British journal of anaesthesia
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Clinical Trial Controlled Clinical Trial
Effect of fentanyl on awakening concentration of sevoflurane.
This study was designed to determine if fentanyl altered MAC-awake (the end-tidal concentration of sevoflurane associated with eye opening to verbal command) in 30 healthy, ASA I patients. During anaesthesia, no other anaesthetics or drugs were given with the exception of sevoflurane. After surgery, end-tidal anaesthetic concentration was maintained constant for at least 15 min. ⋯ In the fentanyl 1-ng ml-1 group, MAC-awake (0.65 (0.10)% or 0.34 (0.05) MAC) did not differ from that in the control group. Logistic regression analysis showed that increasing plasma concentration of fentanyl and increasing age significantly reduced the MAC-awake of sevoflurane. Because the reduction was very small relative to the overall scatter of the MAC-awake, a low plasma concentration of fentanyl did not significantly reduce the MAC-awake of sevoflurane.
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Randomized Controlled Trial Clinical Trial
Effects of hydrocortisone and adrenaline on natural killer cell activity.
We have studied the effects of hydrocortisone and adrenaline on natural killer (NK) cell activity and on the distribution of circulating lymphocyte subpopulations in 30 patients undergoing elective partial laminectomy under general anaesthesia. The patients were allocated to receive adrenaline (group 1, n = 11), hydrocortisone and adrenaline (group 2, n = 11) or neither hydrocortisone nor adrenaline (group 3, n = 8). Group 1 and group 2 patients received local adrenaline infiltration during operation to reduce bleeding. ⋯ In groups 1 and 3, the CD4/CD8 cell ratio did not change significantly during operation. However, compared with groups 1 and 3, group 2 showed a significantly reduced CD4/CD8 cell ratio during operation. Therefore, these results suggest that even in cases of such severe stress that the immune response was depressed by increased serum cortisol concentrations, adrenaline-induced NK cell activity enhancement was preserved.
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Randomized Controlled Trial Clinical Trial
Ondansetron does not inhibit the analgesic effect of alfentanil.
5-Hydroxytryptamine (5-HT) causes antinociception via presynaptic 5-HT3 (5-HT subtype 3) receptors on primary afferent nociceptive neurones in the spinal cord dorsal horn. Therefore, ondansetron (a 5-HT3 receptor antagonist) may increase the perception of a noxious stimulus or decrease the effects of concurrently administered antinociceptive drugs. Using a randomized, double-blind, crossover study design, we have tested this hypothesis in eight healthy volunteers who, on three different days, received either ondansetron and placebo, ondansetron and alfentanil or placebo and alfentanil. ⋯ Ondansetron alone did not change the response to any of the experimental tests, but alfentanil and the combination ondansetron-alfentanil significantly changed the response compared with ondansetron alone. There was no difference between alfentanil alone and the combination ondansetron-alfentanil. We conclude that ondansetron does not change the response to pressure, heat, cold or electrical nociceptive stimuli or antagonize the analgesic effect of alfentanil.