Plasma Concentrations of Select Inflammatory Cytokines Predicts Pain Intensity 48 Hours Post-Shoulder Muscle Injury

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 (β=0.95, SE 0.31; p=.003), IL-1β (β=0.84, SE 0.36; p=.02), IL-2 (β=0.78, SE 0.34; p=.03), and IL-12 p70 (β=0.88, SE 0.40; p=.03) and longitudinal postoperative elevations in GM-CSF (β=1.38, SE 0.57; p=.03), IFNγ (β=1.36, SE 0.6; p=.03), IL-1β (β=1.25, SE 0.59; p=.03), IL-7 (β=1.65, SE 0.7, p=.02), and IL-12 p70 (β=1.17, SE 0.58; p=.04). In contrast, CPSP was associated with lower baseline concentration of IL-8 (β= -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 (β= -0.57, SE 0.26; p=.03), IL-8 (β= -0.68, SE 0.24; p=.006), and IL-13 (β= -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.

The effects of acupressure on post-dressing pain in burn patients: A clinical randomized trial

BACKGROUND AND OBJECTIVES

Burns often cause severe pain, especially during dressing changes. This study aimed to investigate the effect of acupressure on pain during dressing changes in burn patients.

METHODS

This randomized clinical trial was conducted on 76 burn patients. The eligible patients were randomly assigned to the intervention and control groups after obtaining informed consent. Eligible patients were randomly assigned to the intervention and control groups by blocking. The study was conducted over two days using the same method. Before entering the dressing room, acupressure was performed in the intervention group for 10 min in acupressure points and the control group in other points. Pain intensity was measured in two groups 30 min before entering the dressing room and 15 and 30 min after leaving the dressing room using VAS. Finally, the data were analyzed using SPSS software 25th edition.

RESULTS

Pain scores were similar for the two groups before the dressing change. The results of this study revealed a significant decrease in the patient's pain intensity mean in the test group following acupressure compared to the control group on day one which remained on day two (P < 0.05).

CONCLUSION

Considering the experience of severe pain in burn patients, acupressure is recommended as a complementary method along with modern medicine to reduce these patients' pains.

Changes in serum levels of pain mediators in hemiplegic shoulder pain

OBJECTIVE

To provide a new insight into the diagnosis and treatment of hemiplegic shoulder pain (HSP) by investigating changes in serum pain mediators.

DESIGN

Cross-sectional study.

SUBJECTS/PATIENTS

Shoulder pain group (n = 34) and control group (n = 21).

METHODS

Pain-free shoulder mobility, anxiety status, depression status, and shoulder pain were measured by passive range of motion (PROM), self-rating anxiety scale, self-rating depression scale (SDS), and visual analog scale, respectively. The enzyme-linked immunosorbent assay was used to test the serum pain mediators, including interleukin (IL)-1β, IL-2, IL-6, IL-10, nerve growth factor (NGF), tumor necrosis factor-α (TNF-α), substance P (SP), calcitonin gene-related peptide (CGRP), bradykinin (BK), 5-hydroxytryptamine (5-HT), prostaglandin E2 (PGE2), and lysophosphatidic acid (LPA).

RESULTS

Shoulder pain group pain-free PROM significantly lower than control (p < .01), and SDS index score of shoulder pain group was significantly higher than control (p < .05). The rate of spasticity in the flexor elbow muscles is higher in shoulder pain group (p < .01). CGRP, IL-10, and IL-2 were significantly upregulated in shoulder pain group compared with control (p < .01), whereas NGF, TNF-α, IL-6, 5-HT, PGE2, SP, LPA, BK, and IL-1β were significantly decreased (p < .01).

CONCLUSION

Patients with HSP have a higher risk of joint mobility disorders and depression; spasticity may be an important factor in the development of shoulder pain; CGRP is thought to be the major pain mediator in HSP, and HSP may not be inflammatory.

Prognostic models for chronic postsurgical pain-Current developments, trends, and challenges

PURPOSE OF REVIEW

Prognostic models for chronic postsurgical pain (CPSP) aim to predict the likelihood for development and severity of CPSP in individual patients undergoing surgical procedures. Such models might provide valuable information for healthcare providers, allowing them to identify patients at higher risk and implement targeted interventions to prevent or manage CPSP effectively. This review discusses the latest developments of prognostic models for CPSP, their challenges, limitations, and future directions.

RECENT FINDINGS

Numerous studies have been conducted aiming to develop prognostic models for CPSP using various perioperative factors. These include patient-related factors like demographic variables, preexisting pain conditions, psychosocial aspects, procedure-specific characteristics, perioperative analgesic strategies, postoperative complications and, as indicated most recently, biomarkers. Model generation, however, varies and performance and accuracy differ between prognostic models for several reasons and validation of models is rather scarce.

SUMMARY

Precise methodology of prognostic model development needs advancements in the field of CPSP. Development of more accurate, validated and refined models in large-scale cohorts is needed to improve reliability and applicability in clinical practice and validation studies are necessary to further refine and improve the performance of prognostic models for CPSP.

Circulating Inflammatory Biomarkers Predict Pain Change Following Exercise-Induced Shoulder Injury: Findings From the Biopsychosocial Influence on Shoulder Pain Preclinical Trial

Shoulder pain is a highly prevalent musculoskeletal condition that frequently leads to suboptimal clinical outcomes. This study tested the extent to which circulating inflammatory biomarkers are associated with reports of shoulder pain and upper-extremity disability for a high-risk genetic by psychological subgroup (catechol-O-methyltransferase [COMT] variation by pain catastrophizing [PCS]). Pain-free adults meeting high-risk COMT × PCS subgroup criteria completed an exercise-induced muscle injury protocol. Thirteen biomarkers were collected and analyzed from plasma 48 hours after muscle injury. Shoulder pain intensity and disability (Quick-DASH) were reported at 48 and 96 hours to calculate change scores. Using an extreme sampling technique, 88 participants were included in this analysis. After controlling for age, sex, and BMI, there were moderate positive associations between higher c-reactive protein (CRP; βˆ = .62; 95% confidence interval [CI] = -.03, 1.26), interleukin-6 (IL-6; βˆ = 3.13; CI = -.11, 6.38), and interleukin-10 (IL-10; βˆ = 2.51; CI = -.30, 5.32); and greater pain reduction from 48 to 96 hours post exercise muscle injury. Using an exploratory multivariable model to predict pain changes from 48 to 96 hours, we found participants with higher IL-10 were less likely to experience a high increase in pain (βˆ = -10.77; CI = -21.25, -2.69). Study findings suggest CRP, IL-6, and IL-10 are related to shoulder pain change for a preclinical high-risk COMT × PCS subgroup. Future studies will translate to clinical shoulder pain and decipher the complex and seemingly pleiotropic interplay between inflammatory biomarkers and shoulder pain change. PERSPECTIVE: In a preclinical high-risk COMT × PCS subgroup, 3 circulating inflammatory biomarkers (CRP, IL-6, and IL-10) were moderately associated with pain improvement following exercise-induced muscle injury.

The major pain source of rotator cuff-related shoulder pain: A narrative review on current evidence

BACKGROUND

Rotator cuff-related shoulder pain (RCRSP) was proposed to have a complex pain mechanism, but the exact aetiology is still unclear. A recent review summarised the updated research to analyse the traditional concept of shoulder impingement which may not be accurate. Current studies have demonstrated that mechanical factors including a reduction in subacromial space, scapular dyskinesia and different acromial shapes are unlikely directly contributing to RCRSP.

AIMS

Since the precise RCRSP pain mechanism remains unclear, the aim of this narrative review is to discuss possible sources of pain contributing to RCRSP according to the mechanisms-based pain classifications.

RESULTS AND DISCUSSION

Research findings on potential mechanical nociceptive factors of RCRSP are conflicting; investigations of neuropathic and central pain mechanisms of RCRSP are limited and inconclusive. Overall, available evidence has indicated moderate to strong correlations between RCRSP and chemical nociceptive sources of pain.

CONCLUSION

Results from current research may provide new directions for future studies on the aetiology of RCRSP and its clinical management towards a biochemical view instead of the traditional mechanical hypothesis.

The Usefulness of Serological Inflammatory Markers in Patients with Rotator Cuff Disease—A Systematic Review

Background and Objectives: Rotator cuff disease (RCD) is a prominent musculoskeletal pain condition that spans a variety of pathologies. The etiology and precise diagnostic criteria of this condition remain unclear. The current practice of investigating the biochemical status of RCD is by conducting biopsy studies but their invasiveness is a major limitation. Recent biochemical studies on RCD demonstrate the potential application of serological tests for evaluating the disease which may benefit future clinical applications and research. This systematic review is to summarize the results of available studies on serological biochemical investigations in patients with RCD. Methods: An electronic search on databases PubMed and Virtual Health Library was conducted from inception to 1 September 2021. The inclusion criteria were case-control, cross-sectional, and cohort studies with serological biochemical investigations on humans with RCD. Methodological quality was assessed using the Study Quality Assessment Tool for Observational Cohort and Cross-sectional studies from the National Heart, Lung, and Blood Institute. Results: A total of 6008 records were found in the databases; of these, 163 full-text studies were checked for inclusion and exclusion criteria. Nine eligible studies involving 984 subjects with RCD emerged from this systematic review. The quality of the studies found ranged from poor to moderate. In summarizing all the studies, several fatty acids, nonprotein nitrogen, interleukin-1 β, interleukin-8, and vascular endothelial growth factor were found to be significantly higher in blood samples of patients with RCD than with control group patients, while Omega-3 Intex, vitamin B12, vitamin D, phosphorus, interleukin-10, and angiogenin were observed to be significantly lower. Conclusions: This is the first systematic review to summarize current serological studies in patients with RCD. Results of the studies reflect several systemic physiological changes in patients with RCD, which may prove helpful to better understand the complex pathology of RCD. In addition, the results also indicate the possibility of using serological tests in order to evaluate RCD; however, further longitudinal studies are required.