidine regimens provided acceptable anaesthesia and there were no significant differences between the two regimens in quality of intra-operative anaesthesia, incidence of adverse events or postoperative analgesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Postoperative emesis following otoplasty in children.
Sixty unpremedicated children aged between 3 and 14 years, scheduled for otoplasty, were randomly divided into one of three groups to receive either ondansetron 0.1 mg.kg-1, droperidol 75 micrograms.kg-1, or placebo at induction of anaesthesia. All patients received a standard general anaesthetic using thiopentone, atracurium and halothane. Opioid analgesia was avoided intra-operatively and infiltration with local anaesthetic was used prior to the start of surgery. ⋯ There was no difference between the placebo or droperidol group in the incidence of vomiting or time to ingestion of oral fluids and meals. Three patients in the ondansetron group had a self-terminating nodal rhythm which was not associated with any haemodynamic disturbances. Postoperatively there were no untoward incidents in any of the groups and all patients were discharged home the day after surgery.