Trajectories of postsurgical pain in children: risk factors and impact of late pain recovery on long-term health outcomes after major surgery

Acquired Exchange Protein Directly Activated by Cyclic Adenosine Monophosphate Activity Induced by p38 Mitogen-activated Protein Kinase in Primary Afferent Neurons Contributes to Sustaining Postincisional Nociception

BACKGROUND

The molecular mechanisms responsible for sustained pain after tissue injury are largely unknown. The aim of this study was to clarify the role of exchange protein directly activated by cyclic adenosine monophosphate (EPAC) in sustained postincisional nociception, using tissue injury-induced nociceptor priming, and involvement of p38 mitogen-activated protein kinase (p38MAPK) in EPAC-mediated nociceptor priming.

METHODS

Plantar incisions were made in the hind paws of Sprague-Dawley rats (n = 144). Nociceptor priming was confirmed by behavior testing followed by prostaglandin E2 injection 14 to 21 days after the incision. ESI-09, a selective EPAC inhibitor, was administered to assess its effects on nociceptor priming. Expression of two isoforms of EPAC (EPAC1/EPAC2) in dorsal root ganglions from naive rats and those 14 days after the incision was detected by immunohistochemistry and Western blotting. Separately, FR167653, a selective p38MAPK inhibitor, was administered to assess its effect on EPAC1/EPAC2 expression and the development of nociceptor priming.

RESULTS

Prostaglandin E2 injection 14 to 21 days after the plantar incision induced persistent mechanical hyperalgesia for 7 days. EPAC1/EPAC2 expression in dorsal root ganglion neurons was trivial in naive rats (7.7 ± 4.8% for EPAC1; 6.3 ± 4.1% for EPAC2) but markedly increased 14 days after the incision (21.0 ± 9.4% and 20.1 ± 3.8%, respectively). ESI-09 treatment inhibited prostaglandin E2-induced persistent mechanical hypersensitivity but had no effect on incision-induced acute nociceptive hypersensitivity. Treatment with FR167653 before the incision inhibited the development of nociceptor priming and incision-induced EPAC1/EPAC2 expression (8.5 ± 5.4% and 7.6 ± 3.3%, respectively).

CONCLUSIONS

Transient inflammatory stimulation causes long-lasting nociceptive hypersensitivity via nociceptor priming during the subacute period after incision. Acquired EPAC activity by p38MAPK in the dorsal root ganglion neurons is a key for this event.

Prevalence and Predictors of Chronic Postsurgical Pain in Children: A Systematic Review and Meta-Analysis

Emerging research suggests that pain may persist longer-term for many children after major surgery, with significant effects on their health outcomes. This systematic review identified the prevalence of chronic postsurgical pain (CPSP) in children after surgery, and determined presurgical biomedical and psychosocial risk factors associated with CPSP prevalence or severity. Prospective studies assessing CPSP 3 to 12 months after surgery in children 6 to 18 years of age published in English in MedLine, EMBASE, PsycINFO, and Cochrane Database of Systematic Reviews since 1996 were eligible for inclusion. Of 16,084 abstracts yielded by the search, 123 full articles were assessed for eligibility, and 12 studies were included in the review. Overall quality of included studies assessed using the Quality in Prognostic Studies tool was low. On the basis of 4 studies with a total of 628 participants across all surgery types, median prevalence of CPSP across studies was 20% (25th percentile = 14.5%, 75th percentile = 38%) at 12 months after surgery. Presurgical pain intensity, child anxiety, child pain coping efficacy, and parental pain catastrophizing were the only presurgical factors identified as predictive of CPSP. Biological and medical factors assessed were not associated with CPSP in any study. Well designed studies examining prevalence and predictors of CPSP are critically needed in children.

PERSPECTIVE

In this systematic review, the median prevalence of CPSP in children was 20% across studies. Presurgical pain intensity, and child and parent psychosocial factors predicted CPSP. Additional resources and interventions are needed for youth who report persistent pain after surgery.

Trajectory of Postoperative Wound Pain Within the First 2 Weeks Following Posterior Spinal Fusion Surgery in Adolescent Idiopathic Scoliosis Patients

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

The aim of this study was to determine and evaluate the trajectory of surgical wound pain from day 1 to day 14 after posterior spinal fusion (PSF) surgery in patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Information regarding how the postoperative pain improves with time offers invaluable information not only to the patients and parents but also to assist the clinician in managing postoperative pain.

METHODS

AIS patients who were planned for elective PSF surgery from September 2015 to December 2015 were prospectively recruited into this study. All patients underwent a similar pain management regimen with patient-controlled anesthesia (PCA) morphine, acetaminophen, celecoxib, and oxycodone hydrochloride.

RESULTS

A total of 40 patients (36 F:4 M) were recruited. The visual analogue score (VAS) pain score was highest at 12 hours postoperation (6.0 ± 2.3). It reduced to 3.9 ± 2.2 (day 4), 1.9 ± 1.6 (day 7), and 0.7 ± 1.1 (day 14). The total PCA usage in all patients was 12.4 ± 9.9 mg (first 12 hours), 7.1 ± 8.0 mg (12 to 24 hours), 5.6 ± 6.9 (24-36 hours), and 2.1 ± 6.1 mg (36-48 hours). The celecoxib capsules usage was reducing from 215.0 ± 152.8 mg at 24 hours to 55.0 ± 90.4 mg on day 14. The acetaminophen usage was reducing from 2275 ± 1198 mg at 24 hours to 150 ± 483 mg at day 14. Oxycodone hydrochloride capsules consumption rose to the peak of 1.4 ± 2.8 mg on day 4 before gradually reducing to none by day 13.

CONCLUSION

With an adequate postoperation pain regimen, significant pain should subside to a tolerable level by postoperative day 4 and negligible by postoperative day 7. Patient usually can be discharged on postoperative day 4 when the usage of PCA morphine was not required.

LEVEL OF EVIDENCE

2.

Factors Predicting Parent Anxiety Around Infant and Toddler Postoperative and Pain

BACKGROUND AND OBJECTIVES

Understanding of parent anxiety and its effect on infant postoperative pain is limited. We sought to identify psychological factors associated with preoperative anxiety for parents of infants and toddlers undergoing elective surgery and to determine whether parent anxiety is associated with child postoperative pain.

METHODS

This was a prospective cohort study of consecutively eligible patients aged ≤18 months undergoing craniofacial surgery and their parents. Preoperative parent assessment included anxiety, coping, parent health locus of control, and self-efficacy. Postoperative inpatient child pain scores and medication use were collected. Analyses included hierarchical multivariable logistic and linear regression models.

RESULTS

Parents (n = 71, 90% female) of young children (mean age 6.6 months) undergoing cleft lip or palate (n = 59) or cranial vault repair (n = 13) were enrolled. Maladaptive coping (odds ratio 1.3; 95% confidence interval, 1.1-1.6), low parent self-efficacy (odds ratio 2.4; 95% confidence interval, 1.3-4.5), and external locus of control (odds ratio 1.74; 95% confidence interval, 1.1-2.9) were independently associated with high parental anxiety. The adjusted odds of moderate/severe parent anxiety was 3.6 (95% confidence interval, 1.5-9.1) higher with each SD increase in maladaptive coping. High parental anxiety was correlated with significantly higher hospital mean child pain scores (1.87 points on 0-10 scale; 95% confidence interval, 0.42-3.70; P = .045).

CONCLUSIONS

Coping and self-efficacy are modifiable factors that contribute to parent anxiety before and during hospitalization and may be targets for intervention. Infants and toddlers undergoing elective craniofacial surgery with highly anxious parents may be at greater risk for higher postoperative pain.

Predicting the pain continuum after adolescent idiopathic scoliosis surgery: A prospective cohort study

BACKGROUND

Chronic postsurgical pain (CPSP) affects half a million children annually in the United States, with dire socioeconomic consequences, including long-term disability into adulthood. The few studies of CPSP in children are limited by sample size, follow-up duration, non-homogeneity of surgical procedure and factors evaluated.

METHODS

In a prospective study of 144 adolescents undergoing a single major surgery (spine fusion), we evaluated demographic, perioperative, surgical and psychosocial factors as predictors of a continuum of postsurgical pain: immediate, pain maintenance at 2-3 months (chronic pain/CP) and persistence of pain a year (persistent pain/PP) after surgery.

RESULTS

We found an incidence of 37.8% and 41.8% for CP and PP. CP and acute pain were both significant predictors for developing PP (p-value <0.001 and 0.003). Preoperative pain and higher postoperative opioid requirement was significantly associated with CP (p = 0.015, p = 0.002), while Childhood Anxiety Sensitivity Index (p = 0.002) and surgical duration (p = 0.014) predicted PP. The final regression models had reasonable predictive accuracy (c-statistic of 0.73 and 0.83 for CP and PP, respectively). Anxiety scores and catastrophizing for child and parent were found to be significantly correlated (p = 0.005, p = 0.013 respectively). Pain trajectories revealed that 65% of patients who developed PP reported CP and high pain trends; however, 33% of those who developed PP could not be identified using solely pain criteria.

CONCLUSION

Persistent postsurgical pain in children is a significant problem. It can be predicted in part by combinations of psychological and clinical variables, which may provide evidence-based measures to prevent development of CPSP in the future.

SIGNIFICANCE

In a homogeneous cohort of adolescents undergoing spine fusion, we report a high incidence of persistent postsurgical pain (41.8%) predicted by child anxiety, perioperative pain, and surgical duration. Our results stress timely preventive and therapeutic strategies.

Long-Term Pain and Recovery After Major Pediatric Surgery: A Qualitative Study With Teens, Parents, and Perioperative Care Providers

Research developing targeted treatment focused on coping with children's long-term pain after surgery is needed because of the high prevalence of chronic pain after surgery. This qualitative study aimed to: 1) understand the child's and family's experiences of pain over the course of their surgical experience, and 2) gather stakeholder input regarding potential barriers and facilitators of perioperative intervention delivery. Fifteen children ages 10 to 18 years who underwent recent major surgery, their primary caregivers, and 17 perioperative health care providers were interviewed. Interviews were coded using semantic thematic analysis. The perioperative period presented emotional challenges for families. Families felt unprepared for surgery and pain. Recovery and regaining physical functioning at home was challenging. Families struggled to return to valued activities. Families reported interest in a perioperative psychosocial intervention. Providers endorsed that families would benefit from enhanced coping skills. They emphasized that families would benefit from more detailed preparatory information. Providers suggested that flexible intervention delivery at home would be ideal. Research developing interventions addressing pain and anxiety in children undergoing major surgery is critically needed. The findings of the present study can inform intervention development with the aim of improving short- as well as long-term recovery in children undergoing major surgery.

PERSPECTIVE

This qualitative study examined children and their parents' experience of long-term pain and recovery after major surgery, identifying barriers and facilitators of perioperative intervention delivery. Families experienced surgery as stressful, and felt underprepared for pain and recovery. Families and health care providers expressed interest in a preoperative intervention teaching coping skills.

Longitudinal and Temporal Associations Between Daily Pain and Sleep Patterns After Major Pediatric Surgery

Approximately 20% of children develop persistent pain after major surgery. Sleep disruption has been implicated as a predictor of children's acute postsurgical pain. However, perioperative sleep patterns have not been longitudinally assessed, and the role of sleep in persistence of postsurgical pain has not been explored. We aimed to examine sleep patterns over 4 months in children having major surgery, and temporal relationships between daily sleep and pain. Sixty children age 10 to 18 (mean = 14.7) years having major surgery completed 7 days of actigraphy sleep monitoring (sleep duration, efficiency), twice daily electronic diaries (sleep quality, pain intensity, medication use), and validated questionnaires at presurgery, 2 weeks, and 4 months postsurgery. Generalized linear models, controlling for age, sex, naps, and medication, showed sleep quality (β [B] = -.88, P < .001) and efficiency (B = -1.50, P = .036) were significantly reduced at 2 weeks compared with presurgery, and returned to baseline by 4 months. Poorer night-time sleep quality was significantly associated with greater next day pain intensity (B = -.15, P = .005). Sleep duration and efficiency were not associated with subsequent pain; daytime pain was not associated with subsequent sleep. Findings suggest sleep quality may be an important target for intervention after surgery in children; research is needed to understand how other sleep parameters may relate to recovery.

PERSPECTIVE

This study assessed longitudinal sleep patterns over 4 months after major pediatric surgery using actigraphy, diaries, and validated measures. Sleep quality and efficiency were significantly reduced at 2 weeks. Poorer sleep quality was associated with greater next day pain intensity suggesting that sleep quality may be an important target for intervention.

Chronic Pain in Children and Adolescents: Diagnosis and Treatment of Primary Pain Disorders in Head, Abdomen, Muscles and Joints

Primary pain disorders (formerly "functional pain syndromes") are common, under-diagnosed and under-treated in children and teenagers. This manuscript reviews key aspects which support understanding the development of pediatric chronic pain, points to the current pediatric chronic pain terminology, addresses effective treatment strategies, and discusses the evidence-based use of pharmacology. Common symptoms of an underlying pain vulnerability present in the three most common chronic pain disorders in pediatrics: primary headaches, centrally mediated abdominal pain syndromes, and/or chronic/recurrent musculoskeletal and joint pain. A significant number of children with repeated acute nociceptive pain episodes develop chronic pain in addition to or as a result of their underlying medical condition "chronic-on-acute pain." We provide description of the structure and process of our interdisciplinary, rehabilitative pain clinic in Minneapolis, Minnesota, USA with accompanying data in the treatment of chronic pain symptoms that persist beyond the expected time of healing. An interdisciplinary approach combining (1) rehabilitation; (2) integrative medicine/active mind-body techniques; (3) psychology; and (4) normalizing daily school attendance, sports, social life and sleep will be presented. As a result of restored function, pain improves and commonly resolves. Opioids are not indicated for primary pain disorders, and other medications, with few exceptions, are usually not first-line therapy.

Pain and Health-Related Quality of Life After Pediatric Inpatient Surgery

Around 4 million children undergo inpatient surgery in the United States each year, however little is known about the impact of surgery and postoperative pain on children's health-related quality of life (HRQOL) during the weeks and months after surgery. We measured pain and HRQOL in a large, heterogeneous pediatric postsurgical population from baseline to 1-month follow-up. Over a 20-month period, parents of 915 children age 2 to 18 years (mean = 9.6 years), 50% male, 56% white, admitted to surgical services at a children's hospital enrolled in the study. Parent participants reported on sociodemographics, child HRQOL, and pain characteristics at baseline and 1 month after discharge. Although most of the children recovered to baseline by 1 month after hospital discharge, 23% of children had a significant decline in HRQOL. Logistic regression analyses found that increasing child age (odds ratio = 2.1 for age 13-18 years) and the presence of moderate-severe postsurgical pain at 1 month (odds ratio = 5.7) were significantly associated with deterioration in HRQOL from baseline to 1-month follow-up (P < .05 for each variable). Although HRQOL returns to the baseline level for most children, a sizeable proportion have significant deterioration in HRQOL associated with continued postsurgical pain at 1 month after hospital discharge from surgery.

PERSPECTIVE

This study addresses an important gap in the literature, examining pain and health-related quality of life in a broad population of children undergoing a wide range of inpatient surgeries. Evaluation of inpatient health services from a patient and family perspective is essential in evaluating outcomes of surgical care.