Anaesthesia
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Randomized Controlled Trial Clinical Trial
Effect of remifentanil with and without atropine on heart rate variability and RR interval in children.
Remifentanil can cause bradycardia either by parasympathetic activation or by other negative chronotropic effects. The high frequency (HF) component of heart rate variability (HRV) is a marker of parasympathetic activity. This study aimed to evaluate the effect of remifentanil on RR interval and on HRV in children. ⋯ Remifentanil induced an RR interval lengthening, i.e. bradycardia, in both groups compared to pretreatment values and was associated with an increase of HF and rmssd only for the REMI group. The parasympathetic inhibition by atropine did not totally prevent remifentanil's negative chronotropic effect. A direct negative chronotropic effect of remifentanil is proposed.
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Multicenter Study
Airway management before, during and after extubation: a survey of practice in the United Kingdom and Ireland.
Summary Complications at extubation remain an important risk factor in anaesthesia. A postal survey was conducted on extubation practice amongst consultant anaesthetists in the United Kingdom and Ireland. The use of short acting drugs encourages anaesthetists to extubate the trachea at lighter levels of anaesthesia. ⋯ Some of these results give concern for patient safety and for training. The importance of teaching and adherence to continued oxygenation until complete recovery is strongly emphasised. Nerve stimulators should be used continually as standard monitoring throughout the anaesthetic period when muscle-relaxing drugs are part of the anaesthetic technique.
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Continuous central pressure monitoring and simultaneous continuous infusion via the same central venous catheter are sometimes necessary. Based on theoretical calculations and experimental measurements, we have determined that pressure monitoring is essentially unaffected if the continuous infusion rate is 50 ml.h(-1) or less for an adult and a paediatric central catheter. At rates > 200 ml.h(-1), the central venous pressure is exaggerated by up to 4 mmHg and 8 mmHg for the adult and paediatric catheters, respectively.
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Brain stem death may be a difficult concept for relatives to understand. Our ITU practice follows published recommendations that the use of explanatory leaflets showing CT scans and observing brain stem death testing in some cases may help relatives to understand that death has occurred. Using this strategy, we interviewed 27 relatives 12 months after bereavement following certification by brain stem testing, investigating their understanding of brain stem death, subsequent attitudes to organ donation, grief reactions and attitudes of those who had observed the tests. ⋯ Only five relatives observed the tests, all were pleased that they had done so as this had confirmed their understanding that death had occurred; however, these relatives had more evidence of psychological distress. No relatives who agreed to organ donation regretted this but three who did not allow donation subsequently expressed regret. Several relatives thought that observing the tests would have helped them to understand that death had occurred, making easier the decision to allow organ donation.
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The I-gel airway is a novel supraglottic airway that uses an anatomically designed mask made of a gel-like thermoplastic elastomer. We studied the positioning and mechanics of this new device in 65 non-embalmed cadavers with 73 endoscopies (eight had repeat insertion), 16 neck dissections, and six neck radiographs. A full view of the glottis (percentage of glottic opening score 100%) occurred in 44/73 insertions, whereas only 3/73 insertions had epiglottis-only views. ⋯ The mean percentage of glottic opening score for the 73 insertions was 82% (95% confidence interval 75-89%). In each of the neck dissections and radiographs the bowl of the device covered the laryngeal inlet. We found that the I-gel effectively conformed to the perilaryngeal anatomy despite the lack of an inflatable cuff and it consistently achieved proper positioning for supraglottic ventilation.