Anesthesiology
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The authors investigated whether the sedative, or hypnotic, action of the general anesthetic dexmedetomidine (a selective alpha -adrenoceptor agonist) activates endogenous nonrapid eye movement (NREM) sleep-promoting pathways. ⋯ The authors propose that endogenous sleep pathways are causally involved in dexmedetomidine-induced sedation; dexmedetomidine's sedative mechanism involves inhibition of the LC, which disinhibits VLPO firing. The increased release of GABA at the terminals of the VLPO inhibits TMN firing, which is required for the sedative response.
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Activation of peripheral excitatory amino acid receptors decreases the duration of local anesthesia.
Postsurgical wound infiltration with the -methyl-d-aspartate receptor antagonist ketamine and bupivacaine can significantly prolong the duration of local anesthesia. One possible mechanism for this effect is that increased glutamate concentrations, caused by tissue damage, sensitize nociceptive primary afferent fibers through activation of peripheral excitatory amino acid receptors. ⋯ These results suggest that shortened lidocaine block durations observed after glutamate injection into the masseter muscle result from sensitization of afferent fibers as well as increases of peak extracellular water content and blood flow in masseter muscle. These effects of glutamate are mediated in part through activation of peripheral excitatory amino acid receptors.
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Randomized Controlled Trial Comparative Study Clinical Trial
Antiemetic prophylaxis for office-based surgery: are the 5-HT3 receptor antagonists beneficial?
Office-based surgery has become increasingly popular because of its cost-saving potential. However, the occurrence of postoperative nausea and vomiting (PONV) can delay patient discharge. Prophylaxis using a combination of antiemetic drugs has been suggested as an effective strategy for minimizing PONV. The authors designed this randomized, double-blinded, placebo-controlled study to assess the efficacy of ondansetron and dolasetron when administered in combination with droperidol and dexamethasone for routine antiemetic prophylaxis against PONV in the office-based surgery setting. ⋯ The addition of dolasetron (12.5 mg) or ondansetron (4 mg) failed to improve the antiemetic efficacy of droperidol (0.625 mg intravenous) and dexamethasone (4 mg intravenous) when they were used for routine prophylaxis in the office-based surgery setting.
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Randomized Controlled Trial Clinical Trial
Antinociceptive effect of low-dose intrathecal neostigmine combined with intrathecal morphine following gynecologic surgery.
The purpose of this study was to determine whether combination of 1-5 microg intrathecal neostigmine would enhance analgesia from a fixed intrathecal dose of morphine. ⋯ The addition of 1-5 microg spinal neostigmine to 100 microg morphine doubled the duration to first rescue analgesic in the population studied and decreased the analgesic consumption in 24 h, without increasing the incidence of adverse effects. The data suggest that low-dose spinal neostigmine may improve morphine analgesia.