Articles: anesthesia.
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Anesthesia and analgesia · Mar 1991
Randomized Controlled Trial Clinical TrialPatient-controlled sedation during epidural anesthesia.
The purpose of this study was to evaluate the feasibility and advantages or disadvantages, if any, of patient-controlled sedation compared with sedation administered by the anesthesiologist during surgical epidural anesthesia. Forty patients were divided at random into two groups with 20 patients in each group. Patients in group 1 received 0.5-1.0 mg intravenous midazolam and 25-50 micrograms intravenous fentanyl in increments administered by the anesthesiologist to achieve intraoperative sedation; patients in group 2 self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 micrograms) in increments using an Abbott Lifecare PCA infuser to achieve sedation. ⋯ This could have been due to a positive psychological effect produced by allowing patient to feel that they have some control over their situation. The findings of this study indicate that patient-controlled sedation using a combination of midazolam and fentanyl is a safe and effective technique that provides intraoperative sedation ranked better by patients than that provided by anesthesiologists using the same drugs. More studies are, however, needed to determine the best choice of drug(s), the doses, the lock-out intervals, and the possible use of continuous infusion with patient-controlled sedation.
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Randomized Controlled Trial Comparative Study Clinical Trial
Accuracy of placement of extradural needles in the L3-4 interspace: comparison of two methods of identifying L4.
The certainty with which the L3-4 vertebral interspace can be identified was investigated by studying 50 cadavers. These were allocated randomly to two groups, differing in the way in which the L4 spinous process was identified. Identification of L4 by physically constructing Tuffier's line on the subject led to an increase in the number of catheters sited at the correct level (P less than 0.01).
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Randomized Controlled Trial Clinical Trial
The electroencephalographic effects of desflurane in humans.
The electroencephalographic (EEG) effects of a new inhaled anesthetic are of interest because of the potential of such agents to produce excitatory (convulsant) activity and because of the potential usefulness of the EEG as an indicator of anesthetic depth and cerebral activity. Accordingly, we examined the EEG in 12 healthy, young male volunteers during desflurane anesthesia. Each subject had a baseline recording and then steady-state exposure to 6, 9, and 12% (0.83, 1.24, and 1.66 MAC) desflurane in O2 alone, and to 3, 6, and 9% desflurane in O2 with 60% N2O. ⋯ Desflurane significantly suppressed EEG activity; prominent burst suppression was seen at 1.24 MAC and higher. Substitution of N2O for 0.42 MAC desflurane reduced the degree of EEG suppression relative to the equipotent administration of desflurane and O2. Quantitative EEG measures for the early doses and for the later, repeated exposures did not differ.
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Randomized Controlled Trial Comparative Study Clinical Trial
Desflurane and isoflurane in surgical patients: comparison of emergence time.
In order to examine the clinical potential of desflurane (difluoromethyl-1-fluoro-2,2,2-trifluoroethyl ether) in humans, a randomized, controlled study was designed to compare time of emergence from anesthesia in patients undergoing elective surgery under desflurane anesthesia to that of patients under isoflurane anesthesia. Twenty-eight patients were randomly divided into four groups. Group 1 received isoflurane 0.65 MAC; group 2, desflurane 0.65 MAC; group 3, isoflurane 1.25 MAC; and group 4, desflurane 1.25 MAC. ⋯ Patients receiving isoflurane 0.65 MAC responded to commands 15.6 +/- 4.3 min after discontinuation of the anesthetic; patients in the desflurane 0.65 MAC group responded in 8.8 +/- 2.7 min (P less than 0.01). Emergence time for isoflurane 1.25 MAC was 30.0 +/- 11.0 min; for desflurane 1.25 MAC it was 16.1 +/- 6.0 min (P less than 0.05). Our results confirm that emergence from desflurane anesthesia is more rapid than from isoflurane.
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Randomized Controlled Trial Clinical Trial
Effects of residual concentrations of isoflurane on the reversal of vecuronium-induced neuromuscular blockade.
Thirty-six anesthetized patients (ASA physical status 1 or 2) undergoing elective surgery were monitored (isometric adductor pollicis mechanical activity) to detect the effects of discontinuing isoflurane anesthesia upon the reversal of vecuronium-induced neuromuscular blockade. Neuromuscular blockade was produced by vecuronium 100 micrograms/kg and additional doses of 20 micrograms/kg until completion of surgery. The patients were randomly divided into three groups: in the control group (n = 12), only fentanyl/N2O was given; in the "isostable" group (n = 12), isoflurane at an end-tidal concentration of 1.25% was maintained throughout anesthesia; in the "isostop" group (n = 12), isoflurane 1.25% was discontinued before neostigmine administration. ⋯ In the isostable group, final mean train-of-four was significantly less (75%) than in the other patients (88%) (P less than 0.01). Mean tetanic fade at 100 Hz was significantly less in the isostable group (31%) than in the isostop group (57%) (P less than 0.01) and control group (84%) (P less than 0.01). We conclude that discontinuing isoflurane anesthesia for 15 min improves the reversal of a vecuronium paralysis.(ABSTRACT TRUNCATED AT 250 WORDS)