Pain
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Clinical Trial
Neurophysiological assessment of spinal cord stimulation in failed back surgery syndrome.
Despite good clinical results, the mechanisms of action of spinal cord stimulation (SCS) for the treatment of chronic refractory neuropathic pain have not yet been elucidated. In the present study, the effects of SCS were assessed on various neurophysiological parameters in a series of 20 patients, successfully treated by SCS for mostly unilateral, drug-resistant lower limb pain due to failed back surgery syndrome. Plantar sympathetic skin response (SSR), F-wave and somatosensory-evoked potentials (P40-SEP) to tibial nerve stimulation, H-reflex of soleus muscle, and nociceptive flexion (RIII) reflex to sural nerve stimulation were recorded at the painful lower limb. ⋯ Analgesia induced by SCS mainly correlated with RIII attenuation, supporting a real analgesic efficacy of the procedure. This study showed that SCS is able to inhibit both nociceptive (RIII-reflex) and non-nociceptive (P40-SEP, H-reflex) myelinated sensory afferents at segmental spinal or supraspinal level, and to increase cholinergic sympathetic skin activities (SSR facilitation). Complex modulating effects can be produced by SCS on various neural circuits, including a broad inhibition of both noxious and innocuous sensory information processing.
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Randomized Controlled Trial
Substance misuse treatment for high-risk chronic pain patients on opioid therapy: a randomized trial.
Chronic pain patients who show aberrant drug-related behavior often are discontinued from treatment when they are noncompliant with their use of opioids for pain. The purpose of this study was to conduct a randomized trial in patients who were prescribed opioids for noncancer back pain and who showed risk potential for or demonstration of opioid misuse to see if close monitoring and cognitive behavioral substance misuse counseling could increase overall compliance with opioids. Forty-two patients meeting criteria for high-risk for opioid misuse were randomized to either standard control (High-Risk Control; N=21) or experimental compliance treatment consisting of monthly urine screens, compliance checklists, and individual and group motivational counseling (High-Risk Experimental; N=21). ⋯ Outcomes consisted of the percent with a positive Drug Misuse Index (DMI), which was a composite score of self-reported drug misuse (Prescription Drug Use Questionnaire), physician-reported abuse behavior (Addiction Behavior Checklist), and abnormal urine toxicology results. Significant differences were found between groups with 73.7% of the High-Risk Control patients demonstrating positive scores on the DMI compared with 26.3% from the High-Risk Experimental group and 25.0% from the Low-Risk Controls (p<0.05). The results of this study demonstrate support for the benefits of a brief behavioral intervention in the management of opioid compliance among chronic back pain patient at high-risk for prescription opioid misuse.
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Randomized Controlled Trial Comparative Study
A comparison of the effect of attention training and relaxation on responses to pain.
This study aimed to investigate the efficacy of an attention training technique (ATT) on pain ratings, threshold and tolerance during the cold pressor task. One hundred and three undergraduate students were randomly assigned to receive either threat-alleviating or threat-inducing information about the task. Participants were then re-randomized to receive either ATT or progressive muscle relaxation (PMR). ⋯ These results show that ATT changes the cognitive processes of internal/external focus and hypervigilance towards sensory pain words, but not difficulty disengaging or mindfulness. Although ATT changed threshold, the fact that neither pain ratings nor tolerance was affected suggests that a single, brief session of ATT may not be sufficient to affect broader change. Nonetheless, this study shows that ATT can change cognitive processes thought to be associated with heightened perception of pain and that this changes how quickly pain is registered and is therefore worthy of further investigation.
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Randomized, double-blind, placebo-controlled trials on neuropathic pain treatment are accumulating, so an updated review of the available evidence is needed. Studies were identified using MEDLINE and EMBASE searches. Numbers needed to treat (NNT) and numbers needed to harm (NNH) values were used to compare the efficacy and safety of different treatments for a number of neuropathic pain conditions. ⋯ A large proportion of neuropathic pain patients are left with insufficient pain relief. This fact calls for other treatment options to target chronic neuropathic pain. Large-scale drug trials that aim to identify possible subgroups of patients who are likely to respond to specific drugs are needed to test the hypothesis that a mechanism-based classification may help improve treatment of the individual patients.
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Pain measurement is a prerequisite for individualized pain management and research into pain interventions. There is a need for reliable and valid pain measures for young children with burns. The aim of this study was to investigate whether the pain observation scale for young children (POCIS), the COMFORT behaviour scale (COMFORT-B) and the nurse observational visual analogue scale (VAS obs) are reliable, valid and clinically useful instruments to measure pain in children with burns aged 0-5years. ⋯ Nurses found POCIS easier and quicker to use, but COMFORT-B was found to indicate pain more accurately. Both POCIS and COMFORT-B are reliable, valid and practical scales for pain measurement in young children with burns and can be used in practice and research. The VAS obs was found to be unreliable.