Intravenous lidocaine in the management of chronic peripheral neuropathic pain: a randomized-controlled trial.

PURPOSE: Neuropathic pain, resulting from injury to the peripheral or central nervous system, is due to upregulation of aberrant sodium channels with neuronal hyperexcitability. Lidocaine blocks these channels and several studies show that intravenous (IV) lidocaine infusion provides significant relief in patients with chronic peripheral neuropathic pain in the short term (for up to six hours). Our objective was to determine if IV lidocaine provides significant pain relief and overall improvement in quality of life in the longer term (for up to four weeks). METHODS: This single site randomized double-blind, crossover trial compared IV lidocaine infusion (5 mg·kg-1) with active placebo infusion containing diphenhydramine (50 mg) in patients with chronic neuropathic pain of peripheral nerve origin of at least six months duration. The primary outcome was average pain intensity reduction from IV lidocaine relative to placebo at four weeks post-infusion. Secondary outcome measures included parameters of physical function, mood, and overall quality of life. RESULTS: We enrolled 34 subjects in this trial-mostly with painful diabetic neuropathy and post-herpetic neuralgia. There were no significant differences between IV lidocaine and placebo infusions at any time point involving any of the outcome measures. Mean (standard deviation) pain intensity at week 4 for the placebo and lidocaine groups were not different [6.58 (1.97) vs 6.78 (1.56), respectively; between-group difference, 0.17; 95% confidence interval, - 0.50 to 0.84]. CONCLUSION: We found no significant long-term analgesic or quality of life benefit from IV lidocaine relative to control infusion for chronic peripheral neuropathic pain. TRIAL REGISTRATION: clinicaltrials.gov (NCT01669967); registered 22 June, 2012.

RéSUMé: OBJECTIF: La douleur neuropathique, résultat d'une lésion du système nerveux périphérique ou central, est due à l'augmentation de canaux sodiques aberrants accompagnée d'une hyperexcitabilité neuronale. La lidocaïne bloque ces canaux et plusieurs études ont démontré qu'une perfusion intraveineuse (IV) de lidocaïne offrait un important soulagement à court terme (pour une durée maximale de six heures) aux patients atteints de douleur neuropathique périphérique chronique. Notre objectif était de déterminer si la lidocaïne IV procurait un soulagement significatif de la douleur et une amélioration globale de la qualité de vie à plus long terme (pour une durée maximale de quatre semaines). MéTHODE: Cette étude randomisée croisée à double insu et mono-site a comparé une perfusion de lidocaïne IV (5 mg·kg−1) à une perfusion de placebo actif contenant de la diphenhydramine (50 mg) chez des patients atteints de douleur neuropathique chronique provenant du système nerveux périphérique et durant depuis au moins six mois. Le critère d'évaluation principal était la réduction moyenne de l'intensité de la douleur procurée par la lidocaïne IV par rapport au placebo à quatre semaines post-perfusion. Les critères d'évaluation secondaires comprenaient divers paramètres pour mesurer la capacité physique fonctionnelle, l'humeur et la qualité de vie globale. RéSULTATS: Nous avons recruté 34 patients pour cette étude, la plupart souffrant de neuropathie diabétique douloureuse et de névralgie post-herpétique. Aucune différence significative n'a été observée entre les perfusions de lidocaïne IV et de placebo, quel que soit le point de mesure dans le temps, pour aucun de nos critères d'évaluation. L'intensité de la douleur moyenne (écart type) à la semaine 4 était similaire dans les groupes placebo et lidocaïne [6,58 (1,97) vs 6,78 (1,56), respectivement; différence intergroupe, 0,17; intervalle de confiance 95 %, − 0,50 à 0,84]. CONCLUSION: Nous n'avons trouvé aucun bienfait significatif sur l'analgésie à long terme ou la qualité de vie d'une perfusion de lidocaïne IV par rapport à une perfusion témoin pour soulager la douleur neuropathique périphérique chronique. ENREGISTREMENT DE L'éTUDE: clinicaltrials.gov (NCT01669967); enregistrée le 22 juin 2012.

Pain medicine--a new credential in Canada.

OBJECTIVE: In 2010, Pain Medicine was formally recognized as a subspecialty in Canada by the Royal College of Physicians and Surgeons of Canada, a national organization with oversight of the medical education of specialists in Canada. The first trainees began their training at the Western University, London, Canada in July, 2014. This article traces the process of Pain Medicine's development as a discipline in Canada and outlines its multiple entry routes, 2-year curriculum, and assessment procedures. DESIGN: The application for specialty status was initiated in 2007 with the understanding that while Anesthesiology would be the parent specialty, the curriculum would train clinicians in a multidisciplinary setting. To receive recognition as a Royal College subspecialty, Pain Medicine had to successfully pass through three phases, each stage requiring formal approval by the Committee on Specialties. The multiple entry routes to this 2-year subspecialty program are described in this article as are the objectives of training, the curriculum, assessment of competency and the practice-eligibility route to certification. The process of accreditation of new training programs across Canada is also discussed. CONCLUSIONS: The new Pain Medicine training program in Canada will train experts in the prevention, diagnosis, treatment and rehabilitation of the spectrum of acute pain, cancer pain and non-cancer pain problems. These physicians will become leaders in education, research, advocacy and administration of this emerging field.

Long-term quit rates after a perioperative smoking cessation randomized controlled trial.

BACKGROUND: While surgery and perioperative smoking cessation interventions may motivate patients to quit smoking in the short term, it is unknown how often this translates into permanent cessation. In this study, we sought to determine the rates of long-term smoking cessation after a perioperative smoking cessation intervention and predictors of successful cessation at 1 year. METHODS: We previously reported short-term results from a perioperative randomized controlled trial comparing usual care with an intervention involving (1) brief counseling by the preadmission nurse, (2) smoking cessation brochures, (3) referral to a telephone quitline, and (4) a free 6-week supply of transdermal nicotine replacement. We now report our 1-year follow-up outcomes. RESULTS: Between October 2010 and April 2012, 168 patients were randomized. At 1 year, 127 patients (76%) were available for follow-up telephone interview. Smoking cessation occurred in 8% of control patients compared with 25% of patients in the intervention group (relative risk, 3.0; 95% confidence interval [CI], 1.2-7.8; P = 0.018). The number needed-to-treat to achieve smoking cessation for 1 patient at 1 year postoperatively was 5.9 (95% CI, 3.4-25.9). Multivariable logistic regression modeling found that the intervention (P = 0.020) and lower nicotine dependency at baseline (P < 0.001) were predictive of success at smoking cessation at 1 year. Poisson regression showed that adjusted for nicotine dependency, those randomized to the intervention group were 2.7 times (95% CI, 1.1-6.7; P = 0.028) more likely to achieve long-term cessation than those in the control group. Adjusted for randomization group, a low level of nicotine dependency resulted in a relative risk of quitting of 5.1 (95% CI, 2.0-12.8; P = 0.001). CONCLUSIONS: This study demonstrates that an intervention designed for a busy preadmission clinic results in decreased smoking rates not only around the time of surgery but also continued benefit in smoking cessation at 1 year. Perioperative care providers have a unique opportunity to assist patients in smoking cessation and achieve long-lasting results.

Physical Functioning and Opioid use in Patients with Neuropathic Pain.

OBJECTIVE: To evaluate the association between opioid dosage and ongoing therapy with physical function and disability in patients with neuropathic pain (NeP). DESIGN: Secondary analysis of a prospective cohort. SETTING: Multicenter clinical NeP registry. SUBJECTS: Seven hundred eighty-nine patients treated for various NeP diagnoses. METHODS: The following measures were included: dependent variables. 12-month self-reported physical function (pain disability index [PDI] and medical outcomes study short form-12 physical function [PCSS-12]); independent variables: baseline opioid dose (none, ≤200 mg and >200 mg of morphine equivalent), ongoing opioid use; potential confounding variables: age, sex, baseline pain intensity, and psychological distress (profile of mood states). Analysis of covariance models was created to examine the relationship between opioid therapy and both physical functioning outcomes with adjustment for confounding. RESULTS: Complete data was available for 535 patients (68%). Compared with the lower and high dose opioid groups, NeP patients not taking opioids had statistically lower disability and higher physical functioning scores, after adjusting for disease severity. Compared with patients prescribed opioid therapy on an ongoing basis, NeP patients who were not prescribed had statistically lower disability and higher physical functioning scores, after adjusting for disease severity. Improvements in disability and physical functioning scores from baseline and 12-months in all groups were modest and may not be clinically significant. CONCLUSIONS: Physical functioning and disability did not improve in patients with NeP who were prescribed opioids compared with those who are not prescribed, even after adjusting for disease severity.

Perspectives on the Royal College of Physicians and Surgeons of Canada new subspecialty program in pain medicine.

PURPOSE: This article describes the rationale for the creation of pain medicine as a subspecialty in Canada and outlines a brief history of its development. PRINCIPAL FINDINGS: For pain medicine to be designated a Royal College subspecialty, it had to meet three requirements: offer sufficient scientific breadth and depth, prove a clearly identifiable unique field of practice, and show a societal need. The application process for subspecialty status was initiated in 2007, and it is anticipated that the first trainees in pain medicine will start their training in July 2014. This article outlines the variety of Royal College subspecialty entry routes as well as the proposed training objectives, curriculum, assessment of competency, practice-eligibility route to certification, and accreditation of training programs across Canada. CONCLUSION: With the inception of this subspecialty, the treatment of acute pain, cancer pain, and chronic non-cancer pain will be further integrated within the Canadian healthcare system.

Use of near infrared spectroscopy to detect impaired tissue oxygen saturation in patients with complex regional pain syndrome type 1.

PURPOSE: Deep tissue hypoxia has been hypothesized in the pathogenesis of complex regional pain syndrome type 1 (CRPS 1) for some patients. The purpose of this study was to determine if near-infrared spectroscopy (NIRS) could detect differences in deep tissue oxygen saturation (StO2) and microcirculatory function in the hands of patients with CRPS 1. METHODS: Tissue oxygen saturation was evaluated at baseline and during an ischemia reperfusion challenge using vascular occlusion testing (VOT) in affected vs unaffected hands of patients with unilateral upper limb CRPS 1. A non-randomized experimental study design was used with baseline StO2 as the primary outcome measure. Secondary outcome measures were occlusion and reperfusion slopes from VOT. Values were compared with the unaffected, contralateral hand and with the dominant and non-dominant hands of sex and age-matched volunteers. Correlations between values derived from NIRS and measures of pain and function from the Brief Pain Inventory (BPI) and the Disability of the Arm, Shoulder and Hand (DASH) questionnaires were explored. RESULTS: Independent of handedness, the baseline StO2 of the affected hands of ten CRPS 1 patients was significantly lower than that of their unaffected hands (-5.8%; 95% confidence interval [CI] -10.6 to -1.0; P = 0.02). The baseline StO2 of affected CRPS 1 hands was also significantly lower than the non-dominant hands of ten volunteers (-7.3%; 95% CI -12.4 to -2.3; P = 0.007). Differences in VOT occlusion and reperfusion slopes did not reveal changes that could be uniquely attributed to CRPS 1. No significant correlations were detected between values derived from VOT and values for pain and function obtained from BPI and DASH questionnaires for patients with CRPS 1. CONCLUSIONS: Hands of patients affected by CRPS 1 of the upper limb showed significantly lower StO2 compared with their unaffected contralateral hand as well as the hands of control subjects. This trial was registered at: ClinicalTrials.gov: NCT01586377.

The effectiveness of a perioperative smoking cessation program: a randomized clinical trial.

BACKGROUND: Cigarette smoking by surgical patients is associated with increased complications, particularly perioperative respiratory problems and poor wound healing. In this study, we sought to determine whether a pragmatic perioperative smoking cessation intervention designed for a busy preadmission clinic would be successful in reducing smoking rates and intraoperative and immediate postoperative complications. METHODS: This randomized controlled trial was conducted at a university-affiliated hospital in London, Ontario, Canada. Patients seen in the preadmission clinic at least 3 weeks preoperatively were randomized to either the control group (84 patients) or the intervention group (84 patients). The control group received no specific smoking cessation intervention. The intervention group received (1) brief counseling by the preadmission nurse, (2) brochures on smoking cessation, (3) referral to the Canadian Cancer Society's Smokers' Helpline, and (4) a free 6-week supply of transdermal nicotine replacement therapy. All outcome assessors and caregivers on the operative day were blinded to group assignment. The primary outcome was the rate of smoking cessation as confirmed by exhaled carbon monoxide breath test. Secondary outcomes included perioperative complications and smoking status at 30 days postoperatively. RESULTS: Between October 2010 and April 2012, 168 patients were recruited into the study. Smoking cessation occurred in 12 patients (14.3%) in the intervention group as compared with 3 patients (3.6%) in the control group (relative risk 4.0; 95% confidence interval [CI], 1.2-13.7; P = 0.03). The overall rate of combined intraoperative and immediate postoperative complications was not significantly different between intervention and control groups (13.1% and 16.7%, respectively; relative risk 0.79; 95% CI, 0.38-1.63; P = 0.67). At follow-up 30 days postoperatively, smoking cessation was reported in 22 patients (28.6%) in the intervention group compared with 8 patients (11%) in controls (relative risk 2.6; 95% CI, 1.2-5.5; P = 0.008). CONCLUSIONS: One of the objections to widespread use of smoking cessation interventions in the preadmission clinic is that it is too labor-intensive. The results of this study show that a smoking cessation intervention, designed to minimize additional use of physician or nursing time, results in decreased smoking rates on the day of surgery and promotes abstinence 30 days postoperatively.

Ultra low-dose naloxone and tramadol/acetaminophen in elderly patients undergoing joint replacement surgery: a pilot study.

OBJECTIVE: A pilot study was conducted to assess whether both the rationale and feasibility exist for future randomized clinical trials to evaluate the combined use of naloxone infusion and tramadol/acetaminophen as opioid-sparing drugs in elderly patients undergoing lower extremity joint replacement surgery. DESIGN: Ten patients 70 years of age or older undergoing either total knee (n=7) or total hip (n=3) arthroplasty were treated prospectively. Each patient received two tablets of tramadol/acetaminophen (Tramacet; Janssen-Ortho Inc, Canada) preoperatively and every 6 h postoperatively, as well as a naloxone infusion started preoperatively at 0.25 microg/kg/h and continued up to 48 h postoperatively. In addition, standard intraoperative care was provided with 0.2 mg of intrathecal morphine, 1.4 mL of 0.75% bupivacaine, and an intra-articular infiltration of 100 mL of 0.3% ropivacaine and 30 mg of ketorolac, as well as standard postoperative morphine via patient-controlled analgesia orders and celecoxib 200 mg twice daily for five days. OUTCOME MEASURES: Compared with seven historical controls, also 70 years of age or older, who had undergone either a total knee (n=4) or total hip (n=3) arthroplasty, postoperative opioid use was reduced by 80%. Except for transient nausea and vomiting in 40% and 20% of patients, respectively, the 10 patients on tramadol/acetaminophen and naloxone tolerated the new regimen without difficulty. CONCLUSION: Consequently, a randomized, double-blinded clinical trial comparing standard therapy versus standard therapy plus these two drugs seems warranted. In such a trial, it would require approximately 20 subjects per treatment arm to detect a 80% decrease in morphine use.

Operant Learning Versus Energy Conservation Activity Pacing Treatments in a Sample of Patients With Fibromyalgia Syndrome: A Pilot Randomized Controlled Trial.

This study's aim was to assess the efficacy of 2 forms of activity pacing in patients with fibromyalgia syndrome (FMS). Treatment-related changes in activity management patterns were also examined. Patients with FMS (n = 178) were randomly assigned to an operant learning (OL; delayed [n = 36] or immediate [n = 54] groups) or an energy conservation (EC; delayed [n = 35] or immediate [n = 53] groups) treatment condition. Of these, 32 OL and 37 EC patients completed treatment. Forty-three patients were allocated to the delayed treatment condition (control group). Repeated measures analyses of variance were used to examine the effects of OL and EC treatments on primary (average pain and usual fatigue), secondary (pain and fatigue interference, physical and psychological function, sleep quality, depressive symptoms, and anxiety symptoms), and tertiary (pain-related activity patterns) outcomes. Neither treatment was effective in reducing average pain or usual fatigue symptoms. Relative to EC, OL patients showed greater improvements in depressive symptoms, whereas nonsignificant trends (P values ranging between .05 and .06) were observed for pain interference, fatigue interference, and psychological function. Both treatments were associated with improvements in sleep quality and physical function, increases in pacing, and decreases in overdoing activity patterns. Reductions in activity avoidance were only found in OL. These findings suggest that OL may be more beneficial than EC and that it could potentially be viewed as an effective stand-alone activity pacing treatment for patients with FMS. Research to determine the extent to which these preliminary findings replicate is warranted. PERSPECTIVE: This article examines the efficacy of 2 forms of activity pacing in patients with fibromyalgia syndrome. The results suggest the possibility that operant learning may be more beneficial than energy conservation and could potentially be viewed as an effective stand-alone activity pacing treatment for patients with fibromyalgia syndrome.

Structural and Functional Brain Changes at Early and Late Stages of Complex Regional Pain Syndrome.

Brain plasticity is demonstrated in complex regional pain syndrome (CRPS), although it is unclear how it modulates at different stages of CRPS. The observation that symptoms can progress over time suggests that the pattern of brain changes might also evolve. We measured structural and functional changes as well as sensorimotor integration at the early stage (ES) and late stage (LS) of CRPS. Twelve ES patients, 16 LS patients, and 16 age- and sex-matched controls were recruited. Gray matter (GM) volume was estimated using voxel-based morphometry. Cerebral perfusion was measured using arterial spin labeling, because it provides a measure of resting neural activity. Connectivity to sensorimotor regions was evaluated using blood-oxygen level-dependent images. The ES group showed reduced GM volume and perfusion in areas associated with spatial body perception, somatosensory cortex, and the limbic system, whereas the LS group exhibited increased perfusion in the motor cortex but no changes in GM volume. However, in the LS group, GM volume in areas associated with pain processing was negatively correlated with average pain levels, likely reflecting a response to ongoing pain. Furthermore, connectivity to sensorimotor cortex showed disruptions in regions associated with motor control and planning, implying impairment of higher-order motor control. PERSPECTIVE: This article presents brain changes at ES and LS of CRPS. We found different patterns of brain changes between these 2 stages. Understanding modulation of brain plasticity at different stages of CRPS could help understand the diversity in outcomes and treatment response and hopefully improve treatment planning.

Sensitivity of the DN4 in Screening for Neuropathic Pain Syndromes.

OBJECTIVES: Several tools have been developed to screen for neuropathic pain. This study examined the sensitivity of the Douleur Neuropathique en 4 Questions (DN4) in screening for various neuropathic pain syndromes. MATERIALS AND METHODS: This prospective observational study was conducted in 7 Canadian academic pain centers between April 2008 and December 2011. All newly admitted patients (n=2199) were approached and 789 eligible participants form the sample for this analysis. Baseline data included demographics, disability, health-related quality of life, and pain characteristics. Diagnosis of probable or definite neuropathic pain was on the basis of history, neurological examination, and ancillary diagnostic tests. RESULTS: The mean age of study participants was 53.5 years and 54.7% were female; 83% (n=652/789) screened positive on the DN4 (≥4/10). The sensitivity was highest for central neuropathic pain (92.5%, n=74/80) and generalized polyneuropathies (92.1%, n=139/151), and lowest for trigeminal neuralgia (69.2%, n=36/52). After controlling for confounders, the sensitivity of the DN4 remained significantly higher for individuals with generalized polyneuropathies (odds ratio [OR]=4.35; 95% confidence interval [CI]: 2.15, 8.81), central neuropathic pain (OR=3.76; 95% CI: 1.56, 9.07), and multifocal polyneuropathies (OR=1.72; 95% CI: 1.03, 2.85) compared with focal neuropathies. DISCUSSION: The DN4 performed well; however, sensitivity varied by syndrome and the lowest sensitivity was found for trigeminal neuralgia. A positive DN4 was associated with greater pain catastrophizing, disability and anxiety/depression, which may be because of disease severity, and/or these scales may reflect magnification of sensory symptoms and findings. Future research should examine how the DN4 could be refined to improve its sensitivity for specific neuropathic pain conditions.

Lower Functional Connectivity of the Periaqueductal Gray Is Related to Negative Affect and Clinical Manifestations of Fibromyalgia.

Fibromyalgia (FM) syndrome is characterized by chronic widespread pain, muscle tenderness and emotional distress. Previous studies found reduced endogenous pain modulation in FM. This deficiency of pain modulation may be related to the attributes of chronic pain and other clinical symptoms experienced in patients with FM. Thus, we tested whether there is a link between the clinical symptoms of FM and functional connectivity (FC) of the periaqueductal gray (PAG), a key node of pain modulation. We acquired resting state 3T functional MRI (rsfMRI) data from 23 female patients with FM and 16 age- and sex- matched healthy controls (HC) and assessed FM symptoms with the Brief Pain Inventory (BPI), Fibromyalgia Impact Questionnaire (FIQ), Hospital Anxiety and Depression Scale (HADS) and Pain Catastrophizing Scale (PCS). We found that patients with FM exhibit statistically significant disruptions in PAG FC, particularly with brain regions implicated in negative affect, self-awareness and saliency. Specifically, we found that, compared to HCs, the FM patients had stronger PAG FC with the lingual gyrus and hippocampus but weaker PAG FC with regions associated with motor/executive functions, the salience (SN) and default mode networks (DMN). The attenuated PAG FC was also negatively correlated with FIQ scores, and positively correlated with the magnification subscale of the PCS. These alterations were correlated with emotional and behavioral symptoms of FM. Our study implicates the PAG as a site of dysfunction contributing to the clinical manifestations and pain in FM.

Brief review: perioperative management of the patient with chronic non-cancer pain.

PURPOSE: Both opioid and non-opioid medications are being utilized increasingly in the treatment of chronic non-cancer pain, and the number of surgical patients receiving large regular doses of opioids is ever-expanding. The perioperative pain control of these patients is often challenging, and is broadening the role of the anesthesiologist as 'perioperative physician'. These patients need to be identified before surgery to plan optimal pain control postoperatively. The purpose of this review is to provide an update on the important considerations in managing the chronic non-cancer pain patient receiving high dose opioids and other adjunctive medications/analgesics. SOURCE: English language articles published between June 1980 and May 2006 were identified by a computerized Medline search using keywords (1/2)chronic pain(1/2), (1/2)opioid dependent(1/2) and (1/2)perioperative(1/2). This same search strategy was repeated and updated using both Medline and Embase. All relevant publications were retrieved and their bibliographies were scanned for additional sources. PRINCIPAL FINDINGS: Although an increasingly common problem for the acute pain service, there is very little published on this topic. Key points include the concept of opioid equivalency, tolerance, the role of adjunctive medications, and the need for good communication between the surgical team, the acute pain service and the patient who is often anxious about the upcoming procedure due to previous unpleasant experiences with poor pain control in hospital. CONCLUSION: Clinical care of the opioid-dependent patient in the perioperative period can be a daunting task. Education to all staff involved in this area needs to be enhanced to improve outcome and patient satisfaction.

Chronic pelvic pain due to peripheral neuropathy: a case report.

BACKGROUND: There are numerous possible causes for chronic pelvic pain. Evaluation of these causes should begin with the least invasive form of assessment. CASE: A 28-year-old woman with chronic pelvic pain underwent an array of investigations and surgical interventions without relief of pain. When she was admitted to hospital because of a flare up of pelvic pain, the chronic pain service was consulted. The presentation of stabbing pain that was reproduced by eliciting focal tenderness over the course of ilioinguinal nerve made nerve entrapment a possible diagnosis. An ilioinguinal nerve block was performed, resulting in resolution of the pain. CONCLUSION: Chronic pelvic pain due to peripheral neuropathy can mimic visceral pain, presenting a diagnostic challenge.

The reciprocal associations between catastrophizing and pain outcomes in patients being treated for neuropathic pain: a cross-lagged panel analysis study.

Catastrophizing is recognized as a key psychosocial factor associated with pain-related negative outcomes in individuals with chronic pain. Longitudinal studies are needed to better understand the temporal relationship between these constructs. The aim of this study was to determine if changes in catastrophizing early in treatment predicted subsequent changes in pain intensity and interference later in treatment, or alternately, if early changes in pain intensity and interference predicted subsequent changes in catastrophizing. A total of 538 patients with neuropathic pain were recruited from 6 multidisciplinary pain clinics across Canada. Study participants were asked to complete measures of catastrophizing, pain intensity, and interference when first seen in the clinic and then again at 3- and 6-month follow-ups. Cross-lagged panel analyses were used to determine the temporal associations among the study variables. The results showed that decreases in catastrophizing early in treatment prospectively predicted improvement in both pain intensity and interference later in treatment. Converse temporal relationships were also found, where a reduction in pain intensity and interference early in treatment predicted a subsequent diminishing of catastrophizing. All 4 unique cross-lagged correlations significantly accounted for an additional 4% to 7% of the total variance. The findings are consistent with theoretical models hypothesizing a causal impact of catastrophizing on pain, suggesting a mutual causation between these factors. The results support that treatments targeting catastrophizing may influence other pain-related outcomes, and conversely that treatments aiming to reduce pain could potentially influence catastrophizing. There may therefore be multiple paths to positive outcomes.

Long-Term Outcome of the Management of Chronic Neuropathic Pain: A Prospective Observational Study.

This prospective observational cohort study addressed the long-term clinical effectiveness of the management of chronic neuropathic noncancer pain at 7 Canadian tertiary pain centers. Patients were treated according to standard guidelines and were followed at 3, 6, 12, 18, and 24 months. Standard outcome measures for pain, mood, quality of life, and overall treatment satisfaction were administered, with the primary outcome measure designated as the composite of 30% reduction in average pain intensity and 1-point decrease in the mean Interference Scale Score (0-10) of the Brief Pain Inventory at 12 months relative to baseline. Of 789 patients recruited, mean age was 53.5 ± 14.2 years (55% female) and mean duration of pain was 4.88 ± 5.82 years. Mean average pain intensity (0-10) at baseline was 6.1 ± 1.9. All standard outcome measures showed statistically significant improvement at 12 months relative to baseline (P < .001). However, only 23.7% attained clinically significant improvement in pain and function at 12 months as the primary outcome measure. Univariable analyses showed poorer outcomes at 12-month follow-up with longer duration of pain (P = .002), greater cigarette use (P = .01), more disability compensation (P = .001), and higher opioid doses at baseline and at 12 months (P < .02). Our present treatment modalities provide significant long-term benefit in only about a quarter of patients with neuropathic pain managed at tertiary care pain clinics. Opioid therapy may not be beneficial for the long term. Perspective: Evidence-based treatment of chronic neuropathic pain provides long-term benefit in only about one-quarter of patients seen in tertiary care centers. Opioid therapy may not be beneficial.

Attitudes toward opioid use for chronic pain: a Canadian physician survey.

OBJECTIVES: To measure chronic pain patient volumes seen in primary care practice; to determine what medications physicians choose for the treatment of moderate to severe chronic pain; to identify barriers to the use of opioids in the treatment of chronic pain; and to assess physicians' attitudes toward the current management of chronic pain in Canada. DESIGN: A computer-assisted telephone survey of 100 regionally representative Canadian physicians with a defined interest in palliative care (PC, n=30) or noncancer pain (GP, n=70). SETTING: A survey was conducted by Ipsos-Reid in June 2001. Only physicians who met the eligibility criteria of having written 20 or more prescriptions for moderate to severe pain in the preceding four weeks or having devoted 20% of time to palliative care were eligible to participate. RESULTS: In one month, the average number of patients with moderate to severe chronic pain seen by PCs was 94.2; the average seen by GPs was 44.7. The pain experienced by 83.3% of GP patients was noncancer related. For chronic cancer pain, an opioid analgesic was the treatment of choice of 79% of physicians (48% preferred morphine, 21% codeine, 10% other). For moderate to severe chronic noncancer pain, opioids were the first-line treatment of only 32% of physicians (16% preferred codeine, 16% major opioids) because a significant number preferred either non-steroidal anti-inflammatory drugs (29%) or acetaminophen (16%). Thirty-five per cent of GPs and 23% of PCs would never use opioids for noncancer pain, even when described as severe. Chronic pain was deemed by 68% of physicians to be inadequately managed. Almost 60% thought that pain management could be enhanced by improved physician education. Identified barriers to opioid use included addiction potential (37%) and side effects (25%). Seventeen per cent of GPs and 10% of PCs thought that regulatory sanctions limited opioid prescribing. CONCLUSIONS: Even among physicians experienced in chronic pain treatment, there is a reluctance to use opioids for severe nonmalignant pain. One-half of the survey participants believed that there was a need for improved physician education in pain management, including the use of opioids.