Chronic pain: an update on burden, best practices, and new advances

Importance Harms and benefits of opioids for chronic noncancer pain remain unclear. Objective To systematically review randomized clinical trials (RCTs) of opioids for chronic noncancer pain. Data Sources and Study Selection The databases of CENTRAL, CINAHL, EMBASE, MEDLINE, AMED, and PsycINFO were searched from inception to April 2018 for RCTs of opioids for chronic noncancer pain vs any nonopioid control. Data Extraction and Synthesis Paired reviewers independently extracted data. The analyses used random-effects models and the Grading of Recommendations Assessment, Development and Evaluation to rate the quality of the evidence. Main Outcomes and Measures The primary outcomes were pain intensity (score range, 0-10 cm on a visual analog scale for pain; lower is better and the minimally important difference [MID] is 1 cm), physical functioning (score range, 0-100 points on the 36-item Short Form physical component score [SF-36 PCS]; higher is better and the MID is 5 points), and incidence of vomiting. Results Ninety-six RCTs including 26 169 participants (61% female; median age, 58 years [interquartile range, 51-61 years]) were included. Of the included studies, there were 25 trials of neuropathic pain, 32 trials of nociceptive pain, 33 trials of central sensitization (pain present in the absence of tissue damage), and 6 trials of mixed types of pain. Compared with placebo, opioid use was associated with reduced pain (weighted mean difference [WMD], −0.69 cm [95% CI, −0.82 to −0.56 cm] on a 10-cm visual analog scale for pain; modeled risk difference for achieving the MID, 11.9% [95% CI, 9.7% to 14.1%]), improved physical functioning (WMD, 2.04 points [95% CI, 1.41 to 2.68 points] on the 100-point SF-36 PCS; modeled risk difference for achieving the MID, 8.5% [95% CI, 5.9% to 11.2%]), and increased vomiting (5.9% with opioids vs 2.3% with placebo for trials that excluded patients with adverse events during a run-in period). Low- to moderate-quality evidence suggested similar associations of opioids with improvements in pain and physical functioning compared with nonsteroidal anti-inflammatory drugs (pain: WMD, −0.60 cm [95% CI, −1.54 to 0.34 cm]; physical functioning: WMD, −0.90 points [95% CI, −2.69 to 0.89 points]), tricyclic antidepressants (pain: WMD, −0.13 cm [95% CI, −0.99 to 0.74 cm]; physical functioning: WMD, −5.31 points [95% CI, −13.77 to 3.14 points]), and anticonvulsants (pain: WMD, −0.90 cm [95% CI, −1.65 to −0.14 cm]; physical functioning: WMD, 0.45 points [95% CI, −5.77 to 6.66 points]). Conclusions and Relevance In this meta-analysis of RCTs of patients with chronic noncancer pain, evidence from high-quality studies showed that opioid use was associated with statistically significant but small improvements in pain and physical functioning, and increased risk of vomiting compared with placebo. Comparisons of opioids with nonopioid alternatives suggested that the benefit for pain and functioning may be similar, although the evidence was from studies of only low to moderate quality.

/pdf/opioids-for-chronic-noncancer-pain-a-systematic-review-and-1daniukrfr.pdf

Opioids for Chronic Noncancer Pain: A Systematic Review and Meta-analysis.

Nociplastic pain: towards an understanding of prevalent pain conditions

https://vbn.aau.dk/ws/files/315348987/1_s2.0_S1526590018304565_main.pdf

Exercise-Induced Hypoalgesia in Pain-Free and Chronic Pain Populations: State of the Art and Future Directions

Fibromyalgia is characterized by chronic widespread pain, fatigue, sleep disturbances and functional symptoms. The etiopathogenesis, diagnostic criteria and classification criteria of fibromyalgia are still debated and, consequently, so are the strategies for treating this condition. Fibromyalgia is the third most frequent musculoskeletal condition, and its prevalence increases with age. However, although diagnosis has improved with the evolution of more accurate diagnostic criteria, a considerable proportion of physicians still fail to recognize the syndrome. Many factors contribute to the development of fibromyalgia in a unique manner: genetic predisposition, personal experiences, emotional-cognitive factors, the mind-body relationship and a biopsychological ability to cope with stress. The multiple components of the pathogenesis and maintenance of the condition necessitate a multi-modal treatment approach. Individually tailored treatment is an important consideration, with the increasing recognition that different fibromyalgia subgroups exist with different clinical characteristics. Consequently, although an evidence-based approach to fibromyalgia management is always desirable, the approach of physicians is inevitably empirical, and must have the aim of creating a strong alliance with the patient and formulating shared, realistic treatment goals.

Fibromyalgia: an update on clinical characteristics, aetiopathogenesis and treatment

Objective The original European League Against Rheumatism recommendations for managing fibromyalgia assessed evidence up to 2005. The paucity of studies meant that most recommendations were ‘expert opinion’.

Methods A multidisciplinary group from 12 countries assessed evidence with a focus on systematic reviews and meta-analyses concerned with pharmacological/non-pharmacological management for fibromyalgia. A review, in May 2015, identified eligible publications and key outcomes assessed were pain, fatigue, sleep and daily functioning. The Grading of Recommendations Assessment, Development and Evaluation system was used for making recommendations.

Results 2979 titles were identified: from these 275 full papers were selected for review and 107 reviews (and/or meta-analyses) evaluated as eligible. Based on meta-analyses, the only ‘strong for’ therapy-based recommendation in the guidelines was exercise. Based on expert opinion, a graduated approach, the following four main stages are suggested underpinned by shared decision-making with patients. Initial management should involve patient education and focus on non-pharmacological therapies. In case of non-response, further therapies (all of which were evaluated as ‘weak for’ based on meta-analyses) should be tailored to the specific needs of the individual and may involve psychological therapies (for mood disorders and unhelpful coping strategies), pharmacotherapy (for severe pain or sleep disturbance) and/or a multimodal rehabilitation programme (for severe disability).

Conclusions These recommendations are underpinned by high-quality reviews and meta-analyses. The size of effect for most treatments is relatively modest. We propose research priorities clarifying who will benefit from specific interventions, their effect in combination and organisation of healthcare systems to optimise outcome.

https://ard.bmj.com/content/annrheumdis/76/2/318.full.pdf

S. Makri

Papers

EULAR revised recommendations for the management of fibromyalgia