British journal of anaesthesia
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Comparative Study Clinical Trial Controlled Clinical Trial
Manoeuvres used to clear the airway during fibreoptic intubation.
Fibreoptic orotracheal endoscopy under general anaesthesia may be more difficult to perform if the upper airway cannot be fully cleared. We have studied the effectiveness of jaw thrust, lingual traction and the application of both manoeuvres simultaneously, in opening up the orolaryngeal airspace in 30 ASA group 1 or 2 patients aged between 16 and 70 yr undergoing elective general surgery requiring orotracheal intubation. Airway clearance was assessed fibreoptically at soft palate level by observing whether or not the uvula or soft palate was apposed to the base of the tongue, and at epiglottic level by observing whether or not the epiglottis was apposed to the posterior pharyngeal wall. ⋯ Applying both jaw thrust and lingual traction simultaneously cleared the airway at both soft palate and epiglottic level in every patient. When used alone, jaw thrust and lingual traction fail to produce full airway clearance in a significant number of patients. Combined jaw thrust and lingual traction clears the airway more effectively but requires two assistants.
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Clinical Trial
Continuous intra-jugular venous blood-gas monitoring with the Paratrend 7 during hypothermic cardiopulmonary bypass.
We measured the accuracy of the continuous intra-vascular blood-gas monitoring system (Paratrend 7, PT7) placed in the jugular venous bulb in 18 adult patients having cardiac or aortic surgery with hypothermic cardiopulmonary bypass (CPB). After induction of anaesthesia, a PT7 sensor was inserted through a 20-gauge venous catheter into the right jugular venous bulb. Blood samples were drawn from the venous catheter and measured with a blood gas analyser (BGA). ⋯ However, precision for oxygen saturation in each patient varied 2.3 to 23.6% (95% CI: 6.3 to 12.9%), which was unsatisfactory for clinical measurements. Deep hypothermia ( approximately 19.6 degrees C) and marked haemodilution ( approximately 13.5%) during CPB did not influence the reliability of the PT7 sensor. Thus, we concluded that continuous intra-jugular venous blood-gas monitoring is clinically feasible using the PT7 and may provide valuable information during CPB.
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Randomized Controlled Trial Comparative Study Clinical Trial
Loss of volition and pain response during induction of anaesthesia with propofol or sevoflurane.
We compared the time to reach two anaesthetic end-points during induction of anaesthesia with a potent inhalation agent (sevoflurane) and an i.v. agent (propofol). We used a method to ensure steady breathing during inhalation induction, and measured loss of tone in the outstretched arm and loss of response to a painful stimulus. Thirty-eight female patients (age 39 (9) yr, weight 65 (11) kg, and height 165 (8) cm) (mean (SD)) were randomly allocated to receive either propofol or sevoflurane. ⋯ The variances of these three measurements were not significantly different, indicating that these dose-response relationships were similar. In contrast, only 11 of the patients given propofol lost the response to pain after 2.5xED(50) had been given. These results support previous evidence of substantial differences between anaesthetic end-points, and show that this evidence can be obtained using a simple and rapid method.
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Multicenter Study
Sedative and analgesic practice in the intensive care unit: the results of a European survey.
Sedation and analgesia are important aspects of patient care on the intensive care unit (ICU), yet relatively little information is available on common sedative and analgesic practice. We sought to assess international differences in the prescription of sedative and analgesic drugs in western European ICUs by means of a short, self-administered questionnaire. Six hundred and forty-seven intensive care physicians from 16 western European countries replied to the questionnaire. ⋯ The use of a sedation scale varied from 72% in the UK and Ireland to 18% in Austria. When used, the most common sedation scale was the Ramsay scale. This study demonstrates substantial international differences in sedative and analgesic practices in western European ICUs.
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Randomized Controlled Trial Clinical Trial
Effects of desflurane on cerebral autoregulation.
The aim of this study was to determine the effects of desflurane, at 1 and 1.5 MAC, on cerebral autoregulation. Data were analysed from eight patients undergoing non-neurosurgical procedure. The blood flow velocity in the middle cerebral artery was measured by transcranial Doppler ultrasound and cerebral autoregulation was assessed by the transient hyperaemic response test. ⋯ An infusion of phenylephrine was used to maintain pre-induction mean arterial pressure and ventilation was adjusted to maintain the pre-induction value of PE'(CO(2)) throughout the study. Two indices derived from the transient hyperaemic response test (the transient hyperaemic response ratio and the strength of autoregulation) were used to assess cerebral autoregulation. Desflurane resulted in a marked and significant impairment in cerebral autoregulation; at concentrations of 1.5 MAC, autoregulation was almost abolished.