Journal of anesthesia
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Journal of anesthesia · Sep 1994
Crossover effects of acidosis on the recovery of neuronal function following glucose-oxygen deprivation in rat hippocampal slices.
The present study was designed to determine whether acidosis modifies the effect of simulated ischemia on neuronal function. Hippocampal evoked potentials were recorded in vitro from the CA1 region after stimulation of the Schaffer collaterals and the change in the evoked potentials was analyzed in response to glucose-oxygen deprivation under variable acid-base conditions ranging from pH 7.4 to pH 4.5. ⋯ The recovery of PS amplitude during recovery from glucose-oxygen deprivation was not significantly inhibited by moderate acidosis of pH 6 and 5.5 but was significantly inhibited when the pH was 5 or lower. The results suggest that severe acidosis may depress PS amplitude and prevent their recovery after reversal of glucose-oxygen deprivation, and that moderate acidosis may have no significant effect on PS amplitudes on their recovery.
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Journal of anesthesia · Sep 1994
The effect of pH adjustment of 1% lidocaine on the onset of sensory and motor blockade of epidural anesthesia in nonpregnant gynecological patients.
Using a double-blind randominzed study protocol, we examined the distribution of sensory blockade and the quality of motor blockade after epidural anesthesia with 1% lidocaine with or without bicarbonate in nonpregnant gynecological patients. Alkalinization significantly decreased the time to onset of sensory blockade. However, there were no statistically significant differences between the low-pH and high-pH groups with respect to motor blockade or the distribution of sensory blockade. We conclude that pH-adjusted 1% lidocaine offers the advantage of a more rapid onset of sensory blockade, while motor blockade and the distribution of anesthesia are unaffected by pH change in epidural anesthesia.
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Journal of anesthesia · Sep 1994
Effects of halothane and enflurane on the peripheral vasoconstriction and shivering induced by internal body cooling in rabbits.
General anesthetic agents have central and peripheral effects on body temperature regulation, and its alterations are related to the depth of anesthesia. To evaluate the effect of halothane and enflurane on thermoregulation, we investigated the threshold of body core temperatures to induce peripheral vasoconstriction and shivering in spontaneously breathing rabbits. Rabbits were anesthetized with halothane or enflurane at 0.0 (control), 0.2, and 0.4 MAC (minimum alveolar concentration). ⋯ The incidence of peripheral vasoconstriction was not significantly affected by halothane or enflurane. However, the incidence of shivering decreased in a dose-dependent fashion with both anesthetic agents. At 0.2 MAC, the incidence of shivering in the enflurane group was significantly higher than that in the halothane group, suggesting that suppression of shivering by halothane is stronger than enflurane.