Articles: general-anesthesia.
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Comparative Study
Respiratory sinus arrhythmia: comparison with EEG indices during isoflurane anaesthesia at 0.65 and 1.2 MAC.
Respiratory sinus arrhythmia (RSA) is a cyclical variation in heart rate during breathing, where the heart rate increases during inspiration and decreases during expiration. RSA and the electroencephalogram (EEG) were monitored in 10 patients undergoing elective surgery with isoflurane and nitrous oxide in oxygen anaesthesia after induction with propofol. All patients were subject to controlled ventilation and recovery from competitive neuromuscular block was facilitated by neostigmine and glycopyrronium (seven patients) or atropine (three patients). ⋯ In contrast, the level of RSA did not decrease significantly with atropine. It is concluded that measurements of RSA could form the basis of a useful index of anaesthetic depth during isoflurane anaesthesia, even during the use of pharmacologically appropriate doses of atropine. However, any effects of atropine on the raw EEG and on indices derived from the EEG, should be characterized further so that these effects are not confused with changes in anaesthetic depth.
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We sought to determine the effectiveness of a magnet placed over the thyroid cartilage in the neck to guide an endotracheal tube into the trachea. Forty patients aged 18 to 60 yr with normal airway anatomy (ASA grade I) who required general anesthesia with an endotracheal tube and paralysis for their surgery were chosen and informed consents were obtained. The tip of the epiglottis was exposed with a No. 3 MacIntosh laryngoscope, and a magnet was held over the thyroid cartilage. ⋯ This magnet-guided technique can be used when it is difficult to expose a patient's larynx. It is noninvasive, simple, and can be used without any delay when expensive flexible fiberoptic endoscopes are not readily available. The procedure takes an average of 1 to 2 min.
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Electroencephalogr Clin Neurophysiol · Mar 1994
Randomized Controlled Trial Clinical TrialBispectral analysis of the electroencephalogram during induction of anesthesia may predict hemodynamic responses to laryngoscopy and intubation.
The use of electroencephalography as a measure of adequacy of anesthesia has achieved limited success. Our purpose was to determine whether the non-linear properties of the electroencephalogram (EEG) as defined by the bispectral index was a better predictor of autonomic responses to endotracheal intubation during opioid-based anesthesia than the linear statistical properties of the EEG formulated by power spectral analysis. Thirty-nine adults scheduled for elective non-cranial surgery had a continuous EEG recorded during induction of anesthesia and endotracheal intubation. ⋯ Heart rate changes did not differentiate between the two groups. There was a significant difference between response groups as measured by the bispectral index which distinguished responders from non-responders independently of the amount of drug given. None of the variables of power spectral analysis accurately distinguished responder from non-responder.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Core hypothermia and skin-surface temperature gradients. Epidural versus general anesthesia and the effects of age.
Inadvertent hypothermia occurs frequently during surgery and may be associated with adverse outcomes. Although various anesthetic agents have been shown to impair thermoregulation, the impairment with regional and general anesthetics has not been directly compared. ⋯ The EA and GA groups had virtually identical core temperature profiles during the intraoperative and post-operative periods. Comparison of skin-surface gradients suggests that EA is associated with less intraoperative upper-body thermoregulatory impairment but greater and persistent post-operative lower-body impairment. During EA, younger patients appeared to maintain thermoregulatory activity relative to the older patients. In patients receiving GA, the age-related differences were minimal.