Pain
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Meta Analysis Comparative Study
A comparison of placebo effects in clinical analgesic trials versus studies of placebo analgesia.
A previous meta-analysis of clinical analgesic trial studies showed generally low magnitudes of placebo analgesia (N. Engl. J. ⋯ This difference as well as differences in effect sizes within studies of placebo mechanisms may be parsimoniously explained by differences in expected pain levels produced by placebo suggestions and by conditioning. Furthermore, some of the studies of placebo analgesic mechanisms indicate that the magnitude of placebo analgesia is higher when the placebo analgesic effect is induced via suggestion combined with conditioning than via suggestion alone or conditioning alone. Based on these findings, we suggest that placebo analgesic effects are most optimally conceptualized in terms of perception of the placebo agent, and therefore a new definition of placebo response is proposed.
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Randomized Controlled Trial Comparative Study Clinical Trial
The effect of high and low frequency electroacupuncture in pain after lower abdominal surgery.
In the present study, we examined the effects of preoperative electroacupuncture (EA) at classical bilateral acupuncture points (Zusanli, also known as ST-36) on postoperative pain and opioid-related side effects. One hundred healthy consenting women undergoing lower abdominal surgery were randomly assigned to four treatment regimens: Group I (n=25), control; Group II (n=25), sham-EA (needle insertion without electrical stimulation); Group III (n=25), low-EA (2 Hz of electrical stimulation); and Group IV (n=25), high-EA (100 Hz of electrical stimulation). EA groups received needle insertion with or without electrical stimulation 20 min prior to anesthesia. ⋯ The incidence of nausea and dizziness during the first 24h after surgery was significantly reduced in both the low-EA and high-EA groups compared with the control and sham-EA groups. We also found that sham-EA exerts a beneficial effect with respect to its pain relieving quality but not the side effect profiles. Our findings demonstrates that preoperative treatment with low-EA and high-EA can reduce postoperative analgesic requirements and associated side effects in patients undergoing lower abdominal surgery.
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Comparative Study
Patient-related barriers to pain management: the Barriers Questionnaire II (BQ-II).
Patients' beliefs can act as barriers to optimal management of cancer pain. The Barriers Questionnaire (BQ) is a tool used to evaluate such barriers. Here, the BQ has been revised to reflect changes in pain management practices, resulting in the Barriers Questionnaire-II (BQ-II), a 27-item, self report instrument. ⋯ BQ-II scores were related to measures of pain intensity and duration, mood, and QOL. Patients who used adequate analgesics for their levels of pain had lower scores on the BQ-II than did patients who used inadequate analgesics. The BQ-II is a reliable and valid measure of patient-related barriers to cancer pain management.
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Comparative Study
Catastrophizing is related to pain ratings, but not nociceptive flexion reflex threshold.
Catastrophizing is reliably associated with increased reports of clinical and experimental pain. To test the hypothesis that catastrophizing may heighten pain experience by increasing nociceptive transmission through spinal gating mechanisms, the present study examined catastrophizing as a predictor of pain ratings and nociceptive flexion reflex (NFR) thresholds in 88 young adult men (n=47) and women (n=41). The NFR threshold was defined as the intensity of electrocutaneous sural nerve stimulation required to elicit a withdrawal response from the biceps femoris muscle of the ipsilateral leg. ⋯ Pain catastrophizing was assessed using the catastrophizing subscale of the coping strategies questionnaire (CSQ). Although catastrophizing was positively related to both NRS and SF-MPQ pain ratings, catastrophizing was not significantly related to NFR threshold. These findings suggest that differential modulation of spinal nociceptive input may not account for the relationship between catastrophizing and increased pain.
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Spinal prostaglandin synthesis has been implicated in acute pain processes and in generation and maintenance of central sensitization, and intrathecal injection of cyclo-oxygenase (COX) inhibitors produce antinociception and reduce hypersensitivity in animals. We herein report a Phase I safety assessment of intrathecal injection of the COX inhibitor, ketorolac, in healthy volunteers, and demonstrate no serious side effects. Preclinical studies suggest a major site of action of COX inhibitors for analgesia lies in the central nervous system, especially the spinal cord. ⋯ One subject had a mild headache 24h after study, resolving the next day. There were no long-term side effects 6 months after study. These data suggest that intrathecal ketorolac does not produce a high incidence of serious adverse events, and they support further investigation for analgesia.