Articles: general-anesthesia.
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Anesthesia and analgesia · Apr 1994
Randomized Controlled Trial Clinical TrialFacilitation of fiberoptic orotracheal intubation with a flexible tracheal tube.
Advancement of a tracheal tube (TT) over a flexible fiberoptic bronchoscope (FOB) is often impeded by obstruction at the arytenoid cartilage or epiglottis. We tested the hypothesis that the use of a flexible, spiral-wound TT, rather than the standard, preformed TT would facilitate tube passage into the trachea over the FOB. Forty patients scheduled to undergo general anesthesia with tracheal intubation were randomized to two groups. ⋯ In the patients randomized to the spiral-wound TT, 95% (19/20) of first attempts were successful (P < 0.0001). Of the 13 regular TTs that were not successfully advanced on the first attempt, seven could not be passed after the second or third attempt (necessitating the use of the cross-over spiral-wound TT). In the only instance in which a spiral-wound tube was not successfully passed into the trachea on the first attempt, passage also was not achieved after the second or third attempt.(ABSTRACT TRUNCATED AT 250 WORDS)
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Clinical Trial Controlled Clinical Trial
Minimum alveolar concentration of isoflurane for tracheal extubation in deeply anesthetized children.
The end-tidal anesthetic gas concentration required to prevent the anesthetized patient from coughing or moving during or immediately after tracheal extubation is not known. ⋯ In 50% of anesthetized children age 4-9 yr tracheal extubation may be accomplished without coughing or moving at 1.27% end-tidal isoflurane concentration.
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Comparative Study
The effects of sevoflurane are similar to those of isoflurane on the neuromuscular block produced by vecuronium.
We have examined the interactions of 1 MAC of isoflurane and sevoflurane (and 66% nitrous oxide in oxygen) with vecuronium, using the EMG response of the abductor digiti minimi to train-of-four (TOF) stimulation of the ulnar nerve. We constructed dose-response curves for vecuronium in 54 patients. ⋯ The rate of recovery of T4:T1 was significantly greater when both anaesthetics were discontinued. However, this rate was similar for both anaesthetics, suggesting that the mechanism of action of the two anaesthetics is similar.
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Anaesth Intensive Care · Apr 1994
Randomized Controlled Trial Comparative Study Clinical TrialPreoperative and postoperative oxygen saturation in the elderly following spinal or general anaesthesia--an audit of current practice.
We have compared the incidence of preoperative and postoperative oxygen desaturation in 20 elderly patients undergoing dynamic hip screw insertion for fractured neck of femur, allocated randomly to two groups to receive subarachnoid anaesthesia (SA, n = 10) or a general anaesthetic (GA, n = 10). Oximetry data were recorded during the preoperative night and the first 48 hours after surgery using Satmaster. Data associated with zero amplitude signal were automatically invalidated by the software and decreases in SpO2 which were preceded by contemporaneous changes in signal amplitude which conformed to a previously described template were assumed to be artefactual and were discarded from final data analysis. ⋯ The differences between the preoperative and postoperative oximetry profiles were examined for each patient and demonstrated a significantly longer time spent with SpO2 < 90% in the GA group compared with the SA group, in all the recorded time periods, except on the day of surgery. The SA group showed an improvement in oxygen saturation postoperatively when compared to the preoperative night, spending less time with an SpO2 < 85%. We conclude that the subarachnoid anaesthetic technique was associated with a lower incidence of postoperative oximetry desaturation when compared with general anaesthetic for these elderly patients undergoing repair of fractured neck of femur.
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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.