The journal of pain : official journal of the American Pain Society
-
Randomized Controlled Trial Multicenter Study
Physician characteristics and variation in treatment outcomes: are better qualified and experienced physicians more successful in treating patients with chronic pain with acupuncture?
The aim of this paper was to quantify the influence of the physician's training and experience in the field of acupuncture on the outcome in patients with chronic pain. Patients visiting their physician because of chronic low back pain, headache, pain due to osteoarthritis of the knee or hip, or neck pain, were included in 4 multicenter, randomized, controlled studies. All patients received routine care; patients in the acupuncture groups received additional acupuncture treatment (on average 10 sessions). The data was pooled, and the 3-month change from baseline of the SF-36 bodily pain subscale as the main outcome defined. A total of 9,990 patients (mean age 49.6 +/- 13.6 years, 68% female) treated by 2,781 physicians (mean age 46.3 +/- 7 years, 37% female) were analyzed. The physicians had 7.3 +/- 5.2 (mean +/- sd) years of experience in acupuncture and their mean duration of formal acupuncture training had been 287 +/- 321 hours. The outcome was markedly improved in the acupuncture group. We identified only 1 physician characteristic with a significant influence on the outcome: Internists performed better (odds ratio OR = 1.49, confidence interval CI: 1.01;2.18; P = .043); orthopedists worse (OR = .79, CI: .62;1; P = .043) than the average physician. Neither the duration of training nor the duration of experience had any impact on the extent of the acupuncture effect. ⋯ In this analysis, physician characteristics such as training did not influence patients' outcome after acupuncture, suggesting that formal training parameters have only a limited influence on treatment effect. Other skills such as the therapeutic relationship, which are difficult to measure, may probably play a more important role and should be taken into consideration.
-
Randomized Controlled Trial
A randomized, controlled trial of oxycodone versus placebo in patients with postherpetic neuralgia and painful diabetic neuropathy treated with pregabalin.
The aim of this randomized double-blind, placebo-controlled, parallel-group study was to evaluate the efficacy, safety, and tolerability of pregabalin in combination with oxycodone or placebo, in patients with either postherpetic neuralgia (PHN) or painful diabetic neuropathy (PDN). After a 7-day washout period, 62 patients were randomized to receive either oxycodone mixture 10 mg/day or placebo mixture for 1 week. Patients were then started on open-label pregabalin (75, 150, 300 and 600 mg/day) according to a forced titration dosing regimen, while continuing the same dosage of oxycodone or placebo for 4 weeks. The primary efficacy measure was a decrease in the pain-intensity score of at least 2cm and a pain score <4cm measured using a 10-cm visual analogue scale (VAS) following pregabalin dosage escalation and treatment for 4 weeks. Secondary efficacy measures included sleep interference and the Neuropathic Pain Scale. There were similar levels of overall efficacy between pregabalin/oxycodone and pregabalin/placebo groups in relieving PHN and PDN related pain. ⋯ Peripheral neuropathic pain presents commonly in clinical practice, and 2 of its most prevalent types are PHN and PDN. Currently available treatments provide some degree of pain relief in approximately 40-60% of patients, leaving the remainder with unremitting pain. Although this study supports the effectiveness of pregabalin in the treatment of PHN or PDN, it also shows that the addition of a low dose of oxycodone at 10mg/day does not enhance the pain-relieving effects of pregabalin.
-
Altered function of endogenous pain modulation has been proposed as a mechanism that may underlie chronic pain conditions. Descending modulation of pain can be examined by diffuse noxious inhibitory controls (DNIC). DNIC comprises a spinal-medullary-spinal pathway that is activated when 2 concomitant painful stimuli are applied at the same time. This pain-inhibitory system can be easily triggered in an experimental setting. Therefore, studies on DNIC can help us to evaluate impairments in descending pain modulation, presumably primarily of inhibitory nature. This review summarizes recent findings on human DNIC trials with a specific focus on sex, age, and ethnic differences in DNIC effects and psychological mediators such as attention, expectation, and pain catastrophizing. Furthermore, the clinical relevance of DNIC studies will be discussed. Different methodological approaches used make it difficult to generalize results, but the research to date has shown good potential for DNIC to help in gaining insights in the underlying mechanisms of chronic pain conditions. ⋯ Recent literature on diffuse noxious inhibitory controls as a model of endogenous pain modulation in clinical pain syndromes was reviewed. DNIC may help to identify patients at risk for development of chronic pain and may open alternatives for treatment options.
-
Fatiguing exercise can affect muscle pain sensitivity and muscle hardness, as seen with work-related neck and shoulder pain. Objective methods to assess muscle pain sensitivity are important because the reliability of manual assessment is generally poor. The aim of this study was (1) to compare coexistence of tender points identified by manual palpation and pressure algometry or hardness assessments and (2) to examine the influence of exercise on muscle pain sensitivity and hardness. Fourteen sites in the upper trapezius muscle were selected for assessments in 12 healthy subjects. Pressure pain thresholds and muscle hardness were examined by computer-controlled pressure algometry at baseline, immediately after static or dynamic exercise, and 20 minutes after static or dynamic exercise. Before recording of pressure pain thresholds, the trapezius muscle was examined for tender points by manual palpation. Two sites with low pressure pain thresholds were typical locations for tender points, and these were the least hard sites. However, manually detected tender points were often (29%) not colocalized with most sensitive sites according to the pressure algometry. A heterogeneous distribution of pressure pain sensitivity and muscle hardness was found in the upper trapezius. The short duration of exercise until exhaustion did not change muscle sensitivity or muscle hardness in asymptomatic muscles. ⋯ This study confirms clinical findings with heterogeniosity in pain sensitivity and hardness across the upper trapezius muscle. Developments of new techniques that objectively can identify tender points are important, but thus far, manual palpation is best clinical practice.