Pain
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The present report describes a nation-wide survey on the incidence, the indications and the efficacy of spinal cord stimulation (SCS), as assessed by the Belgian health authorities. The direct motive for this survey was the rapidly growing expenditures resulting from the increasing use of SCS. Between 1983 and 1992, nearly 700 SCS devices were implanted for a population of less than 10 million inhabitants. ⋯ In a third study, the impact of psychiatric screening on patient selection was evaluated. Of the 100 candidates, 36 were withheld from implantation with a SCS device because of psychiatric contra-indications. Patients who had received a positive psychiatric advice showed a significantly better therapeutic outcome than patients for whom the psychiatrist had made reservations.
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Recent studies have suggested that morphine-3-glucuronide (M3G) may antagonize the analgesic effects of morphine and morphine-6-glucuronide (M6G). To investigate this hypothesis, steady-state concentrations of morphine, M6G and M3G in serum and cerebrospinal fluid (CSF) were measured in 11 patients receiving chronic morphine therapy (9 orally and 2 subcutaneously) for treatment of cancer-related pain. All patients appeared to have morphine-resistant pain and had elected to proceed to intrathecal bupivacaine or percutaneous cordotomy. ⋯ The median molar ratios for CSF/serum distribution of morphine, M6G and M3G were 1.23, 0.12 and 0.14, respectively. Thus, despite their relatively poor ability to penetrate into the CSF, the high serum concentrations of M6G and M3G resulted in substantial concentrations of these metabolites in the CSF. Nevertheless, M3G/M6G ratios in our morphine-resistant patients were similar to published values in patients with well-controlled pain, suggesting that the hypothesis that M3G plays a major role in morphine-resistance is not correct.
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Randomized Controlled Trial Clinical Trial
The cold pressor test in children: methodological aspects and the analgesic effect of intraoral sucrose.
To determine whether intraoral sucrose has analgesic-like effects in pre-pubertal children and to explore the utility of an ethical and viable laboratory test of nociceptive stimulation in this age group, 8-11-year-olds (n = 42) underwent the cold pressor test (CPT) at 10 degrees C on each of 2 successive days, while holding either 24% sucrose or water in their months. Outcome measures used were threshold (time at which the arm first started to hurt), tolerance (when children removed their arms because they could not stand it any more) and visual analogue scale (VAS) ratings of the intensity of sensation. To ensure validity of the data obtained in this age group, some responses were rejected according to established decision rules and blind to group assignment. ⋯ Inability to perform adequately on the VAS also occurred, but was not related to age. Holding sucrose in the mouth was associated with a significant 35% prolongation of the children's threshold times relative to water, but there was no detectable effect on tolerance and intensity ratings. It is concluded that the analgesic properties of intraoral sucrose, seen previously in human newborns and rat pups, may also be present in pre-pubertal children.(ABSTRACT TRUNCATED AT 250 WORDS)
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Cryoanalgesia, the technique of freezing peripheral nerves, is used clinically for the treatment of postoperative and chronic pain. Paradoxically, this same technique produces characteristics in a rat model suggestive of neuropathic pain. We have developed a peripheral neuropathy model by freezing the proximal sciatic nerve (sciatic cryoneurolysis, SCN) using a cryoprobe cooled to -60 degrees C in a 30/5/30 sec freeze-thaw-freeze sequence. ⋯ The transient time course of certain behaviors including hypoesthesia and possible return of limb sensation, autotomy, touch-evoked allodynia, foot edema and the presence of spontaneous nociceptive behaviors demonstrate a multiple phase nociceptive process. The temporary nature of these nociceptive behaviors is in sharp contrast to the prolonged bilateral mechanical allodynia evident when these behaviors subside. The surgical anesthetics used during the SCN procedure are shown to variably alter or suppress autotomy following SCN.(ABSTRACT TRUNCATED AT 250 WORDS)