Volume 3, Issue 1

Background The use of opioids for chronic non-cancer pain (CNCP) remains very controversial. There are a number of randomized controlled trials (RCTs) showing efficacy and safety in the short-term, but long-term data are limited. Methods This article contains 10 case reports (followed to 2011) that were selected from a survey of 84 patients with intractable CNCP treated with opioids and followed every 3 months now for a median of 10 years. The previous published survey of this group reported outcomes of pain severity, adverse effects, pain relief, satisfaction, mood, problematic opioid use, tolerance, physical dependency, functional status, health-related quality of life (HRQL), immune status and sexual function. The outcome measures for that study included a numerical rating scale (NRS) for pain, Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory Interference Scale (BPI-I), the Pain Disability Index (PDI), and for Health Related Quality of Life (HRQL) the Short Form Health Survey 12 version 2 (SF12v2). These selected patient reports were chosen to illustrate some important aspects of the diagnostic categories of CNCP, the opioids and doses used, particular issues (concurrent addiction history, bipolar disorder, and combination therapy), disease-specific and other outcomes (pain severity and relief, adverse effects, mood, function) and duration of follow-up with complex pain problems. Results Opioids were found to be safe and effective in the long-term for these particular patients, as well as in the larger group from which they originate. Most patients in the total sample reported 50% or greater relief and a moderate improvement in disability. Scores for functional status and HRQL were not severely affected (PDI and BPI-I ratings moderate or less and SF12v2 slightly below normative values for age). Problematic use, tolerance, and serious adverse effects including constipation were not major issues. Conclusion These 10 reports of patients with intractable CNCP treated with opioids with some success over many years put a face on some of the participants in the larger survey of 84 suggesting that this approach is effective and safe for some patients over many years. Implications These data may not be generalizable to a larger population of patients with CNCP because of the probable selection of patients who benefit and who do not have intolerable adverse effects.

Background and purpose Fibromyalgia (FM) is a chronic pain syndrome, which affects up to 5% of the general population. The aetiology of FM is unclear. The lack of specific diagnostic laboratory tests or imaging options combined with the severe burden on both patients and society caused by the FM syndrome demands the development of valid instruments able to measure the current health status of the FM patients. The Fibromyalgia Impact Questionnaire (FIQ) is the most widely used of these instruments. Our objective was to translate the Fibromyalgia Impact Questionnaire (FIQ) into Finnish and evaluate its validity in Finnish speaking FM patients. Methods FIQ was translated by two bilingual researchers into the Finnish version (Finn-FIQ) and linked to the categories of International Classification of Functioning, Disability and Health (ICF). Finn-FIQ was administered to 162 patients who had prior fibromyalgia diagnoses M79.0 according to ICD-10 year 2006 version. They also filled in the Health Assessment Questionnaire (HAQ), the Rand 36-item Health Survey (RAND-36), the Beck Depression Inventory IA (BDIIA), the Chronic Pain Acceptance Questionnaire (CPAQ), the International Physical Activity Questionnaire Short Form (IPAQ), and they assessed their general well-being on a 0–100 mm visual analogue scale while attending a clinical check-up visit. Internal consistency was estimated according to Cronbach’s alpha internal consistency. An exploratory factor analysis was performed to identify related items and to show construct validity. Correlation coefficients were calculated by the Spearman method. Results From the 162 participants 153 were female and 9 male, 119 (73%) had an active job or were students, 21 (13%) were unemployed, 16 (10%) were retired and 6 (4%) were on sick leave. The mean age was 47 years. The internal consistency value (95% CI) was 0.90 for the overall Finn-FIQ. The factor analysis performed for construct analysis showed that Finn-FIQ was loaded on 4 factors. These factors were loaded on components of ICF and explained 69% of total variance. Significant correlations were obtained between patients own assessments of general well-being and Finn-FIQ total score ( r = 0.64 [95% CI 0.53–0.73]) and also between Finn-FIQ total score and HAQ total score ( r = 0.56 [95% CI 0.44–0.66]). Finn-FIQ questions had significant correlations with RAND-36 domains. Conclusion Finn-FIQ is a valid and feasible instrument to mirror the functioning of FM patients according to its internal consistency, correlation to general well-being, convergent validity and response rate. It covers the main components of the ICF framework hence reflecting the whole spectrum of functioning. Implications In our study Finn-FIQ was proven as a valid instrument with Finnish speaking FM patients. Original FIQ and other validated translations have already confirmed their place in fibromyalgia research. After this study Finnish fibromyalgia research can be included in those using the best-known instrument in validated form and native language. Current study showed also Finn-FIQ’s ability to measure functioning of the FM patients, and it had good applicability among Finnish speaking patients. Therefore it can be recommended also for monitoring individual FM patients and their functioning for example during different treatment trials.

Background and methods Pain Study Tracking Ongoing Responses for a Year (PainSTORY) is a longitudinal study generating some quantitative and limited qualitative data concerning the experiences of individual patients with non-malignant chronic pain. Research was conducted across 13 European countries and a total of 294 patients completed the full evaluation process over 12 months. Adult patients (>18 years old) scoring >4 on an 11-point numeric pain rating scale (NRS-11) for most days during an average week were eligible. Four waves of interviews (W1–W4) were conducted over 12 months and information was recorded regarding pain levels, the impact of pain, pain treatment and treatment-associated side effects. Results At 3 months, 95% of respondents rated their worst pain level over the past week as ≥4. Most respondents had felt this pain level for ≥1 year, with 47% of patients reporting NRS-11 scores of 8–10 for >2 years. At 12 months, 93% of respondents still rated their worst pain level over the past week as ≥4. The overall net percentage of respondents with ≥4 pain intensity did not change substantially over 12 months of follow up. However, 40% (119/294) of patients felt their current pain level increased and 41% (121/294) felt their current pain level decreased during this time, with just 18% (53/294) of respondents reporting no change (1% of respondents not stated). At 3 months, 30% of respondents reported being managed by a pain specialist within the last 3 months, decreasing to 13% 9–12 months later. Patients were typically taking a combination of prescribed and non-prescribed medications; approximately 10% at W1 and 14% at 12 months were prescribed a strong opioid. Among those whose current pain level decreased over the year, a slightly lower proportion of patients were taking prescription medication (78%) at 12 months than in either the group with no change to their current pain level (85%), or the group whose pain level increased over the 12 month period (87%). Pain negatively affected quality of life, with respondents reporting difficulties with daily activities, including sleeping, walking, family and social interaction. Approximately half of respondents taking prescription medication reported suffering from ‘constipation and associated symptoms’. In spite of no change in pain intensity, 51% of patients were happy with their pain management at W4. Conclusions The heavy individual and societal burden of uncontrolled chronic pain is demonstrated in this study. This silent epidemic has not attracted the focus of attention that it deserves. Despite the significant negative impact on individual quality of life, patients evolve to a position where they believe that chronic pain is inevitable and untreatable. implications It is clear that there is a real need for a coordinated response by healthcare providers and planners across European countries. Minimum standards of care should be developed and implemented at national level. Healthcare professionals and students of these disciplines must be educated to recognise, assess and manage pain within a reasonable timeframe. Patients who are not responding to standard measures must have rapid and easy access to a comprehensive, inter-disciplinary pain service.

Introduction Experimental pain studies can provide unique insight into the dimensions of pain and into individual differences in pain responsiveness by controlling different aspects of pain-eliciting stimuli and pain measures. In experimental pain studies, pain responsiveness can be assessed as pain threshold, pain tolerance or pain ratings. The test-theoretical qualities of these different measures, however, have not yet been completely documented. In the current study, several of these qualities were investigated in a pain experiment applying different algometric techniques. The objective of the study was to investigate the reliability (test–retest) and the convergent validity (correspondence) of the different methods found in the literature of measuring pressure-pain threshold, and the interrelationship between pressure-pain threshold, pressure-pain tolerance, and pressure-pain ratings. Methods Sixty-six healthy female subjects were enrolled in the study. All pressure stimuli were applied by a trained investigator, using a digital algometer with a 1 cm 2 rubber tip. Pressure-pain thresholds were assessed repeatedly on six different body points (i.e. left and right calf one third of total calf muscle length below the popliteal space), the lower back (5 cm left and right from the L3), and left and right forearm (thickest part of brachioradialis muscle). Next, pressure-pain tolerance was measured on the thumbnail of the non-dominant hand, followed by rating affective and sensory components (on visual analogue scales) of a stimulus at tolerance level. Last, affective and sensory ratings were obtained for two pressure intensities. Results With intraclass correlations above .75 for pain responses per body point, test–retest reliability was found to be good. However, values obtained from all first measurements were significantly higher as compared with the two succeeding ones. Convergent validity of pain thresholds across different body points was found to be high for all combinations assessed (Cronbach’s alpha values >.80), but the highest for bilateral similar body parts (>.89). Finally, principal components analysis including measures of threshold, tolerance and pain ratings yielded a three-factor solution that explained 81.9% of the variance: Moderate-level stimulus appraisal & pain tolerance; Pain threshold; Tolerance-level stimulus appraisal . Conclusion and implications Findings of the current study were used to formulate recommendations for future algometric pain studies. Concerning pressure-pain threshold, it is recommended to exclude first measurements for every body point from further analyses, as these measurements were found to be consistently higher compared with the following measurements. Further, no more than two consecutive measurements (after the first measurement) are needed for a reliable mean threshold value per body point. When combining threshold values of several body points into one mean-aggregated threshold value, we suggest to combine bilateral similar points, as convergent validity values were highest for these combinations. The three-factor solution that was found with principal components analyses indicates that pressure-pain threshold, subjective ratings of moderate intensity stimuli, and subjective ratings of the maximum (tolerance) intensity are distinct aspects of pain responsiveness. It is therefore recommended to include a measure of each of these three dimensions of pain when assessing pressure pain responsiveness. Some limitations of our study are discussed.

Introduction Correctly identifying chronic pain patients with posttraumatic stress disorder (PTSD) is important because the comorbidity of a chronic pain condition and PTSD is found to compromise treatment success. In addition, the existence of PTSD is associated with pain sensitisation, elevated levels of pain, and disability. Furthermore, the diagnostic criteria for PTSD has changed dramatically in the last two decades which has had a profound impact on the reported prevalence rates of PTSD in chronic pain samples. To our knowledge, no study has employed the DSM-IV criteria for estimating the prevalence of PTSD in chronic pain patients referred consecutively for multidisciplinary pain rehabilitation. Aim The aim of the present study was to assess the prevalence of significant traumatic stressors and PTSD in chronic pain patients referred consecutively to multidisciplinary pain rehabilitation. We wanted to investigate whether specific pain diagnoses were more related to PTSD than others. Moreover, we investigated the possible association of altered sensory processing (hypersensitivity or hyposensitivity) and PTSD. Methods Data were collected from two Scandinavian multidisciplinary pain centres (Denmark and Finland). All patients referred consecutively were assessed for PTSD and sensitisation at admission. A total of 432 patients were assessed, of which 304 (DK, N =220, female n = 144; FIN, N =84, female n = 44) were admitted and consented to participate. All patients had to be diagnosed with a non-malign chronic pain condition lasting for at least 6 months (median = 6.0 years). The Harvard Trauma Questionnaire was employed to measure PTSD symptoms, using the DSM-IV criteria. To measure altered sensory processing, anaesthetists performed quantitative sensory testing on admission. Patients were asked to report if cold, brush, and pinprick mechanical stimulation resulted in decreased or increased sensation or pain. Results stimulation resulted in decreased or increased sensation or pain. Results : A high prevalence of PTSD was found in both consecutive samples. Using the DSM-IV criteria, 23% fulfilled the criteria for a possible PTSD diagnosis. There were no gender differences in PTSD. The three most reported traumatic events: traffic accidents, serious illness personally or in the family, and the actual loss of someone, were reported as the primary traumatic events by almost 50% of those with PTSD. No particular pain diagnosis was significantly related to PTSD. However, hypersensitivity to cold and hyposensitivity to brush were significantly associated with PTSD. Discussion The prevalence of PTSD in the present study was 23%. Earlier studies finding a lower prevalence rate of PTSD may reflect the use of older diagnostic criteria for PTSD or other estimates, for instance PTSD symptom cut-off scores. Conclusion The study emphasised the importance of screening all chronic pain patients for PTSD at admission for pain rehabilitation, using up to date diagnostic tools. Implications Untreated PTSD may exacerbate or maintain the pain condition and negatively affect outcome of pain rehabilitation.

Pain after total knee arthroplasty (TKA) is difficult to control. A recently developed and increasingly popular method for postoperative analgesia following knee and hip arthroplasty is Local Infiltration Analgesia (LIA) with ropivacaine, ketorolac and epinephrine. This method is considered to have certain advantages, which include administration at the site of traumatized tissue, minimal systemic side effects, faster postoperative mobilization, earlier postoperative discharge from hospital and less opioid consumption. One limitation, which may prevent the widespread use of LIA is the lack of information regarding plasma concentrations of ropivacaine and ketorolac. The aim of this academically initiated study was to detect any toxic or near-toxic plasma concentrations of ropivacaine and ketorolac following LIA after TKA. Methods Forty patients scheduled for primary total knee arthroplasty under spinal anaesthesia, were randomized to receive either local infiltration analgesia with a mixture of ropivacaine 300 mg, ketorolac 30mg and epinephrine or repeated femoral nerve block with ropivacaine in combination with three doses of 10mg intravenous ketorolac according to clinical routine. Plasma concentration of ropivacaine and ketorolac were quantified by liquid chromatography–mass spectrometry (LC–MS). Results The maximal detected ropivacaine plasma level in the LIA group was not statistically higher than in the femoral block group using the Mann–Whitney U -test ( p = 0.08). However, the median concentration in the LIA group was significantly higher than in the femoral block group ( p < 0.0001; Mann–Whitney U -test). The maximal plasma concentrations of ketorolac following administration of 30mg according to the LIA protocol were detected 1 h or 2 h after release of the tourniquet in the LIA group: 152–958 ng/ml (95% CI: 303–512 ng/ml; n = 20). The range of the plasma concentration of ketorolac 2–3 h after injection of a single dose of 10mg was 57–1216 ng/ml (95% CI: 162–420 ng/ml; n = 20). Conclusion During the first 24 h plasma concentration of ropivacaine seems to be lower after repeated femoral block than after LIA. Since the maximal ropivacaine level following LIA is detected around 4–6 h after release of the tourniquet, cardiac monitoring should cover this interval. Regarding ketorolac, our preliminary data indicate that the risk for concentration dependent side effects may be highest during the first hours after release of the tourniquet. Implication Femoral block may be the preferred method for postoperative analgesia in patients with increased risk for cardiac side effects from ropivacaine. Administration of a booster dose of ketorolac shortly after termination of the surgical procedure if LIA was used may result in an increased risk for toxicity.

Background and purpose A growing number of people are using computers. Shoulder and neck pain occur commonly during computer work. Peripheral and central sensitization may play a major role in establishing and maintaining several chronic pain conditions. We have previously reported that a 90 min simulated computer office-work induced substantial pain in the shoulders and neck. We hypothesized that the development of pain during the computer work may be related to sensitization. The aim of the present study was to examine if the 90 min computer work induced deep tissue muscle hyperalgesia manifested as altered pressure pain thresholds (PPTs). Methods Twenty-two subjects with chronic shoulder and neck pain (pain group) and 26 healthy and pain free subjects (reference group) performed a standardized computer office-work task with use of a computer-mouse and with time pressure and high precision demands continuously for 90 min. The pressure pain threshold was measured with a pressure algometer in shoulder and forearm muscles (bilaterally in upper trapezius and extensor carpi radialis), and at sternum, before and 15 min and 30 min after the computer work task. Results The PPTs before starting the computer work were not different between the groups at any of the five locations. In both groups, the PPTs in the active and inactive side of the upper trapezius as well as in the extensor carpi radialis of the forearm operating the computer mouse were significantly reduced after the 90 min computer work compared with the pre-work levels. In the pain group, also the PPT in the inactive resting forearm was significantly reduced. The changes seen in PPTs from pre-to post-work were not significantly different between the groups, except for the inactive resting forearm where the groups exhibited different time course. Conclusion A decrease in pressure pain thresholds of involved muscles suggests that computer office-work can induce deep tissue hyperalgesia within 90 min. The development of pain during the computer work indicates peripheral sensitization as the predominant mechanism. Decreased pressure pain thresholds also in sites distant from pain areas may indicate a contribution from central sensitization in the subjects with chronic shoulder and neck pain. Implications The lasting pain after work and the reduced PPTs both in involved and distant musculature may indicate need for frequent pauses during computer work, especially when performed with time pressure and high precision demands, in order to avoid pain to increase and sustain after work, and thus to prevent the possibility of pain to become chronic.