Pain
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Randomized Controlled Trial Clinical Trial
Effectiveness of oral sucrose and simulated rocking on pain response in preterm neonates.
Feeding and carrying have been interventions used by caregivers throughout history in relieving distress in infants. Recent studies on the food substance sucrose have elucidated the comforting effect of the taste component of feeding while studies of rocking have examined the comforting effect of the vestibular component of carrying. The purpose of this study was to determine the effectiveness of sucrose and simulated rocking alone and in combination on diminishing pain response in preterm neonates undergoing routine heelstick procedure in the neonatal intensive care unit (NICU). ⋯ Although the simulated rocking did promote quiet sleep, which has been reported in earlier studies to blunt pain response, there was no difference between simulated rocking and control groups in either facial expressions indicative of pain or heart rate. The implication of these results is that sucrose, but not simulated rocking may be a means of diminishing pain from minor procedures in preterm infants. Further research is needed on the use of sucrose for more than one procedure as well as examining the contact component of natural rocking, as opposed to simulated rocking.
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Randomized Controlled Trial Clinical Trial
Classical conditioning and the placebo effect.
Stimulus substitution models posit that placebo responses are due to pairings of conditional and unconditional stimuli. Expectancy theory maintains that conditioning trials produce placebo response expectancies, rather than placebo responses, and that the expectancies elicit the responses. ⋯ Verbal information reversed the effect of conditioning trials on both placebo expectancies and placebo responses, and the magnitude of the placebo effect increased significantly over 10 extinction trials. These data disconfirm a stimulus substitution explanation and provide strong support for an expectancy interpretation of the conditioned placebo enhancement produced by these methods.
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Comparative Study Clinical Trial Controlled Clinical Trial
Neuropathic pain and prolonged regional inflammation as two distinct symptomatological components in complex regional pain syndrome with patchy osteoporosis--a pilot study.
To reappraise symptomatology of complex regional pain syndrome (CRPS), we investigated the clinical symptoms of seven patients with CRPS who showed associated patchy osteoporosis. The incidence of moderate to severe spontaneous pain, burning pain, mechanical allodynia was higher in patients with significant nerve injury than in those without. Periarticular tenderness adjacent to osteoporotic bones, abnormalities of blood flow, edema and impairment of motor function were seen in both groups of patients. Our clinical observations of patients with CRPS associated with patchy osteoporosis suggest that CRPS may have the following two distinct components: (1) neuropathic pain that includes severe spontaneous pain or severe persistent mechanical allodynia and (2) prolonged regional inflammation, the early phase of which could be indicated by positive inflammatory symptoms of pain (tenderness), heat, redness, swelling and loss of function and their alleviation with corticosteroids.
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Clinical Trial
The expression of pain in infants and toddlers: developmental changes in facial action.
Age-related changes in the facial expression of pain during the first 18 months of life have important implications for our understanding of pain and pain assessment. We examined facial reactions video recorded during routine immunization injections in 75 infants stratified into 2-, 4-, 6-, 12-, and 18-month age groups. Two facial coding systems differing in the amount of detail extracted were applied to the records. ⋯ Temperament was not related to the degree of pain expressed. Systematic variations in parental soothing behaviour indicated accommodation to the age of the child. Reasons for the differing patterns of facial activity are examined, with attention paid to the development of inhibitory mechanisms and the role of negative emotions such as anger and anxiety.
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The present study found in lightly anesthetized rats that the radiant heat-evoked tail flick (TF) reflex was markedly inhibited by a unilateral electrical stimulation (a 20 ms train of 0.2 ms, 100 Hz, 30-100 microA pulses) of the ventrolateral orbital cortex (VLO), with the tail flick latency (TFL) being increased. The mean threshold of VLO stimulation for producing inhibition of the TF reflex was 39.2 +/- 8.7 microA (n = 26), and this inhibitory effect increased following increasing stimulation intensity from 40 to 70 microA. The inhibition developed and remained during the stimulation and disappeared rapidly after termination of the stimulation. ⋯ The difference was significant between the TFL changes produced by VLO stimulation before and after PAG lesion (P < 0.01). The results suggest that the antinociception elicited by VLO stimulation is mediated by PAG, leading to activation of the brainstem descending inhibitory system which depresses the nociceptive transmission at the spinal level. The role played by VLO in pain modulation was discussed in association with the proposed endogenous analgesic system consisting of spinal cord-Sm-VLO-PAG-spinal cord.