Pain
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Safe and efficient use of spinal drugs requires neurotoxicologic animal studies before ethical application. We have evaluated the neurotoxicologic interruptions of intrathecal administration of midazolam in rabbits. Eighteen white New Zealand rabbits were randomly assigned into three groups consisting of six rabbits each. ⋯ Light and fluorescence microscopy evaluations were performed on transverse spinal cord sections by a neurohistopathologist in a blind fashion. Midazolam and preservative free midazolam treated rabbits showed significant histologic changes in light and fluorescence microscopy. The histologic and vascular lesions with the use of midazolam and preservative free midazolam suggested neurotoxic effects; thus chronic intrathecal administration of midazolam should be avoided in humans.
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The behaviour of rats with spinal nerve ligation-induced neuropathic pain was studied using tests developed to measure depression and anxiety. Adult male Sprague-Dawley rats were tested with the open field test, elevated plus maze, two compartment test and forced swimming test. Spontaneous motility was measured in a photocell observation box. ⋯ The results were also comparable when rats that developed a high degree of neuropathy were compared with the rats with low degree of neuropathy and the sham operated group. In conclusion, spinal nerve ligation injury of the spinal nerves L5-6 induces mechanical and cold allodynia, but it does not seem to produce general suffering or measurable anxiety to the animals. Furthermore, tests for anxiety and depression were not able to predict which animals were vulnerable to express symptoms of neuropathic pain after nerve injury.
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Multicenter Study Clinical Trial
Anesthesia-based pain services improve the quality of postoperative pain management.
Anesthesia-based pain services are facilitating improvements in the quality of care of surgical patients by developing and directing institution-wide perioperative analgesia programs that include interdisciplinary collaborations. However, the impact of anesthesia-based pain services has not been evaluated in a systematic fashion. This prospective multisite study (n = 23 hospitals) utilized a standardized approach to evaluate the quality of pain care provided to patients who were and who were not cared for by an anesthesia-based pain service. ⋯ Patients who received pain service care reported significantly lower pain intensity scores; had lower levels of pain in the postoperative period; had a lower incidence of pruritus, sedation, and nausea; and experienced significantly less pain than expected. In addition, these patients were more likely to receive patient education about postoperative pain management; were more satisfied with their postoperative pain management; and were discharged sooner from the hospital. The findings from this study demonstrate that the care provided by anesthesia-based pain services has a significant impact on patient outcomes.
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We tested both pain thresholds and pain tolerance in patients with Alzheimer's disease (AD) by means of phasic and tonic noxious stimuli. In the first case, electrical stimulation was used, whereas in the second case arm ischemia was studied. By comparing AD patients with normal subjects of the same age, we found no differences in stimulus detection and pain thresholds, whereas a clearcut increase in pain tolerance was present in AD patients. ⋯ In addition, analysis of the EEG power spectra indicated that patients with low alpha and high delta peaks showed an increase in pain tolerance to both electrical stimulation and ischemia. These findings show that, whereas the sensory-discriminative component of pain is maintained in AD patients, pain tolerance is altered and depends on cognitive and affective factors. Thus, pain tolerance is tightly related to the severity of the disease according to the rule, 'the more severe the MMSE and EEG changes, the higher the tolerance to pain'.
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Comparative Study Clinical Trial
Differential inhibitory effect on human nociceptive skin senses induced by local stimulation of thin cutaneous fibers.
It is known that stimulation of thin cutaneous nerve fibers can induce long lasting analgesia through both supraspinal and segmental mechanisms, the latter often exhibiting restricted receptive fields. On this basis, we recently developed a new method, termed cutaneous field stimulation (CFS), for localized stimulation of A delta and C fibers in the superficial part of the skin. In the present study, we have evaluated the effects of CFS on non-nociceptive and nociceptive skin senses. ⋯ Fabric evoked prickle, was not affected by CFS. Neither homo- nor heterotopical TENS induced any marked analgesic effects. It is concluded that different qualities of nociception can be differentially controlled by CFS.