Articles: general-anesthesia.
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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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Minerva anestesiologica · Mar 1994
Comparative Study Clinical Trial Controlled Clinical Trial[Respiratory exchange during laparoscopic and laparotomic cholecystectomy].
The utility of laparoscopic cholecystectomy in reducing postoperative pain and patient's hospital discharge is already known. Nevertheless peritoneal gas insufflation required by surgical procedure can modify respiratory homeostasis during general anesthesia. The aim of this study was to evaluate the effect of laparoscopic cholecystectomy on pulmonary dead spaces and alveolar gas exchange during inhalation anesthesia compared with traditional laparotomic cholecystectomy. ⋯ VDphy/VT, VDalv/VT, P(a-Et)CO2 and A-aDO2 increased significantly in the CL-S compared to the CL-T group (p < 0.05). No differences were found in the VDan/VT. These results can be explained by analteration of the ventilation to perfusion ratio (VA/Q) with an increase of high VA/Q regions due to the antitrendelenburg positioning with a redistribution of blood flow towards basal zones.(ABSTRACT TRUNCATED AT 250 WORDS)
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High fractions of inspired oxygen are commonly used during general anesthesia in birds. Observations in ducks anesthetized with halothane or pentobarbital indicated that high fractions of inspired oxygen depress ventilation. The purpose of this study was to test the hypothesis that ducks hypoventilate when breathing high fractions of inspired oxygen, compared with the same ducks breathing low fractions of inspired oxygen. ⋯ Respiratory rate decreased as the fraction of inspired oxygen increased, but not significantly. There was a significant decrease in tidal volume as PaCO2 increased. Hyperoxia was observed to contribute to hypoventilation in ducks anesthetized with isoflurane in oxygen.
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Minerva anestesiologica · Mar 1994
[Monitoring of cuff pressure in double-lumen endotracheal tubes during anesthesia for thoracic surgery].
It is well known that cuff overinflation in endotracheal tubes may cause serious damage to the tracheal mucosa. Cuff overinflation is also related to the diffusion of nitrous oxide across the cuff membrane, thus giving way to a progressive volume/pressure increase up to overcoming, critical capillaric perfusion pressure. The kinetics of hi-lo cuff-pressure in single-lumen endotracheal tubes during general anesthesia using nitrous oxide has been well documented. ⋯ In ten of these case, special equipment was used in order to keep the cuff-pressures steady and at the lowest sealing level. The pressure shows the same trend in both cuffs but, depending on the medium calibre of the main left bronchus and the volume/pressure relations of the endobronchial cuffs, the pressure in the latter increases faster. The investigation was performed using an original equipment developed by the authors; such equipment is able not only to monitor the cuff-pressures, but also to maintain them at steady controlled levels (below 20 cm water seal), by means of counterregulating all the volume variations due either to anesthetic requirements, or to the diffusion of nitrous oxide.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Changes in haemodynamic variables during transurethral resection of the prostate: comparison of general and spinal anaesthesia.
We have compared changes in haemodynamic variables before and during transurethral resection of the prostate in 22 patients under general or spinal anaesthesia. In the general anaesthetic group there was a significant decrease in cardiac output (mean 32% (SEM 5%)) and mean arterial pressure (14% (3%)) after induction of anaesthesia and a significant decrease (27% (3%)) in heart rate before the start of resection. ⋯ We conclude that with both these anaesthetic techniques the greatest changes in haemodynamic variables occurred shortly after induction, and that these changes were greater during general than spinal anaesthesia. The resection period was not associated with significant haemodynamic changes.