Anesthesia and analgesia
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Anesthesia and analgesia · May 1993
Randomized Controlled Trial Comparative Study Clinical TrialDesflurane versus propofol anesthesia: a comparative analysis in outpatients.
This study compares the induction, hemodynamic, and recovery characteristics of a general anesthetic with desflurane to one with propofol. Sixty outpatients presenting for orthopedic surgery received either a propofol induction of anesthesia followed by desflurane and nitrous oxide (Group 1), a propofol induction followed by propofol infusion and nitrous oxide (Group 2), a desflurane and nitrous oxide induction and maintenance (Group 3), or a desflurane induction and maintenance (Group 4). The quality of induction was inferior in Groups 3 and 4 with more breath-holding and excitation than in Groups 1 and 2. ⋯ Although there was no difference between the groups in postoperative narcotic requirement, more patients in Group 3 vomited (50%) than in either Group 2 (0%) or Group 4 (12.5%). Hemodynamically, the anesthetics were very similar. Although desflurane was a difficult drug to use for induction of anesthesia, this study demonstrates that desflurane is a suitable maintenance anesthetic for ambulatory surgery because it provides a rapid awakening and an intermediate recovery similar to propofol.
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Anesthesia and analgesia · May 1993
Randomized Controlled Trial Comparative Study Clinical TrialPupillary response to noxious stimulation during isoflurane and propofol anesthesia.
We studied the effects of noxious stimuli on arterial blood pressure, heart rate, pupil size, and the pupillary light reflex in 13 volunteers anesthetized with either isoflurane or propofol. Those given isoflurane (n = 8) were anesthetized twice, in a randomly selected order, once at an end-tidal concentration of 0.8% and once at 1.2%. An intense noxious stimulus was provided by electrical stimulation applied to skin of the abdominal wall (65-70 mA, 100 Hz). ⋯ During one propofol anesthetic, an esmolol infusion (100 micrograms.kg-1 x min-1) was started 10 min before stimulation to determine whether this agent would blunt the pupillary response. The pupillary light reflex increased more than 200% during both propofol anesthetics with or without esmolol; once again, heart rate and blood pressure changed little. We conclude that with these experimental conditions, the pupil is a more sensitive measure of noxious stimulation than the commonly used variables of arterial blood pressure and heart rate.
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Anesthesia and analgesia · May 1993
Randomized Controlled Trial Comparative Study Clinical TrialIntranasal meperidine titration for postoperative pain relief.
A prospective, randomized, double-blind study investigating the efficacy of intranasal meperidine as compared with intravenous (i.v.) administration for postoperative pain relief is described. The study was limited to the initial titration of pain relief during a 2-h period immediately after surgery. Sixty women having undergone a hysterectomy were studied. ⋯ The total dose of meperidine was 76.5 mg (range, 40.5-135.0) in the intravenous group and 104.4 mg (range, 27-135.0) in the nasal group (P < 0.05). One patient in each group showed a brief decrease in arterial hemoglobin oxygen saturation to < 90%. No patient complained of pain or burning in the nose.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · May 1993
Randomized Controlled Trial Comparative Study Clinical TrialComparison of an ephedrine infusion with crystalloid administration for prevention of hypotension during spinal anesthesia.
This study was designed to compare the efficacy of an ephedrine infusion with crystalloid administration for reducing the incidence of hypotension during spinal anesthesia. Fifty-four ASA I patients scheduled for postpartum tubal ligations under spinal anesthesia were randomly allocated to receive either 15 mL/kg of crystalloid (crystalloid group) or an ephedrine infusion (infusion group). Spinal anesthesia was performed using 70-90 mg of hyperbaric 5% lidocaine. ⋯ The incidence of hypotension was 15/27 (55%) in the crystalloid group and 6/27 (22%) in the infusion group (P < 0.05). There was no significant difference between the groups in relation to the level of anesthesia or maximal heart rate, and hypertension did not occur in either group. We conclude that a prophylactic ephedrine infusion is effective for minimizing and managing hypotension associated with spinal anesthesia and compares favorably with crystalloid administration in this patient population in terms of efficacy and incidence of side effects.
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Anesthesia and analgesia · May 1993
Sedative doses of propofol increase beta activity of the processed electroencephalogram.
The effects of sedative infusions of propofol on the processed electroencephalograms (EEG) of eight healthy male volunteers were studied. EEG data for aperiodic analysis were collected during three 5-min periods: before propofol, during propofol infusion, and 30 min after termination of the infusion. After an initial dose of 1 mg/kg, subjects received a propofol infusion titrated to produce a standard level of conscious sedation. ⋯ The change in total power was accompanied by a change in the distribution of power within the EEG spectrum, as the fraction of activity in the beta-band (12-35 Hz) increased during the infusion from 23% +/- 3% to 44% +/- 5% (P < 0.05). Thirty minutes after the infusion was terminated, the distribution of activity within the EEG spectrum had reverted to pre-propofol patterns. The similarity of EEG effects seen with sedative doses of propofol and benzodiazepines suggests that these drugs may share some neurochemical effects.