Pain: an overview

Which patient-specific and surgical characteristics influence postoperative pain after THA in a fast-track setting?

Background

In our hospital a fast-track setting including a multimodal pain protocol is used for total hip arthroplasty (THA). Despite this multimodal pain protocol there is still a large range in reported postoperative pain between patients, which hinders mobilization and rehabilitation postoperatively. The goal of this study was to identify which patient-specific and surgical characteristics influence postoperative pain after THA in a fast-track setting.

Methods

All 74 patients with osteoarthritis of the hip who underwent primary THA procedure by anterior supine intermuscular approach between November 2012 and January 2014 were included in this prospective cohort study. The protocol for pain medication was standardized.

Postoperative pain determined with the Numeric Rating Score was collected at 17 standardized moments. Linear mixed models were used to examine potential patient-specific and surgical factors associated with increased postoperative pain.

Results

Pain patterns differed substantially across individuals. Adjusted for other variables in the model, preoperative use of pain medication (regression coefficient 0.78 (95% CI 0.28–1.26); p = 0.005) and preoperative neuropathic pain scored by DN4 (regression coefficient 0.68 (95% CI 0.15–1.20); p = 0.02) were the only factors significantly associated with higher postoperative pain scores.

Conclusions

The knowledge of which factors are associated with higher postoperative pain scores after THA in a fast-track setting may help optimizing perioperative postoperative pain management and preoperative education of these patients.

Trial registration

The study was retrospectively registered in the ISRCTN registry under identifier ISRCTN15422220 (date of registration: July 25, 2017).

"Pain relieved, but still struggling"-Critically ill patients experiences of pain and other discomforts during analgosedation

AIMS AND OBJECTIVES

To explore how critically ill patients treated according to a strategy of analgosedation experience and handle pain, other discomforts and wakefulness.

BACKGROUND

Patients experience both pain and discomfort while in the intensive care unit. International guidelines recommend focused pain treatment and light sedation. An analgosedation protocol favouring pain management, light sedation and early mobilisation was implemented in our university hospital medical and surgical intensive care unit in Norway in 2014. The analgosedation approach may affect patients' experiences of the intensive care unit stay.

DESIGN

Exploratory, descriptive design using semi-structured interviews.

METHOD

Eighteen adult patients treated in intensive care unit >24 hr and receiving mechanical ventilation were interviewed 1-9 days after intensive care unit discharge. Ten patients were re-interviewed after 3 months. Data were analysed using the "systematic text condensation" approach.

FINDINGS

Four main categories emerged from the analysis: "In discomfort, but rarely in pain," "Struggling to get a grip on reality," "Holding on" and "Handling emotionally trapped experiences." "Pain relieved, but still struggling" was the overarching theme. Analgosedation provided good pain relief, but patients still described frequent physical and psychological discomforts, in particular related to mechanical ventilation, not understanding what was going on, and experiences of delusions. To come to terms with their intensive care unit stay, patients needed to participate, trust in others and endure suffering. After hospital discharge, patients described both repression of experiences and searching for recognition of what they had gone through.

RELEVANCE TO CLINICAL PRACTICE

Despite good pain relief during analgosedation, other discomforts were commonly described. Critically ill patients still experience an intensive care unit stay as a traumatic part of their illness trajectory. Nurses need to attend carefully also to discomforts other than pain.

Immunological Mechanisms Underlying Chronic Pelvic Pain and Prostate Inflammation in Chronic Pelvic Pain Syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is the most common urologic morbidity in men younger than 50 years and is characterized by a diverse range of pain and inflammatory symptoms, both in type and severity, that involve the region of the pelvis, perineum, scrotum, rectum, testes, penis, and lower back. In most patients, pain is accompanied by inflammation in the absence of an invading infectious agent. Since CP/CPPS etiology is still not well established, available therapeutic options for patients are far from satisfactory for either physicians or patients. During the past two decades, chronic inflammation has been deeply explored as the cause of CP/CPPS. In this review article, we summarize the current knowledge regarding immunological mechanisms underlying chronic pelvic pain and prostate inflammation in CP/CPPS. Cumulative evidence obtained from both human disease and animal models indicate that several factors may trigger chronic inflammation in the form of autoimmunity against prostate, fostering chronic prostate recruitment of Th1 cells, and different other leukocytes, including mast cells, which might be the main actors in the consequent development of chronic pelvic pain. Thus, the local inflammatory milieu and the secretion of inflammatory mediators may induce neural sensitization leading to chronic pelvic pain development. Although scientific advances are encouraging, additional studies are urgently needed to establish the relationship between prostatitis development, mast cell recruitment to the prostate, and the precise mechanisms by which they would induce pelvic pain.

Stability of a Baclofen and Clonidine Hydrochloride Admixture for Intrathecal Administration

Implantable infusion pumps for the intrathecal administration of analgesics are commonly used in the treatment of severe or intractable chronic pain. Drugs used in these pumps include morphine, baclofen, clonidine, hydromorphone, meperidine, fentanyl, and bupiva-caine. This study investigates the chemical and physical stability of baclofen (1000 mcg/mL) and clonidine hydrochloride (200 mcg/mL) at 37°C for 10 weeks using a stability-indicating HPLC assay. The formulations included baclofen alone, clonidine hydrochloride alone, and a mixture of the two drugs. At each time point, the amount of drug remaining was greater than 90% of original. Week 10 percentages were 99.7% for baclofen alone, 100.7% for clonidine alone, and 103.2% and 101.1% for baclofen and clonidine hydrochloride, respectively in the drug mixture. These results demonstrate the stability of this admixture for long-term intrathecal administration.

Assessing Suffering in Experimental Pain Models

Abstract. Although suffering is a central issue in pain, there is only little research on this topic. The aim of this study was to assess suffering in an experimental context using various stimulation methods and durations, and to examine which psychological or psychophysiological measures covary with pain-related suffering. Twenty-one healthy volunteers participated in two experiments in which we used tonic thermal and phasic electric stimuli with short and long stimulus durations. The participants rated pain intensity, unpleasantness, and pain-related suffering on separate visual analog scales (VAS) and completed the Pictorial Representation of Illness and Self Measure (PRISM), originally developed to assess suffering in chronic illness. We measured heart rate, skin conductance responses (SCRs), and the electromyogram (EMG) of the musculus corrugator supercilii. For both heat and electric pain, we obtained high ratings on the suffering scale confirming that suffering can be evoked in experimental pain conditions. Whereas pain intensity and unpleasantness were highly correlated, both scales were less highly related to suffering, indicating that suffering is distinct from pain intensity and unpleasantness. Higher suffering ratings were associated with more pronounced fear of pain and increased private self-consciousness. Pain-related suffering was also related to high resting heart rate, increased SCR, and decreased EMG during painful stimulation. These results offer an approach to the assessment of suffering in an experimental setting using thermal and electric pain stimulation and shed light on its psychological and psychophysiological correlates.

Liposomal bupivacaine versus indwelling interscalene nerve block for postoperative pain control in shoulder arthroplasty: a prospective randomized controlled trial

BACKGROUND

Pain management strategies following shoulder arthroplasty vary significantly. Liposomal bupivacaine (LB) is an extended-release delivery of a phospholipid bilayer encapsulating bupivacaine that can result in drug delivery up to 72 hours. Prior studies in lower extremity surgery demonstrated efficacy of LB in comparison to a single-shot peripheral nerve block; however, no study has investigated LB in a total shoulder arthroplasty population. Therefore, this study compared LB vs. an indwelling interscalene nerve block (IINB).

METHODS

This is a prospective, randomized study of 83 consecutive shoulder arthroplasty patients; 36 patients received LB and a "bridge" of 30 mL of 0.5% bupivacaine, and 47 patients received an IINB. Postoperative visual analog scale pain levels, opiate consumption measured with oral morphine equivalents, length of hospital stay, and postoperative complications were recorded. Continuous variables were compared using an analysis of variance with significance set at P < .05.

RESULTS

Visual analog scale pain scores were statistically higher in the LB cohort immediately postoperatively in the postanesthesia care unit (7.25 vs. 1.91; P = .000) as well as for the remainder of postoperative day 0 (4.99 vs. 3.20; P = .005) but not for the remainder of admission. Opiate consumption was significantly higher among the LB cohort in the postanesthesia care unit (31.79 vs. 7.47; P = .000), on postoperative day 0 (32.64 vs. 15.04; P = .000), and for the total hospital admission (189.50 vs. 91.70, P = .000). Complication numbers and length of stay were not statistically different.

CONCLUSION

Use of an IINB provides superior pain management in the immediate postoperative setting as demonstrated by decreased narcotic medication consumption and lower subjective pain scores.

Feelings of Clinician-Patient Similarity and Trust Influence Pain: Evidence From Simulated Clinical Interactions

Pain is influenced by many factors other than external sources of tissue damage. Among these, the clinician-patient relationship is particularly important for pain diagnosis and treatment. However, the effects of the clinician-patient relationship on pain remain underexamined. We tested the hypothesis that patients who believe they share core beliefs and values with their clinician will report less pain than patients who do not. We also measured feelings of perceived clinician-patient similarity and trust to see if these interpersonal factors influenced pain. We did so by experimentally manipulating perceptions of similarity between participants playing the role of clinicians and participants playing the role of patients in simulated clinical interactions. Participants were placed in 2 groups on the basis of their responses to a questionnaire about their personal beliefs and values, and painful thermal stimulation was used as an analog of a painful medical procedure. We found that patients reported feeling more similarity and trust toward their clinician when they were paired with clinicians from their own group. In turn, patients' positive feelings of similarity and trust toward their clinicians-but not clinicians' feelings toward patients or whether the clinician and patient were from the same group-predicted lower pain ratings. Finally, the most anxious patients exhibited the strongest relationship between their feelings about their clinicians and their pain report. These findings increase our understanding of context-driven pain modulation and suggest that interventions aimed at increasing patients' feelings of similarity to and trust in health care providers may help reduce the pain experienced during medical care.

PERSPECTIVE

We present novel evidence that the clinician-patient relationship can affect the pain experienced during medical care. We found that "patients" in simulated clinical interactions who reported feeling more similarity and trust toward their "clinicians" reported less pain, suggesting that increasing feelings of clinician-patient similarity and trust may reduce pain disparities.

Chronic Pain as a Hypothetical Construct: A Practical and Philosophical Consideration

Pain has been defined by the International Association for the Study of Pain (IASP) as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” Chronic pain is usually described as pain that has persisted for 3–6 months and/or beyond the expected time of healing. The numerical pain rating (NPR) is the customary metric and often considered as a proxy for the subjective experience of chronic pain. This definition of pain (chronic) has been of significant heuristic value. However, the definition and the models it has spawned tend to encourage the interpretation of pain as a measurable entity and implies that the patient’s experience of pain can be fully comprehended by someone other than the person in pain. Several major models of pain have been scrutinized and found to propagate the notion of pain as a ‘thing’ and fall prey to biomedical reductionism and Cartesian (mind-body) dualism. Furthermore, the NPR does not appear to capture the complexity of chronic pain and correlates poorly with other clinically meaningful outcomes. It, and other aspects of the current notion of chronic pain, appear to be an extension of our reliance on the philosophical principles of reductionism and materialism. These and other shortcomings identified in the IASP definition have resulted in an increased interest in a reexamination and possible updating of our view of pain (chronic) and its definition. The present paper describes an alternative view of pain, in particular chronic pain. It argues that chronic pain should be understood as a separate phenomenon from, rather than an extension of, acute pain and interpreted as a hypothetical construct (HC). HCs are contrasted to intervening variables (IV) and the use of HCs in science is illustrated. The acceptance of the principles of nonlinearity and emergence are seen as important characteristics. The practical implications and barriers of this philosophical shift for assessment, treatment, and education are explored. The patient’s narrative is presented as a potential source of important phenomenological data relating to their ‘experience’ of pain. It is further proposed that educational and academic endeavors incorporate a discussion of the process of chronification and the role of complexity theory.

Attention to pain! A neurocognitive perspective on attentional modulation of pain in neuroimaging studies

Several studies have used neuroimaging techniques to investigate brain correlates of the attentional modulation of pain. Although these studies have advanced the knowledge in the field, important confounding factors such as imprecise theoretical definitions of attention, incomplete operationalization of the construct under exam, and limitations of techniques relying on measuring regional changes in cerebral blood flow have hampered the potential relevance of the conclusions. Here, we first provide an overview of the major theories of attention and of attention in the study of pain to bridge theory and experimental results. We conclude that load and motivational/affective theories are particularly relevant to study the attentional modulation of pain and should be carefully integrated in functional neuroimaging studies. Then, we summarize previous findings and discuss the possible neural correlates of the attentional modulation of pain. We discuss whether classical functional neuroimaging techniques are suitable to measure the effect of a fluctuating process like attention, and in which circumstances functional neuroimaging can be reliably used to measure the attentional modulation of pain. Finally, we argue that the analysis of brain networks and spontaneous oscillations may be a crucial future development in the study of attentional modulation of pain, and why the interplay between attention and pain, as examined so far, may rely on neural mechanisms shared with other sensory modalities.

Observing continuous change in heart rate variability and photoplethysmography-derived parameters during the process of pain production/relief with thermal stimuli

Continuously monitoring and efficiently managing pain has become an important issue. However, no study has investigated a change in physiological parameters during the process of pain production/relief. This study modeled the process of pain production/relief using ramped thermal stimulation (no pain: 37°C water, process of pain production: a heating rate of 1°C/min, and subject feels pain: water kept at the painful temperature for each subject, with each segment lasting 10 min). In this duration, the variation of the heat rate variability and photoplethysmography-derived parameters was observed. A total of 40 healthy individuals participated: 30 in the trial group (14 males and 16 females with a mean age of 22.5±1.9 years) and 10 in the control group (7 males and 3 females with a mean age of 22.5±1.3 years). The results showed that the numeric rating scale value was 5.03±1.99 when the subjects felt pain, with a temperature of 43.54±1.70°C. Heart rate, R-R interval, low frequency, high frequency, photoplethysmography amplitude, baseline, and autonomic nervous system state showed significant changes during the pain production process, but these changes differed during the period Segment D (painful temperature 10: min). In summary, the study observed that physiological parameters changed qualitatively during the process of pain production and relief and found that the high frequency, low frequency, and photoplethysmography parameters seemed to have different responses in four situations (no pain, pain production, pain experienced, and pain relief). The trends of these variations may be used as references in the clinical setting for continuously observing pain intensity.

Periarticular Injection of Liposomal Bupivacaine Offers No Benefit Over Standard Bupivacaine in Total Knee Arthroplasty: A Prospective, Randomized, Controlled Trial

BACKGROUND

Periarticular injection of liposomal bupivacaine has been adopted as part of multimodal pain management after total knee arthroplasty (TKA).

METHODS

In this prospective, randomized clinical trial, we enrolled 162 patients undergoing primary TKA in a single institution between January 2014 and May 2015. Eighty-seven patients were randomized to liposomal bupivacaine (experimental group), and 75 patients were randomized to free bupivacaine (control group). All patients received spinal anesthesia and otherwise identical surgical approaches, pain management, and rehabilitation protocols. Outcomes evaluated include the patient-reported visual analog pain scores, narcotic consumption, and narcotic-related side effects (Brief Pain Inventory) within 96 hours after surgery as well as functional outcomes using the Knee Society Score and the Short-Form 12 measured preoperatively and at 4-6 weeks after surgery.

RESULTS

There were no statistically significant differences between the groups in terms of postoperative daily pain scores, narcotic consumption (by-day and overall), or narcotic-related side effects. There were no statistically significant differences between the groups in terms of surgical (P = .76) and medical complications or length of hospital stay (P = .35). There were no statistically significant differences in satisfaction between the groups (P = .56) or between the groups in postoperative Knee Society Score (P = .53) and the Short-Form 12 at 4-6 weeks (P = .82, P = .66).

CONCLUSION

As part of multimodal pain management protocol, periarticular injection of liposomal bupivacaine compared with bupivacaine HCl did not result in any clinically or statistically significant improvement of the measured outcomes following TKA.

Acceptance and Commitment Therapy for Pediatric Chronic Pain: Theory and Application

Acceptance and Commitment Therapy (ACT) is a third wave behavior therapy approach which aims to increase engagement in activities that bring meaning, vitality, and value to the lives of individuals experiencing persistent pain, discomfort, or distress. This goal is particularly relevant when these aversive experiences cannot be effectively avoided or when avoidance efforts risk their exacerbation, all of which may be common experiences in children and adolescents with chronic pain conditions. The primary aim of the present paper is to review and summarize the extant literature on the application, utility, and evidence for using ACT with pediatric chronic pain populations by: (1) defining the theoretical assumptions of the ACT model; (2) summarizing research study findings and relevant measures from the published literature; and (3) critically discussing the strengths, limitations and areas in need of further development.

Life Stress and Health: A Review of Conceptual Issues and Recent Findings

Life stress is a central construct in many models of human health and disease. The present article reviews research on stress and health, with a focus on (a) how life stress has been conceptualized and measured over time, (b) recent evidence linking stress and disease, and (c) mechanisms that might underlie these effects. Emerging from this body of work is evidence that stress is involved in the development, maintenance, or exacerbation of several mental and physical health conditions, including asthma, rheumatoid arthritis, anxiety disorders, depression, cardiovascular disease, chronic pain, human immunodeficiency virus/AIDS, stroke, and certain types of cancer. Stress has also been implicated in accelerated biological aging and premature mortality. These effects have been studied most commonly using self-report checklist measures of life stress exposure, although interview-based approaches provide a more comprehensive assessment of individuals' exposure to stress. Most recently, online systems like the Stress and Adversity Inventory (STRAIN) have been developed for assessing lifetime stress exposure, and such systems may provide important new information to help advance our understanding of how stressors occurring over the life course get embedded in the brain and body to affect lifespan health.

Leveraging Multi-Modal Sensing for Mobile Health: A Case Review in Chronic Pain

Active and passive mobile sensing has garnered much attention in recent years. In this paper, we focus on chronic pain measurement and management as a case application to exemplify the state of the art. We present a consolidated discussion on the leveraging of various sensing modalities along with modular server-side and on-device architectures required for this task. Modalities included are: activity monitoring from accelerometry and location sensing, audio analysis of speech, image processing for facial expressions as well as modern methods for effective patient self-reporting. We review examples that deliver actionable information to clinicians and patients while addressing privacy, usability, and computational constraints. We also discuss open challenges in the higher level inferencing of patient state and effective feedback with potential directions to address them. The methods and challenges presented here are also generalizable and relevant to a broad range of other applications in mobile sensing.

Ten weeks of physical-cognitive-mindfulness training reduces fear-avoidance beliefs about work-related activity: Randomized controlled trial

People with chronic musculoskeletal pain often experience pain-related fear of movement and avoidance behavior. The Fear-Avoidance model proposes a possible mechanism at least partly explaining the development and maintenance of chronic pain. People who interpret pain during movement as being potentially harmful to the organism may initiate a vicious behavioral cycle by generating pain-related fear of movement accompanied by avoidance behavior and hyper-vigilance.This study investigates whether an individually adapted multifactorial approach comprised of biopsychosocial elements, with a focus on physical exercise, mindfulness, and education on pain and behavior, can decrease work-related fear-avoidance beliefs.As part of a large scale 10-week worksite randomized controlled intervention trial focusing on company initiatives to combat work-related musculoskeletal pain and stress, we evaluated fear-avoidance behavior in 112 female laboratory technicians with chronic neck, shoulder, upper back, lower back, elbow, and hand/wrist pain using the Fear-Avoidance Beliefs Questionnaire at baseline, before group allocation, and again at the post intervention follow-up 10 weeks later.A significant group by time interaction was observed (P < 0.05) for work-related fear-avoidance beliefs. The between-group difference at follow-up was -2.2 (-4.0 to -0.5), corresponding to a small to medium effect size (Cohen's d = 0.30).Our study shows that work-related, but not leisure time activity-related, fear-avoidance beliefs, as assessed by the Fear-avoidance Beliefs Questionnaire, can be significantly reduced by 10 weeks of physical-cognitive-mindfulness training in female laboratory technicians with chronic pain.

`Why Can't They Do Anything for a Simple Back Problem?'

In order to examine expectations for pain treatment and outcome and to determine whether they are influential in maintaining health service consumption 16 adults suffering from chronic pain were interviewed. Transcripts were subjected to thematic analysis. The six main themes to emerge were labelled: Unmet Expectations; Health Professionals; the Importance of Self; Getting Something Done; Back to Square One; and Perceptions of the Future with Ruminations on the Past. Participants revealed considerable agency as they continued in a quest to engage and re-engage with the gatekeepers of health care facilities. The implications for pain management providers are discussed.

A Brain Signature to Differentiate Acute and Chronic Pain in Rats

The transition from acute pain to chronic pain entails considerable changes of patients at multiple levels of the nervous system and in psychological states. An accurate differentiation between acute and chronic pain is essential in pain management as it may help optimize analgesic treatments according to the pain state of patients. Given that acute and chronic pain could modulate brain states in different ways and that brain states could greatly shape the neural processing of external inputs, we hypothesized that acute and chronic pain would show differential effects on cortical responses to non-nociceptive sensory information. Here by analyzing auditory-evoked potentials (AEPs) to pure tones in rats with acute or chronic pain, we found opposite influences of acute and chronic pain on cortical responses to auditory inputs. In particular, compared to no-pain controls, the N100 wave of rat AEPs was significantly enhanced in rats with acute pain but significantly reduced in rats with chronic pain, indicating that acute pain facilitated cortical processing of auditory information while chronic pain exerted an inhibitory effect. These findings could be justified by the fact that individuals suffering from acute or chronic pain would have different vigilance states, i.e., the vigilance level to external sensory stimuli would be increased with acute pain, but decreased with chronic pain. Therefore, this auditory response holds promise of being a brain signature to differentiate acute and chronic pain. Instead of investigating the pain system per se, the study of pain-induced influences on cortical processing of non-nocicpetive sensory information might represent a potential strategy to monitor the progress of pain chronification in clinical applications.

Differences in the body pressure-related sensory changes between the floor and mattress in a static supine position for physiotherapy research: a randomized controlled pilot trial

[Purpose] This study was performed to investigate the difference in body pressure-related sensory changes between the floor and mattress in a static supine position for physiotherapy research. [Subjects and Methods] To analyze body pressure, the Body Pressure Measurement System was used. Body pressure sensors were attached to mattresses and the floor beneath the subjects. The level of pain was evaluated using pain score tools before the static supine position was adopted, at 1, 5, 10, and 15 min, and in total for specific body points. [Results] In analysis of digitized images, there was no significant difference observed between floor and mattress body pressure values at the start position. However, the head pressure intensity was significantly higher than that of the other body parts. In analysis of pain scores, all body part pain scores except those for both legs were significantly higher for the floor than for the mattress. Furthermore, the pain scores of the floor group were significantly increased at minute 1 compared with those of the mattress group. [Conclusion] These results suggest that properties that change in a time-dependent manner and postural changes need to be carefully considered when applying physical therapy.

Clinical features for diagnosis and management of patients with PRDM12 congenital insensitivity to pain

Background

Congenital insensitivity to pain (CIP) is a rare extreme phenotype characterised by an inability to perceive pain present from birth due to lack of, or malfunction of, nociceptors. PRDM12 has recently been identified as a new gene that can cause CIP. The full phenotype and natural history have not yet been reported.

Methods

We have ascertained five adult patients and report their clinical features.

Results

Based on our findings, and those of previous patients, we describe the natural history of the PRDM12-CIP disorder, and derive diagnostic and management features to guide the clinical management of patients.

Conclusions

PRDM12-CIP is a distinct and diagnosable disorder, and requires specific clinical management to minimise predictable complications.

Life events, anxiety, social support, personality, and alexithymia in female patients with chronic pain: A path analysis

INTRODUCTION

This study sought to identify a model that explains the relationship between psychosocial factors and chronic pain in female patients, and to explore all of these constructs in a single study and provide a more holistic examination of the overall psychosocial factors that female patients with chronic pain encounter.

METHODS

Female patients with chronic pain (n = 147), aged 20-65 (M = 34.9 years, SD = 11.25), from an outpatient pain clinic completed a cross-sectional self-report questionnaire on anxiety, life events, personality, social support, and alexithymia. Data were analyzed by means of path analysis.

RESULTS

The direct effect of anxiety on female patients with chronic pain was greatest among all the paths. Personality and alexithymia led to chronic pain in female patients only indirectly, mediated by life events. The personality factors of neuroticism and extraversion were associated positively with social support, which had an indirect effect on the influence of life events on chronic pain. However, alexithymia was associated negatively with social support, which had an indirect effect on the influence of life events on chronic pain.

DISCUSSION

Our findings provide evidence that life events are a mediator in the relationship between personality, social support, alexithymia, and chronic pain in female patients.

Three job stress models and their relationship with musculoskeletal pain in blue- and white-collar workers

OBJECTIVES

Musculoskeletal pain has been found to co-occur with psychosocial job stress. However, different conceptualizations of job stress exist, each emphasizing different aspects of the work environment, and it is unknown which of these aspects show the strongest associations with musculoskeletal pain. Further, these associations may differ for white-collar vs. blue-collar job types, but this has not been tested. The present study examined the independent and combined contributions of Effort-RewardImbalance (ERI), Job-Demand-Control (JDC) and Organizational Justice (OJ) to musculoskeletal pain symptoms among white- and blue-collar workers.

METHODS

Participants of a cross-sectional study (n=1634) completed validated questionnaires measuring ERI, JDC, and OJ, and reported the frequency of pain during the previous year at four anatomical locations (lower back, neck or shoulder, arms and hands, and knees/feet). Pain reports were summarized into a single musculoskeletal symptom score (MSS). Analyses were stratified for white- and blue-collar workers.

RESULTS

Among white-collar workers, ERI and OJ were independently associated with MSS. In addition to these additive effects, significant 2-way and 3-way interactions indicated a synergistic effect of job stressors in relation to reported pain. In blue-collar workers, ERI and JDC independently associated with MSS, and a significant 3-way interaction was observed showing that the combination of job stressors exceeded an additive effect.

CONCLUSION

ERI influences pain symptoms in both occupational groups. OJ was independent significant predictor only among white-collar workers, whereas JDC had additive predictive utility exclusively among blue-collar workers. Simultaneous exposure to multiple job stress factors appeared to synergize pain symptom reporting.

[The pain experience according to a phenomenological view on palliative care]

In palliative care, people with advanced or terminal phase cancer represent a significant proportion of patients. Persuaded that the pain and suffering they experience will never disappear from their daily life, patients are exposed to successive fracture triggered by psychosocial/physical factors. Furthermore, the difficulty in palliative care is that the pain is also a subjective phenomenon. However, the only information available to indicate pain remains the quantitative assessment of the patient or the observation of his/her behaviour. Pain caused by cancer optimally exhibits the difficulty of pain assessment, where a patient may properly assess, through their somatic pain, their own experience of pain expressed according to the consequence of illness on their history and personality.

OBJECTIVES

This exploratory study aims to show how the development of analogical subjective speech has an effect on the pain experience in patients with cancer. Indeed, the hypothesis is that one can reduce the sensation of pain by transforming the emotional experience via a figurative/discursive activity due to an elaboration work and clarification of the painful experience. Method-Four terminally ill patients passed the "L'Épreuve des Trois Arbres" (three-tree test) (ETA), which consisted in drawing trees and telling their story. The ETA aims to facilitate the expression of the overall experience according to a person's perspective on a specific situation. In this experiment, quantitative and qualitative data were collected. More specifically, the quantitative data was based on the assessment of somatic pain using the visual analog scale (VAS) of 1 to 10 (0 = no pain, 10 = unbearable pain) and a qualitative analysis assessed with the ETA, which focused on the meaning of pain, a subjective component that can increase the expression of somatic pain. The pain experience is assessed before and after the execution of the ETA using the VAS.

RESULTS

The results show a reduction of painful sensation and its behavioural expression. This could be due to the refocusing of attention and transformation of emotional experience through a figurative and discursive activity.

DISCUSSION

The ETA seems to reduce somatic pain by allowing verbalization. The emotional repression of some patients who inhibited the expression of their pain would explain the increase of painful sensation. The psychological approach associated with the theme of the tree offers an opportunity to expound upon the experience of pain in an analogical mode, situating the current painful personal experience in a specific biography. Furthermore, part of the suffering highlighted in protocols was the break that makes the announcement of illness. It generated a sense of rupture between the time before and after, sometimes until a real crisis of identity, which can take on one of the facets of depression. ETA encourages the rebuilding of a psychic continuity between before and after the disease.

Cultural adaptation and reproducibility validation of the Brazilian Portuguese version of the Pain Assessment in Advanced Dementia (PAINAD-Brazil) scale in non-verbal adult patients

Objective

To adapt the Pain Assessment in Advanced Dementia (PAINAD) scale to Brazilian Portuguese with respect to semantic equivalence and cultural aspects, and to evaluate the respective psychometric properties (validity, feasibility, clinical utility and inter-rater agreement).

Methods

Two-stage descriptive, cross-sectional retrospective study involving cultural and semantic validation of the Brazilian Portuguese version of the scale, and investigation of its psychometric properties (validity, reliability and clinical utility). The sample consisted of 63 inpatients presenting with neurological deficits and unable to self-report pain.

Results

Semantic and cultural validation of the PAINAD scale was easily achieved. The scale indicators most commonly used by nurses to assess pain were “Facial expression”, “Body language” and “Consolability”. The Brazilian Portuguese version of the scale has proved to be valid and accurate; good levels of inter-rater agreement assured reproducibility.

Conclusion

The scale has proved to be useful in daily routine care of hospitalized adult and elderly patients in a variety of clinical settings. Short application time, ease of use, clear instructions and the simplicity of training required for application were emphasized. However, interpretation of facial expression and consolability should be given special attention during pain assessment training.

Somatosensory and affective contributions to emotional, social, and daily functioning in chronic pain patients

OBJECTIVE

The present study tested the independent and interactive contributions of the somatosensory component of pain (pain intensity) and the affective component of pain (pain unpleasantness) on emotional, social, and daily functioning in chronic pain patients.

SUBJECTS

Participants were 472 patients seeking treatment for chronic orofacial pain. Mean age of the sample was 46.0 years (standard deviation [SD] = 14.67, range 18-78), with 82.2% female. Average pain duration at the time of initial appointment was 75.7 months (SD = 106.66).

METHODS

Participants completed self-report measures of pain intensity, unpleasantness, and functional outcomes at the time of their first appointment. These data were later extracted from participant's de-identified medical records. Multivariate linear regression was used to test the interaction of pain intensity and unpleasantness on outcome measures of emotional, social, and daily functioning.

RESULTS

Results revealed that pain intensity contributed to poorer functional outcomes but higher levels of social support even after controlling for pain unpleasantness. After controlling for pain intensity, unpleasantness was associated with higher pain interference and affective distress. There was also pain intensity by unpleasantness interaction on pain interference. Specifically, at lower levels of pain unpleasantness, changes in pain intensity produced greater changes in pain interference than they did at higher levels of pain unpleasantness.

CONCLUSIONS

Results suggest that both intensity and unpleasantness contribute unique variance to functional outcomes. The results highlight the importance of interventions that not only try to reduce pain levels but also reduce levels of pain unpleasantness.

Health trajectories of family caregivers: associations with care transitions and adult day service use

OBJECTIVE

The study examines family caregivers' health changes over 1 year on four health dimensions and explores the association of differential health trajectories with adult day service (ADS) use and caregiving transitions.

METHOD

The participants were 153 primary caregivers of individuals with dementia (IWDs) who provided information on care situations and their own health at baseline, 6-month, and 12-month interviews.

RESULTS

Caregivers showed increasing functional limitations and decreasing bodily pain over time, whereas role limitation and general health perception remained stable. Furthermore, caregivers' trajectories of functional limitation were associated with their extent of ADS use at baseline and their relatives' placement.

DISCUSSION

Health is multidimensional; all dimensions of caregiver health do not change in a uniform manner. The findings underscore the importance of the association of caregiving transitions and caregiver health and the potential health benefits of ADS use for family caregivers.

Current dilemmas in the assessment of suffering in palliative care

Objective:

Although relief from suffering is essential in healthcare and palliative care, few efforts have aimed at defining, operationalizing, and developing standards for its detection, assessment, and relief. In order to accurately explore and identify factors that contribute to suffering, more attention needs to be focused on quality assessment and measurement, not only for assessment purposes but also to test the effectiveness of interventions in relieving suffering. The scope of the present paper is to discuss the strategies that aid in the detection and assessment of the suffering experience in patients with chronic illnesses and/or in palliative care settings, and the dilemmas commonly encountered regarding the quality of available assessment measures.

Method:

A general description of instruments available for suffering assessment is provided. Matters regarding the accuracy of the measures are discussed. Finally, some dilemmas regarding the quality of the measures to screen for and assess suffering are presented.

Results:

There have been some achievements toward adequate suffering assessment. However, a more robust theoretical background is needed, and empirical evidence aimed at supporting it is required. In addition, further examination of the psychometric characteristics of instruments in different populations and cultural contexts is needed.

Significance of results:

An interesting number of assessment measures are now available for use in the palliative care setting, employing innovative approaches. However, further examination and validation in different contexts is required to find high-quality tools for detection of suffering and assessment of the results of intervention.

Spirituality: what is its role in pain medicine?

BACKGROUND

For many years, spirituality has been regarded as an integral aspect of patient care in fields closely allied to pain medicine such as palliative and supportive care. Despite this, it has received relatively little attention within the field of pain medicine itself. Reasons for this may include a lack of understanding of what spirituality means, doubtfulness of its relevance, an uncertainty about how it may be addressed, or a lack of awareness of how addressing spirituality may be of benefit.

METHODS

A review of the literature was conducted to determine the changing conceptual frameworks that have been applied to pain medicine, the emergence of the biopsychospiritual approach and what that means as well as evidence for the benefits of incorporation of this approach for the management of pain.

RESULTS

Although the concept of spirituality is broad, there is now greater consensus on what is meant by this term. Many authors and consensus panels have explored the concept and formulated a conceptual framework and an approach that is inclusive, accessible, relevant, and applicable to people with a wide range of health conditions. In addition, there is accumulating evidence that interventions that address the issue of spirituality have benefits for physical and emotional health.

CONCLUSIONS

Given the firm place that spirituality now holds within other fields and the mounting evidence for its relevance and benefit for people with pain, there is increasing evidence to support the inclusion of spiritual factors as an important component in the assessment and treatment of pain.

Pain and nociception: mechanisms of cancer-induced bone pain

Cancer pain, especially pain caused by metastasis to bone, is a severe type of pain, and unless the cause and consequences can be resolved, the pain will become chronic. As detection and survival among patients with cancer have improved, pain has become an increasing challenge, because traditional therapies are often only partially effective. Until recently, knowledge of cancer pain mechanisms was poor compared with understanding of neuropathic and inflammatory pain states. We now view cancer-induced bone pain as a complex pain state involving components of both inflammatory and neuropathic pain but also exhibiting elements that seem unique to cancer pain. In addition, the pain state is often unpredictable, and the intensity of the pain is highly variable, making it difficult to manage. The establishment of translational animal models has started to reveal some of the molecular components involved in cancer pain. We present the essential pharmacologic and neurobiologic mechanisms involved in the generation and continuance of cancer-induced bone pain and discuss these in the context of understanding and treating patients. We discuss changes in peripheral signaling in the area of tumor growth, examine spinal cord mechanisms of sensitization, and finally address central processing. Our aim is to provide a mechanistic background for the sensory characteristics of cancer-induced bone pain as a basis for better understanding and treating this condition.

Liposomal bupivacaine and clinical outcomes

In the multimodal approach to the management of postoperative pain, local infiltration and regional blocks have been increasingly utilized for pain control. One of the limitations of local anesthetics in the postoperative setting is its relatively short duration of action. Multivesicular liposomes containing bupivacaine have been increasingly utilized for their increased duration of action. Compared with bupivacaine HCl, local infiltration of liposomal bupivacaine has shown to have an increase in duration of action and causes delay in peak plasma concentration. In this article, we attempt to review the clinical literature surrounding liposomal bupivacaine and its evolving role in perioperative analgesia. This new bupivacaine formation may have promising implications in postoperative pain control, resulting in increased patient satisfaction and a decrease in both hospital stay and opioid-induced adverse events (AEs). Although more studies are needed, the preliminary clinical trials suggest that liposomal bupivacaine has predictable pharmacokinetics, a similar side effect profile compared with bupivacaine HCl, and is effective in providing increased postoperative pain control.

Cryotherapy suppresses tendon inflammation in an animal model

Cryotherapy (or cold treatment) has been a popular treatment to relieve pain caused by injuries to tissues such as tendons. However, the exact mechanisms behind the beneficial effects of cryotherapy in tendons remain largely unclear. As prostaglandin E₂ (PGE₂) is known to be a major mediator of acute inflammation in tissues, which is related to tissue pain, we hypothesized that the beneficial effects of cryotherapy in tendons are mediated by downregulation of PGE₂ levels. To test this hypothesis, we applied cold treatment to mouse patellar and Achilles tendons using two animal models: exhaustive mouse treadmill running and acute mouse tendon injury by needle penetration. We then measured the levels of PGE₂ and protein expression levels of COX-2, an enzyme responsible for PGE₂ production in tissues, under both experimental conditions. We found that treadmill running increased PGE₂ levels in both patellar and Achilles tendons compared to control mice without running. Cold treatment for 30 min after treadmill running was sufficient to reduce PGE₂ levels to near baseline control levels in both tendons. An extension of cold treatment to 60 min resulted only in a marginal decrease in patellar tendons, but a marked decrease in Achilles tendons. Moreover, COX-2 protein levels in both tendons were also lowered by cold treatment, suggesting that the reduction of PGE₂ levels in tendons by cold treatment is at least in part due to the decreased COX-2 expression. Similarly, in the acutely injured tendons, 30 min of cold treatment after needle penetration reduced PGE₂ levels when compared to the controls at room temperature (22°C). This decrease was sustained up to at least 3 h after the administration of cryotherapy. Given that PGE₂ is a known pain sensitiser, the results of this study suggest that the ability of cold treatment to reduce pain may be attributable to its ability to decrease PGE₂ production in tendons.

Clinical pain in schizophrenia: a systematic review

Studies about clinical pain in schizophrenia are rare. Conclusions on pain sensitivity in people with schizophrenia are primarily based on experimental pain studies. This review attempts to assess clinical pain, that is, everyday pain without experimental manipulation, in people with schizophrenia. PubMed, PsycINFO, Embase.com, and Cochrane were searched with terms related to schizophrenia and pain. Methodological quality was assessed with the Mixed Methods Appraisal Tool. Fourteen studies were included. Persons with schizophrenia appear to have a diminished prevalence of pain, as well as a lower intensity of pain when compared to persons with other psychiatric diseases. When compared to healthy controls, both prevalence and intensity of pain appear to be diminished for persons with schizophrenia. However, it was found that this effect only applies to pain with an apparent medical cause, such as headache after lumbar puncture. For less severe situations, prevalence and intensity of pain appears to be comparable between people with schizophrenia and controls. Possible underlying mechanisms are discussed. Knowledge about pain in schizophrenia is important for adequate pain treatment in clinical practice.

PERSPECTIVE

This review presents a valuable insight into clinical pain in people with schizophrenia.

Ibuprofen and/or paracetamol (acetaminophen) for pain relief after surgical removal of lower wisdom teeth

BACKGROUND

Both paracetamol and ibuprofen are commonly used analgesics for the relief of pain following the surgical removal of lower wisdom teeth (third molars). In 2010, a novel analgesic (marketed as Nuromol) containing both paracetamol and ibuprofen in the same tablet was launched in the United Kingdom, this drug has shown promising results to date and we have chosen to also compare the combined drug with the single drugs using this model. In this review we investigated the optimal doses of both paracetamol and ibuprofen via comparison of both and via comparison with the novel combined drug. We have taken into account the side effect profile of the study drugs. This review will help oral surgeons to decide on which analgesic to prescribe following wisdom tooth removal.

OBJECTIVES

To compare the beneficial and harmful effects of paracetamol, ibuprofen and the novel combination of both in a single tablet for pain relief following the surgical removal of lower wisdom teeth, at different doses and administered postoperatively.

SEARCH METHODS

We searched the Cochrane Oral Health Group'sTrials Register (to 20 May 2013); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 4); MEDLINE via OVID (1946 to 20 May 2013); EMBASE via OVID (1980 to 20 May 2013) and the metaRegister of Controlled Trials (to 20 May 2013). We checked the bibliographies of relevant clinical trials and review articles for further studies. We wrote to authors of the identified randomised controlled trials (RCTs), and searched personal references in an attempt to identify unpublished or ongoing RCTs. No language restriction was applied to the searches of the electronic databases.

SELECTION CRITERIA

Only randomised controlled double-blinded clinical trials were included. Cross-over studies were included provided there was a wash out period of at least 14 days. There had to be a direct comparison in the trial of two or more of the trial drugs at any dosage. All trials used the third molar pain model.

DATA COLLECTION AND ANALYSIS

All trials identified were scanned independently and in duplicate by two review authors, any disagreements were resolved by discussion, or if necessary a third review author was consulted. The proportion of patients with at least 50% pain relief (based on total pain relief (TOTPAR) and summed pain intensity difference (SPID) data) was calculated for all three drugs at both two and six hours postdosing and meta-analysed for comparison. The proportion of participants using rescue medication over both six and eight hours was also collated and compared. The number of patients experiencing adverse events or the total number of adverse events reported or both were analysed for comparison.

MAIN RESULTS

Seven studies were included, they were all parallel-group studies, two studies were assessed as at low risk of bias and three at high risk of bias; two were considered to have unclear bias in their methodology. A total of 2241 participants were enrolled in these trials.Ibuprofen was found to be a superior analgesic to paracetamol at several doses with high quality evidence suggesting that ibuprofen 400 mg is superior to 1000 mg paracetamol based on pain relief (estimated from TOTPAR data) and the use of rescue medication meta-analyses. The risk ratio for at least 50% pain relief (based on TOTPAR) at six hours was 1.47 (95% confidence interval (CI) 1.28 to 1.69; five trials) favouring 400 mg ibuprofen over 1000 mg paracetamol, and the risk ratio for not using rescue medication (also favouring ibuprofen) was 1.50 (95% CI 1.25 to 1.79; four trials).The combined drug showed promising results, with a risk ratio for at least 50% of the maximum pain relief over six hours of 1.77 (95% CI 1.32 to 2.39) (paracetamol 1000 mg and ibuprofen 400 mg) (one trial; moderate quality evidence), and risk ratio not using rescue medication 1.60 (95% CI 1.36 to 1.88) (two trials; moderate quality evidence).The information available regarding adverse events from the studies (including nausea, vomiting, headaches and dizziness) indicated that they were comparable between the treatment groups. However, we could not formally analyse the data as it was not possible to work out how many adverse events there were in total.

AUTHORS' CONCLUSIONS

There is high quality evidence that ibuprofen is superior to paracetamol at doses of 200 mg to 512 mg and 600 mg to 1000 mg respectively based on pain relief and use of rescue medication data collected at six hours postoperatively. The majority of this evidence (five out of six trials) compared ibuprofen 400 mg with paracetamol 1000 mg, these are the most frequently prescribed doses in clinical practice. The novel combination drug is showing encouraging results based on the outcomes from two trials when compared to the single drugs.

Controlled release of analgesic drugs from porous bioresorbable structures for various biomedical applications

Pain is one of the most common patient complaints encountered by health professionals and remains the number one cause of absenteeism and disability. In the current study, analgesic-eluting bioresorbable porous structures prepared using the freeze-drying of inverted emulsions technique were developed and studied. These drug-eluting structures can be used for coating fibers or implants, or for creating standalone films. They are ideal for forming biomedically important structures that can be used for various applications, such as wound dressings that provide controlled release of analgesics to the wound site in addition to their wound dressing role. Our investigation focused on the effects of the inverted emulsion's parameters on the shell microstructure and on the resulting drug-release profile of ibuprofen and bupivacaine. The release profiles of ibuprofen formulations exhibited a diffusion-controlled pattern, ranging from several days to 21 days, whereas bupivacaine formulations exhibited an initial burst release followed by a three-phase release pattern over a period of several weeks. Higher organic to aqueous phase ratios and higher polymer contents reduced the burst release of both drugs and prolonged their release due to lower porosity. Overall, the drug-eluting porous structures loaded with either ibuprofen or bupivacaine demonstrated a promising potential for use in various applications that require pain relief.

"Nonmedical" prescription opioid use in North America: a call for priority action

Nearly four years after the United States Congress heralded a "decade of pain control and research", chronic pain remains a mounting public health concern worldwide. The escalating prevalence of chronic pain in recent years has been paralleled by a rise in prescription opioid availability, misuse, and associated human and social costs. However, national monitoring surveys in the U.S. and Canada currently fail to differentiate between prescription opioid misuse for the purposes of euphoria versus pain or withdrawal management. Furthermore, there is a lack of evidence-based guidelines for pain management among high-risk individuals, and a glaring lack of education for practitioners in the areas of pain and addiction medicine. Herein we propose multiple avenues for intervention and research in order to mitigate the individual, social and structural problems related to undertreated pain and prescription opioid misuse.

Effects of an individually tailored Web-based chronic pain management program on pain severity, psychological health, and functioning

BACKGROUND

It is estimated that 30% of adults in the United States experience daily chronic pain. This results in a significant burden on the health care system, in particular primary care, and on the workplace. Chronic pain management with cognitive-behavioral psychological treatment is effective in reducing pain intensity and interference, health-related quality of life, mood, and return to work. However, the population of individuals with chronic pain far exceeds the population of therapists that can provide this care face-to-face. The use of tailored, Web-based interventions for the management of chronic pain could address limitations to access by virtue of its unlimited scalability.

OBJECTIVE

To examine the effects of a tailored Web-based chronic pain management program on subjective pain, activity and work interference, quality of life and health, and stress.

METHODS

Eligible participants accessed the online pain management program and informed consent via participating employer or health care benefit systems; program participants who completed baseline, 1-, and 6-month assessments were included in the study. Of the 645 participants, the mean age was 56.16 years (SD 12.83), most were female (447/645, 69.3%), and white (505/641, 78.8%). Frequent pain complaints were joint (249/645, 38.6%), back (218/645, 33.8%), and osteoarthritis (174/654, 27.0%). The online pain management program used evidence-based theories of cognitive behavioral intervention, motivational enhancement, and health behavior change to address self-management, coping, medical adherence, social support, comorbidities, and productivity. The program content was individually tailored on several relevant participant variables.

RESULTS

Both pain intensity (mean 5.30, SD 2.46), and unpleasantness (mean 5.43, SD 2.52) decreased significantly from baseline to 1-month (mean 4.16, SD 2.69 and mean 4.24, 2.81, respectively) and 6-month (mean 3.78, SD 2.79 and mean 3.78, SD 2.79, respectively) assessments (P<.001). The magnitude of the 6-month effects were large. Trends for decreases in pain interference (36.8% reported moderate or enormous interference) reached significance at 6 months (28.9%, P<.001). The percentage of the sample reporting fair or poor quality of life decreased significantly from 20.6% at baseline to 16.5% at 6 months (P=.006).

CONCLUSIONS

Results suggest that the tailored online chronic pain management program showed promising effects on pain at 1 and 6 months posttreatment and quality of life at 6 months posttreatment in this naturalistic study. Further research is warranted to determine the significance and magnitude of the intervention's effects in a randomized controlled trial.

The downward spiral of chronic pain, prescription opioid misuse, and addiction: cognitive, affective, and neuropsychopharmacologic pathways

Prescription opioid misuse and addiction among chronic pain patients are emerging public health concerns of considerable significance. Estimates suggest that more than 10% of chronic pain patients misuse opioid analgesics, and the number of fatalities related to nonmedical or inappropriate use of prescription opioids is climbing. Because the prevalence and adverse consequences of this threat are increasing, there is a pressing need for research that identifies the biobehavioral risk chain linking chronic pain, opioid analgesia, and addictive behaviors. To that end, the current manuscript draws upon current neuropsychopharmacologic research to provide a conceptual framework of the downward spiral leading to prescription opioid misuse and addiction among chronic pain patients receiving opioid analgesic pharmacotherapy. Addictive use of opioids is described as the outcome of a cycle initiated by chronic pain and negative affect and reinforced by opioidergic-dopamingeric interactions, leading to attentional hypervigilance for pain and drug cues, dysfunctional connectivity between self-referential and cognitive control networks in the brain, and allostatic dysregulation of stress and reward circuitry. Implications for clinical practice are discussed; multimodal, mindfulness-oriented treatment is introduced as a potentially effective approach to disrupting the downward spiral and facilitating recovery from chronic pain and opioid addiction.

Improvement of pain, sleep, and quality of life in chronic pain patients with vitamin D supplementation

OBJECTIVES

To evaluate the effects of vitamin D supplementation in outpatient veterans with multiple areas of chronic pain.

METHODS

A case series was performed as an outpatient vitamin D supplementation quality improvement project. A total of 28 US veterans with multiple areas of chronic pain and low serum 25-hydroxyvitamin D [25(OH)D] (<30 ng/mL) concentrations at baseline were identified in a major Veterans Affairs Medical Center from May 2009 till November 2010. They were supplemented with vitamin D 1200 IU daily if serum 25(OH)D was in the insufficient range (20 to 29 ng/mL) or 50,000 IU weekly if serum 25(OH)D was in the deficient range (<20 ng/mL). Standardized outcome measures were assessed before and after supplementation, including pain assessed by the 0 to 10 pain score and the bodily pain domain score of the Veterans Rand 36 item, sleep by the Pittsburgh Sleep Quality Index, and quality of life (QoL) by the Veterans Rand 36 item.

RESULTS

Participants reported no side effects during the study. Relative to baseline, pain, sleep, and QoL all improved except for role-functioning emotional. The improvements remained significant in pain score (P<0.001), sleep latency (P=0.019), sleep duration (P=0.012), bodily pain (P=0.014), general health (P=0.006), vitality (P=0.048), and social functioning (P=0.017) after controlling for age, sex, race, body mass index, season, baseline serum 25(OH)D concentration subgroup, and whether or not participants received additional procedural intervention during the supplementation period.

CONCLUSIONS

Standardized vitamin D supplementation in veterans with multiple areas of chronic pain can be effective in improving their pain levels, sleep, and various aspects of QoL.