Articles: general-anesthesia.
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Anasthesiol Intensivmed Notfallmed Schmerzther · Oct 1995
Review[Clinical potency of nitrous oxide--is MAC the gold standard?].
Nitrous oxide is delivered during most cases of general anaesthesia. Though it has a history of approx. 150 years there is no univocal understanding about its clinical potency. Research studies during the last 10 years support, however, the view that 1. the potency of nitrous oxide in the clinical settings is only 1/3 of the potency as estimated from the MAC value; 2. the potency of combinations of nitrous oxide and volatile anaesthetics is represented more appropriately by quantities which are derived from the EEG than by the addition of MAC fractions. The findings of the last 10 years do not support the hypothesis, that the addition of nitrous oxide to the breathing gas is more beneficial than waiving the use of nitrous oxide.
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Anesthesia and analgesia · Oct 1995
Randomized Controlled Trial Clinical TrialThe effects of anesthesia with increasing end-expiratory concentrations of sevoflurane on midlatency auditory evoked potentials.
We studied midlatency auditory evoked potentials (MLAEP) during general anesthesia with increasing end-expiratory concentrations of sevoflurane in 12 patients scheduled for elective gynecologic surgery. After oral premedication with 20 mg clorazepate dipotassium, anesthesia was induced with etomidate (0.2 mg/kg intravenously [IV]). Vecuronium (0.1 mg/kg) was given for neuromuscular block, and controlled ventilation with sevoflurane in 100% O2 was instituted. ⋯ In contrast, MLAEP showed marked dose-dependent, statistically significant increases in the latencies of Na, Pa, Nb, and P1 and decreases in the amplitudes of Na/Pa, Pa/Nb, and Nb/P1. Under 2 vol% of sevoflurane, MLAEPs were severely attenuated or abolished. Based on these observations, > or = 1.5 vol% sevoflurane should suppress phenomena such as auditory perceptions, intraoperative wakefulness, and awareness.