Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Postoperative analgesia by intra-articular neostigmine in patients undergoing knee arthroscopy.
Recently, the spinal administration of neostigmine was shown to produce a dose-dependent analgesia. However, this analgesia is limited by adverse effects. The purpose of this study was to examine the analgesic action of peripheral muscarinic receptors by administering intra-articular neostigmine after operation in patients undergoing knee arthroscopy. ⋯ Intra-articular injection of the acetylcholinesterase inhibitor neostigmine produced a moderate but significant analgesic effect. Several mechanisms such as the hyperpolarization of neurons, reduction in the release of pronociceptive neurotransmitters, or activation of the nitric oxide-cyclic guanosine monophosphate pathway might mediate this peripheral cholinergic antinociception by elevating endogenous acetylcholine.
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Randomized Controlled Trial Comparative Study Clinical Trial
The dose-response relation of intrathecal fentanyl for labor analgesia.
This study determined the dose-response relation of intrathecal fentanyl for labor analgesia and described the onset, duration, and quality of analgesia when used as the sole analgesic. ⋯ Intrathecal fentanyl produces rapid, profound labor analgesia with minimal side effects. These data indicate that there is little benefit to increasing the dose beyond 25 microg when it is used as the sole agent for intrathecal labor analgesia.
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Clinical Trial Controlled Clinical Trial
Susceptibility to upper airway obstruction during partial neuromuscular block.
Airway obstruction after anesthesia may be caused or exaggerated by residual neuromuscular block, with loss of muscle support for collapsible upper airway structures. ⋯ Neuromuscular block with a TOF ratio of 50% can be present yet clinically difficult to detect in patients recovering from anesthesia. This degree of block has no effect on airway patency in volunteers, even during challenge. Airway obstruction during recovery from anesthesia thus is more likely to be caused by residual effects of general anesthetic agents or centrally acting analgesics, either alone or perhaps in concert with residual neuromuscular block.
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Comparative Study
Effects of intravenous anesthetics on normal and passively sensitized human isolated airway smooth muscle.
General anesthetics may modify airway responsiveness. The authors investigated the effect of thiopental, propofol, and etomidate on airway smooth muscle. ⋯ Whereas thiopental contracts human isolated bronchi, propofol and etomidate reduce histamine-induced contraction in human isolated airway smooth muscle that were either not sensitized or passively sensitized with asthmatic serum. This effect involves inhibition of both electro- and pharmacomechanical coupling.