Pain
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Comparative Study
An integrated undergraduate pain curriculum, based on IASP curricula, for six health science faculties.
Pain education, especially for undergraduates, has been identified as important to changing problematic pain practices, yet, no published data were found describing an integrated, interprofessional pain curriculum for undergraduate students. Therefore, this project aimed to develop, implement, and evaluate an integrated pain curriculum, based on the International Association for the Study of Pain curricula [http://www.iasp-pain.org/curropen.html], for 540 students from six Health Science Faculties/Departments. Over an 18-month period, the University of Toronto Centre for the Study of Pain's Interfaculty Pain Education Committee developed a 20-h undergraduate pain curriculum to be delivered during a 1-week period. ⋯ Ratings were highest for the patient-related content and panel, and the small-group discussions with Standardized Patients. Overall evaluations were positive, and statistically significant changes were demonstrated in students' pain knowledge and beliefs. This unique and valuable learning opportunity will be repeated with some modifications next year.
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Comparative Study
Amplitudes of laser evoked potential recorded from primary somatosensory, parasylvian and medial frontal cortex are graded with stimulus intensity.
Intensity encoding of painful stimuli in many brain regions has been suggested by imaging studies which cannot measure electrical activity of the brain directly. We have now examined the effect of laser stimulus intensity (three energy levels) on laser evoked potentials (LEPs) recorded directly from the human primary somatosensory (SI), parasylvian, and medial frontal cortical surfaces through subdural electrodes implanted for surgical treatment of medically intractable epilepsy. LEP N2* (early exogenous/stimulus-related potential) and LEP P2** (later endogenous potential) amplitudes were significantly related to the laser energy levels in all regions, although differences between regions were not significant. ⋯ The lack of correlation of parasylvian cortical N2* with laser energy and pain intensity may be due to the unique anatomy of this region, or the small sample, rather than the lack of activation by the laser. Differences in thresholds of the energy correlation with amplitudes were not significant between regions. These results suggest that both exogenous in endogenous potentials evoked by painful stimuli, and recorded over SI, parasylvian, and medial frontal cortex of awake humans, encode the intensity of painful stimuli and correlate with the pain evoked by painful stimuli.
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Comparative Study
Exaggerated nociceptive responses on morphine withdrawal: roles of protein kinase C epsilon and gamma.
On withdrawal from opioids many patients experience a heightened sensitivity to stimuli and an exaggerated pain response. The phenomenon has been little studied in infants. We present evidence that in postnatal day 7 rats an exaggerated nociceptive ventral root response of spinal cords in vitro and withdrawal-associated thermal hyperalgesia in vivo are dependent on protein kinase C (PKC), and we document the roles of PKC and gamma isozymes. ⋯ In contrast, thermal hyperalgesia during spontaneous withdrawal was inhibited by both PKC and gamma inhibitors. The consistency between the in vivo and in vitro findings with respect to naloxone-precipitated withdrawal provides further evidence that the sVRP reflects nociceptive neurotransmission. In addition the difference between naloxone-precipitated and spontaneous withdrawal in vivo suggests that in postnatal day 7 rats, morphine exposure produces an early phase of primary afferent sensitization dependent upon PKC translocation, followed by a later phase involving spinal sensitization mediated by PKC gamma.
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Comparative Study
Determinants of prescribing meperidine compared to morphine in hospitalized patients.
Morphine is a preferred narcotic since meperidine forms toxic metabolites. Determinants of meperidine use have been poorly described. The objective of this study is to explore factors associated with the ordering of meperidine versus morphine. ⋯ Though meperidine has little role in the routine management of hospital pain, we found it continues to be used frequently. Importantly, meperidine is ordered more frequently for patients who receive shorter courses of narcotics. Our study suggests that interventions targeted at more appropriate use of meperidine rather than complete elimination might be more acceptable to physicians while minimizing the risk of toxicity.
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Comparative Study
Cold and heat pain assessment of the human oesophagus after experimental sensitisation with acid.
The aim of the present study was to investigate the effect of thermal stimulation of the oesophagus before and after sensitisation with acid. In 17 healthy subjects a stimulation bag was used to re-circulate water at 5 and 60 degrees C for up to 90 s in the lower part of the oesophagus. The area under the temperature curve was used to assess the caloric load. ⋯ After sensitisation the words used to describe the sensations to heat pain stimuli shifted from a warmth quality towards a more burning quality in most subjects. This multi-modal sensory testing study showed that acid sensitises the oesophagus to heat but not to cold pain. This may account for the modality-specific symptoms and hypersensitivity reported in patients suffering from, e.g. gastro-oesophageal reflux disease.