The revised International Association for the Study of Pain definition of pain: concepts, challenges, and compromises

Background factors for chronic low back pain resistant to cognitive behavioral therapy

This study examined the factors that inhibit the therapeutic effects of cognitive behavioral therapy (CBT) and clarify the adaptation judgment criteria of CBT. We included patients with chronic low back pain and allocated them to the adaptation (with visual analog scale [VAS] improvement) or non-adaptation group (without VAS improvement). The patients were analyzed using various psychological tests. CBT improved depressive symptoms and catastrophic thinking; however, they were not correlated with the VAS and did not directly affect low back pain improvement. The non-adaptation group showed an unexplainable/vague sense of anxiety; an excessive focus on searching for pain; a strong intimacy desire; a strong tendency of medical dependency; and fantasy or distortion of the actual experience, especially self-image. Moreover, the patients showed a low ability to objectively express or attribute meaning to pain due to poor language skills, attention-deficit hyperactivity disorder, and emotional value judgment. Individuals with the aforementioned characteristics of pre-CBT psychological tests should select a different treatment approach given the high poor-adaption possibility. Even patients with depressive or anxious symptoms are not necessarily adaptable for CBT. Therefore, pre-CBT tests for treatment suitability are necessary. Future studies should establish a protocol for psychotherapy suitable for the non-adaptation group.

The prevalence of fatigue among Chinese nursing students in post-COVID-19 era

BACKGROUND

Due to the COVID-19 outbreak, all teaching activities in nursing schools were suspended in China, and many nursing students were summoned to work in hospitals to compensate for the shortage of manpower. This study examined the prevalence of fatigue and its association with quality of life (QOL) among nursing students during the post-COVID-19 era in China.

METHODS

This was a multicenter, cross-sectional study. Nursing students in five Chinese universities were invited to participate. Fatigue, depressive and anxiety symptoms, pain and QOL were measured using standardized instruments.

RESULTS

A total of 1,070 nursing students participated. The prevalence of fatigue was 67.3% (95% CI [64.4-70.0]). Multiple logistic regression analysis revealed that male gender (P = 0.003, OR = 1.73, 95% CI [1.20-2.49]), and being a senior nursing student (second year: OR = 2.20, 95% CI [1.46-3.33], P < 0.001; third year: OR = 3.53, 95% CI [2.31-5.41], P < 0.001; and fourth year OR = 3.59, 95% CI [2.39-5.40], P < 0.001) were significantly associated with more severe fatigue. In addition, moderate economic loss during the COVID-19 pandemic (OR = 1.48, 95% CI [1.08-3.33], P < 0.015; compared to low loss), participants with more severe depressive (OR = 1.48, 95% CI [1.22-1.78], P < 0.001) and anxiety symptoms (OR = 1.12, 95% CI [1.05-1.20], P = 0.001), and more severe pain (OR = 1.67, 95%CI [1.46-1.91], P < 0.001) were significantly associated with reported more severe fatigue. After controlling for covariates, nursing students with fatigue had a lower overall QOL score compared to those without (F (1, 1070) = 31.4, P < 0.001).

CONCLUSION

Fatigue was common among nursing students in the post-COVID-19 era. Considering the negative impact of fatigue on QOL and daily functioning, routine physical and mental health screening should be conducted for nursing students. Effective stress-reduction measures should be enforced to assist this subpopulation to combat fatigue and restore optimal health.

Clinical validation of the short and long UNESP-Botucatu scales for feline pain assessment

Background

The UNESP-Botucatu multidimensional feline pain assessment scale (UFEPS) is a valid and reliable instrument for acute pain assessment in cats. However, its limitations are that responsiveness was not tested using a negative control group, it was validated only for ovariohysterectomy, and it can be time-consuming. We aimed to evaluate the construct and criterion validity, reliability, sensitivity, and specificity of the UFEPS and its novel short form (SF) in various clinical or painful surgical conditions.

Methods

Ten client-owned healthy controls (CG) and 40 client-owned cats requiring pain management for clinical or surgical care (20 clinical and 20 surgery group (12 orthopedic and eight soft tissue surgeries) were recruited. Three evaluators assessed pain, in real-time, in clinical cases before and 20 min after rescue analgesia and in surgical cases before and up to 6.5 hours postoperatively, by using the visual analog, numerical ratio, and a simple descriptive scale, in this order, followed by the UFEPS-SF, UFEPS and Glasgow multidimensional feline pain (Glasgow CMPS-Feline) in random order. For the surgical group, rescue analgesia (methadone 0.2 mg/kg IM or IV and/or dipyrone 12.5 mg/kg IV) was performed when the UFEPS-SF score was ≥4 or exceptionally according to clinical judgement. If a third interventional analgesia was required, methadone (0.1-0.2 mg/kg IM) and ketamine (1 mg/kg IM) were administered. For the clinical group, all cats received rescue analgesia (methadone 0.1-0.2 mg/kg IM or IV or nalbuphine 0.5 mg/kg IM or IV), according to the clinician in charge, regardless of pain scores. Construct (1-comparison of scores in cats undergoing pain vs pain-free control cats by unpaired Wilcoxon-test and 2-responsiveness to analgesia by paired Wilcoxon test) and concurrent criterion validity (Spearman correlation of the total score among scales), inter-rater reliability, specificity and sensitivity were calculated for each scale (α = 0.05).

Results

Reliability ranged between moderate and good for the UFEPS and UFEPS-SF (confidence intervals of intraclass coefficients = 0.73-0.86 and 0.63-0.82 respectively). The Spearman correlation between UFEPS and UFEPS-SF was 0.85, and their correlation with Glasgow CMPS-Feline was strong (0.79 and 0.78 respectively), confirming criterion validity. All scales showed construct validity or responsiveness (higher scores of cats with clinical and postoperative pain vs healthy controls, and the reduction in scores after rescue analgesia). The sensitivity and specificity of the UFEPS, UFEPS-SF and Glasgow CMPS-Feline were moderate (sensitivity 83.25, 78.60% and 74.28%; specificity 72.00, 84.67 and 70.00%, respectively).

Conclusions

Both UFEPS and UFEPS-SF showed appropriate concurrent validity, responsiveness, reliability, sensitivity, and specificity for feline acute pain assessment in cats with various clinical and orthopedic and soft tissue surgical conditions.

Development of Non-opioid Analgesics Targeting Two-pore Domain Potassium Channels

Two-pore domain potassium (K2P) channels are a diverse family of potassium channels. K2P channels generate background leak potassium currents to regulate cellular excitability and are thereby involved in a wide range of neurological disorders. K2P channels are modulated by a variety of physicochemical factors such as mechanical stretch, temperature, and pH. In the the peripheral nervous system (PNS), K2P channels are widely expressed in nociceptive neurons and play a critical roles in pain perception. In this review, we summarize the recent advances in the pharmacological properties of K2P channels, with a focus on the exogenous small-molecule activators targeting K2P channels. We emphasize the subtype-selectivity, cellular and in vivo pharmacological properties of all the reported small-molecule activators. The key underlying analgesic mechanisms mediated by K2P are also summarized based on the data in the literature from studies using small-molecule activators and genetic knock-out animals. We discuss advantages and limitations of the translational perspectives of K2P in pain medicine and provide outstanding questions for future studies in the end.

Ultrasound-guided peripheral intravenous catheters insertion in patient with difficult vascular access: Short axis/out-of-plane versus long axis/in-plane, a randomized controlled trial

PURPOSE

The aim of this study was to evaluate the rate of successful peripheral cannulation between short-axis and long-axis ultrasound guided techniques.

METHODS

A single-center, two-arm randomized controlled, intention-to-treat, open-label study was conducted at the Emergency Department, between August and November 2020. Patients requiring a peripheral intravenous catheter insertion and identified as having a difficult intravascular access, were enrolled and followed for up to 96 h.The primary endpoint was the correct placement of the peripheral intravenous catheter. The secondary endpoints were number of venipunctures, intra-procedural pain, local complications, and positive blood return during the follow up.

RESULTS

A total of 283 patients were enrolled: 141 subjects were randomized to the short-axis and 142 to the long-axis group. Success rate was 96.45% (135/141; 95% CI, 91.92%-98.84%) in the short-axis group compared with 92.25% (132/142; 95% CI, 86.56%-96.07%) in the long-axis group (p = 0.126). No significant differences were found in terms of intraprocedural pain and local complications. Higher rate of positive blood return at 72 h [3/17 long-axis, 14/17 short-axis (p = 0.005)] and 96 h [1/10 long-axis, 9/10 short-axis 96 h, (p = 0.022)] was found for the short-axis group.

CONCLUSIONS

No differences were found between short-axis and long-axis techniques in terms of success rate, intraprocedural pain, and local complications. Despite this, a slightly higher success rate, a lower number of venipunctures, and a higher rate of positive blood return at 72 and 96 h together with an easier ultrasound technique could suggest a short-axis approach.

Correlation between Biomarkers of Pain in Saliva and PAINAD Scale in Elderly People with Cognitive Impairment and Inability to Communicate

The pain assessment in advanced dementia (PAINAD) appears to be a clinically useful tool. However, the salivary determination of tumor necrosis factor receptor type II (sTNF-RII) and secretory IgA (sIgA) as pain biomarkers is still incipient. The aim was to correlate the PAINAD score with sTNF-RII and sIgA biomarker levels in the saliva of patients with advanced dementia. In this regard, a cross-sectional study was conducted. The sample consisted of 75 elderly patients with a clinical diagnosis of dementia and a global deterioration scale (GDS) score of 5 to 7. The PAINAD scale was determined by a previously trained professional and the collection of salivary samples was performed using the passive secretion method. Human sTNF-RII and sIgA using ELISA kits. The results showed a correlation between the PAINAD scale (numeric, binary, and recoded) and sTNF-RII and sIgA (p < 0.001). No association between the sociodemographic and clinical variables and the PAINAD scale was found (p > 0.05). Between 97.3% and 96.2% of patients with pain on the PAINAD scale also showed pain based on the sTNF-RII levels; in all of them, sIgA levels did not fit the logistic models. Therefore, the correlation highlights the usefulness of this scale and confirms the usefulness of sTNF-RII and sIgA as biomarkers of pain.

Sigma-1 receptor antagonist (BD-1063) potentiates the antinociceptive effect of quercetin in neuropathic pain induced by chronic constriction injury

Neuropathic pain is characterized by the presence of hyperalgesia and allodynia. Pharmacological treatments include the use of antiepileptics such as pregabalin or gabapentin, as well as antidepressants; however, given the role of the sigma-1 receptor in the generation and maintenance of pain, it has been suggested that sigma-1 receptor antagonists may be effective. There are also other alternatives that have been explored, such as the use of flavonoids such as quercetin. Due to the relevance of drug combinations in therapeutics, the objective of this work was to evaluate the effect of the combination of BD-1063 with quercetin in a chronic sciatic nerve constriction model using the "Surface of Synergistic Interaction" analysis method. The combination had preferable additive or synergistic effects, with BD-1063 (17.8 mg/kg) + QUER (5.6 mg/kg) showing the best antinociceptive effects. The required doses were also lower than those used individually to obtain the same level of effect. Our results provide the first evidence that the combination of a sigma-1 receptor antagonist and the flavonoid quercetin may be useful in the treatment of nociceptive behaviors associated with neuropathic pain, suggesting a new therapeutic alternative for this type of pain.

Hand therapists' perspectives and practices related to musculoskeletal pain: A biopsychosocial lens

BACKGROUND

While the biopsychosocial model is advocated for pain management, biomedical approaches continue to dominate in practice. Understanding musculoskeletal clinicians' perspectives and practices related to pain can inform training needs to optimize care. Little is known regarding the viewpoint of hand therapists who may not have exposure to modern pain models.

OBJECTIVE

To explore hand therapists' perspectives and practices related to musculoskeletal pain using a biopsychosocial lens.

METHODS

This interpretive descriptive qualitative study was embedded in an explanatory sequential mixed methods design. Thirteen hand therapists in the United States were purposefully sampled based on low and high scores on the Revised Neurophysiology of Pain Questionnaire. Each therapist participated in one semi-structured virtual interview. Data were analyzed using open and a priori codes, which were synthesized into themes that aligned with each domain of the biopsychosocial model.

FINDINGS

Participants described "balancing local tissues and the brain," "empowering through education and function," and "looking beyond the individual." Recognition of multidimensional components of pain reinforced participants' awareness that "pain is always real."

DISCUSSION

Hand therapists appreciated pain as a multidimensional phenomenon, with biological, psychological, and social facets. However, a potential bias toward structural pathology warrants additional training to promote high-value musculoskeletal care.

Basic Mechanisms of Pain in Osteoarthritis: Experimental Observations and New Perspectives

The specific changes in the peripheral neuronal pathways underlying joint pain in osteoarthritis are the focus of this review. The plasticity of the nociceptive system in osteoarthritis and how this involves changes in the structural, physiologic, and genetic properties of neurons in pain pathways are discussed. The role of the neurotrophin, nerve growth factor, in these pathogenic processes is discussed. Finally, how neuronal pathways are modified by interaction with the degenerating joint tissues they innervate and with the innate immune system is considered. These extensive cellular interactions provide a substrate for identification of targets for osteoarthritis pain.

Chronic Pain: What Does It Mean? A Review on the Use of the Term Chronic Pain in Clinical Practice

Chronic pain is nowadays used as an umbrella term referring to a wide range of clinical conditions, such as fibromyalgia, migraine, or long-standing pain states without actual known causes. However, labeling a patient’s clinical condition with the term “chronic pain”, when dealing with pain lasting longer than 3 months, might be misleading. This paper aims at analyzing the possible pitfalls related to the use of the term “chronic pain” in the clinical field. It appears, indeed, that the term “chronic pain” shows a semantic inaccuracy on the basis of emerging scientific evidences on the pathogenesis of different long-standing pain states. The major pitfalls in using this label emerge in clinical settings, especially with patients having a biomedical perspective on pain or from different cultures, or with healthcare providers of other medical specialties or different disciplines. A label solely emphasizing temporal features does not help to discern the multifaceted complexity of long-standing pain states, whose onset, maintenance and exacerbation are influenced by a complex and interdependent set of bio-psycho-social factors. Thus, finding a more meaningful name might be important. We call upon the necessity of bringing awareness and implementing educational activities for healthcare providers, as well as for the public, on the biopsychosocial approach to assess, prevent and care of chronic pain. Further research on the etiopathogenetic processes of chronic pain states is also required, together with examinative diagnostic methods, to individuate the most appropriate label(s) representing the complex long-standing pain states and to avoid adopting the term “chronic pain” inappropriately.

Chronic Pain in Dogs and Cats: Is There Place for Dietary Intervention with Micro-Palmitoylethanolamide?

The management of chronic pain is an integral challenge of small animal veterinary practitioners. Multiple pharmacological agents are usually employed to treat maladaptive pain including opiates, non-steroidal anti-inflammatory drugs, anticonvulsants, antidepressants, and others. In order to limit adverse effects and tolerance development, they are often combined with non-pharmacologic measures such as acupuncture and dietary interventions. Accumulating evidence suggests that non-neuronal cells such as mast cells and microglia play active roles in the pathogenesis of maladaptive pain. Accordingly, these cells are currently viewed as potential new targets for managing chronic pain. Palmitoylethanolamide is an endocannabinoid-like compound found in several food sources and considered a body's own analgesic. The receptor-dependent control of non-neuronal cells mediates the pain-relieving effect of palmitoylethanolamide. Accumulating evidence shows the anti-hyperalgesic effect of supplemented palmitoylethanolamide, especially in the micronized and co-micronized formulations (i.e., micro-palmitoylethanolamide), which allow for higher bioavailability. In the present paper, the role of non-neuronal cells in pain signaling is discussed and a large number of studies on the effect of palmitoylethanolamide in inflammatory and neuropathic chronic pain are reviewed. Overall, available evidence suggests that there is place for micro-palmitoylethanolamide in the dietary management of chronic pain in dogs and cats.

Pain medicine as a career

Pain is one of the most common causes of seeking medical care. In the day to day clinical practice, incidence of pain of some origin is next only to common cold. The average life span of an Indian has also increased and this population is vulnerable to chronic and cancer pain. Anaesthesiologists are well-versed with the art and science of treating pain and their role as pain physician is a natural extension of the professional work. ‘Pain Medicine’ is growing as a speciality. Last two decades have seen an explosive growth in the scientific study of pain and anaesthesiologists taking up pain medicine as a career. Postgraduate students can certainly adopt this super speciality. This article highlights the merits and depicts various aspects of ‘pain medicine’ as a career.

Pain behavior in SCN9A (Nav1.7) and SCN10A (Nav1.8) mutant rodent models

The two voltage gated sodium channels Nav1.7 and Nav1.8 are expressed in the peripheral nervous system and involved in various pain conditions including inflammatory and neuropathic pain. Rodent models bearing deletions or mutations of the corresponding genes, Scn9a and Scn10a, were created in order to understand the role of these channels in the pathophysiological mechanism underlying pain symptoms. This review summarizes the pain behavior profiles reported in Scn9a and Scn10a rodent models. The complete loss-of-function or knockout (KO) of Scn9a or Scn10a and the conditional KO (cKO) of Scn9a in specific cell populations were shown to decrease sensitivity to various pain stimuli. The Possum mutant mice bearing a dominant hypermorphic mutation in Scn10a revealed higher sensitivity to noxious stimuli. Several gain-of-function mutations were identified in patients with painful small fiber neuropathy. Future knowledge obtained from preclinical models bearing these mutations will allow understanding how these mutations affect pain. In addition, the review gives perspectives for creating models that better mimic patients' pain symptoms in view to developing novel analgesic strategies.

Pain-like behavior in mice can be induced by the environmental context in which the pain stimulus was previously given

It has been known for decades that classical conditioning influences pain perception. However, the precise mechanism of pain modified by conditioning remains unclear, partly because of the lack of dedicated behavioral tests. In the present study, we aimed to develop a new method to detect conditioned pain using mice that were injected with formalin as an unconditioned nociceptive stimulus into the hind paw repetitively under a neutral environment. On the test day, the mice exhibited a pain-like behavior without the application of a pain stimulus in the environment. These results demonstrate that a conditioned nociceptive response can be induced by exposure alone to the environmental context in which the pain was previously experienced. The conditioned nociceptive response was sustained for at least 2 weeks. Furthermore, the conditioned nociceptive response was reduced by fentanyl but not by ibuprofen, pregabalin or fluvoxamine. This method may be useful for studying the mechanisms of irritable chronic pain and for the development of novel therapeutic strategies.

Arm movement adaptation to concurrent pain constraints

How do humans coordinate their movements in order to avoid pain? This paper investigates a motor task in the presence of concurrent potential pain sources: the arm must be withdrawn to avoid a slap on the hand while avoiding an elbow obstacle with an electrical noxious stimulation. The results show that our subjects learned to control the hand retraction movement in order to avoid the potential pain. Subject-specific motor strategies were used to modify the joint movement coordination to avoid hitting the obstacle with the elbow at the cost of increasing the risk of hand slap. Furthermore, they used a conservative strategy as if assuming an obstacle in 100% of the trials.

Paediatricians' Views on Pain in Children with Profound Intellectual and Multiple Disabilities

Pain is a frequent issue in children with profound intellectual and multiple disabilities (PIMD). Its identification and treatment can prove highly challenging for primary care physicians, mainly because of the children’s limited communication abilities. We used an online survey to explore paediatricians’ views regarding the experience and management of pain in children with PIMD and invited 480 professionals working in the canton of Vaud, Switzerland, to take part. We received 121 responses (participation rate 25.5%). A large majority of respondents provided care to children with PIMD. All paediatricians considered that these children feel pain at least as much as typically developing children. However, paediatricians had mixed views on their tolerance to pain. More than 90% held the view that their pain is under-assessed and undertreated. The principal barriers they reported to appropriate management were communication limitations with the child, difficulties in pain assessment, lack of knowledge about children with disabilities and lack of experience. Paediatricians have complex opinions regarding how children with PIMD experience pain and how to manage this problem. Professional education and training on the specificities of children with PIMD, including how to address their pain, seem necessary to foster paediatricians’ ability and confidence in approaching this complex issue.

Pain, Pathophysiological Mechanisms, and New Therapeutic Options for Alternative Analgesic Agents in Sheep: A Review and Investigation

Simple Summary

The purpose of this review is to provide current data on the definition and types of pain, describe its neuropharmacological and pathological mechanisms, and present a comparative analysis of the results obtained after intracerebroventricular (ICV) infusion of voltage-gated calcium channel inhibitors (VGCCIs) such as diltiazem, nifedipine, and verapamil, cholecystokinin receptor antagonists (PD, proglumide), and glutamatergic receptor antagonists (L-AP₃, DL-AP₃) during experimental distension of the duodenal and/or descending colonic wall. This method was used as a model for suppressing pain in sheep based on viscero-visceral inhibitory reflex, measured by the inhibition of behavioral symptoms of stress, degree of reticulo-ruminal motility, and changes in plasma cortisol and catecholamine concentration. After ICV infusion, all tested substances suppressed, to varying degrees, the viscero-visceral inhibitory reflex, tachycardia, hyperventilation, bleating, and gnashing of the teeth, whereas they increased the levels of cortisol and plasma catecholamines in sheep. These substances could be potential non-narcotic agents for the treatment of visceral intestinal pain (intestinal colic) in sheep, but clinical confirmation of the substances’ efficacy for treating intestinal colic is needed.

Abstract

Relief from suffering is the guiding principle of medical and veterinary ethics. Medical care for animals should be carried out to meet all welfare conditions. The need for pain management is demonstrated by recent monographs devoting attention to this urgent ethical need. Little data, however, are available on the prevention and attenuation of pain in sheep. After administration of narcotic analgesics used for severe visceral pain, sheep react with a state of excitement. Therefore, it was decided to experimentally investigate the usefulness of potential non-narcotic drugs to relieve pain in sheep with intestinal colic caused by 10 min of mechanical distension of their duodenal and/or descending colonic wall. The results indicate the potential usefulness of VGCCIs (diltiazem, nifedipine, verapamil), cholecystokinin receptor antagonists (PD, proglumide), and metabotropic glutaminergic receptor antagonists (mGluRAs), such as L-AP₃, DL-AP₃. As a premedication, these substances prevented the occurrence of symptoms of acute intestinal pain including atony of reticulo-rumen, tachycardia, hyperventilation, moaning, gnashing of teeth, hypercortisolemia, and catecholaminemia; hence, these substances are considered potential agents in the treatment of sheep visceral pain.

Prevalência da dor em estudantes universitários

Objetivo: revisar estudos sobre a prevalência e os fatores relacionados a dor em estudantes universitários brasileiros.Métodos: revisão sistemática com registro na Prospero (CRD42020204197), de artigos publicados em periódicos nacionais e internacionais, nas bases Pubmed, Ebsco, Lilacs, Medline, Portal da BVS, Google Acadêmico e SciELO. Descritores: “Pain”, “Chronic Pain”, Students”, “Students, Health Occupations” e “Universities”. Incluídos: a) estudos observacionais; b) transversais; c) publicados em periódicos nacionais ou internacionais; d) redigidos em inglês ou português; e) desenvolvidos com acadêmicos, em instituições de ensino superior brasileiras; f) que tenham avaliado a prevalência e fatores relacionados a dor; g) Tais estudos deviam estar disponíveis na íntegra. Não foram realizadas restrições quanto ao período de publicação dos estudos. Excluídos: h) estudos que não relataram a metodologia aplicada para mensuração do desfecho; i) estudos com instrumentos que não avaliaram a dor como desfecho primário, posteriormente apresentando dados insuficientes para análise dos resultados; j) estudos com acadêmicos de outros países; e k) estudos com inconsistência dos dados relacionados a amostra e seus principais resultados. O risco de viés foi avaliado com a escala Downs and Black e a proposta por Hoy.Resultados: as buscas identificaram 67 artigos, contudo, após análise, 10 foram incluídos. Esses eram estudos transversais, publicados entre 2011 e 2019, sendo cinco deles da região Nordeste. A amostra totalizou 3.268 acadêmicos, sendo 68% mulheres. A prevalência da dor variou entre 14,4% e 98% e a dor crônica entre 11,5% e 59,7%. A maior percepção da dor autorrelatada foi de 4,12 ± 2,15. As principais queixas álgicas foram nas regiões de lombar e de membros superiores. Na análise metodológica, os estudos possuem moderado a alto risco de viés.Conclusões: por fim, as evidências indicam uma alta prevalência de dor, bem como sua cronificação em universitários. Contudo, estudos com adequado rigor metodológico ainda são necessários para a confirmação dos resultados apresentados.

Prevalence and correlates of low back pain among undergraduate medical students in Serbia, a cross-sectional study

Background

Low back pain (LBP) is a serious health problem among medical students. We aimed to investigate the prevalence and associated factors for LBP among Serbian medical students.

Methods

A cross-sectional study was performed among medical students at one University in Serbia. Data was collected by a self-reported questionnaire. Logistic regression was used to determine the factors associated with LBP; results from the analyses were expressed as odds ratios (OR) with 95% confidence intervals (CI).

Results

The study sample comprised 499 medical students, giving a response rate of 92.9%. The mean age of the participants was 22.0 ± 2.2 years (range 18–34). Overall, 20.8% (104/499) of medical students had LBP at the time of study. Cigarette smoking (OR = 2.5, 95% CI [1.5–4.2], p = 0.001), stress during classes (OR = 1.8, 95% CI [1.1–3.0], p = 0.039), incorrect sleeping position (OR = 1.9, 95% CI [1.2–3.1], p = 0.006) and family history of LBP (OR = 1.6, 95% CI [1.1–2.7], p = 0.047) were independently associated with high prevalence of LBP at the time of the study.

Conclusions

LBP is a highly prevalent health problem in medical students in Serbia. The association between LBP and cigarette smoking, stress during classes, incorrect sleeping position and LBP in family history has been observed in medical students.

A Multi-Method Approach to Understand Parent Behaviors During Child Acute Pain

Abstract. Parent behaviors strongly predict child responses to acute pain; less studied are the factors shaping parent behaviors. Heart rate variability (HRV) is considered a physiological correlate of emotional responding. Resting or “trait” HRV is indicative of the capacity for emotion regulation, while momentary changes or “state” HRV is reflective of current emotion regulatory efforts. This study aimed to examine: (1) parent state HRV as a contributor to parent verbal behaviors before and during child pain and (2) parent trait HRV as a moderator between parent emotional states (anxiety, catastrophizing) and parent behaviors. Children 7–12 years of age completed the cold pressor task (CPT) in the presence of a primary caregiver. Parents rated their state anxiety and catastrophizing about child pain. Parent HRV was examined at 30-second epochs at rest (“trait HRV”), before (“state HRV-warm”), and during their child’s CPT (“state HRV-cold”). Parent behaviors were video recorded and coded as coping-promoting or distress-promoting. Thirty-one parents had complete cardiac, observational, and self-report data. A small to moderate negative correlation emerged between state HRV-cold and CP behaviors during CPT. Trait HRV moderated the association between parent state catastrophizing and distress-promoting behaviors. Parents experiencing state catastrophizing were more likely to engage in distress-promoting behavior if they had low trait HRV. This novel work suggests parents who generally have a low (vs. high) HRV, reflective of low capacity for emotion regulation, may be at risk of engaging in behaviors that increase child distress when catastrophizing about their child’s pain.

Patient and provider perspectives on patient-centered chronic pain management

BACKGROUND

Fifty million American adults have chronic pain, and nearly 20 million have high-impact, or disabling, chronic pain, with higher prevalence associated with advancing age. Patient-centered pain management has been cited as a national priority to ensure that patient values and preferences guide clinical decisions. However, explicit, and practical strategies for implementing patient-centered pain management have not been disseminated.

AIMS

The aim of this study was to elicit perceptions, beliefs, and experiences of patient-centered pain management among adults with chronic pain as well as among providers that could be used to develop recommendations for implementation and evaluation of patient-centered pain management.

DESIGN

A descriptive qualitative study.

SETTINGS/PARTICIPANTS

Fourteen adults with chronic pain were recruited from the communities. Besides, five providers caring for patients with chronic pain at an outpatient spine center affiliated to one academic hospital joined this study.

METHODS

Each focus group lasted about 1 hour, which was recorded and transcribed verbatim. Data were analyzed using Erlingsson and Brysiewicz's content analysis to identify themes and develop recommendations.

RESULTS

Four overarching themes emerged, including: (1) patient and (2) provider characteristics affecting patient-centered pain management; (3) processes and (4) outcomes of patient-centered pain management. We also visually depicted the determinants, processes, and outcomes of patient-centered pain management among providers and individuals with chronic pain.

CONCLUSIONS

Patients emphasized their desire for a provider that listens, genuinely cares, and sees them holistically to provide the best individual and tailored care for them. Providers focused on setting realistic expectations, vocalizing the significance of pain education at a young age, and balancing patient satisfaction and opioid prescriptions. While patients can be empowered to self-manage their chronic pain due to patient-centered pain care, provider mental exhaustion and mistrust of providers among patients resulted from suboptimal pain management.

Intraepidermal Nerve Fiber Density as Measured by Skin Punch Biopsy as a Marker for Small Fiber Neuropathy: Application in Patients with Fibromyalgia

Small fiber neuropathy (SFN) is a type of peripheral neuropathy that occurs from damage to the small A-delta and C nerve fibers that results in the clinical condition known as SFN. This pathology may be the result of metabolic, toxic, immune-mediated, and/or genetic factors. Small fiber symptoms can be variable and inconsistent and therefore require an objective biomarker confirmation. Small fiber dysfunction is not typically captured by diagnostic tests for large-fiber neuropathy (nerve conduction and electromyographic study). Therefore, skin biopsies stained with PGP 9.5 are the universally recommended objective test for SFN, with quantitative sensory tests, autonomic function testing, and corneal confocal imaging as secondary or adjunctive choices. Fibromyalgia (FM) is a heterogenous syndrome that has many symptoms that overlap with those found in SFN. A growing body of research has shown approximately 40-60% of patients carrying a diagnosis of FM have evidence of SFN on skin punch biopsy. There is currently no clearly defined phenotype in FM at this time to suggest whom may or may not have SFN, though research suggests it may correlate with severe cases. The skin punch biopsy provides an objective tool for use in quantifying small fiber pathology in FM. Skin punch biopsy may also be repeated for surveillance of the disease as well as measuring response to treatments. Evaluation of SFN in FM allows for better classification of FM and guidance for patient care as well as validation for their symptoms, leading to better use of resources and outcomes.

Health-Related Quality of Life and Psychological Features in Post-Stroke Patients with Chronic Pain: A Cross-Sectional Study in the Neuro-Rehabilitation Context of Care

This study aims at exploring disability, health-related quality of life (HrQoL), psychological distress, and psychological features in post-stroke patients with chronic pain. An observational cross-sectional study involving 50 post-stroke patients (25 with chronic pain and 25 without pain) was conducted. The primary outcome was the self-reported level of disability and HrQoL which were both assessed through the Stroke Impact Scale 3.0. Both psychological distress and specific psychological features (i.e., self-efficacy, coping strategies, psychological flexibility, perceived social support) were examined. Post-stroke patients with chronic pain reported statistically significant higher levels of disability and worse HrQoL, higher psychological distress and inflexibility, as well as a lower level of self-efficacy and problem-oriented coping strategies than patients without pain (p < 0.001). Finally, correlation analysis in the group of stroke survivors with pain showed that higher levels of disability were significantly related to higher psychological distress. This study confirms the negative influence of chronic pain on disability and HrQoL in post-stroke patients and presents preliminary insights on the association between chronic pain, disability, HrQoL, psychosocial distress, and the patient’s approach in dealing with personal difficulties and emotions. These findings carry further implications for multidisciplinary management of post-stroke patients with chronic pain.

Experimentally evoked pain in Alzheimer's disease

BACKGROUND

Pain continues to be underrecognized and undertreated in Alzheimer's disease (AD) while existing guidance about pain assessment and management in dementia is not widespread. Brain regions involved in pain processing and modulation are damaged during AD, and the pain experience in AD is not well understood. Experimental pain studies using psychophysics can further our understanding of the pain experience in AD, which may lead to improved assessment and management of pain in people living with AD.

OBJECTIVE

A systematic review was conducted to explicate the current understanding of experimentally evoked pain in AD from primary research using psychophysical methods.

DATA SOURCES

Peer-reviewed publications were found via PubMed, CINAHL, and PsycINFO. A total of 18 primary research, peer-reviewed full articles that met inclusion criteria were included, representing 929 total participants.

CONCLUSIONS

Experimentally evoked pain in people with AD demonstrates that despite cognitive impairment and a reduced ability to effectively communicate, individuals with AD experience pain similar to or more unpleasant than cognitively intact older adults. This may mean amplified pain unpleasantness in people with AD.

IMPLICATIONS FOR PRACTICE

Our current best practices need to be widely disseminated and put into clinical practice. Self-report of pain continues to be the gold standard, but it is ineffective for noncommunicative patients and those unable to understand pain scales or instructions because of memory/cognitive impairment. Instead, pain treatment should be ethically initiated based on patient reports and behaviors, caregiver/surrogate reports, review of the medical record for painful conditions, analgesic trials, and regular reassessments.

Therapeutic Advances in Diabetes, Autoimmune, and Neurological Diseases

Since 2015, 170 small molecules, 60 antibody-based entities, 12 peptides, and 15 gene- or cell-therapies have been approved by FDA for diverse disease indications. Recent advancement in medicine is facilitated by identification of new targets and mechanisms of actions, advancement in discovery and development platforms, and the emergence of novel technologies. Early disease detection, precision intervention, and personalized treatments have revolutionized patient care in the last decade. In this review, we provide a comprehensive overview of current and emerging therapeutic modalities developed in the recent years. We focus on nine diseases in three major therapeutics areas, diabetes, autoimmune, and neurological disorders. The pathogenesis of each disease at physiological and molecular levels is discussed and recently approved drugs as well as drugs in the clinic are presented.

Neuroimmune interactions and osteoarthritis pain: focus on macrophages

Bidirectional interactions between the immune system and the nervous system are increasingly appreciated as playing a pathogenic role in chronic pain. Unraveling the mechanisms by which inflammatory pain is mediated through communication between nerves and immune cells may lead to exciting new strategies for therapeutic intervention. In this narrative review, we focus on the role of macrophages in the pathogenesis of osteoarthritis (OA) pain. From regulating homeostasis to conducting phagocytosis, and from inducing inflammation to resolving it, macrophages are plastic cells that are highly adaptable to their environment. They rely on communicating with the environment through cytokines, growth factors, neuropeptides, and other signals to respond to inflammation or injury. The contribution of macrophages to OA joint damage has garnered much attention in recent years. Here, we discuss how macrophages may participate in the initiation and maintenance of pain in OA. We aim to summarize what is currently known about macrophages in OA pain and identify important gaps in the field to fuel future investigations.

Telerehabilitation for Pain Management

Telerehabilitation for pain management uses communication technology to minimize geographic barriers. Access to such technology has proven critically important during the coronavirus disease-2019 pandemic and has been useful for patients with chronic pain disorders unable to travel. The evaluation and treatment of such disorders requires a whole health approach that individualizes treatment options and delivers care through a biopsychosocial approach. The goals of care are unchanged from an in-person patient-provider experience. Telerehabilitation can be successfully implemented in pain management with appropriate consideration for staging an evaluation, a structured approach to the visit, and application of standard clinical metrics.

A Healing Journey with Chronic Pain: A Meta-Ethnography Synthesizing 195 Qualitative Studies

Objective

There is a large body of research exploring what it means for a person to live with chronic pain. However, existing research does not help us understand what it means to recover. We aimed to identify qualitative research that explored the experience of living with chronic pain published since 2012 and to understand the process of recovery.

Design

A synthesis of qualitative research using meta-ethnography.

Methods

We used the seven stages of meta-ethnography. We systematically searched for qualitative research, published since 2012, that explored adults’ experiences of living with, and being treated for, chronic pain. We used constant comparison to distill the essence of ideas into themes and developed a conceptual model.

Results

We screened 1,328 titles and included 195 studies. Our conceptual model indicates that validation and reconnection can empower a person with chronic pain to embark on a journey of healing. To embark on this journey requires commitment, energy, and support.

Conclusions

The innovation of our study is to conceptualize healing as an ongoing and iterating journey rather than a destination. Health interventions for chronic pain would usefully focus on validating pain through meaningful and acceptable explanations; validating patients by listening to and valuing their stories; encouraging patients to connect with a meaningful sense of self, to be kind to themselves, and to explore new possibilities for the future; and facilitating safe reconnection with the social world. This could make a real difference to people living with chronic pain who are on their own healing journeys.

Agreement and reliability of the Feline Grimace Scale among cat owners, veterinarians, veterinary students and nurses

This study aimed to evaluate the agreement and reliability of the Feline Grimace Scale (FGS) among cat owners, veterinarians, veterinary students and nurses/technicians. Raters (n = 5/group) scored 100 images using the FGS (ear position, orbital tightening, muzzle tension, whiskers position and head position). Intra-class correlation coefficients (ICC) were used to assess inter- and intra-rater reliability. Agreement between each group and the veterinarian group (gold-standard) was calculated using the Bland-Altman method. Effects of gender, age and number of cats owned on FGS scores were assessed using linear mixed models. Inter-rater reliability was good for FGS final scores (ICC > 0.8). The muzzle and whiskers yielded lower reliability (ICC = 0.39 to 0.74). Intra-rater reliability was excellent for students and veterinarians (ICC = 0.91), and good for owners and nurses (ICC = 0.87 and 0.81, respectively). A very good agreement between all groups and veterinarians (bias < 0.1 and narrow limits of agreement) was observed. Female raters assigned higher FGS scores than males (p = 0.006); however, male raters were underrepresented in this study. Scores were not affected by age or number of cats owned. The FGS is reliable for feline acute pain assessment when used by individuals with different experience.

Perception of discomfort by mechanical ventilation patients in the Intensive Care Unit: A qualitative study

BACKGROUND

Routine care in intensive care units (ICU) results in patient pain and discomfort. While pain is treated with analgesics, discomfort is generally not well characterised or addressed. Since many ICU patients communicate only non-verbally, practitioners often cannot discern between pain or discomfort when treating such patients, potentially leading to inappropriate analgesic administration. A first step in discriminating between pain and discomfort is understanding how patients perceive their discomfort.

OBJECTIVE

To describe mechanically ventilated ICU patients' perceptions of discomfort and how they differentiate discomfort from pain.

METHOD

A qualitative descriptive study using semi-structured interviews conducted with 13 patients in a Medical and General ICU who survived mechanical ventilation. Transcripts were analysed using content analysis.

FINDINGS

Two main discomfort themes were identified: unpleasant physical sensations and unpleasant psychological feelings. Each theme was further divided into subcategories. Most patients did not describe high levels of pain and did not associate physical discomfort with pain.

CONCLUSIONS

Discomfort, as described by patients, stems from both physical sensations and psychological feelings. Pain was less often described as a negative ICU experience, while other non-pain sources of discomfort were more likely to be recalled. Therefore, practitioners should not only focus on treating pain but also on treating overall comfort to improve the quality of the ICU experience and potentially decrease post-ICU psychological sequela.

Neonates as intrinsically worthy recipients of pain management in neonatal intensive care

One barrier to optimal pain management in the neonatal intensive care unit (NICU) is how the healthcare community perceives, and therefore manages, neonatal pain. In this paper, we emphasise that healthcare professionals not only have a professional obligation to care for neonates in the NICU, but that these patients are intrinsically worthy of care. We discuss the conditions that make neonates worthy recipients of pain management by highlighting how neonates are (1) vulnerable to pain and harm, and (2) completely dependent on others for pain management. We argue for a relational account of ethical decision-making in the NICU by demonstrating how an increase in vulnerability and dependence may be experienced by the healthcare community and the neonate's family. Finally, an ethical framework for decisions around neonatal pain management is proposed, focussing on surrogate decision-making and the importance of compassionate action through both a reflective and an affective empathy. As empathy can be highly motivating against pain, we propose that, in addition to educational programs that raise awareness and knowledge of neonatal pain and pain management, healthcare professionals must cultivate empathy in a collective manner, where all members of the NICU team, including parents, are compassionate decision-makers.

Pain, Smell, and Taste in Adults: A Narrative Review of Multisensory Perception and Interaction

Every day our sensory systems perceive and integrate a variety of stimuli containing information vital for our survival. Pain acts as a protective warning system, eliciting a response to remove harmful stimuli; it may also be a symptom of an illness or present as a disease itself. There is a growing need for additional pain-relieving therapies involving the multisensory integration of smell and taste in pain modulation, an approach that may provide new strategies for the treatment and management of pain. While pain, smell, and taste share common features and are strongly linked to emotion and cognition, their interaction has been poorly explored. In this review, we provide an overview of the literature on pain modulation by olfactory and gustatory substances. It includes adult human studies investigating measures of pain threshold, tolerance, intensity, and/or unpleasantness. Due to the limited number of studies currently available, we have structured this review as a narrative in which we comment on experimentally induced and clinical pain separately on pain–smell and pain–taste interaction. Inconsistent study findings notwithstanding, pain, smell, and taste seem to interact at both the behavioral and the neural levels. Pain intensity and unpleasantness seem to be affected more by olfactory substances, whereas pain threshold and tolerance are influenced by gustatory substances. Few pilot studies to date have investigated these effects in clinical populations. While the current results are promising for the future, more evidence is needed to elucidate the link between the chemical senses and pain. Doing so has the potential to improve and develop novel options for pain treatment.

Beyond Pain: A Study on the Variance of Pain Thresholds Within BDSM Interactions in Dominants and Submissives

BACKGROUND

BDSM is an acronym describing bondage and discipline, dominance and submission, and sadism and masochism. Afflicting or receiving pain is usually an important part of the BDSM interaction.

AIM

This research will focus on better understanding the aspect of pain within a BDSM interaction.

METHODS

Submissive and dominant counterparts of 35 couples were recruited to participate in a BDSM interaction, of which 34 dominants and 33 submissives were included in the analyses. A non-BDSM interested control group (n = 27) was included to control for social interaction, of which 24 were included in the analyses.

OUTCOMES

This research investigates the differences in (i) baseline pain thresholds, (ii) the impact of a BDSM interaction on those thresholds, and (iii) threshold moderating factors like pain cognition between submissive and dominant BDSM participants and control individuals.

RESULTS

BDSM practitioners have a higher pain threshold overall and a BSDM interaction will result in a temporary elevation of pain thresholds for submissives. Additionally, pain thresholds in dominants will be dependent upon their fear of pain and tendency to catastrophize pain and submissives will experience less fear of pain than the control group.

CLINICAL IMPLICATIONS

By further enhancing our understanding of the mechanisms behind a BDSM interaction in this way, we aspire to relieve the stigma these practitioners still endure.

STRENGTHS & LIMITATIONS

This is one of the first studies of its kind with a large sample size compared to similar research, which makes it a significant contribution to the field. It must be mentioned that there is a possible selection bias because recruitment was only done through the Flemish BDSM community and specifically those who visit clubs. Additionally, pain threshold remains a subjective measurement, which must be taken into account.

CONCLUSION

This study helps shed further light on the biological processes behind a BDSM interaction through pain threshold measurements. Wuyts E, De Neef N, Coppens V, et al. Beyond Pain: A Study on the Variance of Pain Thresholds Within BDSM Interactions in Dominants and Submissives. J Sex Med 2021;18:556-564.

Chronic Abdominal Pain in General Practice

Background and Summary: Chronic abdominal pain is a challenging complaint for both primary care providers and gastroenterologists alike, due to a broad differential diagnosis and sometimes extensive and negative workup. In the absence of red flag features that herald more acute conditions, the majority of patients with chronic abdominal pain have a benign cause or a functional disorder (e.g., irritable bowel syndrome). The costs associated with a diagnostic workup are an expensive burden to health care. A systematic approach for evaluating patients and initiating a management plan are recommended in the primary care setting. Undiagnosed abdominal pain should be investigated starting with a detailed history and physical examination. Diagnostic investigations should be limited and adapted according to the clinical features, the alarm symptoms, and the symptom severity. This review will focus on the diagnostic tools which general practitioners utilize in the evaluation of chronic abdominal pain. Key Messages: The primary role of the general practitioner is to differentiate an organic disease from a functional one, to refer to a specialist, or to provide treatment for the underlying cause of pain. The functional disorders should be considered after the organic pathology has been confidently excluded. Once a diagnosis of functional pain is established, repetitive testing is not recommended and the patient should be referred to receive psychological support (e.g., cognitive therapy) associated with available pharmacological therapeutic options.

Role of VVZ-149, a Novel Analgesic Molecule, in the Affective Component of Pain: Results from an Exploratory Proof-of-Concept Study of Postoperative Pain following Laparoscopic and Robotic-Laparoscopic Gastrectomy

OBJECTIVE

VVZ-149 is a small molecule that both inhibits the glycine transporter type 2 and the serotonin receptor 5 hydroxytryptamine 2 A. In a randomized, parallel-group, and double-blind trial (NCT02844725), we investigated the analgesic efficacy and safety of VVZ-149 Injections, which is under clinical development as a single-use injectable product for treating moderate to severe postoperative pain.

METHODS

Sixty patients undergoing laparoscopic and robotic-laparoscopic gastrectomy were randomly assigned to receive a 10-hour intravenous infusion of VVZ-149 Injections or placebo, initiated approximately 1 hour before completion of surgical suturing. Major outcomes included pain intensity and opioid consumption via patient-controlled analgesia and rescue analgesia provided "as needed." The treatment efficacy of VVZ-149 was further examined in a subpopulation requiring early rescue medication, previously associated with the presence of high levels of preoperative negative affect in a prior Phase 2 study (NCT02489526).

RESULTS

Pain intensity was lower in the VVZ-149 (n = 30) than the placebo group (n = 29), reaching statistical significance at 4 hours post-emergence (P < .05), with a 29.5% reduction in opioid consumption for 24 hours and fewer demands for patient-controlled analgesia. In the rescued subgroup, VVZ-149 further reduced pain intensity (P < .05) with 32.6% less opioid consumption for 24 hours compared to placebo patients.

CONCLUSIONS

VVZ-149 demonstrated effective analgesia with reduced postoperative pain and opioid requirements. Consistent with the results from the previous Phase 2 study, patients with early rescue requirement had greater benefit from VVZ-149, supporting the hypothesis that VVZ-149 may alleviate the affective component of pain and mitigate excessive use of opioids postoperatively.

Prevalence and characteristics of new-onset pain in COVID-19 survivours, a controlled study

BACKGROUND

We assessed whether COVID-19 is associated with de novo pain and de novo chronic pain (CP).

METHODS

This controlled cross-sectional study was based on phone interviews of patients discharged from hospital after COVID-19 compared to the control group composed of individuals hospitalized during the same period due to non-COVID-19 causes. Patients were classified as having previous CP based on the ICD-11/IASP criteria, de novo pain (i.e. any new type of pain, irrespective of the pain status before hospital stay), and de novo CP (i.e. persistent or recurring de novo pain, lasting more than 3 months) after COVID-19. We assessed pain prevalence and its characteristics, including headache profile, pain location, intensity, interference, and its relationship with fatigue, and persistent anosmia. Forty-six COVID-19 and 73 control patients were included. Both groups had similar sociodemographic characteristics and past medical history.

RESULTS

Length of in-hospital-stay and ICU admission rates were significantly higher amongst COVID-19 survivours, while mechanical ventilation requirement was similar between groups. Pre-hospitalisation pain was lower in COVID-19 compared to control group (10.9% vs. 42.5%; p = 0.001). However, the COVID-19 group had a significantly higher prevalence of de novo pain (65.2% vs. 11.0%, p = 0.001), as well as more de novo headache (39.1%) compared to controls (2.7%, p = 0.001). New-onset CP was 19.6% in COVID-19 patients and 1.4% (p = 0.002) in controls. These differences remained significant (p = 0.001) even after analysing exclusively (COVID: n = 40; controls: n = 34) patients who did not report previous pain before the hospital stay. No statistically significant differences were found for mean new-onset pain intensity and interference with daily activities between both groups. COVID-19 pain was more frequently located in the head/neck and lower limbs (p < 0.05). New-onset fatigue was more common in COVID-19 survivours necessitating inpatient hospital care (66.8%) compared to controls (2.5%, p = 0.001). COVID-19 patients who reported anosmia had more new-onset pain (83.3%) compared to those who did not (48.0%, p = 0.024).

CONCLUSION

COVID-19 was associated with a significantly higher prevalence of de novo CP, chronic daily headache, and new-onset pain in general, which was associated with persistent anosmia.

SIGNIFICANCE

There exists de novo pain in a substantial number of COVID-19 survivours, and some develop chronic pain. New-onset pain after the infection was more common in patients who reported anosmia after hospital discharge.

Is central sensitization an important determinant of functional disability in patients with chronic inflammatory arthritides?

Background

Central sensitization (CS) is a condition characterized by a disproportionate response to pain stimuli. We sought to investigate the prevalence of CS in patients with inflammatory arthritides and its association with measures of disease activity and functional disability.

Methods

We conducted an observational retrospective study in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) patients. We administered to all the subjects in the study the CS inventory (CSI), a questionnaire that has been used for the diagnosis of CS. Demographic and clinical characteristics were collected as well as measures or disease activity [i.e. Simple Disease Activity Index, Disease Activity Score in PsA (DAPSA)] and functional disability [Health Assessment Questionnaire Disability Index (HAQ-DI)]. Patients with fibromyalgia were excluded from the analyses. The primary outcome measure was the presence of functional disability as assessed by HAQ-DI >1.

Results

We enrolled 150 patients with inflammatory arthritides (78 PsA and 72 RA). Prevalence of CS was observed in 35.3% of the overall sample (29% in RA, 42.9% in PsA). Binary logistic regressions showed a strong, independent and linear association between functional disability and CS in both PsA and RA patients. The strength of this association was greater in PsA than in RA.

Conclusion

CS is an important determinant of functional disability in patients with chronic inflammatory arthritides. PsA appeared to be more vulnerable to CS. In addition, in the presence of CS, DAPSA did not adequately capture the occurrence of functional disability. Therefore, special attention should be paid to PsA patients, in whom the concomitant diagnosis of CS should be routinely ruled out.

Estrogen receptors in pain modulation: cellular signaling

Sensory perception and emotional disorders are disproportionally represented in men and women and are thus thought to be modulated by different sex hormones in various conditions. Among the most important hormones perceived to affect sensory processing and transduction is estrogen. Numerous previous researchers have endeavored to demonstrate that estrogen is capable of modulating the activity of sensory neurons in peripheral and central sites in female, male, or castrated animals. However, the underlying mechanisms of its modulation of neuronal activity are somewhat unclear. In the present review, we discuss the possible cellular and molecular mechanisms involved in the modulation of nociception by estrogen.

Efficacy and Safety of N-acetylcysteine for the Management of Chronic Pain in Adults: A Systematic Review & Meta-analysis

OBJECTIVE

To assess the efficacy and safety of N-acetylcysteine in the treatment of chronic pain.

METHODS

A systematic search was carried out until April 2020 for clinical studies of N-acetylcysteine in the management of any persistent or recurrent chronic pain condition for adults ≥ 18 years old. Risk of Bias was assessed using the validated risk of bias tools. When appropriate, a meta-analysis using a random-effects model was performed, with a fixed-effect model for sensitivity analysis.

RESULTS

Nine studies (n = 863) were included (5 randomized controlled trials [RCTs], 2 open-label non-comparative studies and 2 comparative studies), that evaluated patients with sickle cell disease (3), complex regional pain syndrome (1), pelvic pain/endometriosis (2), rheumatoid arthritis (1), diabetic neuropathy (1), and chronic neuropathic pain (1). In the pooled analysis of 3 RCTs, N-acetylcysteine did not reduce pain intensities (SMD -0.21, 95% CI -0.33 to 0.75, random-effects), improve functional outcomes (SMD 0.21, 95% CI -0.33 to 0.75) or quality of life (SMD 0.60, 95% CI -4.44 to 5.64); however, sensitivity analysis with a fixed effect model demonstrated an effect for pain intensities and function. Due to adverse events being inconsistently reported, no conclusion could be made regarding safety of N-acetylcysteine in chronic pain.

CONCLUSIONS

While there is some evidence to indicate N-acetylcysteine may provide analgesic efficacy for certain pain conditions, there is insufficient evidence to provide definitive evidence on NAC in chronic pain management. Larger-size RCTs spanning a variety of chronic pain conditions are needed to determine N-acetylcysteine's role, if any, in pain medicine.

Effectiveness and harms of clinical decision support systems for referral within chronic pain practice: protocol for a systematic review and meta-analysis

BACKGROUND

Chronic pain is a common public health problem with negative consequences for individuals and societies. Fortunately, interdisciplinary chronic pain management has been shown to be effective for improving patients' outcomes and strongly recommended in clinical practice guidelines. Appropriate referral within the healthcare system based on individuals' needs and available services is essential to optimise health-related outcomes and maximise resources. Clinical decision support systems have been shown to be effective for supporting healthcare professionals in different practices. However, there is no knowledge synthesis on clinical decision support systems for referral within chronic pain practice. We aim to identify the clinical decision support systems for referral within chronic pain practices and assess their content, effectiveness, harms, and validation parameters.

METHODS

Using the methodology of Cochrane reviews, we will perform a systematic review and meta-analysis based on studies meeting the following criteria: Population, patients with chronic pain and/or healthcare professionals working in chronic pain; Intervention, clinical decision support systems for referral within chronic pain practice; Comparison, any other clinical tool, any usual care or practices; Outcomes, clinical outcomes of patients measuring how patients feel, function or survive including benefits, adverse effects, continuity of care, care appropriateness, care satisfaction, quality of life, healthcare professional performance, and cost outcomes; and Study design: randomized controlled trials, non-randomized controlled trials, before and after controlled studies and interrupted time series. We will search relevant literature with the support of an information specialist using Medline, Embase, PsycInfo, CINHAL, Web of Science and Cochrane Library from their inception onwards. Two reviewers will independently complete study selection, data extraction and risk of bias assessment. We will analyse data to perform both narrative syntheses and meta-analysis if appropriate.

DISCUSSION

Findings of this review will contribute to enhancing chronic pain care and research. Clinical decision support systems identified as effective in this review can be investigated for implementation in clinical practice and impact on improving patient, clinical and health system outcomes. Clinical decision support systems not yet ready for implementation that require further improvement will also be identified.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration: CRD42020158880 .

Predictors of Mental Health Status among Older United States Adults with Pain

Poor mental health is common among older adults with pain, resulting in high economic burden and impaired quality of life. This retrospective, cross-sectional database study aimed to identify characteristics associated with good mental health status among United States (US) adults aged ≥50 years with self-reported pain in the last four weeks using a weighted sample of 2017 Medical Expenditure Panel Survey data. Hierarchical multivariable logistic regression models were used to identify statistically significant predictors of good (versus poor) perceived mental health status. From a weighted population of 57,074,842 individuals, 85.5% (95% confidence interval (CI) = 84.4%, 86.7%) had good perceived mental health. Good mental health was associated most strongly with physical health status (adjusted odds ratio (AOR) = 9.216, 95% CI = 7.044, 12.058). Employed individuals were 1.7 times more likely to report good mental health versus unemployed (AOR = 1.715, 95% CI = 1.199, 2.452). Individuals who had completed less than high school education (AOR = 0.750, 95% CI = 0.569, 0.987) or who reported having a limitation (AOR = 0.513, 95% CI = 0.384, 0.684) were less likely to report good mental health. These key characteristics can be utilized to predict mental health status, which may be investigated to better manage concurrent pain and poor mental health.

Emotional awareness and other emotional processes: implications for the assessment and treatment of chronic pain

Emotional awareness (EA) is a key emotional process that is related to the presence and severity of chronic pain (CP). In this report, we describe primary and secondary emotions, discuss the distinction between emotional states and emotional regulation/processing, and summarize theory and research highlighting the significance of EA for CP. We describe ways to assess EA and diagnose centrally-mediated CP, for which emotional processes appear most relevant. We review several psychological interventions designed to enhance EA as well as several broader emotional processing treatments developed to address trauma and psychosocial conflicts underlying many patients' pain. We conclude by offering our perspective on how future integration of emotional processing into pain care could promote recovery from CP.

The Role of Mental Imagery in Parkinson's Disease Rehabilitation

Parkinson’s disease (PD) is a disabling neurodegenerative disease whose manifestations span motor, sensorimotor, and sensory domains. While current therapies for PD include pharmacological, invasive, and physical interventions, there is a constant need for developing additional approaches for optimizing rehabilitation gains. Mental imagery is an emerging field in neurorehabilitation and has the potential to serve as an adjunct therapy to enhance patient function. Yet, the literature on this topic is sparse. The current paper reviews the motor, sensorimotor, and sensory domains impacted by PD using gait, balance, and pain as examples, respectively. Then, mental imagery and its potential for PD motor and non-motor rehabilitation is discussed, with an emphasis on its suitability for addressing gait, balance, and pain deficits in people with PD. Lastly, future research directions are suggested.

Sorting pain out of salience: assessment of pain facial expressions in the human fetus

Supplemental Digital Content is Available in the Text.

Acute pain facial expressions can be detected/scored in human fetuses. We propose a seven-item scale to differentiate pain facial expressions from rest/acoustic stimuli ones.

Introduction:

The question of whether the human fetus experiences pain has received substantial attention in recent times. With the advent of high-definition 4-dimensional ultrasound (4D-US), it is possible to record fetal body and facial expressions.

Objective:

To determine whether human fetuses demonstrate discriminative acute behavioral responses to nociceptive input.

Methods:

This cross-sectional study included 5 fetuses with diaphragmatic hernia with indication of intrauterine surgery (fetoscopic endoluminal tracheal occlusion) and 8 healthy fetuses, who were scanned with 4D-US in 1 of 3 conditions: (1) acute pain group: Fetuses undergoing intrauterine surgery were assessed in the preoperative period during the anesthetic injection into the thigh; (2) control group at rest: Facial expressions at rest were recorded during scheduled ultrasound examinations; and (3) control group acoustic startle: Fetal facial expressions were recorded during acoustic stimulus (500–4000 Hz; 60–115 dB).

Results:

Raters blinded to the fetuses’ groups scored 65 pictures of fetal facial expressions based on the presence of 12 items (facial movements). Analyses of redundancy and usefulness excluded 5 items for being of low discrimination capacity (P>0.2). The final version of the pain assessment tool consisted of a total of 7 items: brow lowering/eyes squeezed shut/deepening of the nasolabial furrow/open lips/horizontal mouth stretch/vertical mouth stretch/neck deflection. Odd ratios for a facial expression to be detected in acute pain compared with control conditions ranged from 11 (neck deflection) to 1,400 (horizontal mouth stretch). Using the seven-item final tool, we showed that 5 is the cutoff value discriminating pain from nonpainful startle and rest.

Conclusions:

This study inaugurates the possibility to study pain responses during the intrauterine life, which may have implications for the postoperative management of pain after intrauterine surgical interventions

Moving With Pain: What Principles From Somatic Practices Can Offer to People Living With Chronic Pain

This article brings together research from the fields of chronic pain management and somatic practices to develop a novel framework of principles to support people living with persistent pain. These include movement-based approaches to awareness of the internal body (interoception), the external environment (exteroception) and movement in space (proprioception). These significantly work with the lived subjective experiences of people living with pain, to become aware of body signals and self-management of symptoms, explore fear and pleasure of movement, and understand how social environments impact on pain. This analysis has potential to create new ways of supporting, understanding and articulating pain experiences, as well as shaping the future of somatic practices for chronic pain.

Cortical Modulation of Nociception

Nociception is the neuronal process of encoding noxious stimuli and could be modulated at peripheral, spinal, brainstem, and cortical levels. At cortical levels, several areas including the anterior cingulate cortex (ACC), prefrontal cortex (PFC), ventrolateral orbital cortex (VLO), insular cortex (IC), motor cortex (MC), and somatosensory cortices are involved in nociception modulation through two main mechanisms: (i) a descending modulatory effect at spinal level by direct corticospinal projections or mostly by activation of brainstem structures (i.e. periaqueductal grey matter (PAG), locus coeruleus (LC), the nucleus of raphe (RM) and rostroventral medulla (RVM)); and by (ii) cortico-cortical or cortico-subcortical interactions. This review summarizes evidence related to the participation of the aforementioned cortical areas in nociception modulation and different neurotransmitters or neuromodulators that have been studied in each area. Besides, we point out the importance of considering intracortical neuronal populations and receptors expression, as well as, nociception-induced cortical changes, both functional and connectional, to better understand this modulatory effect. Finally, we discuss the possible mechanisms that could potentiate the use of cortical stimulation as a promising procedure in pain alleviation.

Sex differences and the endocannabinoid system in pain

Cannabis use has been increasing in recent years, particularly among women, and one of the most common uses of cannabis for medical purposes is pain relief. Pain conditions and response to analgesics have been demonstrated to be influenced by sex, and evidence is emerging that this is also true with cannabinoid-mediated analgesia. In this review we evaluate the preclinical evidence supporting sex differences in cannabinoid pharmacology, as well as emerging evidence from human studies, both clinical and observational. Numerous animal studies have reported sex differences in the antinociceptive response to natural and synthetic cannabinoids that may correlate to sex differences in expression, and function, of endocannabinoid system components. Female rodents have generally been found to be more sensitive to the effects of Δ⁹-THC. This finding is likely a function of both pharmacokinetic and pharmacodynamics factors including differences in metabolism, differences in cannabinoid receptor expression, and influence of ovarian hormones including estradiol and progesterone. Preclinical evidence supporting direct interactions between sex hormones and the endocannabinoid system may translate to sex differences in response to cannabis and cannabinoid use in men and women. Further research into the role of sex in endocannabinoid system function is critical as we gain a deeper understanding of the impact of the endocannabinoid system in various disease states, including chronic pain.