Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of different modes of noninvasive ventilatory support: effects on ventilation and inspiratory muscle effort.
The aims of noninvasive ventilation include the correction of hypoventilation and unloading of inspiratory muscles. Volume cycled flow generators, bi-level positive airway pressure and continuous positive airway pressure techniques have all been used with face and nasal masks. We have compared these modes of ventilatory support, administered by a nasal mask in stable, awake outpatients with chronic obstructive pulmonary disease or neuromusculo-skeletal disease in respect of their effects on ventilation, inspiratory muscle effort and oxygen saturation. ⋯ Only the volume cycled flow generator increased minute ventilation significantly. Ventilation and inspiratory muscle effort were unaffected by continuous positive airway pressure but oxygen saturation was lower than during spontaneous ventilation. In awake, stable outpatients acclimatised to nasal ventilation there were no clinically significant differences between volume cycled flow generator and bi-level positive airway pressure techniques, but continuous positive airway pressure was less effective.
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Randomized Controlled Trial Clinical Trial
Teaching fibreoptic intubation. Effect of alfentanil on the haemodynamic response.
A technique for teaching fibreoptic orotracheal intubation in patients under general anaesthesia is described and evaluated. A standard general anaesthetic was administered to 60 patients presenting for elective gynaecological surgery. Patients were randomly assigned to receive either alfentanil 10 micrograms.kg-1 or a placebo, and to be intubated either by a consultant experienced in the use of the fibreoptic bronchoscope or by an inexperienced trainee under instruction. ⋯ The hypertensive response to fibreoptic intubation was suppressed in those patients who received alfentanil (p < 0.001). The increase in heart rate was not suppressed, but was attenuated when these patients were compared with those who had received the placebo (p < 0.001). Alfentanil 10 micrograms.kg-1 minimises the haemodynamic response when teaching fibreoptic orotracheal intubation under general anaesthesia.
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Randomized Controlled Trial Clinical Trial
Teaching fibreoptic intubation in anaesthetised patients.
One hundred ASA grade 1 and 2 patients requiring orotracheal intubation for various general surgical procedures were randomly assigned to receive either expert rigid laryngoscopic or novice fibreoptic orotracheal intubation under total intravenous anaesthesia. Five anaesthesia residents in the 4th year, with no prior experience in fibreoptic laryngoscopy, participated in a fibreoptic training course, viewing two instructional videos and practising on the intubation manikin. Each resident intubated 20 patients in a randomised fashion either as an expert laryngoscopist or as a fibreoptic novice. ⋯ The haemodynamic profile was similar for fibreoptically intubated and conventionally intubated patients and there was no difference between the first two or the last two fibreoptic or rigid intubations. The study was designed to detect a difference of 10% in means (assuming alpha = 0.05 and beta < or = 0.2). The incidence of postoperative sore throat, dysphagia or hoarseness was similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Delayed ACTH response to human corticotropin releasing hormone during cardiopulmonary bypass under diazepam-high dose fentanyl anaesthesia.
The inhibitory effect of high dose fentanyl (0.1 mg.kg-1) and diazepam (0.5 mg.kg-1) anaesthesia on the pituitary-adrenal response to coronary artery surgery during cardiopulmonary bypass was assessed by comparison of the adrenocorticotropic hormone and cortisol responses to intravenous boluses of either 0.1 mg (n = 14) or 0.2 mg (n = 14) human corticotropin releasing hormone administered 5 min after starting cardiopulmonary bypass, with the responses obtained in a control group (n = 14). Blood samples were taken before inducing anaesthesia, just before cardiopulmonary bypass and at 5, 20, 35, 50, 65 and 80 min thereafter. ⋯ Plasma cortisol concentrations did not vary between the three groups at any sampling time. During cardiopulmonary bypass the early adrenocorticotropic responses to human corticotropin releasing hormone are blunted but later there is a good response, suggesting that the inhibitory effect of high dose fentanyl and diazepam anaesthesia takes place in the hypothalamus.