Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Quantitative sensory testing and human surgery: effects of analgesic management on postoperative neuroplasticity.
Altered central nervous system sensory processing (neuroplasticity) is a basic mechanism underlying postoperative pain that can be made visible using quantitative sensory testing. Using quantitative sensory testing, the authors investigated how perioperative analgesia affects postoperative neuroplasticity and how this relates to clinical pain measures. ⋯ Without analgesia, neuroplasticity after surgery was inhibitory the first 24 h and followed at 5 days by excitation. Fentanyl efficiently preempted this hyperalgesia, but hyperalgesia was greater with ketorolac than with placebo. Clinical pain measures neither reflected the different effects of ketorolac and fentanyl on postoperative neuroplasticity nor permitted prediction of postoperative neuroplasticity. The information obtained by perioperative quantitative sensory testing is separate from and additional to that from clinical pain measures and may enable more mechanism-based approaches to surgical analgesia management in the future.
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Comparative Study
Spinal adrenergic and cholinergic receptor interactions activated by clonidine in postincisional pain.
Previous pharmacologic and molecular studies suggest that the alpha(2)-adrenoceptor subtype A is the target for spinally administered alpha(2)-adrenergic agonists, i.e., clonidine, for pain relief. However, intrathecally administered alpha(2) C antisense oligodeoxynucleotide was recently reported to decrease antinociception induced by clonidine in the rat, suggesting non-A sites may be important as well. The current study sought to determine the subtype of alpha(2) adrenoceptors activated by clonidine in a rodent model for human postoperative pain, and to examine its interaction with spinal cholinergic receptors. ⋯ Both alpha(2) A and alpha(2) non-A adrenoceptors, as well as spinal cholinergic activation, are important to the antihypersensitivity effect of clonidine after surgery. ST91 is more efficacious in this model than clonidine and relies entirely on alpha(2) non-A adrenoceptors.
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Outpatient knee surgery has come to involve increasingly complex procedures. The authors present observational data from a nerve block algorithm designed for the care of outpatients undergoing knee surgery. The aim of this report is to demonstrate differences in pain and unplanned hospital admission associated with surgical complexity and nerve blocks used. ⋯ For complex knee surgery, the use of FSB was associated with less pain; the use of FNB or FSB (vs. no block) was associated with fewer hospital admissions.