Observed Pain Behaviors Research Articles

Racial Differences in Movement-Related Appraisals and Pain Behaviors Among Adults With Chronic Low Back Pain

Research documents racial disparities in chronic low back pain (CLBP). Few studies have examined racial disparities in movement-related appraisals and no studies have examined anticipatory appraisals prior to or pain behaviors during functional activities among individuals with CLBP. This cross-sectional study examined racial differences in anticipatory appraisals of pain, concerns about harm, and anxiety, appraisals of pain and anxiety during movement, and observed pain behaviors during 3 activities of daily living (supine-to-standing bed task, sitting-to-standing chair task, floor-to-waist lifting task) in a sample (N = 126) of non-Hispanic Black (31.0%), Hispanic (30.2%), and non-Hispanic White (38.9%) individuals with CLBP. Hispanic participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed and chair tasks compared to non-Hispanic White participants. Hispanic participants reported more pain during the bed task and more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants reported more expected pain, concerns about harm, and pre-movement anxiety prior to the bed task and more pre-movement anxiety prior to the chair task compared to non-Hispanic White participants. Non-Hispanic Black participants reported more anxiety during the bed and chair tasks compared to non-Hispanic White participants. Non-Hispanic Black participants were observed to have significantly more verbalizations of pain during the bed task compared to non-Hispanic White participants. Current findings identify racial disparities in important cognitive-behavioral and fear-avoidance mechanisms of pain. Results indicate a need to revisit traditional theoretical and treatment models in CLBP, ensuring racial disparities in pain cognitions are considered. PerspectiveThis study examined racial disparities in anticipatory and movement-related appraisals, and pain behaviors during activities of daily living among Non-Hispanic Black, Non-Hispanic White, and Hispanic individuals with CLBP. Racial disparities identified in the current study have potentially important theoretical implications surrounding cognitive-behavioral and fear-avoidance mechanisms of pain.

Assessing pain using facial recognition software among Aboriginal aged care residents with cognitive impairment: A retrospective cohort study.

To assess the observed pain behaviours of Aboriginal residents with cognitive impairment in aged care facilities and compare these results with a matched national sample of non-Aboriginal residents. Observed pain behaviours of Aboriginal residents (N= 87) with cognitive impairment in aged care facilities across the Northern Territory of Australia were assessed using PainChek® Adult and compared with data from a matched national sample of non-Aboriginal residents (N= 420). Pain scores were derived from inbuilt automated facial recognition and analysis software plus a series of digital checklists requiring manual input by care staff. The median total pain score for the Aboriginal residents was 2 (IQR 1-4) and for the matched external residents was 3 (IQR 2-5). In a multivariable negative binomial regression model, this difference in total pain score was statistically significant (p< 0.001). The pain score derived from the automated facial recognition and analysis component of the PainChek® Adult app was not statistically different between the two groups when adjusted for multiple observations and context of observation (odds ratio=1.06, 95% confidence interval 0.97-1.16, p= 0.169). We found under-reporting of observed pain signs and behaviours for Aboriginal aged care residents by assessors. Further training in the assessment of pain in Aboriginal and Torres Strait Islander aged care residents may be necessary and a continuing shift in clinical practice to using technology and point-of-care assessment.

Platelet-rich plasma combined with ozone prevents cartilage destruction and improves weight-bearing asymmetry in a surgery-induced osteoarthritis rabbit model.

Osteoarthritis (OA) is the most common degenerative disease in older adults and its treatment remains unsatisfactory. This study aimed to evaluate the effectiveness and explore the therapeutic mechanisms of the combination of platelet-rich plasma (PRP) and ozone (O3) for knee OA. Thirty male rabbits were randomly divided into five groups (Control group, OA group, PRP group, O3 group, and PRP + O3 group). Rabbit model of OA were induced by improved Hulth surgery. Gross articular observation, histopathological examination and cartilage scoring system were used to assess the articular cartilage destruction. The bone morphogenetic protein-2 (BMP-2) mRNA expression in joint fluid was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression of type II collagen, matrix metalloproteinase-1 (MMP-1) of cartilage was detected via Immunohistochemistry. Pain behavior was observed by percent ipsilateral weight-bearing (PIW) asymmetry. The content of platelet in PRP was increased by 6.2-times that in whole blood. Among induced OA groups (the OA, PRP, O3 and PRP + O3 group), PRP + O3 significantly inhibited the surgically induced increase in gross articular alterations, histopathological damage of cartilage and Mankin score when compared to the OA, PRP and O3 groups (P<0.05). Observed pain behavior by weight-bearing asymmetry, in the PRP + O3 group was reversed at 3 and 6 weeks after the administration of PRP + O3 (PIW asymmetry: -10.66%±1.172%). In addition, surgery-induced BMP-2 mRNA expression was significantly downregulated after the treatment of PRP, O3 and PRP + O3 (P<0.01). PRP + O3 group significantly increased the expression of type II collagen but decreased MMP-1 of cartilage in comparison to OA, PRP and O3 groups (P<0.05) by immunohistochemical analysis. PRP combined with O3 may prevent cartilage destruction and improve weight-bearing asymmetry by restoring homeostasis between anabolism and catabolism of extracellular matrix in progressive OA. Furthermore, a combination of PRP and O3 might achieve even better results than the two agents alone.

Mast Cell-Specific Receptor/Corticotropin-Releasing Factor Axis Regulates Alcohol Withdrawal-Associated Headache

Rehabilitation from alcohol addiction or abuse is challenging due to alcohol withdrawal symptoms. Headache is a severe alcohol withdrawal symptom that frequently contributes to rehabilitation failure. Despite the need for treating alcohol withdrawal-induced headache, there is no appropriate therapeutic option available. Development of improved therapeutics will depend on obtaining a clearer understanding of alcohol withdrawal-induced headache pain mechanisms. Here, we show that the mast cell-specific receptor MrgprB2 controls development of alcohol withdrawal-induced headache. Withdrawing alcohol from alcohol-acclimated mice induces strong headache behaviors, including facial allodynia, facial pain expressions, and reduced walking movement, symptoms often observed in humans suffering from headache. Observed pain behaviors were abolished in MrgprB2-deficient mice. We observed in vivo spontaneous activation and hypersensitization of trigeminal ganglia neurons in alcohol withdrawal mice, but not in MrgprB2-deficient mice. Corticotropin-releasing factor (CRF) was increased in dura mater after alcohol withdrawal. Injection of CRF into dura mater resulted in activation of trigeminal ganglia neurons and vasodilation, which was accompanied by headache behavior. In cells, CRF evoked Ca2+ transients via MrgprB2 or human MrgprX2. The results indicate that alcohol withdrawal causes headache via mast cell degranulation in dura mater. The process is under control of MrgprB2/MrgprX2, which would appear to represent a potential target for treating alcohol withdrawal-related headache.

Multidimensional Self-report Assessment of Children's Acute Pain in an Inpatient Setting.

This study assessed the feasibility of administering a multidimensional, self-report pain assessment protocol to children in an inpatient, acute pain context, and sought insight into the interrelationships between sensory, affective, and evaluative pain dimensions. A total of 132 children (5 to 16 y) experiencing acute pain were recruited from acute pain ward rounds or the short-stay surgical unit. A multidimensional self-report assessment protocol was administered, assessing pain intensity, pain-related affect, bother, perceived unfairness, and pain expectations (for tomorrow and in 1 wk). Duration of protocol administration was assessed and ease of administration was rated. Pain-related behaviors were rated using the Face, Legs, Activity, Cry, and Consolability (FLACC) Scale. The duration of protocol administration was <2.5 minutes, on average, for all age groups. Median ease of protocol administration was 7/10 for 5- to 7-year-olds and 8/10 for older age groups. Pain-related bother was higher for 14- to 16-year-olds, relative to younger age groups, and significantly correlated with perceived unfairness (r=0.59, P<0.01), intensity (r=0.76, P<0.01), and affect (r=0.33, P<0.05). For younger age groups, bother was significantly positively correlated only with pain intensity (rs=0.59 to 0.79, Ps<0.01) and affect (rs=0.4 to 0.71, Ps <0.05). A stepwise multiple regression analysis found multidimensional self-reported information (especially pain intensity and perceived unfairness), accounted for significant additional amount of variance, beyond that explained by age, pain duration, and observed pain behavior. Sensory, affective, and evaluative aspects of children's clinical, acute pain experience may be assessed using self-report tools, which provide unique and valuable information about their pain experience.

Pain Behaviour Scale (PaBS): An Exploratory Study of Reliability and Construct Validity in a Chronic Low Back Pain Population.

Objectives To examine the interrater and intrarater reliability and construct validity of the Pain Behaviour Scale during standard physical performance tests in people with chronic low back pain and to confirm the test-retest reliability of the physical performance tests in this population. The Pain Behaviour Scale (PaBS) is an observational scale that was recently designed to uniquely measure both the presence and severity of observed pain behaviours. Methods Twenty-two participants with chronic low back pain were observed during performance of five physical performance tests by two raters. Pain behaviours were assessed using the Pain Behaviour Scale. The Visual Analogue Scale and Modified Oswestry Disability Index were used to measure pain and disability, respectively. Descriptive statistics were used to report demographic features of participants. Reliability was analyzed using ICCs. Rater agreement was analyzed using the weighted Cohen's kappa. Correlations between PaBS, self-reported measures, and physical performance tests were calculated using Pearson's product-moment correlations. Results The PaBS demonstrated excellent interrater (ICC2,1 = 1.0, 95% CI: 0.9 to 1.0) and intrarater (ICC3,1 = 0.9, 95% CI: 0.8 to 1.0) reliability. Component physical performance tests (i.e., time and distance) demonstrated good test-retest (0.6–1.0) reliability. Perfect agreement in the reporting of pain behaviours was found (95–100%). Correlations between pain behaviour severity and pain intensity (r = 0.6) and disability (r = 0.6) were moderate. Moderate correlations were found between pain behaviours and physical performance tests in sit to stand (r = 0.5), trunk flexion (r = 0.4), timed up and go (r = 0.4), and 50-foot walk (r = 0.4). Conclusion The Pain Behaviour Scale is a valid and reliable tool for measuring the presence and severity of pain behaviour, and the physical performance tests are reliable tests.

Spouse criticism and hostility during marital interaction: effects on pain intensity and behaviors among individuals with chronic low back pain.

Individuals with chronic pain may experience negative responses from spouse, family, and friends. Responses such as overt criticism and hostility may be associated with worsening pain and function for chronic pain sufferers. We used a laboratory procedure to evaluate whether variability in spouse criticism/hostility exhibited toward chronic low back pain (CLBP) patients during a conflictual discussion predicted variability in patient pain and function during a subsequent pain-induction task. Chronic low back pain patients (n = 71) and their spouses (n = 71) participated in a 10-minute discussion followed by the patient undergoing a 10-minute structured pain behavior task (SPBT). Spouse criticism/hostility perceived by patients and patient Beck Depression Inventory-II (BDI) scores correlated significantly and positively with pain intensity during the SPBT, whereas perceived spouse hostility, patient BDI scores, and spouse trait hostility correlated significantly and positively with observed pain behaviors during the SPBT. Spouse criticism/hostility coded by raters from video recordings interacted significantly with patient BDI scores, such that observed spouse criticism/hostility was related significantly and positively with pain behaviors only for patients with high BDI scores. Patient sex interacted significantly with observed spouse criticism/hostility, such that observed spouse criticism/hostility was related significantly and positively with pain behaviors only for female patients. Results support the hypothesis that spouse criticism and hostility-actually expressed or perceived-may worsen CLBP patient symptoms. Further, women patients and patients high in depressive symptoms appeared most vulnerable to spouse criticism/hostility. Thus, negative marital communication patterns may be appropriate targets for intervention, especially among these 2 at risk groups.

Which Facial Descriptors Do Care Home Nurses Use to Infer Whether a Person with Dementia Is in Pain?

Pain assessment in people with advanced dementia relies strongly on observable pain behaviors, such as facial expressions, body movement, and vocalizations. However, the process of inferring pain in others based on such observations is not well understood. We aimed to investigate which features of facial expressions caregivers rely on when inferring the presence and intensity of pain in people with dementia. A questionnaire, including items on 13 facial descriptors, which were extracted from established observational scales for pain in dementia, was sent to 366 nursing homes in Germany. We asked the nurses to observe patients with dementia and then rate their observations using the facial descriptors, as well as to provide an overall pain estimate of the residents' pain. We used regression analyses to identify which facial descriptors nurses use most commonly to infer whether a person with dementia is in pain and to grade the pain's intensity. Seventy-nine nursing homes participated (22% response rate), and a total of 284 completed observer ratings were returned. The observed individuals suffered from moderate to severe dementia and were observed in everyday care situations. The average pain estimated by the caregivers was slight to moderate. Mainly anatomically based descriptors ("frowning," "narrowed eyes") and indicators of emotional arousal ("looking tense," looking frightened") significantly predicted the overall pain ratings by nurses, explaining approximately 45% of the variance. Although all presented facial descriptors were used by the nurses, some descriptors were used clearly more frequently than others to infer whether a resident with dementia was in pain. Development of observational pain tools and training in their use should consider the preexisting assumptions that nurses use to infer pain as well as their potential bias.

Effect of cryotherapy on pain management at the puncture site of arteriovenous fistula among children undergoing hemodialysis

ObjectiveTo evaluate the effectiveness of cryotherapy in managing the pain at the puncture site of Arterio-Venous Fistula (AVF) among children undergoing maintenance hemodialysis (HD). MethodsA one-group pre-post quasi-experiment was performed in two HD centers affiliated with Cairo University. The experiment involved 40 children with AVF undergoing HD. Before puncturing, cryotherapy was applied using 2 cm–3 cm pieces of frozen distilled water in a plastic bag. Pain was assessed subjectively and objectively in two dialysis sessions before and after cryotherapy. A part from a physiological assessment of vital signs, pain was assessed using the Wong–Baker Faces Pain and the Observed Pain Behavior rating scales. All research ethics were applied. ResultsHD had a median duration of four years, while cryotherapy had a median application time of 8.8 min. The Wong–Baker Faces Pain score and almost all observed pain behaviors significantly decreased after cryotherapy. Significant improvements were observed in respiratory rate before and after needle puncture and in oxygen saturation after needle puncture. A lower skin dryness was observed after cryotherapy (12.5%) than before cryotherapy (52.5%; p < 0.001). ConclusionsCryotherapy can effectively reduce the venipuncture pain among children with AVF undergoing maintenance HD. However, the confounding effects of distraction and the non-randomized design used must be both considered when interpreting the findings. This study recommends the use of cryotherapy in managing needle puncture pain. Further research must adopt a randomized trial design with a placebo to support further the benefits of this procedure.

Abstract PR317

Background & Objectives: Our previous study showed that results showed that MBD1 knockout mice showed dramatically higher pain thresholds in Mechanical, Thermal, and Cold test in acute pain and SNL-pain models compared to wild-type mice. However, it remains unknown how MBD1 to regulate genesis of acute pain and chronic pain. This observation led us to hypothesize that MBD1 might regulate some related factors of pain. So, we first investigated both the mRNA and protein level of pain-related opioid receptors and potassium channels in the dorsal root ganglia, spinal cord and cortex, and determined whether MBD1 targeted tissue-specific subtypes of opioid receptors and/or potassium channels. Second, we used MBD1-AAV5 overexpression viral to treat those specific tissue sites and observed pain behavior and related expression of pain related mRNA and proteins. Finally, we determined whether MBD1 co-localization with opioid receptors or potassium channels gene in a single DRG cell or not. Materials & Methods: All experiments were carried out with the approval of the Animal Care Committee at Rutgers New Jersey Medical School. For detected opioid receptors or potassium channels mRNA, we used RT-qPCR to detect Oprm1, Oprk1, Oprd1, Kcna1 and Kcna2 mRNA gene expression and used western blot to detected mu, kappa, delta, Kv1.1 and Kv1.2 protein expression on the level of dorsal root ganglia, the spinal cord and cortex. For in vivo experiments, wild-type mice were microinjected with GFP-AAV5 viral (1 µl) or MBD1-AAV5 viral (1 µl) in DRG. CPP test was carried out to test the spontaneous pain behavior. Overexpression of MBD1 in wild-type mice induced spontaneous pain behavior after 6 weeks. On week 8, DRG was collected. For in vitro experiments, cultured DRG neurons were exposed to GFP or MBD1-AAV5 viral and proteins were assessed by Western blot. Single cell RT-PCR was carried out to test whether MBD1 co-localization with opioid receptors or potassium channels gene in a single DRG cell or not. Results: Oprm1, Oprk1, and Kcna2 mRNA gene expressed at high levels in DRG, spinal cord and cortex, but not midbrain. Interestingly, only mu opioid receptor and Kv1.2 receptor protein significantly increased in DRG, other proteins and sites were not altered. These increases were blocked by MBD1 over-expression in DRG, and MBD1 over-expression can cause spontaneous pain behavior. Furthermore, MBD1 overexpression in cultured DRG neurons down-regulate mu opioid receptor and Kv1.2 receptor protein expression. Single cell RT-PCR assay revealed that MBD1 co-localization with mu opioid receptor and Kv1.2 receptor gene in a single DRG cell. Conclusion: Our findings indicate that Expression of mu opioid receptor and Kv1.2 controlled by MBD1 in the dorsal root ganglion. Disclosure of Interest: None declared

Soluble Mediators Derived from Lactobacillus rhamnosus GG (LGG) Decrease Visceral Pain Hypersensitivity Induced by Early Life Stress

Maternal separation of rat pups is a robust and reliable model of early life stress that induces long‐term alterations to behavior and brain neurochemistry. These changes are particularly apparent with respect to the microbiota‐gut‐brain axis where probiotic feeding has been shown to ameliorate some of these stress‐induced alterations. It is possible that biologically relevant products of probiotic metabolism are involved in such effects, and therefore could deliver the required benefits without requiring the live organism to be present. In this study the effects of a specific preparation of soluble mediators from the probiotic Lactobacillus rhamnosus GG (LGG) were evaluated. Previously, immunomodulatory properties of this material have been demonstrated both in vitro and in vivo. Production conditions have been standardized with cultivation and downstream processing steps such as desalting, sterile filtration and lyophilization. The maternal separation protocol was conducted as described in O'Mahony et al., 2009. Rats were separated from their mothers for 3 hrs/day from postnatal day (PND) 2 to 12. Starting at weaning (PND 21), both non‐separated (NS) and maternally separated (MS) offspring were randomized into separate experimental groups and were provided drinking water with or without supplementation of LGG soluble mediators. Supplementation of the lyophilized materials was benchmarked to the number of LGG viable cells during cultivation to give a dose equivalent to a range from 1.3×108 to 4.3×108 viable LGG/animal/day throughout the study until PND 85. Visceral hypersensitivity was assessed with the colorectal distension test conducted at PND 79. There were no differences in body weight or water and food intake across groups. MS rats demonstrated visceral hypersensitivity to colorectal distension reflected by a lower pain threshold when compared to NS rats, which was ameliorated by the LGG soluble mediators (p=0.03). There were no differences in the number of observed pain behaviors between treatment groups. Interestingly, the increased pain threshold in rats that received LGG soluble mediators was not observed in animals that received unconditioned culture medium subjected to the same processing steps as the LGG soluble mediators. This indicated the presence of specific bioactives in the culture medium secreted by LGG during growth. In conclusion, administration of LGG soluble mediators in rats reversed the altered visceral pain sensitivity induced by MS. Further studies are needed to elucidate specific mechanism of actions related to gut and brain neurochemistry.Support or Funding InformationSupported by Science Foundation Ireland and Mead Johnson Nutrition.

A supplemental report to a randomized cluster trial of a 20-week Sun-style Tai Chi for osteoarthritic knee pain in elders with cognitive impairment

ObjectiveThis was a secondary data analysis of a cluster-randomized clinical trial that tested the efficacy of a 20-week Sun-style Tai Chi (TC) program in reducing pain in community-dwelling elders with cognitive impairment and knee osteoarthritis (OA). The study also examined whether elders’ level of cognitive function was related to the outcomes of the TC program. MethodElders (N=55) were recruited from 8 study sites. Each site was randomly assigned to participate in either a 20-week TC or an education program. Verbal report of pain was measured by a Verbal Descriptor Scale (VDS) at weeks 1, 5, 9, 13, 17 and 21 (designated as times 1–6). Pain behaviors and analgesic intake were also recorded at times 1–6. ResultsAt post-test, scores on the VDS and observed pain behaviors were significantly better in the TC group than in the control group (p=0.008–0.048). The beneficial effects of TC were not associated with cognitive ability. ConclusionThese results suggest that TC can be used as an adjunct to pharmacological intervention to relieve OA pain in elders with cognitive impairment.Trial registration: Clinical Trial.gov NCT01528566.

Patient perception of pain versus observed pain behavior during a standardized electrodiagnostic test.

Clinicians often assume that observations of pain behavior are adequate for assessment of patient pain perception during procedures. This has not been tested during a standardized electrodiagnostic experience. During a prospective trial including extensive, standardized electrodiagnostic testing on persons with lumbar stenosis, vascular claudication, and asymptomatic volunteers, the subjects and an observer rated levels of pain. In 60 subjects, observers significantly under-rated pain (Visual Analog Scale 3.17 ± 2.23 vs. 4.38 ± 2.01, t = -4.577, df = 59, P < 0.001). Perceived pain during testing related to bodily pain as measured by the visual analog, McGill, Pain Disability, and Quebec scales, but not age, duration of symptoms, Tampa kinesiphobia, Center for Epidemiological Studies Depression scale, or SF-36 health quality of life. Persons with worse pain syndromes may perceive more pain during testing than others. Clinicians and researchers should understand that patients may have more pain than they recognize.

Oral sucrose as analgesia for neonates: How effective and safe is the sweet solution? A review of the literature

The objective of this literature review was to evaluate the safety and effectiveness of sucrose as analgesia for neonates. The review synthesizes the evidence relating to an emerging common clinical practice to assist practitioners to provide evidence based care. A search of published articles was undertaken with forty-six articles returned of which ten met the inclusion criteria. Newborns needing intensive care are routinely subjected to invasive procedures that cause distress and pain but numerous studies have shown that pain relief remains poorly managed. Sucrose is becoming the accepted non-pharmacological intervention for managing acute procedural pain. Administration has been associated with calming effects and reductions in observed pain behaviours in preterm and term infants aged up to 1 year. This review found that in preterm and full term neonates up to the first month of life there is evidence to suggest that oral sucrose, with or without non-nutritive sucking, is effective and safe for reducing pain responses. A number of studies found that other non-pharmacological methods such as breastfeeding and non-nutritive sucking can also be effective. It is recommended that future studies investigate the potential effects after continuous use of sucrose during painful procedures for very preterm and sick infants.

Metabolic brain activity suggestive of persistent pain in a rat model of neuropathic pain

Persistent pain is a central characteristic of neuropathic pain conditions in humans. Knowing whether rodent models of neuropathic pain produce persistent pain is therefore crucial to their translational applicability. We investigated the spared nerve injury (SNI) model of neuropathic pain and the formalin pain model in rats using positron emission tomography (PET) with the metabolic tracer [18F]fluorodeoxyglucose (FDG) to determine if there is ongoing brain activity suggestive of persistent pain. For the formalin model, under brief anesthesia we injected one hindpaw with 5% formalin and the FDG tracer into a tail vein. We then allowed the animals to awaken and observed pain behavior for 30min during the FDG uptake period. The rat was then anesthetized and placed in the scanner for static image acquisition, which took place between minutes 45 and 75 post-tracer injection. A single reference rat brain magnetic resonance image (MRI) was used to align the PET images with the Paxinos and Watson rat brain atlas. Increased glucose metabolism was observed in the somatosensory region associated with the injection site (S1 hindlimb contralateral), S1 jaw/upper lip and cingulate cortex. Decreases were observed in the prelimbic cortex and hippocampus. Second, SNI rats were scanned 3weeks post-surgery using the same scanning paradigm, and region-of-interest analyses revealed increased metabolic activity in the contralateral S1 hindlimb. Finally, a second cohort of SNI rats was scanned while anesthetized during the tracer uptake period, and the S1 hindlimb increase was not observed. Increased brain activity in the somatosensory cortex of SNI rats resembled the activity produced with the injection of formalin, suggesting that the SNI model may produce persistent pain. The lack of increased activity in S1 hindlimb with general anesthetic demonstrates that this effect can be blocked, as well as highlights the importance of investigating brain activity in awake and behaving rodents.

Temporal associations between spouse criticism/hostility and pain among patients with chronic pain: A within-couple daily diary study

Chronic musculoskeletal pain can strain marriages, perhaps even to the point of engendering spouse criticism and hostility directed toward patients. Such negative spouse responses may have detrimental effects on patient well-being. While results of cross-sectional studies support this notion, we extended these efforts by introducing expressed emotion (EE) and interpersonal theoretical perspectives, and by using electronic diary methods to capture both patient and spouse reports in a prospective design. Patients with chronic low back pain (CLBP) and their spouses (N=105 couples) reported on perceived spouse behavior and patient pain 5 times/day for 14days using Personal Data Assistants (PDAs). Concurrent and lagged within-couple associations between patient’s perceptions of spouse criticism/hostility and patient self-reported pain and spouses’ observations of patient pain behaviors revealed that (1) patient perceived spouse criticism and hostility were correlated significantly with pain intensity, and spouse observed patient pain behavior was related significantly with patient perceived hostility at the same time point; (2) patient perceived spouse hostility significantly predicted patient pain intensity 3hours later, and spouse observed pain behaviors significantly predicted patient perceived spouse hostility 3hours later. Results support both EE and interpersonal models, and imply that a comprehensive model would combine these conceptualizations to fully illustrate how spouse criticism/hostility and patient pain interact to produce a negative spiral. Given that marital interactions are amenable to clinical intervention, improved insight into how spouse behavior and patient pain are tightly linked will encourage productive translational efforts to target this neglected area.

Validity of an Observation Method for Assessing Pain Behavior in Individuals With Multiple Sclerosis

ContextPain is a common and complex experience for individuals who live with multiple sclerosis (MS) and it interferes with physical, psychological, and social function. A valid and reliable tool for quantifying observed pain behaviors in MS is critical to understand how pain behaviors contribute to pain-related disability in this clinical population. ObjectivesTo evaluate the reliability and validity of a pain behavioral observation protocol in individuals who have MS. MethodsCommunity-dwelling volunteers with MS (N=30), back pain (N=5), or arthritis (N=8) were recruited based on clinician referrals, advertisements, fliers, web postings, and participation in previous research. Participants completed the measures of pain severity, pain interference, and self-reported pain behaviors and were videotaped doing typical activities (e.g., walking and sitting). Two coders independently recorded frequencies of pain behaviors by category (e.g., guarding and bracing) and interrater reliability statistics were calculated. Naïve observers reviewed videotapes of individuals with MS and rated their pain. The Spearman's correlations were calculated between pain behavior frequencies and self-reported pain and pain ratings by naïve observers. ResultsInterrater reliability estimates indicated the reliability of pain codes in the MS sample. Kappa coefficients ranged from moderate (sighing=0.40) to substantial agreements (guarding=0.83). These values were comparable with those obtained in the combined back pain and arthritis sample. Concurrent validity was supported by correlations with self-reported pain (0.46–0.53) and with self-reports of pain behaviors (0.58). Construct validity was supported by a finding of 0.87 correlation between total pain behaviors observed by coders and mean pain ratings by naïve observers. ConclusionResults support the use of the pain behavior observation protocol for assessing pain behaviors of individuals with MS. Valid assessments of pain behaviors of individuals with MS could lead to creative interventions in the management of chronic pain in this population.

Biological sex and social setting affects pain intensity and observational coding of other people’s pain behaviors

This experiment examines the impact of biological sex and audience composition on laboratory-induced ischemic pain intensity and observational coding of other people’s pain behaviors. Situational context was manipulated by varying the sex and number of audience stimuli in the laboratory setting during the pain task and during observational evaluations of other people’s pain suffering. The analyses revealed sex differences in felt pain intensity and observable pain behaviors, with male subjects reporting lower pain intensity and evidencing fewer pain behaviors than female subjects on average. Follow-up analyses revealed that, after controlling for social anxiety, audience composition was linked to felt pain intensity, and this relation was moderated by participant sex and audience sex, such that only male subjects showed decreased pain intensity with increasing number of female audience members. Sex differences were also found in the rating of other people’s pain behaviors, with male observers rating the pain of others lower than female observers. Composition of the audience influenced observers’ pain ratings such that the presence of more male subjects in the audience correlated with lower observer ratings, whereas the presence of more female subjects correlated with higher observer ratings. This is the first study to show that the sex and the composition of the social context in which pain is experienced affects the intensity of felt pain and the evaluation of other people’s pain suffering. Implications of the findings for measuring and interpreting pain suffering in male and female patients by male and female treatment providers in health care settings are discussed.

The Analgesic Properties of Intraoral Sucrose

The treatment of pain is an essential component of the clinical and ethical care of infants. Despite evidence-based practice consensus statements recommending that infants receive analgesia during minor painful procedures, numerous studies have shown that procedural pain remains poorly managed in this population. Oral sucrose administration has been associated with calming effects and reductions in observed pain behaviors with preterm and term infants aged up to 1 year. The objective of this integrative review is to synthesize findings from published randomized controlled trials evaluating the efficacy and safety of oral sucrose as a preprocedural intervention for mild to moderate procedural pain in infants. Overall, studies indicate that oral sucrose is an effective, safe, convenient, and immediate-acting analgesic for reducing crying time and significantly decreases biobehavioral pain response following painful procedures with infants.

Pain: Putting the Whole Person at the Centre

In the current climate of patient-centred or client-centred care, it is increasingly important to recognize the unique personal experience of pain. As physical therapy students in the 1970s, the authors frequently wondered why the amount of pain experienced in response to a specific injury did not appear to be uniform among patients. Why did some patients have more post-op pain than others? Why did each person behave so differently in response to pain and injury? Why did some patients develop chronic pain after a shoulder injury or become disabled by back pain, whereas others did not, even though they appeared to have a similar injury? At that time there was no “physiological explanation” for the differences in individual outcomes. In fact, we now know that one of the common misconceptions among health care professionals was that the intensity and quality of pain experienced by each person should directly reflect the type and extent of tissue injury.1 This mistaken belief often led clinicians to dichotomize the mind/body experience of pain, so that the clinical approach focused on isolating and treating tissue injury, with little effort to consider the person experiencing the pain. Individual differences in the pain experience and in observed pain behaviours were often considered—consciously or unconsciously—to be “in the patient's head.” Thankfully, pain research has grown exponentially in the last 30 years, and we now understand that pain actually is “in the brain” and that differences in each person's pain experience reflect the individual's unique nervous-system processing, based on a complex integration of genetic,2,3 biopsychomotor,4–6 and social/environmental factors. For example, recent genetic research has identified individual differences in pain tolerance and pain threshold.7 In addition, with the advent of central nervous system imaging, the roles of so-called non-physiological factors in pain processing have actually been visualized in the form of brain activity.