Mechanism-Based Pharmacological Treatment for Chronic Non-cancer Pain in Adolescents: Current Approaches and Future Directions

Chronic Postsurgical Pain in Children and Adolescents: A Call for Action

Chronic postsurgical pain (CPSP) affects a significant proportion of children and adolescents after major surgery and is a detriment to both short- and long-term recovery outcomes. While clinical characteristics and psychosocial risk factors for developing CPSP in children and adults are well established in the literature, there has been little progress on the prevention and management of CPSP after pediatric surgery. Limited evidence to support current pharmacologic approaches suggests a fundamentally new paradigm must be considered by clinicians to both conceptualize and address this adverse complication. This narrative review provides a comprehensive evaluation of both the known and emerging mechanisms that support our current understanding of CPSP. Additionally, we discuss the importance of optimizing perioperative analgesic strategies to mitigate CPSP based on individual patient risks. We highlight the importance of postoperative pain trajectories to identify those most at risk for developing CPSP, the early referral to multi-disciplinary pain clinics for comprehensive evaluation and treatment of CPSP, and additional work needed to differentiate CPSP characteristics from other chronic pain syndromes in children. Finally, we recognize ongoing challenges associated with the universal implementation of available knowledge about pediatric CPSP into practically useful care plans for clinicians.

The Pharmacological Treatment of Neuropathic Pain in Children

The International Association for the Study of Pain (IASP) defines neuropathic pain as pain caused by a lesion or disease of the somatosensory nervous system. It is characterized as a clinical condition in which diagnostic studies reveal an underlying cause of an abnormality in the peripheral or central nervous system. Many common causes of neuropathic pain in adults are rare in children. The purpose of this focused narrative review is, to 1) provide an overview of neuropathic pain in children, 2) highlight unique considerations related to the diagnosis and mechanisms of neuropathic pain in children, and 3) perform a comprehensive analysis of the pharmacological treatments available. We emphasize that data for routine use of pharmacological agents in children with neuropathic pain are largely inferred from adult literature with little research performed on pediatric populations, yet have clear evidence of harms to pediatric patients. Based on these findings, we propose risk mitigation strategies such as utilizing topical treatments whenever possible, assessing pain phenotyping to guide drug class choice, and considering pharmaceuticals in the broader context of the multidisciplinary treatment of pediatric pain. Furthermore, we highlight important directions for future research on pediatric neuropathic pain treatment.

Current Evidence for Biological Biomarkers and Mechanisms Underlying Acute to Chronic Pain Transition across the Pediatric Age Spectrum

Chronic pain is highly prevalent in the pediatric population. Many factors are involved in the transition from acute to chronic pain. Currently, there are conceptual models proposed, but they lack a mechanistically sound integrated theory considering the stages of child development. Objective biomarkers are critically needed for the diagnosis, risk stratification, and prognosis of the pathological stages of pain chronification. In this article, we summarize the current evidence on mechanisms and biomarkers of acute to chronic pain transitions in infants and children through the developmental lens. The goal is to identify gaps and outline future directions for basic and clinical research toward a developmentally informed theory of pain chronification in the pediatric population. At the outset, the importance of objective biomarkers for chronification of pain in children is outlined, followed by a summary of the current evidence on the mechanisms of acute to chronic pain transition in adults, in order to contrast with the developmental mechanisms of pain chronification in the pediatric population. Evidence is presented to show that chronic pain may have its origin from insults early in life, which prime the child for the development of chronic pain in later life. Furthermore, available genetic, epigenetic, psychophysical, electrophysiological, neuroimaging, neuroimmune, and sex mechanisms are described in infants and older children. In conclusion, future directions are discussed with a focus on research gaps, translational and clinical implications. Utilization of developmental mechanisms framework to inform clinical decision-making and strategies for prevention and management of acute to chronic pain transitions in children, is highlighted.

The Psychosocial Characteristics and Somatosensory Function of Children and Adolescents Who Meet the Criteria for Chronic Nociplastic Pain

Purpose

Nociplastic pain distinguishes individuals with pain and hypersensitivity in body regions with apparently normal tissues, without any signs of neuropathy, but with contribution of central and/or peripheral sensitization. There is a lack of literature describing nociplastic pain in the pediatric population. The objective of this study was to investigate the differences between pediatric patients with nociplastic pain compared with patients with non-nociplastic pain.

Patients and Methods

This study included 414 pediatric patients followed at an interdisciplinary centre for complex pain. All patients underwent an exhaustive pain assessment consisting of face-to-face interviews, validated self-report questionnaires and quantitative sensory testing. Recently established criteria for chronic nociplastic pain, and quantitative sensory testing was used to describe and stratify our cohort.

Results

One hundred and sixty-five patients (40%) were stratified as having possible nociplastic pain and two hundred and forty-nine (60%) patients, as non-nociplastic pain. Patients with nociplastic pain displayed pain hypersensitivity in the region of pain, more symptoms of panic and social phobia, and worse sleep quality than patients with non-nociplastic pain. The proportion of patients achieving a meaningful clinical outcome after completion of their treatment (medications, physiotherapy, psychology, nursing, social worker, and/or interventional procedures) was lower in patients with nociplastic pain (62%) than those without nociplastic pain (86%).

Conclusion

Our results suggest that patients who meet the criteria for nociplastic pain can be identified in a population of children and adolescents being treated in a center for complex pain. Combining screening with validated questionnaires and quantitative sensory testing facilitates the phenotyping and graded severity of patients with nociplastic pain in daily clinical practice.

The Treatment of Pediatric Pain in Spain: A Survey Study

Pain is a common experience among children and adolescents, and pain management in this population is a challenge to clinicians. The aims of this study were to increase our understanding of current practices in the management of both acute and chronic pediatric pain in Spain, explore potential barriers to ideal practices, and identify professional needs as perceived by healthcare professionals. A total of 277 healthcare professionals took part, all of whom had wide experience in managing children and adolescents with pain (M [SD] age = 44.85, [10.73]; 75% women). Participants had to respond to a web-based survey with 50 questions related to pain education, organizational characteristics of their pain programs (including the characteristics of the patients treated), and current practices in the assessment and treatment of children and adolescents with pain. Almost all the participants (93%) acknowledged important gaps in their training, and only 47% reported that they had received specific education on the management of pediatric pain during their undergraduate and postgraduate studies. A third (31%) were members of multidisciplinary teams, and almost all (99%) understood that protocols to guide the management of pain in young people were necessary. However, only a few of them used a protocol to assess and treat (56% and 48%, respectively) acute and chronic pain (24% and 23%, respectively). The data also showed that a lack of pain education, coordination of professionals, and guidelines was perceived as an important barrier in the care provided to children and adolescents with pain in Spain. The findings of this study can now be used by healthcare professionals in Spain interested in managing pediatric pain, as well as policymakers concerned to improve the education of professionals and the care given to young people with pain.