Pain
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Comparative Study
Profiles of opioid analgesia in humans after intravenous bolus administration: alfentanil, fentanyl and morphine compared on experimental pain.
This report examines the relationship of plasma drug concentration to analgesic effect following bolus doses of alfentanil, fentanyl and morphine and assesses individual differences in analgesic response among volunteers. We predicted that the 3 opioids would yield disparate analgesic profiles because their physicochemical and pharmacokinetic characteristics differ. Ten healthy volunteers received intravenous bolus doses of either alfentanil, fentanyl, morphine or normal saline on different days. ⋯ Fentanyl exhibited a marked hysteresis. We observed noteworthy individual differences in analgesic response with all 3 drugs but these differences were greatest for morphine and least for alfentanil. Inter- and intrasubject variability in analgesic response across drugs is related to the physicochemical properties of the drugs tested.
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There is currently no classification system for chronic pain patients that has achieved consensus. The lack of a classification that is used consistently across settings has impaired advance of knowledge and treatment of chronic pain patients. Recently, an empirically derived multivariate classification system, the Multiaxial Assessment of Pain (MAP) patients, has been developed. ⋯ These data suggest that the psychosocial and behavioral responses associated with chronic pain are common to diverse samples of pain patients despite differences in demographic characteristics and medical diagnosis. The implications of these results for research and clinical practice are discussed. The potential utility of a polydiagnostic approach using more traditional medically based classifications such as proposed by the IASP (Merskey, H., Pain, Suppl. 3 (1986) S1-S225) complemented by classification based on the MAP psychosocial-behaviorally based taxonomy are examined.
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In order to study the effects of compensation and litigation, 201 chronic pain patients were selected from a sample of 444: 99 were working, 15 were working and litigating, 53 were receiving Worker's Compensation, and 34 were receiving Worker's Compensation and litigating. Employment (working vs. Worker's Compensation) and litigation status (litigating vs. not litigating) were analyzed in a 2 x 2 factorial design with measures of pain, disability, psychological distress, and selected demographics as dependent variables. ⋯ The results indicate clear differences in self-reports of disability associated with both employment and litigation status. They also suggest that litigation may function as a coping response for patients who are distressed by the adversarial nature of the Worker's Compensation system. Limitations of the study as well as suggestions for further research also are discussed.
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An increasing number of chronic pain treatment outcome studies have appeared in the literature. In general, these studies support the efficacy of multidisciplinary pain programs, as well as specific treatment modalities such as biofeedback and relaxation. Reviews of this literature have tended to be cautiously optimistic. ⋯ In this paper 3 rarely discussed topics that are implicit within most treatment outcome studies and that need to be given greater attention are examined. These topics include: (1) referral patterns to pain clinics (who are referred to pain clinics, when, and how representative is the referred sample?); (2) failure to enter treatment (e.g., exclusion criteria, lack of available financial support to cover the cost of treatment, patient's refusal to accept recommendations), and consequently, the representativeness of the treated sample; and (3) patient's attrition. In this paper we discuss each of these factors as they underscore important qualifications that have to be made in evaluating treatment outcome studies.
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Autonomic variables have been recommended as measures of the affective-motivational component of the pain response in objective algesimetry. In the present study components of heart rate responses to painful heat stimuli and their relation to stimulus and sensation variables were analyzed. Twelve healthy subjects served. ⋯ However, differential temporal analysis demonstrates that, until about 3 sec after stimulation, the autonomic response is determined solely by stimulus temperature, whereas, after approximately 6 sec, it is related only to subjective judgement. Accordingly, the heart rate responses reflect both a brief nocifensive reflex induced by the sensory component and, subsequently, a longer-lasting response which seems to be related to affective and/or cognitive evaluation. This separation of different stages of pain-processing by an autonomic indicator may be useful in clinical algesimetry.