Pain
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Practice Guideline Guideline
External validation of IASP diagnostic criteria for Complex Regional Pain Syndrome and proposed research diagnostic criteria. International Association for the Study of Pain.
Recent work in our research consortium has raised internal validity concerns regarding the current IASP criteria for Complex Regional Pain Syndrome (CRPS), suggesting problems with inadequate sensitivity and specificity. The current study explored the external validity of these IASP criteria for CRPS. A standardized evaluation of signs and symptoms of CRPS was conducted by study physicians in 117 patients meeting IASP criteria for CRPS, and 43 patients experiencing neuropathic pain with established non-CRPS etiology (e.g. diabetic neuropathy, post-herpetic neuralgia). ⋯ A decision rule, requiring at least two sign categories and four symptom categories to be positive optimized diagnostic efficiency, with a diagnosis of CRPS likely to be accurate in up to 84% of cases, and a diagnosis of non-CRPS neuropathic pain likely to be accurate in up to 88% of cases. These results indicate that the current IASP criteria for CRPS have inadequate specificity and are likely to lead to overdiagnosis. Proposed modifications to these criteria substantially improve their external validity and merit further evaluation.
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Randomized Controlled Trial Clinical Trial
Relief of postoperative pain with jaw relaxation, music and their combination.
The aim of this randomized controlled trial was to determine the effect of jaw relaxation, music and the combination of relaxation and music on postoperative pain after major abdominal surgery during ambulation and rest on postoperative days 1 and 2. Opioid medication provided for pain, following abdominal surgery, does not always give sufficient relief and can cause undesired side effects. Thus, additional interventions such as music and relaxation may provide more complete relief. ⋯ At post ambulation those using relaxation did not have significantly less pain than the controls on both days and those using music did not on day 1, although there were some univariate effects. A corresponding significant decrease in mastery of the interventions from pre to post ambulation suggests the need for reminders to focus on the intervention during this increased activity. Physicians and nurses preparing patients for surgery and caring for them afterward, should encourage patients to use relaxation and music as adjuvants to medication for postoperative pain.
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Comparative Study
A comparison of diffuse noxious inhibitory controls in men and women.
Results from clinical and experimental pain studies provide consistent evidence of sex differences in pain perception, with women reporting more clinical pain and demonstrating lower pain threshold and tolerance levels than men. The present study was designed to assess the notion that sex differences in pain perception may be related to differential activation of supraspinal pain modulation systems. ⋯ Application of forearm ischemia was associated with a significant decrease in nociceptive flexion reflex activity in both men and women, however, the degree of attenuation of nociceptive flexion reflex activity was not significantly different between the sexes. These findings suggest that men and women exhibit similar activation of diffuse noxious inhibitory controls, but they do not exclude the possibility of sex differences in other forms of central pain modulation.
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According to the cognitive-behavioral model of chronic pain, patient beliefs about their chronic pain influence their behavioral and psychological functioning. Previous correlational and longitudinal studies have supported this hypothesis. However, since previous research has relied almost exclusively on patient self-report to assess both beliefs and functioning, shared method variance may explain some of the relationships found. ⋯ Measures of patient beliefs were more strongly associated with self-report measures of pain behaviors and functioning than with spouse and observer ratings of patient pain behaviors. However, significant associations between patient beliefs and both spouse- and observer-reported frequency of patient pain behaviors were found. These findings argue for the generalizability of the relationship found between patient beliefs and patient behaviors across assessment domains, and for the continued application of the cognitive-behavioral model to the understanding of patient adjustment to chronic pain.
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The present study was designed to evaluate the oral efficacy and bioavailability of ketamine. Antinociceptive efficacy was determined with the rat formalin test and oral bioavailability by the measurement of plasma and brain concentrations of ketamine and its major metabolite, norketamine. Oral ketamine in a dose range from 30 to 180 mg/kg or saline was given prior to intraplantar formalin and the flinching behavior was measured. ⋯ Competition binding assays for the [3H]MK-801-labeled non-competitive site of the N-methyl-D-aspartate receptor (NMDA) receptor revealed that both norketamine and ketamine displaced [3H]MK-801 at low micromolar concentrations with Ki values of 2.5 and 0.3 mM in the forebrain, and 4.2 and 1.0 mM in the spinal cord, respectively. Spinal norketamine was approximately equipotent to ketamine in producing antinociceptive effects during phase 2 of the formalin test. Thus, norketamine appears to contribute to the antinociceptive effects of oral ketamine through its NMDA receptor antagonist activity.