Anaesthesia
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Randomized Controlled Trial Clinical Trial
Power spectral analysis of the electroencephalogram during increasing end-expiratory concentrations of isoflurane, desflurane and sevoflurane.
We studied the effects of increasing end-expiratory concentrations of isoflurane (0.3, 0.6, 0.9, 1.2 vol.%) (n = 12 patients), desflurane (1.5, 3.0, 4.5, 6.0 vol.%) (n = 12 patients) and sevoflurane (0.5, 1.0, 1.5, 2.0 vol.%) (n = 12 patients) on power spectral analysis of the electroencephalogram (EEG). Spectral edge frequency (SEF), total power (TP) and relative power in the delta, theta, alpha and beta band were calculated. ⋯ SEF decreased, TP and relative power in the delta and theta band increased, power in the beta band decreased in a dose-dependent fashion with comparable regression lines. This indicates that MAC equivalent administration of isoflurane, desflurane and sevoflurane in clinically applied dose ranges is associated with equipotent EEG suppression.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
TCI compared with manually controlled infusion of propofol: a multicentre study.
This prospective, randomised multicentre study was designed to determine the clinical profile of 'Diprifusor' target controlled infusion compared with manually controlled infusion of propofol in 562 patients, aged 18-85 years, in a range of surgical procedures in 29 centres. The dose of propofol required for loss of consciousness was statistically significantly lower in the target controlled infusion group [1.69 (0.50) vs. 2.31 (0.75) mg.kg-1, p < 0.001] but the overall rate of propofol administration was slightly, but significantly, higher [12.1 (5.1) vs. 11.0 (6.0) mg.kg-1.h-1, p < 0.05]. The target concentration (CT) required for induction decreased with increasing age and ASA class, with premedication and with the administration of an opioid before induction. ⋯ Despite the lack of experience of most investigators in using target controlled infusion, the clinical profiles of both propofol administrations were similar. Data suggest that the clinical profile of target controlled infusion may be improved with experience, for example by more active titration of CT to effect. Target controlled infusion may well become the preferred choice for anaesthetists.
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Randomized Controlled Trial Clinical Trial
Clinical utility of EEG parameters to predict loss of consciousness and response to skin incision during total intravenous anaesthesia.
We studied 30 female patients undergoing elective surgery, to assess the reliability of electroencephalogram spectral edge frequency and median frequency to predict loss of consciousness and movement in response to skin incision during total intravenous anaesthesia. Each patient received a different combination of propofol (1, 2, 3, 4, 5 or 6 micrograms.ml-1) and sufentanil (0.1, 0.2, 0.3, 0.5 or 1.0 ng.ml-1) target concentrations for induction of anaesthesia using target controlled infusions, assigned randomly. ⋯ The probabilities of 50% and 95% no response for spectral edge frequency were 13.4 Hz and 6.8 Hz, respectively. The variability of the data limited the predictive value, so that spectral edge frequency was a poor predictor and median frequency was no predictor of response in the individual patient during total intravenous propofol/sufentanil anaesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effect of EMLA and semicircular subcutaneous anaesthesia in the prevention of tourniquet pain during plexus block anaesthesia of the arm.
In 54 patients who were to undergo surgery of the upper extremity in plexus block anaesthesia the effect of 5 g EMLA (group E) on tourniquet pain was examined and compared with the effect of a semicircular subcutaneous anaesthesia using 10 ml 0.25% bupivacaine (group B) or 10 ml 1% mepivacaine (group M). Among the patients with satisfactory brachial plexus analgesia allowing for surgery (n = 51), the incidence of tourniquet pain was not significantly different between groups E, M and B. Notably, there was no significant difference in the time of tourniquet application. We conclude that topical application of EMLA is as effective as a semicircular subcutaneous anaesthesia with mepivacaine or bupivacaine in the prevention of tourniquet pain during brachial plexus anaesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Postoperative respiratory function in children after abdominal surgery. A comparison of epidural and intramuscular morphine analgesia.
Thirty children undergoing urological and abdominal surgery were entered into a randomised trial comparing the effects of epidural and intramuscular morphine on postoperative respiratory function. The forced vital capacity and the forced expired volume in 1 s were measured before and 6 h after surgery and on each of the following seven days. Significant decreases (p < 0.01) in forced vital capacity and forced expired volume in 1 s were seen after surgery. ⋯ There were no statistically significant differences between the two groups during the study with respect to forced vital capacity and forced expired volume in 1 s. The quality of analgesia was better in the epidural morphine group than in the intramuscular morphine group. The incomplete recovery of pulmonary function suggests that pain is not the only cause of postoperative respiratory changes in these patients.