Pain
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Randomized Controlled Trial Clinical Trial
A double-blind comparison between epidural morphine and epidural clonidine in patients with chronic non-cancer pain.
In a randomised double-blind study of 20 patients with chronic pain, epidural morphine 5 mg in 5 ml of saline was compared with epidural clonidine 150 micrograms in 5 ml of saline. Thirteen patients had a clinical and radiological diagnosis of arachnoiditis, 6 had low back pain and 1 had post-operative scar pain. There were 18 females and 2 males with an average age of 52 years, range 22-76 years. ⋯ Clonidine was associated with sedation and a fall in blood pressure of greater than 20 mm Hg in all patients, 1 patient required ephedrine to treat hypotension. Twelve patients had pruritus, 7 nausea and 2 vomiting following the morphine. Statistically there was no difference found between morphine and clonidine for short-term (3 h) analgesia in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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In rats anaesthetized with urethane, we have investigated the response of neurones in the ventrobasal complex of the thalamus to noxious ischaemia of the tail, and to graded noxious thermal stimulation of the tail before and after ischaemia. In behavioural experiments conscious rats were exposed to the same experimental procedure. After ischaemia the threshold tail temperature required to elicit both a neuronal response and aversive behaviour in conscious rats, to thermal stimulation, was decreased significantly (P less than 0.01 paired t tests). ⋯ Most thalamic neurones responding to noxious thermal stimulation of the tail also increased firing rate during ischaemia. The latency of response of the thalamic neurones to ischaemia was 12.1 +/- 1.8 min and the latency of the behavioural response to the same stimulus was 11.9 +/- 2.1 min. Ventrobasal thalamic neurones, therefore, which responded to noxious thermal stimulation of the tail also responded to noxious ischaemia, and exhibited a neuronal correlate of post-ischaemic hyperalgesia which paralleled behavioural responses closely.
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Comparative Study Clinical Trial Controlled Clinical Trial
Morphine and ibuprofen compared using the cold pressor test.
The analgesic efficacy of single doses of oral morphine sulphate solution (10 mg) and ibuprofen 600 mg was compared in 12 volunteers using a double-blind, double-dummy, placebo-controlled design on the cold pressor experimental pain model. Measurement of pain intensity was made before medication and then at 30, 60, 90, 120 and 180 min; blood samples were taken at these times for measurement of morphine and glucuronide metabolites by radioimmunoassay. Sessions were at least 5 days apart. ⋯ Ibuprofen was statistically indistinguishable from placebo on all three measures of analgesia. Analgesic effect and plasma concentrations of morphine showed significant correlation (P = 0.053). The study confirmed reports of the opiate sensitivity of the cold pressor model, and the apparent insensitivity of the model to non-steroidal anti-inflammatory drugs.
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Comparative Study
Differential utility of medical procedures in the assessment of chronic pain patients.
Physicians are frequently called upon to evaluate patients with chronic pain to (1) establish the etiology, (2) determine the extent of impairment and disability, and (3) prescribe treatment. In many cases, there is little agreement as to what evaluation procedures should be used or how to weight and integrate these findings. Two studies were conducted to determine the domain of procedures pain specialists believe are most important in evaluation and the clinical utility of each. ⋯ The relevance of each of these procedures in the assessment of 100 pain patients was evaluated. Differential weights for each procedure derived from the survey were highly correlated with clinical practice. The results of the present studies provide a basis for development of a standardized assessment procedure that incorporates statistically derived weights to quantify medical findings.
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Comparative Study
Cluster headache pain vs. other vascular headache pain: differences revealed with two approaches to the McGill Pain Questionnaire.
We compared cluster headache pain and other vascular (migraine and mixed) headache pain on pain intensity ratings and the McGill Pain Questionnaire (MPQ). Cluster headache sufferers reported not only more intense pain and more affective distress, but also different pain qualities than did migraine and mixed headache sufferers. The pain qualities that best distinguished cluster headaches from other vascular headaches were the presence of punctate pressure and thermal sensations and the absence of dull pain. ⋯ This finding may have occurred because MPQ subscale scores include an intensity component and do not provide information about specific pain qualities such as that provided by MPQ sensory items. These findings provide evidence that cluster headaches are characterized by distinct pain qualities and are not simply a more intense version of the same vascular headache pain experienced by migraine and mixed headache sufferers. They further suggest than when the MPQ is used to assess specific pain qualities, sensory items and not the sensory subscale are the preferred units for analysis.