Journal of anesthesia
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Journal of anesthesia · Sep 1994
RETRACTED ARTICLE: Airway occlusion pressure is an indicator of respiratory depression with isoflurane.
The purpose of this study was to elucidate the respiratory depressant effects of isoflurane (0%-1.0%) using airway occlusion pressure (P0.1), a known index of the output of the respiratory centers, in ten anesthetized patients. P0.1 was measured as the pressure change obtained after the first 0.1 sec of spontaneous inspiration against the occluded airway. A significant decrease in minute volume ([Formula: see text]) and a significant increase in PaCO 2 were not observed during the periods of isoflurane 1.0% at the end-tidal concentration compared with those of control period (0% isoflurane) (P<0.05), whereas a significant decrease in P0.1 was observed during the period of isoflurane 0.5%. Our results suggested that P0.1 was a more sensitive indicator of respiratory depression than PaCO 2 or[Formula: see text], and the respiratory center was depressed with a considerably lower concentration (0.5%) of isoflurane.
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Journal of anesthesia · Sep 1994
Assessment of postoperative pain: Contributing factors to the differences between patients and doctors.
This study was undertaken to compare the assessment of pain intensity by 50 patients and by their doctors according to a visual analog scale 5 h and 20 h after major abdominal surgery, and to examine the relationships between the differences in rating of patients and doctors and the factors inherent in the patients which include preoperative expectation of pain, level of anxiety, and the surgical history of the patient. The ratings given by the patients were significantly higher than those given by the doctors at both time periods. ⋯ The results of analysis using Hayashi's quantification theory Type II indicated a moderate association between the rating difference and the patient's age, surgical history, preoperative state of anxiety, and expectation of pain. It is concluded that postoperative pain management, whether in clinical practice or in research, necessitates more consideration of the several above-mentioned individual factors and a preoperative interview in which the patient's level of anxiety and the amount of information the patient has concerning the surgery and post-operative pain is clearly assessed.
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Journal of anesthesia · Sep 1994
Lumbar epidural block reduces cough strength in healthy young subjects.
Effects of lumbar epidural block on maximum expiratory strength were studied in 12 healthy volunteers. Subjects performed maximum expiratory effort against occluded airway at functional residual capacity (FRC) and total lung capacity (TLC) while measuring airway pressure and electromyogram of the abdominal muscles (EMGab). Cough strength was assessed by maximum expiratory pressure (PEmax) and peak EMGab (peak-EMGab). ⋯ Compared with severe reduction in peak-EMGab, PEmax was well maintained at TLC, but changes in PEmax were identical to those in peak-EMGab at FRC. When analgesia spread to higher than T6, PEmax at TLC decreased considerably. We conclude that lumbar epidural block producing analgesia above T6 paralyzes the abdominal muscles and severely impairs the ability of effective cough in healthy young men.
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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.