Pain: an overview

Structural brain anomalies and chronic pain: a quantitative meta-analysis of gray matter volume

The diversity of chronic pain syndromes and the methods employed to study them make integrating experimental findings challenging. This study performed coordinate-based meta-analyses using voxel-based morphometry imaging results to examine gray matter volume (GMV) differences between chronic pain patients and healthy controls. There were 12 clusters where GMV was decreased in patients compared with controls, including many regions thought to be part of the "pain matrix" of regions involved in pain perception, but also including many other regions that are not commonly regarded as pain-processing areas. The right hippocampus and parahippocampal gyrus were the only regions noted to have increased GMV in patients. Functional characterizations were implemented using the BrainMap database to determine which behavioral domains were significantly represented in these regions. The most common behavioral domains associated with these regions were cognitive, affective, and perceptual domains. Because many of these regions are not classically connected with pain and because there was such significance in functionality outside of perception, it is proposed that many of these regions are related to the constellation of comorbidities of chronic pain, such as fatigue and cognitive and emotional impairments. Further research into the mechanisms of GMV changes could provide a perspective on these findings.

PERSPECTIVE

Quantitative meta-analyses revealed structural differences between brains of individuals with chronic pain and healthy controls. These differences may be related to comorbidities of chronic pain.

Alexithymia and depression in a chronic pain patient sample

OBJECTIVE

The aim of the present study was to assess the prevalence of alexithymia in a sample of general chronic pain patients, to explore possible differences in depression and pain variables between alexithymic and nonalexithymic chronic pain patients and to analyze if depression is a mediator between alexithymia and pain disability.

METHODS

Two hundred and seventy-one patients making their first visit to a pain clinic completed the study questionnaire including various pain measures, the Beck Depression Inventory-II (BDI-II) and the 20-item Toronto Alexithymia Scale (TAS-20). The sample was dichotomized to alexithymic and nonalexithymic groups. The means of the study variables were compared between the groups. The correlation analysis of the variables was carried out separately in both groups. Path analysis was done to ascertain the mediation effect of BDI-II between the TAS-20 and pain disability.

RESULTS

Every fifth chronic pain patient was alexithymic. The BDI-II and pain variable scores were significantly higher in the alexithymic group than in the nonalexithymic group. Pain variables were not associated with alexithymia when BDI-II was controlled for. BDI-II worked as a full mediator between TAS-20 and pain disability.

CONCLUSION

The alexithymic patient group was more morbid than the nonalexithymic group. The results suggest that depression is the main factor in pain conditions of alexithymic chronic pain patients. The authors recommend screening and treatment of depression in alexithymic chronic pain patients.

Axonal voltage-gated ion channels as pharmacological targets for pain

Upon peripheral nerve injury (caused by trauma or disease process) axons of the dorsal root ganglion (DRG) somatosensory neurons have the ability to sprout and regrow/remyelinate to reinnervate distant target tissue or form a tangled scar mass called a neuroma. This regenerative response can become maladaptive leading to a persistent and debilitating pain state referred to as chronic pain corresponding to the clinical description of neuropathic/chronic inflammatory pain. There is little agreement to what causes peripheral chronic pain other than hyperactivity of the nociceptive DRG neurons which ultimately depends on the function of voltage-gated ion channels. This review focuses on the pharmacological modulators of voltage-gated ion channels known to be present on axonal membrane which represents by far the largest surface of DRG neurons. Blockers of voltage-gated Na(+) channels, openers of voltage-gated K(+) channels and blockers of hyperpolarization-activated cyclic nucleotide-gated channels that were found to reduce neuronal activity were also found to be effective in neuropathic and inflammatory pain states. The isoforms of these channels present on nociceptive axons have limited specificity. The rationale for considering axonal voltage-gated ion channels as targets for pain treatment comes from the accumulating evidence that chronic pain states are associated with a dysregulation of these channels that could alter their specificity and make them more susceptible to pharmacological modulation. This drives the need for further development of subtype-specific voltage-gated ion channels modulators, as well as clinically available neurophysiological techniques for monitoring axonal ion channel function in peripheral nerves.

The role of the emergency department in the acute management of chronic or recurrent pain

BACKGROUND

Exacerbation of chronic pain is a common presenting problem for patients attending emergency departments (EDs), with many making multiple visits.

AIM

This paper aims to identify the role of the ED in the acute management of patients with persistent or chronic nonmalignant pain through a review of current literature.

METHOD

Four databases were searched using the MeSH and subject search terms "chronic nonmalignant pain", "persistent pain" and "emergency" and synonyms associated with these terms. Literature related to the underlying causes of suboptimal chronic pain management along with the sequelae associated with treatment or management was extracted.

RESULTS

Three main themes emerged: patient expectations and satisfaction, barriers to care, and strategies/principles to improve ED management for this patient group. The presence of these themes appears to be partially due to time limitations for chronic issues in an acute department, accompanied by a lack of clear guidelines.

CONCLUSION

It is evident that the ED is not the ideal setting for managing patients with chronic pain however it is the last resort for many who do present, and who will continue to present should their pain persist. It is time to ensure that the ED provides a consistently supportive, cohesive and integrated approach to managing patients with chronic pain syndromes.

Efficacy of a children's procedural preparation and distraction device on healing in acute burn wound care procedures: study protocol for a randomized controlled trial

Background

The intense pain and anxiety triggered by burns and their associated wound care procedures are well established in the literature. Non-pharmacological intervention is a critical component of total pain management protocols and is used as an adjunct to pharmacological analgesia. An example is virtual reality, which has been used effectively to dampen pain intensity and unpleasantness. Possible links or causal relationships between pain/anxiety/stress and burn wound healing have previously not been investigated. The purpose of this study is to investigate these relationships, specifically by determining if a newly developed multi-modal procedural preparation and distraction device (Ditto™) used during acute burn wound care procedures will reduce the pain and anxiety of a child and increase the rate of re-epithelialization.

Methods/design

Children (4 to 12 years) with acute burn injuries presenting for their first dressing change will be randomly assigned to either the (1) Control group (standard distraction) or (2) Ditto™ intervention group (receiving Ditto™, procedural preparation and Ditto™ distraction). It is intended that a minimum of 29 participants will be recruited for each treatment group. Repeated measures of pain intensity, anxiety, stress and healing will be taken at every dressing change until complete wound re-epithelialization. Further data collection will aid in determining patient satisfaction and cost effectiveness of the Ditto™ intervention, as well as its effect on speed of wound re-epithelialization.

Discussion

Results of this study will provide data on whether the disease process can be altered by reducing stress, pain and anxiety in the context of acute burn wounds.

Trial registration

ACTRN12611000913976

Influence of sociodemographic factors upon pain intensity in patients with temporomandibular joint disorders seen in the primary care setting

Objective: A study is made of the influence of gender, educational level, marital status, income, social support, and perceived general and oral health upon pain intensity in a sample of patients with temporomandibular joint disorders (TMJD) explored in primary care (AP). Design: A review was made of 899 patients from Córdoba Healthcare District (Spain) referred to the primary care TMJD Unit by their primary care physician and/or dentist. Of these subjects, 151 failed to meet the inclusion criteria. The remaining 748 subjects were explored according to the corresponding research diagnostic criteria (RDC/TMJD). A bivariate analysis was made the association of pain intensity to the demographic and psychological characteristics of the patients, and to perceived general and oral health, followed by a multivariate linear regression analysis to explain pain intensity as a function of the rest of the variables. The SPSS version 19.0 statistical package was used. Results: The patient age ranged from 18-86 years, with a mean of 45.8 years (± 15.8), and a female predominance of 5:1. The characteristic pain intensity (CPI) score was almost 15 points higher on average in women than in men (p<0.05). A lower educational level, and separation or divorce, were correlated to an increased intensity of pain. Social support, depression and general and oral health also explained part of pain intensity. The regression model established with these variables accounted for 13.3% of the variability of pain (R2 = 0.133). Conclusions: Women suffer more intense pain than men. Perceived health partially explains the variability of the CPI score. However, it is empirically seen that the variables gender, educational level and marital status exert an important and independent influence upon pain intensity.

Key words:Cranial-mandibular disorders, age, gender, educational level, primary care, research diagnostic criteria for temporomandibular joint disorders (RDC/TMD).

Economic burden of chronic pain

Pain represents a major clinical, social and economic problem, with estimates of its prevalence ranging from 8 to over 60%. The impact of pain on economies is enormous, with the cost of back pain alone equivalent to more than a fifth of one country's total health expenditure and 1.5% of its annual gross domestic product, while in another, it represents three-times the total cost of all types of cancer. However, decision makers have tended to concentrate their attention on a very minor component of the cost burden, namely prescription costs, which, in the case of back pain, represent 1% of the total cost burden. In addition to its economic impact, chronic pain is probably one of the diseases with the greatest negative impact on quality of life. For example, the quality of life for those with migraine has been shown to be at best equal to that for people with arthritis, asthma, diabetes mellitus or depression. The burden that pain imposes on individuals and the enormous costs that society has to bear as a result clearly demonstrate the need for collective thinking in the decision-making process. A broad, strategic perspective - based on evidence relating to effectiveness (including tolerability), efficiency and equity - is required in determining issues relating to the provision of services and resource allocation.

Being a botanist and a gardener: using diagnostic frameworks in general practice patients with medically unexplained symptoms

Patients with multiple medically unexplained symptoms commonly seek treatment in primary care. Many of these patients seem to have a psychological 'core' to their illness that affects the way they experience, conceptualise and communicate their distress. There is considerable debate around diagnosis for this group of patients. Existing diagnoses include somatoform disorders in psychiatry and functional disorders in the medical specialties. Some clinicians use the term 'heartsink' patients, which reflects the interpersonal frustration inherent in some therapeutic relationships. A good diagnosis should be clinically useful, helping clinicians and patients understand and manage illness. Diagnosis should also provide a reliable classification for research and evidence-based treatment. The allegory of the botanist and the gardener has been used to describe diagnosis. For the botanist, a good diagnosis produces a taxonomy that is rigorous and reliable. For the gardener, it informs the way a garden is described and understood in a specific context. Clinicians need both: a 'botanical' type of classification to bring rigour to research and therapy, and clinical 'gardening', which allows for multiple perspectives and diagnostic frameworks. Clinical reasoning is a form of research with therapeutic intent. Botany and gardening represent a mixed-methods approach that can enrich diagnosis. The challenge is to integrate multiple perspectives in clinically helpful ways that help us retain both richness and rigour.

Liposomal bupivacaine: a review of a new bupivacaine formulation

Many attempts have been made to increase the duration of local anesthetic action. One avenue of investigation has focused on encapsulating local anesthetics within carrier molecules to increase their residence time at the site of action. This article aims to review the literature surrounding the recently approved formulation of bupivacaine, which consists of bupivacaine loaded in multivesicular liposomes. This preparation increases the duration of local anesthetic action by slow release from the liposome and delays the peak plasma concentration when compared to plain bupivacaine administration. Liposomal bupivacaine has been approved by the US Food and Drug Administration for local infiltration for pain relief after bunionectomy and hemorrhoidectomy. Studies have shown it to be an effective tool for postoperative pain relief with opioid sparing effects and it has also been found to have an acceptable adverse effect profile. Its kinetics are favorable even in patients with moderate hepatic impairment, and it has been found not to delay wound healing after orthopedic surgery. More studies are needed to establish its safety and efficacy for use via intrathecal, epidural, or perineural routes. In conclusion, liposomal bupivacaine is effective for treating postoperative pain when used via local infiltration when compared to placebo with a prolonged duration of action, predictable kinetics, and an acceptable side effect profile. However, more adequately powered trials are needed to establish its superiority over plain bupivacaine.

Pain processing in the human nervous system: a selective review of nociceptive and biobehavioral pathways

This selective review discusses the psychobiological mediation of nociception and pain. Summarizing literature from physiology and neuroscience, first an overview of the neuroanatomic and neurochemical systems underpinning pain perception and modulation is provided. Second, findings from psychological science are used to elucidate cognitive, emotional, and behavioral factors central to the pain experience. This review has implications for clinical practice with patients suffering from chronic pain, and provides strong rationale for assessing and treating pain from a biopsychosocial perspective.

Cost-effectiveness of tapentadol in severe chronic pain in Spain: a cost analysis of data from RCTs

BACKGROUND

Chronic pain is known to be a significant and common health problem. Tapentadol, a recently developed centrally active, oral analgesic agent is used to treat adults with severe chronic pain that can be adequately managed only with opioid analgesics. Tapentadol has been reported to provide an improved adverse-events (AE) profile compared with other potent opioid analgesics at similar levels of analgesia.

OBJECTIVES

The aim of this study was to compare the cost-effectiveness of tapentadol to that of opioids commonly used as first-line treatment of severe, chronic, nonmalignant pain from the perspective of the health care payer in Spain.

METHODS

A Markov state-transition model was developed to compare the cost-effectiveness of first-line treatment with tapentadol to that of oxycodone, morphine, and transdermal fentanyl (TDF) over a 1-year time horizon. Four health states were defined: (1) treatment discontinuation due to a severe AE; (2) treatment discontinuation due to a lack of efficacy; (3) occurrence of an AE that required medical treatment; and (4) no discontinuation and no AE. If a patient discontinued a treatment, he or she was switched to an alternative, second-line opioid. Data regarding efficacy, tolerability, and utility values (EQ-5D) were derived from randomized clinical trials. Clinical experts estimated the rates of switching to other opioids and the health care resource utilization associated with the treatment of severe chronic pain. Unit costs were derived from public price lists/tariff works and were calculated from the perspective of the National Spanish Health System. The robustness of the model results was tested in extensive sensitivity analyses in which event probabilities, costs, utilities, and treatment-switching rates were altered.

RESULTS

Data from 3 studies (1981 patients) were included in the model. Overall, the model predicted that initiating first-line treatment with tapentadol in patients with severe, chronic, nonmalignant pain was associated with lower costs and greater efficacy versus first-line treatment with oxycodone. Compared with morphine and TDF, tapentadol yielded incremental cost-effectiveness ratios of €2656 and €2069 per quality-adjusted life-year gained, respectively. On extensive 1-way and scenario analyses, findings on the cost-effectiveness of tapentadol were consistent. The probability that tapentadol would be cost-effective compared with each comparator at the willingness-to-pay threshold of €20,000 to €30,000/QALY gained exceeded 90%.

CONCLUSIONS

Based on the findings from the present model, tapentadol is likely to be a cost-effective first-line treatment in patients with severe, chronic, nonmalignant pain in Spain according to the commonly accepted willingness-to-pay thresholds. Compared with morphine and TDF, the incremental cost-effectiveness ratios were low; compared with oxycodone, tapentadol dominated, showing better quality-of-life outcomes at lower costs.

Is a positive clinical outcome after exercise therapy for chronic non-specific low back pain contingent upon a corresponding improvement in the targeted aspect(s) of performance? A systematic review

INTRODUCTION

The effect size for exercise therapy in the treatment of chronic non-specific low back pain (cLBP) is only modest. This review aims to analyse the specificity of the effect by examining the relationship between the changes in clinical outcome (pain, disability) and the changes in the targeted aspects of physical function (muscle strength, mobility, muscular endurance) after exercise therapy.

METHODS

We searched for exercise therapy trials for cLBP published up to 15 April 2010 in Medline, Embase, Cochrane Library, Cinahl, and PEDro. Two independent reviewers selected studies according to the inclusion criteria.

DATA EXTRACTION

one author extracted the data of the articles.

RESULTS

DATA SYNTHESIS

16 studies with a total of 1,476 participants met the inclusion criteria. There was little evidence supporting a relationship between the changes in pain or physical function and the changes in performance for the following measures: mobility (no correlation in 9 studies, weak correlation in 1 study), trunk extension strength (7 and 2, respectively), trunk flexion strength (4 and 1, respectively) and back muscle endurance (7 and 0, respectively). Changes in disability showed no correlation with changes in mobility in three studies and a weak correlation in two; for strength, the numbers were four (no correlation) and two (weak correlation), respectively.

CONCLUSIONS

The findings do not support the notion that the treatment effects of exercise therapy in cLBP are directly attributable to changes in the musculoskeletal system. Future research aimed at increasing the effectiveness of exercise therapy in cLBP should explore the coincidental factors influencing symptom improvement.

Motivation and placebos: do different mechanisms occur in different contexts?

This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic-pituitary-adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state.

Embodying occupational overuse syndrome

This article explores the ways in which embodiedness has become problematic for New Zealand sufferers of occupational overuse syndrome (OOS). While successful rehabilitation could lead back to employment, this was based on the biographical continuity of a bodily hexus that ignored persistent pain. The reality of OOS involved a liminal fragility associated with social isolation, loss of identities, pain and functional disability that was incorporated into re-negotiated identities and biographies with the result that respondents became exquisitely self-absorbed, exercising constant bodily surveillance and discipline in order to manage their symptoms.

Lumiracoxib for acute postoperative dental pain: a systematic review of randomized clinical trials

CONTEXT AND OBJECTIVE

Lumiracoxib is an anti-inflammatory drug that has been used to treat acute dental pain, mainly in postsurgical settings, in which the greatest levels of pain and discomfort are experienced during the first 24 hours. This study aimed to assess the efficacy and safety of lumiracoxib for treating acute postsurgical dental pain.

DESIGN AND SETTING

Systematic review developed at the Brazilian Cochrane Centre, Universidade Federal de São Paulo.

METHODS

An electronic search was conducted in the PubMed, Cochrane Library, Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde), SciELO (Scientific Electronic Library Online) and Embase databases. A manual search was also performed. Only randomized controlled trials were included, and these were selected and assessed by two researchers with regard to the risk of bias.

RESULTS

Three clinical trials with 921 participants were included. Lumiracoxib 400 mg produced onset of analgesia in a shorter time than shown by lumiracoxib 100 mg, celecoxib 200 mg and ibuprofen 400 mg. There was no difference between lumiracoxib 400 mg and rofecoxib 50 mg. In two studies, the mean time taken to attain onset of analgesia for the placebo was not estimated because the number of participants who reached onset was too small.

CONCLUSION

There is evidence with a moderate risk of bias that recommends the use of lumiracoxib for acute postoperative dental pain. However, the adverse effects are not completely known. Given that lumiracoxib is currently available in only three countries, further studies are likely to be rare and discouraged.

Educational level, socio-economic status and relationship with quality of life in elderly residents of the city of Porto Alegre/RS, Brazil

The objective of this study was to verify the index of quality of life of elderly individuals belonging to groups, from different socioeconomic strata in the city of Porto Alegre, Rio Grande do Sul State. The research adopted a transversal model, used to collect data from the SF-36 questionnaire. The sampling is the intentional type and comprised: 61 elderly people in Class A, 80 in Class C, and 84 in Class E. The research was approved by the Committee of Ethics in Research/UFRGS. In relation to the quality of life, Class A presented higher scores than did Classes C and E on the pain, vitality, social aspect and mental health areas. The results also showed a significant difference in quality of life among university educated individuals versus the other schooling groups, on the pain, vitality, mental health and social aspect fields. Quality of life is a complex concept to study, but essential to improve the perception of health and welfare by the elderly.

Feature selection and classification in supporting report-based self-management for people with chronic pain

Chronic pain is a common long-term condition that affects a person's physical and emotional functioning. Currently, the integrated biopsychosocial approach is the mainstay treatment for people with chronic pain. Self-reporting (the use of questionnaires) is one of the most common methods to evaluate treatment outcome. The questionnaires can consist of more than 300 questions, which is tedious for people to complete at home. This paper presents a machine learning approach to analyze self-reporting data collected from the integrated biopsychosocial treatment, in order to identify an optimal set of features for supporting self-management. In addition, a classification model is proposed to differentiate the treatment stages. Four different feature selection methods were applied to rank the questions. In addition, four supervised learning classifiers were used to investigate the relationships between the numbers of questions and classification performance. There were no significant differences between the feature ranking methods for each classifier in overall classification accuracy or AUC ( p > 0.05); however, there were significant differences between the classifiers for each ranking method ( p < 0.001). The results showed the multilayer perceptron classifier had the best classification performance on an optimized subset of questions, which consisted of ten questions. Its overall classification accuracy and AUC were 100% and 1, respectively.

Persistent pain in survivors of torture: a cohort study

CONTEXT

Refugee survivors of torture in the United Kingdom have multiple problems, of which pain may be underrecognized, given the high prevalence recorded in similar populations in Denmark.

OBJECTIVES

To establish in a UK sample the prevalence of persistent pain and to investigate associations between specific pains and torture methods.

METHODS

A cohort of a random 20% sample attending a specialist UK center for survivors of torture in 2005 was taken. All complaints of pain recorded at initial interview were categorized for body site and putative pain mechanism. These were compared with the database of personal variables and data on torture using odds ratios (ORs) and exact probability.

RESULTS

Of 115 men and 63 women, with mean age of 30 years, 78% reported persistent multiple pains, mainly in the head and low back. They had experienced a median of six torture methods. There was a clear association between female abdominal/pelvic/genital pain and rape/sexual assault (17 of 34 vs. zero of 17: exact P<0.001) and between male anal pain and rape (two of nine vs. two of 77: OR=6.00; 95% confidence interval=1.79-20). Tests of foot/leg pain with falaka and shoulder pain with suspension did not show expected associations.

CONCLUSION

A significant relationship emerged between torture and report of persistent pain at a high prevalence. Findings do not support the widespread clinical assumption that complaint of persistent pain after torture is predominantly a manifestation of psychological distress. Rather, complaints of pain in torture survivors should be assessed and treated in relation to physical trauma.

Parents' experiences of caring for a child with chronic pain

Involvement of parents in their children's pain management is universally accepted as best practice, yet there is little understanding of their needs. Twelve parents of children with chronic pain were recruited to this study in which the impact of caring for a child with chronic pain was explored. All parents started in distress, and most moved into a stance that enabled them to balance the child's needs with their own. These parents discussed "stepping back" from their child's distress and gaining mastery over fearful emotional reactions. A minority remained in distress, finding an adaptive response to the child's pain challenging. Catastrophic thinking, fear of pain, and the desire to fulfill a nurturing parental role led parents to place themselves continually "on call." Findings indicate that parents might require support to care effectively for their children, and that many of the actions necessitated by children's pain require complex and counterintuitive decisions.

[Elevated postoperative pain levels following orthopedic surgery. Depression as a strong predictor]

The aim of this study was to examine whether depression is a strong predictor of elevated postoperative pain levels following orthopedic surgery and whether the implementation of standardized pain management is more beneficial for patients with depression. We performed a non-randomized, prospective study with two different groups of patients who underwent orthopedic surgery. Group 1 (n=249) received non-standardized pain therapy whereas group 2 (n = 243) was treated with a standardized pain management concept. Effects of the treatment were monitored with a VAS-based pain assessment protocol. Depression was measured preoperatively with the self-reported Patient Health Questionnaire (PHQ-9). Patients with the probable diagnosis of a current episode of major depression showed significantly higher postoperative pain than patients without a depressive episode. On the other hand, patients with depression benefited from the implementation of standardized pain management. Our data suggest a predictive value of depression for severe postoperative pain. Patients with depression benefited from standardized postoperative pain therapy, but were still suffering from significantly higher postoperative pain.

Keeping the body in play: pain, injury, and socialization in male rugby

This paper discusses participant observation studies of two rugby seasons--one rural high school and one university club--in which one author served as a first aid provider and student athletic trainer, respectively. Through analysis using triangulation, we explored how the rules, athlete's status, and return-to-play boundary influenced decisions when the athlete was in pain and/or injured. The results varied between the groups, suggesting a need for further research on behavioral patterns of high school and university athletes. This study effectively illustrates how social pressure and an athlete's socialization affect individual responses to pain and/or injury and how both pressure an athlete to learn to physically tolerate increasing amounts of pain.

Depression, inflammation, and pain in patients with rheumatoid arthritis

OBJECTIVE

An association between depression and inflammation has been suggested. In patients with rheumatoid arthritis (RA), pain is a major symptom associated with depression and inflammation. We examined the independent associations between depression, the inflammation marker C-reactive protein (CRP) level, and pain in patients with RA.

METHODS

In total, 218 RA outpatients completed self-administered questionnaires, using the Beck Depression Inventory II to measure depressive symptoms and a visual analog scale to quantify their perceived pain. Functional disability and CRP level were also measured.

RESULTS

Depression scores were mildly and positively correlated with the CRP level (r = 0.46, P < 0.001). Both the depression score (standardized beta = 0.35, P < 0.001) and the CRP level (standardized beta = 0.35, P < 0.001) were significantly associated with pain, even after adjustment for clinical covariates in regression analysis. In logistic analysis, the combined effects on the risk of severe pain (pain score in the upper tertile) increased with depression scores and CRP levels linearly.

CONCLUSION

Depression severity and inflammation were associated with each other and appeared to have independent effects on perceived pain. Therefore, a clinical approach that takes into account both the body and the mind could have benefits and could enable optimal pain control.

Can muscle soreness after intensive work-related activities be predicted?

OBJECTIVES

It is currently unknown whether specific determinants are predictive for developing delayed onset muscle soreness (DOMS) after heavy work-related activities. The aim of this study was to analyze whether personal characteristics and performance measures are predictive for onset, intensity, and duration of DOMS after performing work-related activities during a Functional Capacity Evaluation in healthy participants.

METHODS

Included in this study were 197 healthy participants (102 men, 95 women), all working within a broad range of professions. Five groups of predictors were tested in a multiple regression analysis model: personal variables, self-reported activity, self-reported health, perceived effort during the test, and objective outcomes of the test. Twenty-three independent variables were selected and tested with a backward regression analysis.

RESULTS

The onset of DOMS could be explained for 7% by the variables: sex and the work index of the Baecke questionnaire. Variance of intensity of DOMS could be explained for 13% by the variables: age, sex, and VO2max. Variance in duration of DOMS could be explained for 8% by the variables: sex and reported emotional role limitations. Onset, intensity, and duration of DOMS remain unpredictable for 87% or more.

CONCLUSIONS

The results demonstrate that the intensity and duration of self-reported DOMS can only minimally be predicted from the candidate predictors used in this study.

Understanding the nature and mechanism of foot pain

Approximately one-quarter of the population are affected by foot pain at any given time. It is often disabling and can impair mood, behaviour, self-care ability and overall quality of life. Currently, the nature and mechanism underlying many types of foot pain is not clearly understood. Here we comprehensively review the literature on foot pain, with specific reference to its definition, prevalence, aetiology and predictors, classification, measurement and impact. We also discuss the complexities of foot pain as a sensory, emotional and psychosocial experience in the context of clinical practice, therapeutic trials and the placebo effect. A deeper understanding of foot pain is needed to identify causal pathways, classify diagnoses, quantify severity, evaluate long term implications and better target clinical intervention.

Preoperative anxiolytic effect of melatonin and clonidine on postoperative pain and morphine consumption in patients undergoing abdominal hysterectomy: a double-blind, randomized, placebo-controlled study

Recent evidence has demonstrated analgesic, anti-inflammatory, and anxiolytic properties of melatonin. Taking into account that higher anxiety makes the control of postoperative pain more difficult, one can hypothesize that melatonin anxiolytic and analgesic effects improve the control of postoperative pain. Thus, we conducted a randomized, double-blind, placebo-controlled study with 59 patients undergoing abdominal hysterectomy to test the hypothesis that melatonin is as effective as clonidine and that both are more effective than placebo in reducing postoperative pain. Additionally, we compared their anxiolytic effects on postoperative pain. Patients were randomly assigned to receive oral melatonin (5 mg) (n = 20), clonidine (100 microg) (n = 19), or placebo (n = 20) orally. In addition to primary outcomes of pain intensity and analgesic consumption, secondary outcome measures included postoperative state anxiety. In anxious patients 6 hours after surgery, the number of patients needed to be to prevent moderate to intense pain during the first 24 hours after surgery was 1.52 (95% CI, 1.14 to 6.02) and 1.64 (95% CI, 1.29 to 5.93), respectively, in the melatonin and clonidine groups compared with placebo. Also, the anxiolytic effect of melatonin and clonidine resulted in reduced postoperative morphine consumption by more than 30%. However, in the mildly anxious, it was not observed the treatment effect on pain.

PERSPECTIVES

The preoperative anxiolysis with melatonin or clonidine reduced postoperative pain and morphine consumption in patients undergoing abdominal hysterectomy. The effects these 2 drugs were equivalent and greater than with placebo.

Nociceptive and inflammatory responses induced by formalin in the orofacial region of rats: effect of anti-TNFalpha strategies

This study evaluated the effects of different anti-TNFalpha strategies on the nociceptive and inflammatory responses triggered by formalin in the rat orofacial region. Formalin injection (2.5%) into the right upper lip caused a nociceptive response that was biphasic, with the first phase observed between 0 and 3 min and the second phase between 12 and 30 min. Plasma extravasation induced by formalin was time-related and reached the peak at 360 min. The monoclonal antibody anti-TNFalpha (25 and 50 pg/lip) significantly inhibited the second phase of formalin-induced nociceptive behavior, while the first phase remained unaltered. The systemic treatment with the chimeric anti-TNFalpha antibody infliximab also caused a significant inhibition of the second phase. Interestingly, the local administration of infliximab (50 pg/lip) produced a significant reduction of both phases of formalin-induced nociception. In addition, the systemic pretreatment with the preferential inhibitor of TNFalpha synthesis thalidomide (25 and 50 mg/kg, p.o) promoted a marked reduction of the first and second phases of formalin-evoked nociception. The local administration of the monoclonal antibody anti-TNFalpha (25 and 50 pg/lip) or infliximab (50 pg/lip) markedly reduced the plasma extravasation induced by formalin. Otherwise, formalin-elicited plasma extravasation was not significantly affected by the systemic administration of either infliximab (1 mg/kg; s.c) or thalidomide (50 mg/kg, p.o). Present data suggest that blocking TNFalpha effects, through different pharmacological tools, could represent a good alternative to control orofacial inflammatory pain that is refractory to other drugs.

Pain prevalence and pain relief in trauma patients in the Accident & Emergency department

BACKGROUND

Acute pain in the A&E department (ED) has been described as a problem, however insight into the problem for trauma patients is lacking.

OBJECTIVE

This study describes the prevalence of pain, the pain intensity and the effect of conventional pain treatment in trauma patients in the ED.

METHODS

In a prospective cohort study of 450 trauma patients, pain was measured on admission and at discharge, using standardized and validated pain instruments.

RESULTS

The prevalence of pain was high, both on admission (91%) and at discharge (86%). Two thirds of the trauma patients reported moderate or severe pain at discharge. Few patients received pharmacological or non-pharmacological pain relieving treatment during their stay in the ED. Pain decreased in 37% of the patients, did not change at all in 46%, or had increased in 17% of the patients at discharge from the ED. The most effective pain treatment given was a combination of injury treatment and supplementary pharmacological interventions, however this treatment was given to a small group of patients.

CONCLUSIONS

Acute pain in trauma patients is a significant problem in the ED's. Pain itself does not seem to be treated systematically and sufficiently, anywhere in the cycle of injury treatment in the ED.

The effect of exercise on adrenocortical responsiveness of patients with chronic low back pain, controlled for psychological strain

Objective: To investigate the effects of high-intensity aerobic exercise on adrenocortical responsiveness and on standard outcome measures in patients with chronic low back pain.

Design: Controlled clinical trial.

Setting: Physical therapy department of a university general hospital.

Subjects: Sixty-four patients with chronic low back pain were randomly allocated into positive and negative suppression test groups and assigned to exercise protocol.

Interventions: Subjects in the positive and negative dexamethasone suppression test groups received a 12-week high-intensity aerobic exercise programme.

Main outcome measures: Dexamethasone suppression test as an index of adrenocortical responsiveness, pain measured with the McGill Pain Questionnaire, functional status measured with the Roland Morris Disability Questionnaire, and psychological strain measured with the Hospital Anxiety and Depression Scale.

Results: Data analysis in the positive group identified a significant reduction of pain by 30% (t 30 = 11.2, P<0.001), a recovery of the lost functioning by 34% (t 30 = 19.7, P<0.001), a reduction of anxiety/depression by 25% (t 30 = 10.2, P<0.001), and a change in adrenocortical responsiveness by 40% (t30 = 14.1, P<0.001). In the dexamethasone suppression test negative group, data analysis identified a significant reduction of pain by 8% (t31 = 4.2, P<0.001), a recovery of lost functioning by 10% (t31 = 4.8, P<0.001), a reduction of anxiety/depression by 11% (t31 = 5.0, P<0.001), and no change in adrenocortical responsiveness (t31 = 1.2, P=0.22). In univariate analysis between-subject differences were significant for dexamethasone suppression test (F61 = 163, P<0.001), and for anxiety/depression (F61 = 21.3, P<0.001).

Conclusion: Exercise alleviated pain, functional disability and anxiety/depression, also improved adrenocortical responsiveness in patients with chronic low back pain with dexamethasone suppression test positive values.

Sequentially allocated clinical trial of rhythmic stabilization exercises and TENS in women with chronic low back pain

Objective: To examine the effectiveness of rhythmic stabilization exercises and transcutaneous electrical nerve stimulation (TENS) and their combination in treating women with chronic low back pain.

Design: Sequentially allocated, single-blinded and controlled study, with a two-month follow-up.

Setting: The data were collected in a patient rehabilitation setting.

Subjects: A total of 92 women (34—46 years old) with chronic low back pain were studied.

Interventions: Sequential allocation was undertaken into four groups: `rhythmic stabilization' (n=23), `rhythmic stabilization — TENS' (n=23), TENS (n=23), and a placebo group (n = 23). Each programme lasted for four weeks. All outcome measures were assessed prior to, immediately after, four weeks and eight weeks post intervention.

Main measures: Data were obtained on functional disability, pain intensity, trunk extension range of motion, dynamic endurance of trunk flexion and static endurance of trunk extension.

Results: A total of 88 patients provided two-month follow-up data. The `rhythmic stabilization' and the `rhythmic stabilization — TENS' groups displayed statistically significant (P<0.05) improvements in functional disability and pain intensity (ranging from 21.2 to 42.8%), trunk extension range of motion (ranging from 6.5 to 25.5%), dynamic endurance of trunk flexion and static endurance of trunk extension (ranging from 13.5 to 74.3%) compared with the remaining groups.

Conclusions: The rhythmic stabilization programmes resulted in more gains in women with chronic low back pain regarding the present outcome variables compared with the other groups; therefore, its application in female chronic low back pain patients aged 34—46 years is recommended.