Pain
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Clinical Trial
Ultrasound guided, painful electrical stimulation of lumbar facet joint structures: an experimental model of acute low back pain.
Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental model of lumbar facet joint pain. ⋯ Electrical facet joint stimulation induced low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low back pain and demonstrate that generalized hyperalgesia did not develop within minutes of acute low back pain.
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Morphine is widely used to treat moderate to severe postoperative pain. The goal of this study was to characterize the pharmacodynamics of morphine-induced analgesia during intravenous morphine titration in the immediate postoperative period and to evaluate sedation occurrence according to morphine dose in this setting. Two hundred and twenty-eight patients undergoing major orthopedic surgery were included. ⋯ Logistic regression showed that a morphine dose of 20 mg was associated with a high likelihood of sedation occurrence. Our study supported the possibility of modeling the time course of a complex response in the absence of pharmacokinetic data. The current data should lead to a more rational management of the immediate postoperative pain.
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The Multidimensional Pain Inventory (MPI) is one of the most widely used instruments to assess patients' coping with chronic pain. It provides a psychosocial classification system that categorizes patients into three coping styles: Adaptive, Dysfunctional, and Interpersonally Distressed. To date, comprehensive information about the validity of the MPI taxonomy obtained from informants other than the patient has been unavailable. ⋯ Results revealed that partner- and provider-reported MPI ratings corresponded with the self-report patient profiles. The profiles of patients showing classification stability rather than switching of cluster assignment between the two MPI assessments had the highest correspondence with proxy ratings. These results extend prior validity research on the MPI and demonstrate that differential psychological adaptational styles to chronic pain can be reliably recognized by partners and healthcare providers.
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Randomized Controlled Trial
The effect of local anaesthetic on age-related capsaicin-induced mechanical hyperalgesia--a randomised, controlled study.
Adults over 65 years exhibit a prolonged punctate hyperalgesia induced by topical application of capsaicin. The aim of this study was to investigate the role of peripheral afferent input in the slowed resolution of punctate hyperalgesia in older people. Twenty young (25.7+/-4.8 years) and 19 old (74.9+/-4.4 years) healthy adults were recruited, and subjects in each age group were randomly assigned to receive either EMLA cream (a local anaesthetic) (n=10 in each age group) or Sorbolene treatment (n=9 in the older group, n=10 in the young group) after the development of punctate hyperalgesia. ⋯ Stoicism and cautiousness measured with Pain Attitude Questionnaire were negatively correlated with highest pain rating in the young, but not in the older groups. We suggest that the prolonged punctate hyperalgesia in older adults is possibly sustained by central mechanisms, indicating age differences in central plasticity following acute injury. The relationship between such age-related changes and the chronicity of pain in older adults should be further explored.