The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial Multicenter Study
Viscerosomatic facilitation in a subset of IBS patients, an effect mediated by N-methyl-D-aspartate receptors.
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder in which the pathophysiological mechanisms of the pain and hypersensitivity are incompletely understood. IBS patients frequently complain of pain in body regions somatotopically distinct from the gut, suggesting involvement of central hyperalgesic mechanisms. We tested the role of tonic peripheral impulse input by using both repetitive thermal stimuli to the leg and repetitive stimuli to the rectum. Changes in thermal/visceral pain sensitivity after nociceptive thermal/visceral repetitive stimulation were determined. A subset of IBS patients showed enhanced rectal/thermal pain sensitivity after repetitive thermal/rectal stimulation, respectively. IBS patients then received 60 mg dextromethorphan and placebo (diphenhydramine) in a randomized, double-blind, crossover trial. The results showed that 1) a subset of IBS patients had increased visceral/cutaneous hypersensitivity following a series of repetitive nociceptive stimuli and that 2) this increased pain sensitivity was blocked by administration of dextromethorphan. This is the first human study indicating that repetitive stimulation enhances a bidirectional mechanism of secondary hyperalgesia due to viscerosomatic facilitation in IBS patients. These unique findings elucidate mechanisms of somatic hypersensitivity in IBS patients and support an etiologic basis for abnormal N-methyl-D-aspartate receptor mechanisms that may be the target of future therapies for IBS. ⋯ Repetitive stimulation enhances a bidirectional mechanism of secondary hyperalgesia due to viscerosomatic convergence in IBS patients. The findings elucidate unique mechanisms of somatic/visceral hypersensitivity in a subset of IBS patients and further support an etiologic basis for abnormal N-methyl-D-aspartate receptor mechanisms that may be future targets of therapies for IBS.
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Multicenter Study
Pain assessment and intensity in hospitalized children in Canada.
Numerous acute pediatric pain assessment measures exist; however, pain assessment is not consistently performed in hospitalized children. The objective of this study was to determine the nature and frequency of acute pain assessment in Canadian pediatric hospitals and factors influencing it. Pain assessment practices and pain intensity scores documented during a 24-hour period were collected from 3,822 children aged 0 to 18 years hospitalized on 32 inpatient units in 8 Canadian pediatric hospitals. Pain assessment was documented at least once within the 24 hours for 2,615/3,822 (68.4%) children; 1,097 (28.7%) with a pain measure alone, 1,006 (26.3%) using pain narratives alone, and 512 (13.4%) with both a measure and narrative. Twenty-eight percent of assessments were conducted with validated measures. The mean standardized pain intensity score was 2.6/10 (SD 2.8); however, 33% of the children had either moderate (4-6/10) or severe (7-10/10) pain intensity recorded. Children who were older, ventilated, or hospitalized in surgical units were more likely to have a pain assessment score documented. Considerable variability in the nature and frequency of documented pain assessment in Canadian pediatric hospitals was found. These inconsistent practices and significant pain intensity in one-third of children warrant further research and practice change. ⋯ This article presents current pediatric pain assessment practices and data on pain intensity in children in Canadian pediatric hospitals. These results highlight the variability in pain assessment practices and the prevalence of significant pain in hospitalized children, highlighting the need to effectively manage pain in this population.