Pain
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Randomized Controlled Trial Clinical Trial
Auricular acupuncture for pain relief after total hip arthroplasty - a randomized controlled study.
Auricular acupuncture (AA) is known to be effective in treatment of various pain conditions, but still there have been no randomized controlled studies of AA for treatment of acute postoperative pain. Therefore we tested whether AA of specific points is superior to sham acupuncture for complementary analgesia after total hip arthroplasty in a patient-anesthesiologist-evaluator-analyst blinded study. The patients were randomly allocated to receive true AA (lung, shenmen, thalamus and hip points) or sham procedure (4 non-acupuncture points on the auricular helix). ⋯ Pain intensity on VAS-100 and incidence of analgesia-related side effects were similar in both groups. The differences between the groups as regard patients' opinions concerning success of blinding were not significant. Findings from our study demonstrate that AA could be used to reduce postoperative analgesic requirement.
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The aim of this systematic review is to assess the effectiveness of acupuncture as an adjunctive analgesic method to standard anaesthetic procedures for surgery and to determine whether acupuncture has any analgesic-sparing effect. Electronic literature searches for randomised clinical trials (RCTs) of acupuncture during surgery were performed in seven electronic databases. No language restrictions were imposed. ⋯ Strong evidence exists that real acupuncture is not significantly different from placebo acupuncture. For an analgesic-sparing effect of acupuncture, evidence remains inconclusive. In conclusion, this review does not support the use of acupuncture as an adjunct to standard anaesthetic procedures during surgery.
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Neurosteroids are potent blockers of neuronal low-voltage activated (T-type) Ca(2+) channels and potentiators of GABA(A) ligand-gated channels, but their effects in peripheral pain pathways have not been studied previously. To investigate potential analgesic effects and the ion channels involved, we tested the ability of locally injected 5alpha-reduced neurosteroids to modulate peripheral thermal nociception to radiant heat in adult rats in vivo and to modulate GABA(A) and T-type Ca(2+) channels in vitro. The steroid anesthetic alphaxalone (ALPX), the endogenous neurosteroid allopregnanolone (3alpha5alphaP), and a related compound ((3alpha,5alpha,17beta)-3-hydroxyandrostane-17-carbonitrile, (ACN)), induced potent, dose-dependent, enantioselective anti-nociception in vivo and modulation of both T-type Ca(2+) currents and GABA(A)-mediated currents in vitro. ⋯ These results strongly suggest that GABA(A) channels do not contribute to baseline pain transmission, but they can enhance anti-nociception mediated by blockade of T-type Ca(2+) channels. In conclusion, we demonstrate that potent peripheral analgesia induced by 5alpha-reduced neurosteroid is mediated in part by effects on T-type Ca(2+) channels. Our results also reveal a role of GABA-gated ion channels in peripheral nociceptive signaling.
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The nociceptive flexion reflex (NFR) is a polysynaptic withdrawal reflex that occurs in response to painful stimulation. In human studies, NFR responsiveness has been used as a direct measure of nociception as well as an indirect measure of supraspinal modulation of nociceptive transmission. Previous studies have suggested that anxiety may influence NFR responding, and therefore it has been recommended that anxiety be reduced by familiarizing participants with assessment methodology prior to formal NFR assessment. ⋯ Within each assessment session, state anxiety was measured at the beginning of the session and immediately following each NFR threshold assessment. Results indicated that although anxiety increased in response to NFR threshold assessment and was positively related to subjective pain reports, anxiety was not related to observed NFR threshold levels. These findings suggest that individual differences in anxiety do not significantly affect NFR threshold level determinations under standard testing conditions.
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Central neuropathic pain is well known in multiple sclerosis (MS), but the underlying mechanisms are unclear. In the present study we studied sensory function in MS patients with pain, MS patients without pain and healthy subjects in order to clarify the role of sensory abnormalities in pain. Fifty MS patients with pain were randomly recruited from a previous epidemiological MS study in Aarhus County, Denmark. ⋯ Central pain patients did not differ from musculoskeletal pain patients in quantitative sensory testing, but allodynia was more common in MS patients with central pain. Pain patients scored lower in all dimensions of SF-36 compared with pain-free patients and healthy subjects. The results suggest that pain in MS is central in more than half of the patients and is associated with mechanical or thermal hyperalgesia.