European journal of pain : EJP
-
Injured sensory axons trapped in a neuroma or freely regenerating in the distal nerve stump, frequently display ectopic mechanosensitivity, spontaneous impulse discharge or both. This abnormal neural activity is thought to contribute to spontaneous and movement-evoked neuropathic paraesthesias, dysaesthesias and pain, as well as to allodynia and hyperalgesia. ⋯ This suggests that mechanosensitivity and spontaneous firing are aspects of a single underlying pathophysiological process. Copyright 1998 European Federation of Chapters of the International Association for the Study of Pain.
-
The study of the mechanisms of thermal and mechanical hyperalgesia produced in human inflammatory conditions is dependent on a reliable, consistent model. The present investigation shows that the intraplantar administration of zymosan in the rat hindpaw produces a reliable and quantifiable thermal and mechanical hyperalgesia accompanied by oedema that closely mimics the symptoms of inflammation in man. Prior to the intraplantar injection of zymosan, there was no significant difference in withdrawal latencies, mechanical withdrawal thresholds or paw thickness between the left and right hindpaws. ⋯ In addition, at the greatest dose tested (6.25 mg), all rats showed evidence of licking, biting and shaking of the injected hindpaw for up to 30-45 min after injection. These data demonstrate that the intraplantar injection of zymosan is a reliable and quantifiable model of tonic pain characterized by a dose- and time-dependent thermal and mechanical hyperalgesia accompanied by a robust oedema. This model is likely to be a useful, reliable model in which to study further the central and peripheral mechanisms of hyperalgesia.
-
Randomized Controlled Trial Clinical Trial
Comparison of topical anaesthesia methods for venous cannulation in adults.
A prospective, randomized clinical trial was performed in order to assess the efficacy and side-effects of commonly used topical anaesthesia methods in adults receiving peripheral venous cannulation. The study was double-blinded to the degree that the methodologies allowed. One hundred and fifty healthy adults undergoing elective surgery were allocated at random to five groups: EMLA cream, ethyl chloride spray, intracutaneous infiltration with 2% lidocaine, placebo cream and no treatment. ⋯ Spray did not significantly lower puncture pain (26.5) and, in addition, was associated with discomfort (10.5). In adults, EMLA cream significantly reduces puncture pain and represents an acceptable alternate method for topical anaesthesia in venous cannulation. Local lidocaine infiltration is impaired by applicational pain, whereas spraying the puncture site with ethyl chloride has no analgesic benefit.
-
Randomized Controlled Trial Clinical Trial
Multidisciplinary rehabilitation for chronic back pain in an outpatient setting: a controlled randomized trial.
Based on existing models for pain chronicity and effective treatment strategies for patients with chronic low back pain, a multidisciplinary rehabilitation programme for an outpatient group setting was developed. The main treatment components address the patient's physical functional capacity (functional restoring), cognitive and affective processes (pain management strategies), and behavioural and ergonomical aspects (back school elements). Short-term (immediately after intervention) and long-term effects (at 6-months follow-up) of the intervention were assessed in a randomized controlled study. ⋯ In contrast to post-treatment results, there were also significant improvements in strength and endurance. Overall results testify to the effectiveness of the intervention programme. Future studies (with larger sample sizes) should aim at a further improvement of functional capacity and disability perception, an analysis of differential treatment effects, and strategies for an improved long-term maintenance of the changes induced by the programme.
-
Patients with complex regional pain syndrome (CRPS) (n=20) were examined in order to evaluate cutaneous reactions to norepinephrine (NE) on both the affected and the unaffected limb in comparison to healthy controls. Sixteen female and four male patients suffering from very acute and therefore untreated CRPS with a mean duration of 5.5 weeks were included in this study. Two groups of healthy volunteers served as control groups: the first group (n=18) according to the same study protocol as CRPS patients, and the second group (n=10) after warming up one limb. ⋯ The second control group had an increased unilateral skin temperature after warming up (35.0 vs 34.3 degrees C, p<0.006) and demonstrated a significantly increased vasoconstriction on the warmer side (52.0 vs 20.2%, p<0.03) corresponding to findings in patients with acute CRPS. The present study proves that there are signs of decreased sympathetic activity in the affected limb in very acute CRPS. However, no indication was found for increased sensitivity of vascular alpha-receptors in the very acute stages of CRPS, and there was also no indication for a significant direct contribution of the sympathetic nervous system to pain in very acute CRPS.