The role of cytokines in acute and chronic postsurgical pain after major musculoskeletal surgeries in a quaternary pediatric center.

STUDY OBJECTIVE: To determine if baseline cytokines/chemokines and their changes over postoperative days 0-2 (POD0-2) predict acute and chronic postsurgical pain (CPSP) after major surgery. DESIGN: Prospective, observational, longitudinal nested study. SETTING: University-affiliated quaternary children's hospital. PATIENTS: Subjects (≥8 years old) with idiopathic scoliosis undergoing spine fusion or pectus excavatum undergoing Nuss procedure. MEASUREMENTS: Demographics, surgical, psychosocial measures, pain scores, and opioid use over POD0-2 were collected. Cytokine concentrations were analyzed in serial blood samples collected before and up to two weeks after surgery, using Luminex bead arrays. After data preparation, relationships between pre- and post-surgical cytokine concentrations with acute (% time in moderate-severe pain over POD0-2) and chronic (pain score > 3/10 beyond 3 months post-surgery) post-surgical pain were analyzed using univariable and multivariable regression analyses with adjustment for covariates and mixed effects models were used to associate longitudinal cytokine concentrations with pain outcomes. MAIN RESULTS: Analyses included 3,164 repeated measures of 16 cytokines/chemokines from 112 subjects (median age 15.3, IQR 13.5-17.0, 54.5 % female, 59.8 % pectus). Acute postsurgical pain was associated with higher baseline concentrations of GM-CSF (ß = 0.95, SE 0.31; p = 0.003), IL-1ß (ß = 0.84, SE 0.36; p = 0.02), IL-2 (ß = 0.78, SE 0.34; p = 0.03), and IL-12 p70 (ß = 0.88, SE 0.40; p = 0.03) and longitudinal postoperative elevations in GM-CSF (ß = 1.38, SE 0.57; p = 0.03), IFNγ (ß = 1.36, SE 0.6; p = 0.03), IL-1ß (ß = 1.25, SE 0.59; p = 0.03), IL-7 (ß = 1.65, SE 0.7; p = 0.02), and IL-12 p70 (ß = 1.17, SE 0.58; p = 0.04). In contrast, CPSP was associated with lower baseline concentration of IL-8 (ß = -0.39, SE 0.17; p = 0.02), and the risk of developing CPSP was elevated in patients with lower longitudinal postoperative concentrations of IL-6 (ß = -0.57, SE 0.26; p = 0.03), IL-8 (ß = -0.68, SE 0.24; p = 0.006), and IL-13 (ß = -0.48, SE 0.22; p = 0.03). Covariates female (vs. male) sex and surgery type (pectus surgery vs. spine) were associated with higher odds for CPSP in baseline adjusted cytokine-CPSP association models for IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, TNFα, and IL-8, IL-10, respectively. CONCLUSION: We identified pro-inflammatory cytokine profiles associated with higher risk of acute postoperative pain. Interestingly, pleiotropic cytokine IL-6, chemokine IL-8 (which promotes neutrophil infiltration and monocyte differentiation), and monocyte-released anti-inflammatory cytokine IL-13, were associated with lower CPSP risk. Our results suggest heterogenous outcomes of cytokine/chemokine signaling that can both promote and protect against post-surgical pain. These may serve as predictive and prognostic biomarkers of pain outcomes following surgery.

The Role of Cytokines in Acute and Chronic Postsurgical Pain in Pediatric Patients after Major Musculoskeletal Surgeries.

Study Objective: To determine if baseline cytokines and their changes over postoperative days 0-2 (POD0-2) predict acute and chronic postsurgical pain (CPSP) after major surgery. Design: Prospective, observational, longitudinal nested study. Setting: University-affiliated quaternary children's hospital. Patients: Subjects (≥8 years old) with idiopathic scoliosis undergoing spine fusion or pectus excavatum undergoing Nuss procedure. Measurements: Demographics, surgical, psychosocial measures, pain scores, and opioid use over POD0-2 were collected. Cytokine concentrations were analyzed in serial blood samples collected before and after (up to two weeks) surgery, using Luminex bead arrays. After data preparation, relationships between pre- and post-surgical cytokine concentrations with acute (% time in moderate-severe pain over POD0-2) and chronic (pain score>3/10 beyond 3 months post-surgery) pain were analyzed. After adjusting for covariates, univariate/multivariate regression analyses were conducted to associate baseline cytokine concentrations with postoperative pain, and mixed effects models were used to associate longitudinal cytokine concentrations with pain outcomes. Main Results: Analyses included 3,164 measures of 16 cytokines from 112 subjects (median age 15.3, IQR 13.5-17.0, 54.5% female, 59.8% pectus). Acute postsurgical pain was associated with higher baseline concentrations of GM-CSF (ß=0.95, SE 0.31; p=.003), IL-1ß (ß=0.84, SE 0.36; p=.02), IL-2 (ß=0.78, SE 0.34; p=.03), and IL-12 p70 (ß=0.88, SE 0.40; p=.03) and longitudinal postoperative elevations in GM-CSF (ß=1.38, SE 0.57; p=.03), IFNγ (ß=1.36, SE 0.6; p=.03), IL-1ß (ß=1.25, SE 0.59; p=.03), IL-7 (ß=1.65, SE 0.7, p=.02), and IL-12 p70 (ß=1.17, SE 0.58; p=.04). In contrast, CPSP was associated with lower baseline concentration of IL-8 (ß= -0.39, SE 0.17; p=.02), and the risk of developing CPSP was elevated in patients with lower longitudinal postoperative concentrations of IL-6 (ß= -0.57, SE 0.26; p=.03), IL-8 (ß= -0.68, SE 0.24; p=.006), and IL-13 (ß= -0.48, SE 0.22; p=.03). Furthermore, higher odds for CPSP were found for females (vs. males) for IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and TNFα, and for pectus (vs. spine) surgery for IL-8 and IL-10. Conclusion: We identified pro-inflammatory cytokines associated with increased acute postoperative pain and anti-inflammatory cytokines associated with lower CPSP risk, with potential to serve as predictive and prognostic biomarkers.

Transient Reductions in Postoperative Pain and Anxiety with the Use of Virtual Reality in Children.

OBJECTIVE: Virtual reality is a promising method to manage pain. Distraction-based virtual reality (VR-D) is thought to reduce pain by redirecting attention. Although VR-D can reduce pain associated with acutely painful procedures, it is unclear whether VR-D can reduce pain after surgery. We assessed the ability of a single VR-D session to decrease postoperative pain and anxiety and explored whether pain catastrophizing and anxiety sensitivity influenced these outcomes in children after surgery. DESIGN: Single-center, prospective, pilot study. SETTING: Cincinnati Children's Hospital Medical Center (CCHMC). SUBJECTS: Fifty children (7-21 years of age) with postoperative pain followed by the Acute Pain Service. METHODS: Patients received one VR-D session after surgery. Before the session, patients completed pain catastrophizing (Pain Catastrophizing Scale for Children) and anxiety sensitivity (Child Anxiety Sensitivity Index) questionnaires. The primary outcome consisted of changes in pain intensity after VR-D (immediately, 15 minutes, and 30 minutes). Secondary outcomes included changes in pain unpleasantness and anxiety. RESULTS: VR-D use was associated with a decrease in pain intensity immediately and 15 minutes after VR-D. Reductions in pain unpleasantness were observed up to 30 minutes after VR-D. VR-D was also associated with a reduction in anxiety immediately and at 15 minutes. Although patients with higher pain catastrophizing had higher baseline pain intensity and unpleasantness, they did not show larger pain reductions after VR-D than those with lower pain catastrophizing. CONCLUSIONS: VR-D may be beneficial in transiently reducing pain intensity, unpleasantness, and anxiety in children with postoperative pain. This study informs the design of a larger, randomized, controlled study assessing VR-D for acute postoperative pain and anxiety management.

Guided Relaxation-Based Virtual Reality for Acute Postoperative Pain and Anxiety in a Pediatric Population: Pilot Observational Study.

BACKGROUND: Distraction-based therapies, such as virtual reality (VR), have been used to reduce pain during acutely painful procedures. However, distraction alone cannot produce prolonged pain reduction to manage sustained postoperative pain. Therefore, the integration of VR with other pain-reducing therapies, like guided relaxation, may enhance its clinical impact. OBJECTIVE: The goal of this pilot study was to assess the impact of a single guided relaxation-based VR (VR-GR) session on postoperative pain and anxiety reduction in children. We also explored the influence of pain catastrophizing and anxiety sensitivity on this association. METHODS: A total of 51 children and adolescents (7-21 years) with postoperative pain and followed by the Acute Pain Service at Cincinnati Children's Hospital were recruited over an 8-month period to undergo a single VR-GR session. Prior to VR, the patients completed 2 questionnaires: Pain Catastrophizing Scale for Children (PCS-C) and the Child Anxiety Sensitivity Index (CASI). The primary outcome was a change in pain intensity following the VR-GR session (immediately, 15 minutes, and 30 minutes). The secondary outcomes included changes in pain unpleasantness and anxiety. RESULTS: The VR-GR decreased pain intensity immediately (P<.001) and at 30 minutes (P=.04) after the VR session, but not at 15 minutes (P=.16) postsession. Reductions in pain unpleasantness were observed at all time intervals (P<.001 at all intervals). Anxiety was reduced immediately (P=.02) but not at 15 minutes (P=.08) or 30 minutes (P=.30) following VR-GR. Patients with higher CASI scores reported greater reductions in pain intensity (P=.04) and unpleasantness (P=.01) following VR-GR. Pain catastrophizing was not associated with changes in pain and anxiety. CONCLUSIONS: A single, short VR-GR session showed transient reductions in pain intensity, pain unpleasantness, and anxiety in children and adolescents with acute postoperative pain. The results call for a future randomized controlled trial to assess the efficacy of VR-GR. TRIAL REGISTRATION: ClinicalTrials.gov NCT04556747; https://clinicaltrials.gov/ct2/show/NCT04556747.

Guided relaxation-based virtual reality versus distraction-based virtual reality or passive control for postoperative pain management in children and adolescents undergoing Nuss repair of pectus excavatum: protocol for a prospective, randomised, controlled trial (FOREVR Peds trial).

INTRODUCTION: Virtual reality (VR) offers an innovative method to deliver non-pharmacological pain management. Distraction-based VR (VR-D) using immersive games to redirect attention has shown short-term pain reductions in various settings. To create lasting pain reduction, VR-based strategies must go beyond distraction. Guided relaxation-based VR (VR-GR) integrates pain-relieving mind-body based guided relaxation with VR, a novel therapy delivery mechanism. The primary aim of this study is to assess the impact of daily VR-GR, VR-D and 360 video (passive control) on pain intensity. We will also assess the impact of these interventions on pain unpleasantness, anxiety and opioid and benzodiazepine consumption. The secondary aim of this study will assess the impact of psychological factors (anxiety sensitivity and pain catastrophising) on pain following VR. METHODS AND ANALYSIS: This is a single centre, prospective, randomised, clinical trial. Ninety children/adolescents, aged 8-18 years, presenting for Nuss repair of pectus excavatum will be randomised to 1 of 3 study arms (VR-GR, VR-D and 360 video). Patients will use the Starlight Xperience (Google Daydream) VR suite for 10 min. Patients randomised to VR-GR (n=30) will engage in guided relaxation/mindfulness with the Aurora application. Patients randomised to VR-D (n=30) will play 1 of 3 distraction-based games, and those randomised to the 360 video (n=30) will watch the Aurora application without audio instructions or sound. Primary outcome is pain intensity. Secondary outcomes include pain unpleasantness, anxiety and opioid and benzodiazepine consumption. ETHICS AND DISSEMINATION: This study follows Standard Protocol Items: Recommendations for Interventional Trials guidelines. The protocol was approved by the Cincinnati Children's Hospital Medical Center's institutional review board. Patient recruitment began in July 2020. Written informed consent will be obtained for all participants. All information acquired will be disseminated via scientific meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04351776.