Pain—When It Affects the Person

ABSTRACT

A young man with acute maxillofacial injuries and a tracheotomy in intense pain was denied pain relief for several days. Intermittent suctioning of the trachea was agonizing. He became psychologically affected to such an extent that he was totally focused on his pain and suffering and unable to make intelligent decisions regarding his future treatment. He required major maxillofacial surgery but refused consent for the same. A doctor called in to counsel him found that pain was his predominant problem and treated it. The patient was magically transformed to a sensible person, now thinking straight and promptly consenting for surgery. The author, a doctor himself, learned from this experience what a devastating experience pain can have on the person, that one should look for pain to find it, that most of the time pain can be relieved by simple means, and that relief from pain changes the whole attitude of the sufferer.     

Is the Fear Avoidance Model Associated With the Reduced Level of Aerobic Fitness in Patients With Chronic Low Back Pain?

Smeets RJ, van Geel KD, Verbunt JA. Is the fear avoidance model associated with the reduced level of aerobic fitness in patients with chronic low back pain?

Objectives

To compare aerobic fitness of patients with chronic low back pain (CLBP) against healthy controls and to assess whether variables of the fear avoidance model are associated with loss of aerobic fitness.

Design

A case-comparison study.

Setting

Rehabilitation centers.

Participants

Patients with CLBP (n=223), and normative data from healthy subjects (n=18,082).

Interventions

Not applicable.

Main Outcome Measures

Maximal oxygen uptake (V?o₂max) was estimated on the basis of a modified submaximal Åstrand bicycle test performed by patients with CLBP (observed level of aerobic fitness) and compared with the normative data of healthy controls matched for age, sex, and level of sport activity (expected level of aerobic fitness). Pain (visual analog scale); disability (Roland Disability Questionnaire); pain-related fear (Tampa Scale for Kinesiophobia); depression (Beck Depression Inventory); catastrophizing (Pain Catastrophizing Scale); and the level of activity during sport, work/household, and leisure time (Baecke Physical Activity Questionnaire) were assessed. Multiple linear regression analysis was performed with the difference of the observed and expected level of aerobic fitness as dependent variable and putative influential factors including those of the fear avoidance model as independent variables.

Results

V?o₂max could be calculated in 175 (78%) of the patients. Both men and women with CLBP had significant lower V?o₂max than expected (10.3mL/kg lean body mass (LBM)×min⁻¹ and 6.5mL/kg LBM×min⁻¹, respectively; P<.001). The levels of activity during leisure time and work/household were significantly associated with this reduced level of aerobic fitness. However, the variables of the fear avoidance model were not.

Conclusions

Most patients with CLBP-associated disability have a lower level of aerobic fitness, but this is not associated with fear avoidance.     

Factors Associated With Adolescent Chronic Non-Specific Pain,Chronic Multisite Pain,and Chronic Pain With High Disability: The Young–HUNT Study 2008

The aim of this study was to assess the association of chronic pain with different lifestyle factors and psychological symptoms in a large, unselected adolescent population. Pain was evaluated as chronic non-specific pain, chronic multisite pain, and in additional analyses, chronic pain with high disability. The study was performed during 2006 to 2008 in Nord-Trøndelag County, Norway. Adolescents aged 13 to 18 years were invited to participate. The response rate was 78%. The final study population consisted of 7,373. Sedentary behavior and pain were associated only in girls. In both sexes, overweight and obesity were associated with increased odds of pain. Whereas both smoking and alcohol intoxication showed strong associations with pain, the associations were attenuated after adjustments for psychosocial factors. Symptoms of anxiety and depression showed the strongest associations with pain (odds ratio 4.1 in girls and 3.7 in boys). The odds of pain increased gradually by number of unfavorable lifestyle factors reported. This study revealed consistent associations between lifestyle factors, anxiety and depression, and chronic pain, including multisite pain and pain with high disability. The consistency across the different pain categories suggests common underlying explanatory mechanisms, and despite the cross-sectional design, the study indicates several modifiable targets in the management of adolescent chronic pain.PerspectiveThis study showed a clear and consistent relation between different lifestyle factors, anxiety and depression, and the pain categories chronic non-specific pain, multisite pain, and also pain with high disability. Independent of causality, it underlines the importance of a broad perspective when studying, preventing, and treating chronic pain in adolescents.     

Minimally Clinically Significant Differences for Adolescents With Chronic Pain—Variability of ROC-Based Cut Points

Assessing if an individual patient has achieved clinically meaningful changes in pain intensity is a core aspect in the evaluation of pain treatments. The aim of the present study was to define minimally clinically significant differences (MCSDs) for the numerical rating scale (0–10 NRS) in adolescents with chronic pain. Data from 153 adolescents who completed an inpatient treatment were analyzed. MCSDs were defined as those cut points that yielded an optimal balance between sensitivity and specificity with regard to patients' global impression of change. The variability of the empirically defined cut points was quantified using bootstrapping. Our results show that raw changes of 1 NRS point and percent changes of 12.5% can be considered MCSDs both within the full sample and within various subsamples of patients. Applying the MCSDs developed for adults to pediatric patients yielded extremely low sensitivities; for example, only 22% of the children who described global improvement met the 50% decrease in pain criterion. Studies evaluating chronic pain treatments for adolescents should use MCSDs that are specifically developed for this group of patients. Raw changes of 1 point and 12.5% on the 0 to 10 NRS should be considered clinically meaningful. On a methodological level, we call for more systematic studies aimed at defining MCSDs that also address the variability of cut point estimates so as to foster the integration of findings.PerspectiveMany studies are aimed at empirically defining cut points for clinically relevant pain using receiver operating characteristic-based methods. For the first time, we apply these methods to children and show that even when taking into account the variability of the method, cut points specific for children are needed.     

TGF-β1 Attenuates Spinal Neuroinflammation and the Excitatory Amino Acid System in Rats With Neuropathic Pain

Previous studies have reported that the intrathecal (i.t.) administration of transforming growth factor β1 (TGF-β1) prevents and reverses neuropathic pain. However, only limited information is available regarding the possible role and effects of spinal TGF-β1 in neuropathic pain. We aimed to investigate the antinociceptive effects of exogenous TGF-β1 on chronic constriction injury (CCI)-induced neuropathic pain in rats. We demonstrated that sciatic nerve injury caused a downregulation of endogenous TGF-β1 levels on the ipsilateral side of the lumbar spinal dorsal gray matter, and that the i.t. administration of TGF-β1 (.01–10 ng) significantly attenuated CCI-induced thermal hyperalgesia in neuropathic rats. TGF-β1 significantly inhibited CCI-induced spinal neuroinflammation, microglial and astrocytic activation, and upregulation of tumor necrosis factor-α. Moreover, i.t. TGF-β1 significantly attenuated the CCI-induced downregulation of glutamate transporter 1, the glutamate aspartate transporter, and the excitatory amino acid carrier 1 on the ipsilateral side. Furthermore, i.t. TGF-β1 significantly decreased the concentrations of 2 excitatory amino acids, aspartate and glutamate, in the spinal dialysates in CCI rats. In summary, we conclude that the mechanisms of the antinociceptive effects of i.t. TGF-β1 in neuropathy may include attenuation of spinal neuroinflammation, attenuation, or upregulation of glutamate transporter downregulation, and a decrease of spinal extracellular excitatory amino acids.     

Patient-Reported Outcomes and Opioid Use in Outpatients With Chronic Pain

The Weill Cornell Medical College Pain Registry database contains patient characteristics, treatments, and outcomes for a prospective cohort of 1,159 chronic pain patients who were seen at the Weill Cornell Medical College Pain Medicine outpatient clinic from July 8, 2011 to December 10, 2014. Patients aged 45 to 64 years comprised 43% followed by age ≥ 65 years at 37%. Fifty-eight percent were female. Average pain intensity (Brief Pain Inventory) was reported as mild by 22.3% of patients, moderate by 34.7%, and severe by 43.0%. For each pain intensity category, patient's report of average percent pain relief and health state (EuroQOL 5 Dimensions) was inversely related to average pain intensity category, whereas measures of pain interference, number of worst pain locations, and physical and psychological distress were directly related to pain intensity category. Seventy-seven percent of patients received an opioid at 1 or more clinic encounters. Median daily opioid dose in morphine equivalents was 55 with a range from 2 to 1,145 morphine equivalents. Regression analysis revealed that being male was associated with greater likelihood of an opioid ordered and higher average dosage than being female. The registry can identify patient characteristics and treatments that provide new insights into chronic pain management.

Nurses’ Opinions of Pain and the Assessed Need for Pain Medication for the Elderly

The undertreatment of pain in the elderly living in nursing homes is a significant problem. In Swedish nursing homes, the registered nurse on duty is often responsible for 20-40 patients during the day with no daily contact from attending physicians. The aim of this study was to investigate the opinions of registered nurses regarding pain and the assessed need for pain medication for elderly patients using patient scenarios. Two patient scenarios were used in this study; a questionnaire and background information was provided. The scenarios consisted of one smiling patient and one grimacing patient, both with the same numeric rating scale value of pain, blood pressure, pulse rate, and respiration rate. Three questions regarding pain assessment and management followed the scenarios. The questionnaire was sent to all 128 registered nurses working daytime in elderly care in both municipal nursing homes and municipal home care in the mid-Sweden region. A total of 56 nurses participated, providing an answering frequency of 45%. Results showed that registered nurses with more experience did not have the same opinion about pain as the smiling patient and gave inadequate medication, which was not in accordance with recommendations from the county hospital and the World Health Organization.     

Old Friends With New Faces: Are Sodium Channel Blockers the Future of Adjunct Pain Medication Management?

Providers are being asked to decrease the emphasis and overutilization of long-term opioid therapy, but many are left without proper guidance on appropriate utilization of nonopioid therapies. Furthermore, therapeutic options are quite limited and many providers lack confidence in distinguishing available alternatives. When first-line therapy has failed in a patient, there is an apparent lack of knowledge on how to proceed with choosing subsequent therapy. To choose among alternative agents, an understanding of pharmacology, pharmacokinetics, and efficacy in targeting various pain conditions is necessary. This article focuses on the use of the carboxamide class of sodium channel blockers (carbamazepine, oxcarbazepine, eslicarbazepine) for adjunct pain medication management including research updates in pharmacology, pharmacokinetics, and current evidence for pain along with promising areas of research. It is an evidence update for clinical use of sodium channel blockers, clarifies misconceptions regarding their use, and highlights emerging research for improved pain targets that justifies additional study. We performed a complete review of the literature using the search terms, “oxcarbazepine,” “carbamazepine,” and “eslicarbazepine” in conjunction with “pharmacokinetics,” “adverse effects,” “pharmacology,” “voltage-gated sodium channel subtype,” “neuropathic pain,” “inflammatory pain,” “metabolism,” “epoxide metabolite formation,” “drug interactions,” “CYP450 interactions,” “pain phenotype,” and “chronic pain management.” Databases searched included PubMed and Google Scholar. Package inserts were used for drug structure illustration, adverse reactions, and bioavailability. Pharmacology and pharmacokinetic data were taken from randomized controlled trials evaluating this area as well as in vitro published results. For validity, only peer-reviewed literature was included. Evidence for sodium channel blockers in chronic pain management was limited. This review focuses on highlighting the data available for the use of sodium channel blockers for certain pain syndromes as well as underutilized potential. Emerging literature on sodium channel subtypes and their connection to neuropathic, inflammatory, and mechanical pain transmission is elucidated. The authors also scrutinize literature surrounding the pharmacokinetics of oxcarbazepine and eslicarbazepine to provide clearer guidance to the significance of any drug interactions and refute assumptions made on the basis of structural similarity to carbamazepine and its known undesirable drug interactions. Side effect profiles are outlined and compared, emphasizing the differences between agents. Sodium channel blocker doses used in certain pain syndromes are outlined with a call for further research to better understand their place in chronic pain management. Identification of sodium channel subtypes with links to specific pain conditions and the ability to target them hints at the potential for truly individualized therapy. Sodium channel inhibitors are underutilized on the basis of available evidence, and emerging research has identified this area as promising for additional clinical trials to better guide clinical practice.

How Can We Best Reduce Pain Catastrophizing in Adults With Chronic Noncancer Pain? A Systematic Review and Meta-Analysis

Pain catastrophizing (PC), defined as an exaggerated negative cognitive-affective orientation toward pain, is one of the strongest psychological predictors of pain outcomes. Although regularly included as a process variable in clinical trials, there have been no comprehensive reviews of how it can be modified. Using a registered protocol (PROSPERO 2016 CRD42016042761), we searched MEDLINE, PsychINFO, EMBASE, CINAHL, and CENTRAL up to November 2016 for all randomized controlled trials measuring PC in adults with chronic noncancer pain. Two authors independently screened studies and assessed bias risk using the Cochrane tool. Quality of evidence was rated according to Grading of Recommendations Assessment, Development and Evaluation criteria. We included 79 studies (n?=?9,914), which mostly recruited participants with musculoskeletal pain and had low risk of bias. Meta-analyses (standardized mean difference) showed 9 interventions had efficacy compared with waitlist/usual care or active control, although evidence quality was often low. The best evidence (moderate-high quality) was found for cognitive-behavioral therapy, multimodal treatment, and acceptance and commitment therapy. Effects were generally of medium strength and had questionable clinical significance. When only the 8 studies targeting people with high PC were included, effects were larger and more consistent. Multimodal treatment showed the strongest effects when all studies were considered, whereas cognitive-behavioral therapy had the best evidence among targeted studies.