Systematic review of movement-evoked pain versus pain at rest in postsurgical clinical trials and meta-analyses: A fundamental distinction requiring standardized measurement

Predictors of subacute postoperative pain after total knee arthroplasty: A secondary analysis of two randomized trials

BACKGROUND

Methods for identifying high-pain responders undergoing total knee arthroplasty remain important to improve individualized pain management. This study aimed at evaluating pre- and perioperative predictors of pain on Days 2-7 after total knee arthroplasty.

METHODS

This is a secondary analysis of data from 227 patients participating in two randomized trials. Pain outcomes were mean pain during walking on Days 2-7 and on Days 2, 4 and 7. Multivariable linear and logistic regressions were carried out in two steps. First, only preoperative available variables including demographics, comorbidities, pain catastrophizing scale and preoperative pain were evaluated while controlling for trial intervention and recruitment site. In the second step, perioperative variables and pain during walking 24 h postoperatively were added.

RESULTS

The model with only preoperative predictors for mean pain Days 2-7 showed preoperative pain (R-squared 0.097) as the only predictor. In the second model, adding postoperative available variables, only pain 24 h postoperatively (R-squared 0.248) was significant, with a significant main effect of recruitment site. Results for the separate day analysis similarly showed preoperative pain and pain during walking 24 h postoperatively as predictors. The overall best sensitivity (60%) and specificity (74%) for predicting a high-subacute postoperative pain response on Days 2-7 was with cut-off values of VAS 45.5 (out of 100) for pain during walking 24 h postoperatively.

CONCLUSIONS

Postoperative pain during walking at 24 h is predictive of subacute postoperative pain on Days 2-7 after total knee arthroplasty, while preoperative pain was only a weak predictor.

SIGNIFICANCE STATEMENT

This study investigated factors associated with pain after total knee arthroplasty beyond the immediate postoperative period. The analysis revealed significant associations between preoperative pain levels and, particularly, pain 24 h postoperatively, with subsequent subacute pain the following week. These findings can assist in identifying patients who would benefit from enhanced, individualized analgesic interventions to facilitate postoperative recovery.

Through the Lens of Movement-Evoked Pain: A Theoretical Framework of the "Pain-Movement Interface" to Guide Research and Clinical Care for Musculoskeletal Pain Conditions

Over 120 million Americans report experiencing pain in the past 3 months. Among these individuals, 50 million report chronic pain and 17 million report pain that limits daily life or work activities on most days (ie, high-impact chronic pain). Musculoskeletal pain conditions in particular are a major contributor to global disability, health care costs, and poor quality of life. Movement-evoked pain (MEP) is an important and distinct component of the musculoskeletal pain experience and represents an emerging area of study in pain and rehabilitation fields. This focus article proposes the "Pain-Movement Interface" as a theoretical framework of MEP that highlights the interface between MEP, pain interference, and activity engagement. The goal of the framework is to expand knowledge about MEP by guiding scientific inquiry into MEP-specific pathways to disability, high-risk clinical phenotypes, and underlying individual influences that may serve as treatment targets. This framework reinforces the dynamic nature of MEP within the context of activity engagement, participation in life and social roles, and the broader pain experience. Recommendations for MEP evaluation, encompassing the spectrum from high standardization to high patient specificity, and MEP-targeted treatments are provided. Overall, the proposed framework and recommendations reflect the current state of science in this emerging area of study and are intended to support future efforts to optimize musculoskeletal pain management and enhance patient outcomes. PERSPECTIVE: Movement-evoked pain (MEP) is a distinct component of the musculoskeletal pain experience and emerging research area. This article introduces the "Pain-Movement Interface" as a theoretical framework of MEP, highlighting the interface between MEP, pain interference, and activity engagement. Evaluating and treating MEP could improve rehabilitation approaches and enhance patient outcomes.

Combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane block for postoperative analgesia in gastric cancer patients: A double-blinded randomized controlled trial

STUDY OBJECTIVE

We conducted this double-blinded randomized controlled trial to examine whether the combination of dexamethasone and dexmedetomidine as adjuvants of transversus abdominis plane (TAP) block could improve analgesia efficacy and duration for gastric cancer patients.

DESIGN

Randomized controlled trial.

SETTING

The preoperative area, operating room, postanesthesia recovery room and bed ward.

PATIENTS

A total of 312 adult patients (104 per group) with gastric cancer were included.

INTERVENTIONS

Patients received bilateral subcostal TAP block with three different anesthetics (60 ml 0.25% ropivacaine added with 10 mg dexamethasone and 1 μg·kg-1 dexmedetomidine [A] or 10 mg dexamethasone [B] or 1 μg·kg-1 dexmedetomidine [C]).

MEASUREMENTS

The primary outcome was the incidence of moderate-to-severe pain 24 h on movement. Secondary outcomes included incidence of moderate-to-severe pain, pain score, opioids use, recovery quality and adverse events.

MAIN RESULTS

The incidence of moderate-to-severe pain on movement 24 h postoperatively of group A was significantly lower than group B (45.19% vs 63.46%; RR 0.71; 95% CI, 0.55 to 0.92) and group C (45.19% vs 73.08%, RR 0.62; 95% CI, 0.49 to 0.79). The median moving pain scores decreased significantly at 24 h (3.00 [3.00,5.00] vs 4.00 [3.00,6.00] vs 4.00 [3.00,5.00]; P < 0.001). There were significant differences in the opioids consumption within the first 24 h (27.5 [17.0,37.2] vs 30.0 [20.0,42.0] vs 32.0 [25.0,44.0] mg; P = 0.01) and the duration to first rescue analgesia (65.5 ± 26.7 vs 45.9 ± 34.5 vs 49.2 ± 27.2 h; P = 0.04).

CONCLUSIONS

The combination with dexamethasone and dexmedetomidine as adjuvants for TAP block reduced the incidence of moderate-to-severe pain and pain score both on movement and at rest at 24 h with prolonged duration to first rescue analgesia after gastric cancer surgery.

TRIAL REGISTRATION NUMBER

ChiCTR2000037981.

Movement-evoked pain is not associated with pain at rest or physical function in knee osteoarthritis

INTRODUCTION

Knee Osteoarthritis (KOA) is mainly characterized by pain. The assessment of KOA-related pain frequently focuses on different constructs subject to sources of bias or drawbacks, as the classical Pain at Rest (PAR). Movement-evoked pain (MEP), recently defined as 'pain during walking', emerges as a differential concept, since PAR and MEP are driven by different underlying mechanisms. Given the novelty of the MEP approach, its association with PAR or with different performance-based tests has not been studied in KOA yet.

MATERIALS AND METHODS

A cross sectional study was conducted. PAR was measured, alongside the performance of four mobility tests and their corresponding MEP: Timed Up and Go Test, 10-metre Walk Test, 2-Minute Walk Test, and 6-Minute Walk Test. Association and agreement were explored for MEP versus PAR, while the correlation of the tests versus each corresponding MEP-measure was assessed.

RESULTS

Neither association nor agreement were found in the duality MEP versus PAR. Also, the lack of association between the performance of a mobility test and the perceived level of pain during the development of the test was stated.

CONCLUSION

Movement-evoked pain is neither related to pain at rest nor to functional performance in subjects affected by knee osteoarthritis. The results from our study suggest that MEP and pain at rest measure and refer to different constructs in knee osteoarthritis. The implementation of MEP as an outcome in exercise-therapy could enhance the tracking of results, as well as the development of tailored interventions under different conditions.

SIGNIFICANCE

This research elucidates the relevance of MEP, recently defined as 'pain during walking', through the analysis of its association with PAR and with functional performance (measured through four mobility tests) in knee osteoarthritis. The results from our study highlight the absence of either association or agreement between MEP and PAR, fact that supports and endorses the idea that both concepts measure and refer to different constructs in knee osteoarthritis.

A domain-oriented approach to characterizing movement-evoked pain

Introduction

Movement-evoked pain (MEP) impacts a substantial proportion of US adults living with chronic pain. Evidence suggests that MEP is influenced by numerous biopsychosocial factors and mediated by mechanisms differing from those of spontaneous pain. However, both characteristic and mechanistic knowledge of MEP remain limited, hindering effective diagnosis and treatment.

Objectives

We asked (1) can chronic pain, functional, psychosocial, and behavioral measures be grouped into descriptive domains that characterize MEP? and (2) what relationships exist between biopsychosocial factors across multiple domains of MEP?

Methods

We formed 6 characteristic domains from 46 MEP-related variables in a secondary analysis of data from 178 individuals (aged 45-85 years) with knee pain. Ratings of pain during 3 functional activities (ie, Balance, Walking, Chair Stand) were used as primary MEP variables. Pearson correlations were calculated to show linear relationships between all individual domain variables. Relationships between variables were further investigated through weighted correlation network analysis.

Results

We observed a unique combination of pain characteristics associated with MEP apart from general pain. Notably, minutes doing physical activity were inversely associated with multiple variables within 4 of the 6 domains. Weighted correlation network analysis largely supported our classification of MEP domains. Additional interdomain relationships were observed, with the strongest existing between MEP, Mechanical Pain, and Multiple Pain Characteristics and Symptoms. Additional relationships were observed both within and between other domains of the network.

Conclusion

Our analyses bolster fundamental understanding of MEP by identifying relevant mechanistic domains and elucidating biopsychosocial and interdomain relationships.

The influence of exercise therapy dosing on pain and functional outcomes in patients with subacromial pain syndrome: A systematic review

Background

The objective was to identify exercise therapy dosing parameters for subacromial pain syndrome (SAPS) associated with improved pain and function outcomes (via effect sizes) and determine the extent of exercise intervention reproducibility.

Methods

An electronic search of PubMed/MEDLINE, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Cochrane Database of Systematic Reviews, and SportDiscus identified studies that used exercise therapy exclusively to treat SAPS. Exercise therapy dosing parameters were extracted and within-group effect sizes were calculated for all pain and functional outcomes. Template for Intervention Description and Replication and Consensus on Exercise Reporting were used to record intervention reporting. The risk of bias and Grading of Recommendations, Assessment, Development, and Evaluation were assessed by two reviewers.

Results

Twenty-one trials with 674 subjects were included. Effect sizes for pain and function were large in 18 studies, medium in six studies, and small or no effect in four studies, despite the type of supervision. With moderate certainty, effect sizes of pain and function were not influenced by exercise therapy dosing parameters. Intervention reporting was generally poor.

Discussion

Exercise therapy for SAPS was associated with large effect sizes for improvement in pain and function but optimal exercise therapy dosing parameters could not be identified. Strong recommendations conditionally suggest treating SAPS with a variety of exercise therapy dosing parameters.

Movement-evoked Pain versus Pain at Rest in Postsurgical Clinical Trials and in Meta-analyses: An Updated Systematic Review

BACKGROUND

Given the widespread recognition that postsurgical movement-evoked pain is generally more intense, and more functionally relevant, than pain at rest, the authors conducted an update to a previous 2011 review to re-evaluate the assessment of pain at rest and movement-evoked pain in more recent postsurgical analgesic clinical trials.

METHODS

The authors searched MEDLINE and Embase for postsurgical pain randomized controlled trials and meta-analyses published between 2014 and 2023 in the setting of thoracotomy, knee arthroplasty, and hysterectomy using methods consistent with the original 2011 review. Included trials and meta-analyses were characterized according to whether they acknowledged the distinction between pain at rest and movement-evoked pain and whether they included pain at rest and/or movement-evoked pain as a pain outcome. For trials measuring movement-evoked pain, pain-evoking maneuvers used to assess movement-evoked pain were tabulated.

RESULTS

Among the 944 included trials, 504 (53%) did not measure movement-evoked pain (vs. 61% in 2011), and 428 (45%) did not distinguish between pain at rest and movement-evoked pain when defining the pain outcome (vs. 52% in 2011). Among the 439 trials that measured movement-evoked pain, selection of pain-evoking maneuver was highly variable and, notably, was not even described in 139 (32%) trials (vs. 38% in 2011). Among the 186 included meta-analyses, 94 (51%) did not distinguish between pain at rest and movement-evoked pain (vs. 71% in 2011).

CONCLUSIONS

This updated review demonstrates a persistent limited proportion of trials including movement-evoked pain as a pain outcome, a substantial proportion of trials failing to distinguish between pain at rest and movement-evoked pain, and a lack of consistency in the use of pain-evoking maneuvers for movement-evoked pain assessment. Future postsurgical trials need to (1) use common terminology surrounding pain at rest and movement-evoked pain, (2) assess movement-evoked pain in virtually every trial if not contraindicated, and (3) standardize movement-evoked pain assessment with common, procedure-specific pain-evoking maneuvers. More widespread knowledge translation and mobilization are required in order to disseminate this message to current and future investigators.

EDITOR’S PERSPECTIVE

Topical Treatment Is Effective and Safe for Acute Ankle Sprains: The Multi-Center Double-Blind Randomized Placebo-Controlled TRAUMED Trial

BACKGROUND

Topical NSAIDs are widely used to treat ankle sprains. Traumed (Tr14) gel is a multicomponent formulation, demonstrating inflammation-resolution properties.

METHODS

This multicenter, double-blind trial investigated the efficacy and safety of Tr14 gel versus placebo gel and non-inferiority versus 1% diclofenac gel, applied 3×/day for 7 days after acute lateral ankle sprain (EudraCT Number: 2016-004792-50). The primary outcome was AUC for pain on passive movement, assessed by VAS from baseline to Days 4 and 7.

RESULTS

The trial population included 625 patients aged 18 to 78 years. The AUC scores were 187.88 and 200.75 on Day 4 (p = 0.02) and 294.14 and 353.42 on Day 7 (p < 0.001) for Tr14 and placebo, respectively. For Tr14 compared to diclofenac, the AUC scores were 187.50 and 197.19 on Day 4 (p = 0.3804) and 293.85 and 327.93 on Day 7 (p = 0.0017), respectively. On the FAAM-ADL subscale, Tr14 was superior to placebo and non-inferior to diclofenac at all time points. Time to 50% pain improvement was lowest for Tr14 (6.0 days), compared to placebo (7.1 days) and diclofenac (7.0 days). Adverse events were uncommon and minor.

CONCLUSIONS

Tr14 gel is effective and safe in acute ankle sprains, compared to placebo gel and diclofenac gel, and has faster pain resolution.

TRIAL REGISTRATION

The trial was registered in clinicaltrialsregister.eu, EudraCT number 2016-004792-50 on 07.06.2017.

The effect of anterior quadratus lumborum block on morphine consumption in minimally invasive colorectal surgery: a multicentre, double-blind, prospective randomised placebo-controlled trial

We investigated the efficacy and safety of a bilateral anterior quadratus lumborum block in patients undergoing minimally invasive colorectal surgery. This was a two-centre, double-blind, prospective, randomised, placebo-controlled trial including 150 patients undergoing laparoscopic colorectal surgery (left- or right hemicolectomy, sigmoidectomy) who were enrolled in the institutional abdominal enhanced recovery programme. Before induction of anaesthesia, patients received a bilateral anterior quadratus lumborum block in the left and right lateral decubitus position under ultrasound guidance and were allocated randomly to receive 30 ml of ropivacaine 0.375% (n = 75) or placebo (saline 0.9%) (n = 75) bilaterally. Postoperatively, all patients received multimodal intravenous analgesia including paracetamol, ketorolac and patient-controlled analgesia with morphine. The primary outcome was morphine consumption during the first 24 h after tracheal extubation. Secondary outcomes included severity of pain; presence and extent of sensory block; incidence of postoperative nausea and vomiting; and hospital duration of stay. We also investigated the need for, and dose of, rescue analgesia. Safety outcomes included the incidence of adverse events. Mean (SD) 24-hour morphine consumption was no different between patients allocated to ropivacaine and placebo (28.6 (22.3) mg vs. 28.4 (22.5) mg, p = 0.966, respectively). While a sensory block could be detected in significantly more patients allocated to the ropivacaine group, no differences were detected in pain scores or other secondary or safety endpoints. Patient satisfaction scores were high in both groups. In laparoscopic colorectal surgery, adding a bilateral anterior quadratus lumborum block to a standard multimodal analgesia regimen did not reduce opioid consumption or improve pain scores.

Effect of movement-evoked and tonic experimental pain on muscle force production

INTRODUCTION

When performing an exercise or a functional test, pain that is evoked by movement or muscle contraction could be a stronger stimulus for changing how individuals move compared to tonic pain. We investigated whether the decrease in muscle force production is larger when experimentally-induced knee pain is directly associated to the torque produced (movement-evoked) compared to a constant painful stimulation (tonic).

METHODS

Twenty-one participants performed three isometric knee extension maximal voluntary contractions without pain (baseline), during pain, and after pain. Knee pain was induced using sinusoidal electrical stimuli at 10 Hz over the infrapatellar fat pad, applied continuously or modulated proportionally to the knee extension torque. Peak torque and contraction duration were averaged across repetitions and normalized to baseline.

RESULTS

During tonic pain, participants reported lower pain intensity during the contraction than at rest (p < 0.001), whereas pain intensity increased with contraction during movement-evoked pain (p < 0.001). Knee extension torque decreased during both pain conditions (p < 0.001), but a larger reduction was observed during movement-evoked compared to tonic pain (p < 0.001). Participants produced torque for longer during tonic compared to movement-evoked pain (p = 0.005).

CONCLUSION

Our results indicate that movement-evoked pain was a more potent stimulus to reduce knee extension torque than tonic pain. The longer contraction time observed during tonic pain may be a result of a lower perceived pain intensity during muscle contraction. Overall, our results suggest different motor adaptation to tonic and movement-evoked pain and support the notion that motor adaptation to pain is a purposeful strategy to limit pain. This mechanistic evidence suggests that individuals experiencing prevalently tonic or movement-evoked pain may exhibit different motor adaptations, which may be important for exercise prescription.

Psychological predictors of acute postoperative pain after total knee and hip arthroplasty: A systematic review

BACKGROUND

Identifying patients at high risk of acute postoperative pain after total knee or hip arthroplasty (TKA/THA) will facilitate individualized pain management and research on the efficacy of treatment options. Numerous studies have reported that psychological patient factors may influence acute postoperative pain, but most reviews have focused on chronic pain and functional outcomes. This systematic review aims to evaluate which psychological metrics are associated with acute postoperative pain after TKA and THA.

METHODS

A systematic search was conducted using the databases PubMed, EMBASE, Web of Science, and Cochrane Library until June 2022. Full-text articles reporting associations of preoperative psychological factors with acute pain within 48 h of TKA or THA surgery were identified. Quality was assessed using the Quality in Prognostic Studies tool.

RESULTS

Eighteen studies containing 16 unique study populations were included. TKA was the most common procedure, and anxiety and depression were the most evaluated psychological metrics. Several different anesthetic techniques and analgesic regimens were used. The studies were generally rated as having a low to moderate risk of bias. Catastrophizing was associated with acute pain in six studies (of nine), mainly after TKA. In contrast, three studies (of 13) and two studies (of 13) found anxiety and depression, respectively, to be associated with acute postoperative pain.

CONCLUSION

Pain catastrophizing seemed to be the most consistent psychological predictor of acute postoperative pain after TKA. The results for other psychological factors and THA were inconsistent. However, the interpretation of results was limited by considerable methodological heterogeneity.

Correlation Between Pain Intensity and Quality of Recovery After Video-Assisted Thoracic Surgery for Lung Cancer Resection

Purpose

The Quality of Recovery-15 (QoR-15) questionnaire provides a multifaceted assessment of postoperative recovery, and the resulting score is recommended as an endpoint in clinical studies focused on postoperative pain. We aimed to investigate the correlation between the QoR-15 score and postoperative pain intensity in surgical patients.

Patients and Methods

Adult patients who underwent video-assisted thoracoscopic surgery (VATS) for lung cancer resection and were enrolled in a prospective registry or in a previous prospective study were included in this study. Baseline and perioperative data, including the results of assessment using the Korean version of the QoR-15 (QoR-15K) questionnaire at 48 hours postoperatively, were collected from the database. Correlations between the QoR-15K total score, questionnaire dimensions, and postoperative pain intensity at 48 hours postoperatively were determined using the Spearman correlation coefficient (ρ).

Results

We analyzed a total of 137 eligible patients. Significant negative correlations were noted between the QoR-15K total score and pain intensity at rest (ρ = -0.45, 95% confidence interval [CI]: -0.57 - -0.31, P < 0.001) and during coughing (ρ = -0.55, 95% CI: -0.65 - -0.42, P < 0.001) at 48 hours postoperatively. The pain dimension and pain intensity at 48 hours postoperatively showed significant correlations with physical comfort, emotional state, and physical independence dimensions. Multivariable logistic regression revealed a significant negative association between the pain score at 24 hours postoperatively and good or excellent postoperative recovery.

Conclusion

The results support the impact of postoperative pain on the overall postoperative quality of recovery in patients who underwent VATS for lung cancer resection. Moreover, the QoR-15K score may be considered as a primary endpoint in clinical studies on postoperative pain control.

The effect of dexamethasone on functional pain following Transoral Robotic Surgery: a randomized double blinded clinical trial

BACKGROUND

Pain is prevalent after most TransOral Robotic Surgery (TORS) procedures and may limit function i.e. swallowing. Currently, there is limited knowledge regarding optimal pain treatment in TORS.

AIMS/OBJECTIVES

This clinical trial randomized patients to either a high-dose dexamethasone or low-dose dexamethasone treatment in addition to a multimodal basic analgesic protocol. The aim of the trial was to investigate the pain intensity during rest and swallowing using the Visual Analogue Scale (VAS) after TORS lingual tonsillectomy. Secondary outcomes were acceptable food consistency, nausea, vomiting, opioid rescue usage, length of hospitalization, feeding tube placements, readmissions, blood glucose levels and postoperative complications.

METHODS

The trial was conducted between August 2020 and October 2022. Eligible patients were patients scheduled for TORS-L treatment of obstructive sleep apnea syndrome or as part of the diagnostic work-up of head and neck carcinoma of unknown primary.

RESULTS

Eighteen patients were and randomized 1:1. There were overall no significant differences between groups in the reported VAS scores during rest or swallowing (p ≥ .05). Overall, there were no differences in the secondary outcomes.

CONCLUSION

There were no differences in the pain intensity in the two treatment groups allocated to a basic multimodal analgesic package and either high-dose dexamethasone or low-dose dexamethasone treatment. The trial is the first RCT to include pain measurement during a procedure-relevant activity, thus creating a platform for future recovery studies.

Transoral robotic surgery - time for consensus on pain assessment. A review

BACKGROUND

In Head and Neck surgery Transoral Robotic Surgery (TORS) is evolving as a key treatment option for benign and malignant lesions in the oropharynx. Even so, postoperative pain is one of the primary early complaints following TORS. Well established evidence-based procedure specific pain treatment guidelines are available for a variety of other surgical specialties. However, there are no guidelines for TORS.

AIM

This review describes the available data of early pain intensity following TORS during rest and procedure related activity.

METHODS

Literature concerning pain in the immediate postoperative phase following TORS were obtained from two literature databases.

RESULTS

Most data on pain intensity following TORS are based upon a numeric rating scale, e.g. the Visual Analogue Scale and/or analgesic demands. Only one randomized clinical trial is available reflecting that the literature is mainly based on retrospective and a few prospective studies. Only one study analyzed pain during relevant functionality, i.e. swallowing. Overall, the studies suffer from a non-standardized approach and there is a need for transparent information concerning the timing of pain ratings and methodology.

CONCLUSIONS

The evidence for optimal pain control is limited, particularly during surgical relevant activity. Postoperative pain rating during activity is a fundamental element in pain trials in order to enhance recovery thereby calling for future consensus on assessment methodology.

The mechanisms and management of persistent postsurgical pain

An estimated 10%-50% of patients undergoing a surgical intervention will develop persistent postsurgical pain (PPP) lasting more than 3 months despite adequate acute pain management and the availability of minimally invasive procedures. The link between early and late pain outcomes for surgical procedures remains unclear-some patients improve while others develop persistent pain. The elective nature of a surgical procedure offers a unique opportunity for prophylactic or early intervention to prevent the development of PPP and improve our understanding of its associated risk factors, such as pre-operative anxiety and the duration of severe acute postoperative pain. Current perioperative pain management strategies often include opioids, but long-term consumption can lead to tolerance, addiction, opioid-induced hyperalgesia, and death. Pre-clinical models provide the opportunity to dissect mechanisms underpinning the transition from acute to chronic, or persistent, postsurgical pain. This review highlights putative mechanisms of PPP, including sensitisation of peripheral sensory neurons, neuroplasticity in the central nervous system and nociceptive signalling along the neuro-immune axis.

Efficacy of prolonged intravenous lidocaine infusion for postoperative movement-evoked pain following hepatectomy: a double-blinded, randomised, placebo-controlled trial

BACKGROUND

The analgesic effect of intravenous lidocaine varies with the duration of lidocaine infusion and surgery type. We tested the hypothesis that prolonged lidocaine infusion alleviates postoperative pain in patients recovering from hepatectomy over the first 3 postoperative days.

METHODS

Patients undergoing elective hepatectomy were randomly assigned to receive prolonged i.v. lidocaine treatment or placebo. The primary outcome was incidence of moderate-to-severe movement-evoked pain at 24 h postoperatively. The secondary outcomes included incidence of moderate-to-severe pain during movement and at rest throughout the first 3 postoperative days, postoperative opioid consumption, and pulmonary complications. Plasma lidocaine concentration was also monitored.

RESULTS

We enrolled 260 subjects. Intravenous lidocaine lowered the incidence of moderate-to-severe movement-evoked pain at 24 h and 48 h postoperatively (47.7% vs 67.7%, P=0.001; 38.5% vs 58.5%, P=0.001) and reduced movement-evoked pain scores (3.7 [1.7] vs 4.2 [1.6]; mean difference 0.5 [95% confidence interval {CI}: 0.1-0.9]; P=0.018) and morphine equivalent consumption (47.2 [16.7] mg vs 52.6 [19.2] mg; mean difference 5.4 mg [95% CI: 1.0-9.8]; P=0.016) at 24 h postoperatively. Lidocaine also lowered the incidence of postoperative pulmonary complications (23.1% vs 38.5%; P=0.007). Median plasma lidocaine concentrations were 1.5, 1.9, and 1.1 μg ml^-1 (inter-quartile ranges: 1.1-2.1, 1.4-2.6, and 0.8-1.6, respectively) after bolus injection, at the end of the surgery, and 24 h postoperatively.

CONCLUSIONS

Prolonged intravenous lidocaine infusion reduced the incidence of moderate-to-severe movement-evoked pain for 48 h after hepatectomy. However, the reduction in pain scores and opioid consumption by lidocaine was below the minimal clinically important difference.

CLINICAL TRIAL REGISTRATION

NCT04295330.

The effect of pharmacist-initiated perioperative multidisciplinary pharmaceutical care model and clinical pathway on pain management in patients undergoing orthopedic surgery: a before-after study

BACKGROUND

Poor pain control is common in perioperative orthopedic surgeries. However, there is a lack of exploration of the clinical pharmacy practice model for this population.

AIM

To construct a perioperative pharmaceutical care model and clinical pathway for patients undergoing orthopedic surgeries and assess their impact on pain management.

METHOD

This historical before-and-after study was conducted in the Department of Orthopedics of a tertiary hospital in Guangdong Province, China. The control group was surgical patients who received routine diagnosis and treatment. The intervention group received pain management from a multidisciplinary team based on a pharmacist-initiated pharmaceutical care practice model and clinical pathways for medication management. The primary outcome measures were postoperative pain at rest (PAR) and movement-evoked pain (MEP) scores, number of breakthrough pains, and length of hospital stay.

RESULTS

A total of 320 orthopedic surgery patients were included. Among patients with expected moderate or severe postoperative pain (82.5%), significantly lower PAR and MEP scores were observed in the intervention group 24 h after surgeries compared to the control group (p < 0.05). Compared to the control group, hospital stay in the intervention group was shortened by 2.3 days (p < 0.001). However, there were no significant differences in the control of breakthrough pain and the incidence of adverse drug reactions (p > 0.05).

CONCLUSION

Multidisciplinary perioperative pain management practice models and clinical pathways initiated by pharmacists could improve outcome indicators related to pain management and support the role and value of pharmacists.

Is intravenous magnesium sulphate a suitable adjuvant in postoperative pain management? - A critical and systematic review of methodology in randomized controlled trials

A growing worldwide focus on opioid-free anaesthesia entails multimodal analgesic strategies involving non-opioids such as magnesium sulphate (MgSO4). Several systematic reviews have concluded there is beneficial analgesic effect of MgSO4 administration but do not take considerable heterogeneity among the studies into consideration. Medical literature published until June 2021 was searched in PubMed/Medline, Embase, Central and Web of Science: The final search yielded a total of 5,672 articles. We included only randomised controlled trials assessing the effect of intravenous MgSO4 on opioid consumption and acute postoperative pain when compared to either placebo or standardized analgesic treatment. The primary aim was to compare the homogeneity of essential variables and confounders. A post-hoc meta-analysis demonstrated a reduction in both postoperative morphine consumption (-6.12 mg) and pain score (-12.32 VAS points) in favour of the MgSO4-groups. Data for meta-analysis was missing from 19 studies (45%) on morphine consumption and 29 studies (69%) for pain score, the majority of which reports no effect for either morphine consumption or pain score. The calculated heterogeneity among the included studies was considerable for both outcomes; I 2=91% for morphine consumption and I 2=96% for pain score. Although we found a per se reduction in opioid consumption and pain score, methodological heterogeneity and clinical shortcomings of pre-, intra-, and post anaesthetic data precludes conclusions on clinical importance of intraoperative intravenous MgSO4. In addition, the reduction is likely less than what can be gained from using standardized analgesic treatment.

Physical activity in the first postoperative week in 132 knee arthroplasty patients randomized to 3 different analgesic regimens

BACKGROUND

The aim of this study was to investigate whether objectively recorded physical activity in the first week after surgery in total knee arthroplasty patients differed between patients allocated to 3 different analgesic regimens.

METHODS

A total of 132 total knee arthroplasty patients wore activity monitors 24 hours a day from day 1 after surgery for 6 consecutive days. The time mobilized (stepping/standing) and the number of steps were recorded. This study was a sub-study of a randomized controlled study comparing tapentadol extended-release (ER), oxycodone controlled-release (CR), or a non-opioid placebo analgesic regimen.

RESULTS

The placebo group spent significantly more time mobilized than the tapentadol ER and the oxycodone CR groups (P = .016 and .042, respectively), but no statistically significant differences were found between the groups in the number of steps taken. The activity levels of patients in all groups increased in the first week after surgery.

CONCLUSION

Patients in the non-opioid placebo group spent more time mobilized the first week after surgery than those in the tapentadol ER and the oxycodone CR groups, while the number of steps was not different between the groups.

A Novel Movement-Evoked Pain Provocation Test for Older Adults With Persistent Low Back Pain: Safety, Feasibility, and Associations With Self-reported Physical Function and Usual Gait Speed

OBJECTIVES

Low back pain (LBP) is highly prevalent and disabling for older adults. Movement-evoked pain is an emerging measure that may help to predict disability; but is not currently a part of geriatric LBP clinical care. This study tested the safety and feasibility of a new Movement-Evoked Provocation Test for Low Back Pain in Older Adults (MEPLO). We also compared associations between movement-evoked pain via 2 different scoring methods and disability-associated outcomes.

MATERIALS AND METHODS

Thirty-nine older adults with persistent LBP provided baseline recalled and resting pain ratings, self-reported physical function, and usual gait speed. Participants then completed MEPLO, involving 4 tasks essential for functional independence: chair rises, trunk rotation, reaching, and walking. Movement-evoked pain was then quantified using the traditional change score (delta) method of pain premovement to postmovement; and also, a new aggregate method that combines pain ratings after the 4 tasks.

RESULTS

No safety or feasibility issues were identified. Compared with the delta score, the aggregate score was more strongly associated with self-reported physical function (beta: -0.495 vs. -0.090) and usual gait speed (beta: -0.450 vs. -0.053). Similarly, the aggregate score was more strongly associated with self-reported physical function than recalled and resting pain (beta: -0.470, -0.283, and 0.136, respectively).

DISCUSSION

This study shows the safety and feasibility of testing movement-evoked pain in older adults with persistent LBP, and its potential superiority to traditional pain measures. Future studies must validate these findings and test the extent to which MEPLO is implementable to change with geriatric LBP standard of care.

A scoping review on the methods of assessment and role of resilience on function and movement-evoked pain when experiencing a musculoskeletal injury

BACKGROUND

Resilience refers to an individual's ability to maintain effective functioning, by resisting, withstanding or recovering from stressors or adversity, including pain associated with physical injury (J Clin Psychol Med Settings 28:518-28, 2021). The aim of this scoping review is to determine the role of resilience in the experience of movement-evoked pain (MEP) and return to functional activity following a musculoskeletal injury.

METHODS

This review conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews and the scoping review protocol of the Joanna Briggs Institute (JBI). Five databases and one grey literature database were searched using predetermined key words and index terms to capture published and unpublished records on the topic. Two authors independently screened the title and abstract of each record, with the full-text of eligible records being reviewed. Papers were eligible for inclusion if they examined the population, concept and context of interest, were written in English and the full text was available. Data were extracted from each eligible record to guide discussion of the available literature on this topic.

RESULTS

Of 4771 records, 2695 articles underwent screening based on their title and abstract. After title and abstract screening 132 articles were eligible for full text review, with 24 articles included in the final analysis. This review identified that psychological resilience has primarily been investigated in the context of a range of age-related pathologies. The choice of functional and movement-evoked pain assessments in the included studies were often guided by the pathology of interest, with some being general or injury specific.

CONCLUSION

This scoping review identified inconsistent conclusions regarding the role of resilience in the experience of MEP and the ability to return to function for older adults with a musculoskeletal injury. This scoping review highlights the need for longitudinal research to be conducted that allows a broader age range, including younger adults, to determine if multidimensional resilience may promote recovery form musculoskeletal injury.

Intraoperative abobotulinumtoxinA alleviates pain after surgery and improves general wellness in a translational animal model

Pain after surgery remains a significant healthcare challenge. Here, abobotulinumtoxinA (aboBoNT-A, DYSPORT) was assessed in a post-surgical pain model in pigs. Full-skin-muscle incision and retraction surgery on the lower back was followed by intradermal injections of either aboBoNT-A (100, 200, or 400 U/pig), vehicle (saline), or wound infiltration of extended-release bupivacaine. We assessed mechanical sensitivity, distress behaviors, latency to approach the investigator, and wound inflammation/healing for 5-6 days post-surgery. We followed with immunohistochemical analyses of total and cleaved synaptosomal-associated protein 25 kD (SNAP25), glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1(Iba1), calcitonin gene-related peptide (CGRP) and substance P (SP) in the skin, dorsal root ganglia (DRG) and the spinal cord of 400 U aboBoNT-A- and saline-treated animals. At Day 1, partial reversal of mechanical allodynia in aboBoNT-A groups was followed by a full reversal from Day 3. Reduced distress and normalized approaching responses were observed with aboBoNT-A from 6 h post-surgery. Bupivacaine reversed mechanical allodynia for 24 h after surgery but did not affect distress or approaching responses. In aboBoNT-A-treated animals cleaved SNAP25 was absent in the skin and DRG, but present in the ipsilateral dorsal horn of the spinal cord. In aboBoNT-A- versus saline-treated animals there were significant reductions in GFAP and Iba1 in the spinal cord, but no changes in CGRP and SP. Analgesic efficacy of aboBoNT-A appears to be mediated by its activity on spinal neurons, microglia and astrocytes. Clinical investigation to support the use of aboBoNT-A as an analgesic drug for post-surgical pain, is warranted.

Effectiveness and safety of path-based analgesic regimens designed by clinical pharmacists based on the type of biliary and pancreatic surgery

WHAT IS KNOWN AND OBJECTIVE

As the incidence of postoperative pain in patients with biliary and pancreatic diseases has gradually increased, how to control postoperative pain has received increasing research attention. By reading pain management guidelines and multidisciplinary communication and cooperation, clinical pharmacists designed multi-mode analgesia regimens based on surgical types, in order to provide strong evidence for the effectiveness and safety of postoperative analgesia regimens and better serve patients.

METHODS

Data from biliary or pancreatic surgery performed at Nanjing Drum Tower Hospital from 2019 to 2021 were collected. Take October 2020 as the time point to compare the outcomes before and after the implementation of the path-based postoperative analgesic regimens. The primary outcomes were NRS pain scores, sleep quality, and incidence of adverse reactions. Length of stay was a secondary outcome.

RESULTS AND DISCUSSION

A total of 268 and 239 patients were enrolled in the study and control groups, respectively. Four path-based postoperative analgesic management regimens significantly reduced patients' static and dynamic NRS scores in the 24 h (p < 0.05). The patients' sleep quality were better than controls (p > 0.05). The incidence of adverse reactions and the length of stay in the study group were numerically lower than controls. Moderate analysis indicated that four analgesia regimens are more precise and better meet actual clinical needs.

WHAT IS NEW AND CONCLUSION

Effective and safe postoperative pain management is particularly important for clinical purposes. Path-based postoperative analgesia regimens based on different types of surgery overcome the disadvantages of overly broad and generalized traditional guidelines, which play an important role in providing personalized and precise clinical services. Further, study findings provide evidence that four path-based analgesic regimens can reduce postoperative pain and reduce the length of hospital stay, which may provide a better direction for clinical postoperative pain management.

No place for routine use of modified-release opioids in postoperative pain management

Modified-release opioid tablets were introduced into surgical practice in the belief that they provided superior pain relief and reduced nursing workload, and they rapidly became embedded into many perioperative pathways. Although national and international guidelines for the management of postoperative pain now advise against the use of modified-release opioids, they continue to be prescribed in many centres. Recognition that modified-release opioids show lack of benefit and increased risk of harm compared with immediate-release opioids in the acute, postoperative setting has become clear. Their slow onset and offset make rapid and safe titration of these opioids impossible, including down-titration as the patient recovers; pain relief may be less effective; they have been associated with an increased incidence of opioid-related adverse drug events, increased length of hospital stay, and higher readmission rates; and they lead to higher rates of opioid-induced ventilatory impairment and persistent postoperative opioid use. Evidence indicates that modified-release opioids should not be used routinely in the postoperative period.

The duration of postoperative analgesic use after total knee arthroplasty and nomogram for predicting prolonged analgesic use

Background

Total knee arthroplasty is currently a reliable treatment for end-stage knee osteoarthritis. However, chronic postsurgical pain (CPSP) is substantially thought to reduce patient satisfaction. NSAID-based oral analgesics were used to manage CPSP, but research on the duration of postoperative analgesic use (DAU) and prolonged analgesic use (PAU) are presently scarce.

Methods

Preoperative, perioperative, and one-year or above postoperative follow-up data were collected from 162 patients who underwent total knee arthroplasty between 1 June 2018 and 1 March 2019, and the DAU and the discontinuation time of each patient after discharge were recorded. Observational statistical analysis, diagnostic test, and predictive nomogram construction were performed on the collected data.

Results

The 3-month DAU has good diagnostic utility for poor outcome of postoperative months twelve (POM12). The constructed nomogram shows that gender, preoperative Numeric Rating Scale (NRS) movement pain scores, duration of surgery, postoperative days three (POD3) moderate to severe movement pain, and POD3 pain rescue medication were significant prognostic predictors of PAU after discharge. The area under the curve (AUC) of the 3-month, 6-month, and 12-month nomogram receiver operating characteristic (ROC) curves were calculated to be 0.741, 0.736, and 0.781.

Conclusion

PAU was defined as more than three months of NSAID-based oral analgesic use after TKA. Prognostic predictors of PAU after TKA were identified, and visualized nomogram was plotted and evaluated. The evaluation indicated that the prediction model had the good predictive ability and was a valuable tool for predicting PAU after discharge.

Objective and Quantitative Evaluation of Spontaneous Pain-Like Behaviors Using Dynamic Weight-Bearing System in Mouse Models of Postsurgical Pain

Background

The paucity of objective and reliable measurements of pain-like behaviors has impeded the translatability of mouse models of postsurgical pain. The advanced dynamic weight-bearing (DWB) system enables evaluation of spontaneous pain-like behaviors in pain models. This study investigated the suitability and efficiency of the DWB system for assessing spontaneous pain-like behaviors and analgesic therapies in murine models of postsurgical pain.

Methods

Male adult C57BL/6JJcl mice were subjected to multiple surgical pain models with distinct levels of invasiveness, including a superficial incisional pain model involving only hind paw skin incision, deep incisional pain model that also involved incision and elevation of the underlying hind paw muscles, and orthopedic pain model involving tibial bone fracture and fixation with a pin (fracture and pinning [F/P] model). Spontaneous pain-like behaviors post-surgery were evaluated using weight distribution, pawprint area of the operated paw in the DWB system, and guarding pain score. Mechanical hypersensitivity was assessed using the von Frey test. The therapeutic effects of analgesics (diclofenac and buprenorphine for the deep incision model and diclofenac for the F/P model) were evaluated using the DWB system and von Frey test.

Results

The von Frey test demonstrated contradictory results between superficial and deep incisional pain models. The DWB system captured weight distribution changes in the operated hind paw, in accordance with the invasiveness and time course of wound healing in these surgical pain models. The reduction in weight-bearing on the operated paw correlated with guarding score, degree of paw swelling, and local expression of inflammatory mediators. DWB enabled accurate evaluation of the pharmacological effects of analgesics for detecting attenuation of surgery-induced weight-bearing changes in these models.

Conclusion

The DWB system serves as an objective and reliable method for quantifying pain-like behaviors and evaluating the therapeutic effects of analgesics in mouse models of postsurgical pain models.

SABER-Bupivacaine Reduces Postoperative Pain and Opioid Consumption After Arthroscopic Subacromial Decompression: A Randomized, Placebo-Controlled Trial

INTRODUCTION

Shoulder arthroscopy can result in substantial postoperative pain. Sucrose acetate isobutyrate extended-release bupivacaine (SABER-Bupivacaine; trade name Posimir) is a novel depot formulation of bupivacaine designed to provide analgesia at the surgical site for up to 72 hours. The objective of this study was to evaluate the effect of SABER-Bupivacaine on pain and opioid consumption after arthroscopic subacromial decompression and to assess short-term and long-term safety.

METHODS

In this double-blind, placebo-controlled trial, 78 subjects were randomized in a 2:1 ratio to SABER-Bupivacaine 5 mL or SABER-placebo 5 mL injected into the subacromial space just before skin closure. Twenty-nine additional subjects were randomized on an exploratory basis to bupivacaine hydrochloride 20 mL, also injected subacromially. Subjects rated pain intensity on a 0 to 10 scale over the first 3 postoperative days and received intravenous or oral morphine for breakthrough pain. The coprimary efficacy end points were pain intensity on 90° shoulder flexion and cumulative morphine intake from 0 to 72 hours after surgery. The time to first use of opioid rescue analgesia was a secondary end point.

RESULTS

The mean (SD) pain intensity was 5.16 (1.94) for SABER-Bupivacaine and 6.43 (1.77) for placebo (P = 0.012). The median consumption of intravenous morphine equivalents was 4.0 mg for SABER-Bupivacaine and 12.0 mg for placebo (P = 0.010). The median time to first use of morphine rescue was 12.4 hours for SABER-Bupivacaine and 1.2 hours for placebo (P = 0.014). The corresponding values for bupivacaine hydrochloride were 5.16 (2.38), 8.0 mg, and 1.4 hours. The incidence and severity of treatment-emergent adverse events were similar for all treatment groups, and no functional or radiographic differences were noted at the 6-month follow-up.

DISCUSSION

Compared with placebo, SABER-Bupivacaine reduced pain and opioid analgesic consumption over 72 hours after arthroscopic subacromial decompression and prolonged the time to first use of opioid rescue analgesia. No safety signals were noted during the immediate postoperative period or at 6-month follow-up.

CE: Assessing Movement-Evoked Pain

ABSTRACT

One of the most common and nuanced tasks that nurses perform is pain assessment, particularly in acute postoperative settings where frequent reassessments are needed. Most assessments are limited to obtaining a pain intensity score with little attention paid to the conditions necessitating the assessment or the factors contributing to the pain. Pain is frequently assessed during rest, but seldom during periods of movement or activity, which is a crucial omission given that acute postoperative movement-evoked pain (MEP) is intense and a common barrier to healing and restoration of function. In addition to physical limitations, MEP can impede cognitive, emotional, and social functioning in ways that can contribute to chronic pain, mood disorders, and disability. Professional and regulatory standards are moving away from a focus on pain intensity to an emphasis on its context, impact on function, and associated distress. Thus, there are many driving forces compelling nurses to integrate MEP assessments into practice to expedite the restoration of biopsychosocial functioning in postoperative patients. The authors discuss the clinical significance of a MEP assessment as well as protocols and tools for completing such assessments.

Exercise to prevent shoulder problems after breast cancer surgery: the PROSPER RCT

BACKGROUND

Upper limb problems are common after breast cancer treatment.

OBJECTIVES

To investigate the clinical effectiveness and cost-effectiveness of a structured exercise programme compared with usual care on upper limb function, health-related outcomes and costs in women undergoing breast cancer surgery.

DESIGN

This was a two-arm, pragmatic, randomised controlled trial with embedded qualitative research, process evaluation and parallel economic analysis; the unit of randomisation was the individual (allocated ratio 1 : 1).

SETTING

Breast cancer centres, secondary care.

PARTICIPANTS

Women aged ≥ 18 years who had been diagnosed with breast cancer and were at higher risk of developing shoulder problems. Women were screened to identify their risk status.

INTERVENTIONS

All participants received usual-care information leaflets. Those randomised to exercise were referred to physiotherapy for an early, structured exercise programme (three to six face-to-face appointments that included strengthening, physical activity and behavioural change strategies).

MAIN OUTCOME MEASURES

The primary outcome was upper limb function at 12 months as assessed using the Disabilities of Arm, Hand and Shoulder questionnaire. Secondary outcomes were function (Disabilities of Arm, Hand and Shoulder questionnaire subscales), pain, complications (e.g. wound-related complications, lymphoedema), health-related quality of life (e.g. EuroQol-5 Dimensions, five-level version; Short Form questionnaire-12 items), physical activity and health service resource use. The economic evaluation was expressed in terms of incremental cost per quality-adjusted life-year and incremental net monetary benefit gained from an NHS and Personal Social Services perspective. Participants and physiotherapists were not blinded to group assignment, but data collectors were blinded.

RESULTS

Between 2016 and 2017, we randomised 392 participants from 17 breast cancer centres across England: 196 (50%) to the usual-care group and 196 (50%) to the exercise group. Ten participants (10/392; 3%) were withdrawn at randomisation and 32 (8%) did not provide complete baseline data. A total of 175 participants (89%) from each treatment group provided baseline data. Participants' mean age was 58.1 years (standard deviation 12.1 years; range 28-88 years). Most participants had undergone axillary node clearance surgery (327/392; 83%) and 317 (81%) had received radiotherapy. Uptake of the exercise treatment was high, with 181 out of 196 (92%) participants attending at least one physiotherapy appointment. Compliance with exercise was good: 143 out of 196 (73%) participants completed three or more physiotherapy sessions. At 12 months, 274 out of 392 (70%) participants returned questionnaires. Improvement in arm function was greater in the exercise group [mean Disabilities of Arm, Hand and Shoulder questionnaire score of 16.3 (standard deviation 17.6)] than in the usual-care group [mean Disabilities of Arm, Hand and Shoulder questionnaire score of 23.7 (standard deviation 22.9)] at 12 months for intention-to-treat (adjusted mean difference Disabilities of Arm, Hand and Shoulder questionnaire score of -7.81, 95% confidence interval -12.44 to -3.17; p = 0.001) and complier-average causal effect analyses (adjusted mean difference -8.74, 95% confidence interval -13.71 to -3.77; p ≤ 0.001). At 12 months, pain scores were lower and physical health-related quality of life was higher in the exercise group than in the usual-care group (Short Form questionnaire-12 items, mean difference 4.39, 95% confidence interval 1.74 to 7.04; p = 0.001). We found no differences in the rate of adverse events or lymphoedema over 12 months. The qualitative findings suggested that women found the exercise programme beneficial and enjoyable. Exercise accrued lower costs (-£387, 95% CI -£2491 to £1718) and generated more quality-adjusted life years (0.029, 95% CI 0.001 to 0.056) than usual care over 12 months. The cost-effectiveness analysis indicated that exercise was more cost-effective and that the results were robust to sensitivity analyses. Exercise was relatively cheap to implement (£129 per participant) and associated with lower health-care costs than usual care and improved health-related quality of life. Benefits may accrue beyond the end of the trial.

LIMITATIONS

Postal follow-up was lower than estimated; however, the study was adequately powered. No serious adverse events directly related to the intervention were reported.

CONCLUSIONS

This trial provided robust evidence that referral for early, supported exercise after breast cancer surgery improved shoulder function in those at risk of shoulder problems and was associated with lower health-care costs than usual care and improved health-related quality of life.

FUTURE WORK

Future work should focus on the implementation of exercise programmes in clinical practice for those at highest risk of shoulder problems.

TRIAL REGISTRATION

This trial is registered as ISRCTN35358984.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 15. See the NIHR Journals Library website for further project information.

Do psychological factors relate to movement-evoked pain in people with musculoskeletal pain? A systematic review and meta-analysis

BACKGROUND

A growing body of evidence has demonstrated the importance of implementing movement-evoked pain in conventional pain assessments, with a significant role for psychological factors being suggested. Whether or not to include these factors in the assessment of movement-evoked pain has not yet been determined.

OBJECTIVES

The aim of this systematic review is to explore the association between psychological factors and movement-evoked pain scores in people with musculoskeletal pain.

METHODS

For this systematic review with meta-analysis, four electronic databases (PubMed, Medline, WOS, and Scopus) were searched. Cross-sectional studies, longitudinal cohort studies, and randomized controlled trials investigating the association between movement-evoked pain and psychological factors in adults with musculoskeletal pain were considered. Meta-analysis was conducted for outcomes with homogeneous data from at least 2 studies. Fischer-Z transformations were used as the measure of effect. Quality of evidence was assessed using the National Institutes of Health's Quality assessment tool for observational cohort and cross-sectional studies and Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

Meta-analyses and grading the quality of evidence revealed moderate evidence for a relation between movement-evoked pain and depressive symptoms (Fisher-z=0.27; 95%CI: 0.17, 0.36; 5 studies (n=440)), pain-related fear (Fisher-z=0.35; 95%CI: 0.26, 0.44; 6 studies (n=492)), and pain catastrophizing (Fisher-z=0.47; 95%CI: 0.36, 0.58; 4 studies (n=312)) in people with musculoskeletal pain.

CONCLUSIONS

Movement-evoked pain is weakly to moderately associated to depressive symptoms, pain-related fear, and pain catastrophizing in people with musculoskeletal pain.

Alpha lipoic acid attenuates evoked and spontaneous pain following surgical skin incision in rats

Our previous studies have implicated CaV3.2 isoform of T-type Ca2+ channels (T-channels) in the development of postsurgical pain. We have also previously established that different T-channel antagonists can alleviate in vivo postsurgical pain. Here we investigated the analgesic potential of another T-channel blocker and endogenous antioxidant molecule, α-lipoic acid (ALA), in a postsurgical pain model in rats. Our in vivo results suggest that single and repetitive intraperitoneal injections of ALA after surgery or preemptively, significantly reduced evoked mechanical hyperalgesia following surgical paw incision. Furthermore, repeated preemptive systemic injections of ALA effectively alleviated spontaneous postsurgical pain as determined by dynamic weight-bearing testing. We expect that our preclinical study may lead to further investigation of analgesic properties and mechanisms of analgesic action of ALA in patients undergoing surgery.

Developing consensus on core outcome domains for assessing effectiveness in perioperative pain management: results of the PROMPT/IMI-PainCare Delphi Meeting

ABSTRACT

Postoperative pain management is still insufficient, leading to major deficits, including patient suffering, impaired surgical recovery, long-term opioid intake, and postsurgical chronic pain. Yet, identifying the best treatment options refers to a heterogeneous outcome assessment in clinical trials, not always reflecting relevant pain-related aspects after surgery and therefore hamper evidence synthesis. Establishing a core outcome set for perioperative pain management of acute pain after surgery may overcome such limitations. An international, stepwise consensus process on outcome domains ("what to measure") for pain management after surgery, eg, after total knee arthroplasty, sternotomy, breast surgery, and surgery related to endometriosis, was performed. The process, guided by a steering committee, involved 9 international stakeholder groups and patient representatives. The face-to-face meeting was prepared by systematic literature searches identifying common outcome domains for each of the 4 surgical procedures and included breakout group sessions, world-café formats, plenary panel discussions, and final voting. The panel finally suggested an overall core outcome set for perioperative pain management with 5 core outcome domains: physical function (for a condition-specific measurement), pain intensity at rest, pain intensity during activity, adverse events, and self-efficacy. Innovative aspects of this work were inclusion of the psychological domain self-efficacy, as well as the specific assessment of pain intensity during activity and physical function recommended to be assessed in a condition-specific manner. The IMI-PROMPT core outcome set seeks to improve assessing efficacy and effectiveness of perioperative pain management in any clinical and observational studies as well as in clinical practice.

The feasibility and efficacy of perioperative auricular acupuncture technique via intradermal needle buried for postoperative movement-evoked pain after open radical gastrectomy: A randomized controlled pilot trial

INTRODUCTION

Auricular acupuncture is widely used in the treatment of pain. Recently, the most commonly used method of auricular acupuncture is to embed an intradermal needle into the skin to enhance analgesia through continuous stimulation. We aimed to explore the efficacy and feasibility of this form of auricular acupuncture in the treatment of postoperative movement-evoked pain.

METHODS

This single-blind randomized controlled pilot trial was conducted between 23/8/2019 and 10/1/2020. Forty patients were recruited and randomised to either the control group (n = 20) or the experimental group (n = 20). Patients in the control group received sham auricular acupuncture, while patients in the experimental group received auricular acupuncture. A standard routine analgesia was performed in both groups. The patients with NRS score≥4 were given rescue analgesia. Postoperative pain, use of opioids and other analgesics, postoperative recovery and patient's satisfaction were recorded.

RESULTS

The credibility and feasibility of auricular acupuncture for postoperative pain were high in both groups. After auricular acupuncture, the scores of the postoperative movement-evoked pain had a tendency to decrease, but no significant difference was observed between two groups at any time point (P = 0.234∼0.888). The data on postoperative pain at rest confirmed that no significant difference was observed between two groups within 48 h of surgery (P = 0.134∼0.520), and the postoperative pain at rest scores decreased over time; however, from the third day, the pain at rest scores of the experimental group were decreased, and significant differences were observed between the two groups (P = 0.039∼0.047). As for use of rescue analgesic, total opioid consumption and the incidence of postoperative nausea and vomiting, there were no significant differences between the two groups (P = 0.311, P = 0.101, P = 0.661) . In terms of patients' satisfaction, the score of the experimental group was higher than that of the control group, and a significant difference was observed between the two groups (P = 0.000). As for adverse events, two participants reported pain and one patient reported discomfort at the insertion sites during the process of auricular acupuncture intervention, but they both were minor and tolerable.

CONCLUSION

Auricular acupuncture may have a relief effect on mild postoperative pain at rest with pain score below 3, suggesting that it may be a feasible adjuvant method to relieve mild pain at rest. However, more multi-centre and large-sample studies are needed to verify this result.

The Prospective Prognostic Value of Biopsychosocial Indices of Sensitivity to Physical Activity Among People With Back Pain

OBJECTIVES

Many people living with musculoskeletal pain conditions experience a range of negative biopsychosocial responses to physical activity, referred to as increased sensitivity to physical activity (SPA), that may undermine successful rehabilitation. This exploratory study aims to provide the first prospective analysis of the potential prognostic value of 3 biopsychosocial indices of SPA in relation to rehabilitation outcomes. This study also aimed to shed light on the cross-sectional interrelationships between these 3 biopsychosocial indices of SPA.

MATERIALS AND METHODS

Adults with back pain were evaluated upon starting physical therapy and then again 3 months later. The initial testing session consisted of self-reported pain-related questionnaires and assessment of activity-related changes in pressure pain thresholds (SPA-Sensory), pain intensity ratings (SPA-Pain), and situational catastrophizing (SPA-Psych). The 3-month follow-up consisted of self-reported disability and pain questionnaires. Correlational and hierarchical linear regression analyses were conducted.

RESULTS

A total of 97 participants completed both the initial visit and 3-month follow-up. The SPA-Pain index and the SPA-Psych index were significantly intercorrelated, but neither were correlated with the SPA-Sensory index. The SPA-Sensory index was not correlated with outcomes. The SPA-Pain index was correlated only with cross-sectional disability and pain outcomes. The SPA-Psych index was the only SPA index significantly correlated with outcomes both cross-sectionally and at 3-month follow-up. After controlling for baseline pain/disability and pain catastrophizing, SPA-Psych was no longer a significant prognostic factor for pain, but remained a significant prognostic factor for disability at 3-month follow-up (β=0.272, t=2.674, P=0.008, R2 Δ=5.60%).

DISCUSSION

This study highlights the importance of conceptualizing and measuring SPA as a biopsychosocial (rather than unidimensional) construct and points toward the added prognostic value of this construct. Implications for future research and practice are discussed.

Study Protocol Modeling Evoked Pain in Older African Americans With Knee Osteoarthritis

BACKGROUND

African American (AA) older adults with knee osteoarthritis experience more severe chronic pain and advanced physical disability. One of the most prominent stimuli that provokes knee pain is movement. Research suggests that, compared to Whites, AAs report significantly higher movement-evoked pain (MEP) in the knee. However, little is known about the biopsychosocial-behavioral mechanisms underlying MEP.

OBJECTIVES

The aim of the study was to present a study protocol to (a) characterize the biopsychosocial-behavioral mechanisms that predict MEP in AAs with knee osteoarthritis and (b) develop a targeted, mechanism-based self-management intervention to reduce MEP and maximize movement.

METHODS

An observational, mixed-methods cohort study will enroll 90 AA/Black adults (ages 55-90 years) to understand intraindividual and interindividual effects on MEP. Participants will complete assessments of MEP, function and gait, biopsychosocial-behavioral questionnaires, quantitative sensory testing, and 7-day ecological momentary assessments of pain and related symptoms. For the qualitative phase, focus groups will be conducted to co-construct a mechanism-based pain self-management intervention.

RESULTS

We will develop phenotypes of MEP based on biopsychosocial-behavioral predictors and correlate measures of MEP with function. Our central hypothesis is that higher levels of MEP will predict lower self-reported function and poorer performance on functional tasks and that multiple biopsychosocial and behavioral factors will be associated with MEP and function. Predictors may serve as risk or protective factors for MEP and physical function. In targeting the biopsychosocial-behavioral mechanisms of MEP, we anticipate that older AAs may request that intervention components include culturally tailored self-management education, movement/physical activity training, treatment decision-making skills, coaching, spirituality, and social/kinship support.

CONCLUSION

Osteoarthritis is now the single most common cause of disability, mobility limitations, and persistent pain in older adults-especially AA older adults. To our knowledge, this will be the first study to systematically phenotype MEP in an older racial minority population with knee osteoarthritis and will be relevant for reducing knee pain and improving function.

Cryoanalgesia for postsurgical pain relief in adults: A systematic review and meta-analysis

Background

Despite advances in pain management, postoperative pain continues to be an important problem with significant burden. Many current therapies have dose-limiting adverse effects and are limited by their short duration of action. This review examines the evidence for the efficacy and safety of cryoanalgesia in postoperative pain.

Materials and methods

This review was registered in PROSPERO and prepared in accordance with PRISMA. MEDLINE, EMBASE, and Cochrane databases were searched until July 2020. We included randomized controlled trials (RCTs) of adults evaluating perioperatively administered cryoanalgesia for postoperative pain relief.

Results

Twenty-four RCTS were included. Twenty studies examined cryoanalgesia for thoracotomy, two for herniorrhaphy, one for nephrectomy and one for tonsillectomy. Meta-analysis was performed for thoracic studies. We found that cryoanalgesia with opioids was more efficacious than opioid analgesia alone for acute pain (mean difference [MD] 2.32 units, 95 % confidence interval [CI] -3.35 to -1.30) and persistent pain (MD 0.81 units, 95 % CI -1.10 to -0.53) after thoracotomy. Cryoanalgesia with opioids also resulted in less postoperative nausea compared to opioid analgesia alone (relative risk [RR] 0.23, 95 % CI 0.06 to 0.95), but there was no difference in atelectasis (RR 0.38, 95 % CI 0.07 to 2.17).

Conclusion

Heterogeneity in comparators and outcomes were important limitations. In general, reporting of adverse events was incomplete and inconsistent. Many studies were over two decades old, and most were limited in how they described their methodology. Considering the potential, larger RCTs should be performed to better understand the role of cryoanalgesia in postoperative pain management.

Identification of preoperative predictors for acute postsurgical pain and for pain at three months after surgery: a prospective observational study

Identifying patients at risk is the start of adequate perioperative pain management. We aimed to identify preoperative predictors for acute postsurgical pain (APSP) and for pain at 3 months after surgery to develop prediction models. In a prospective observational study, we collected preoperative predictors and the movement-evoked numerical rating scale (NRS-MEP) of postoperative pain at day 1, 2, 3, 7, week 1, 6 and 3 months after surgery from patients with a range of surgical procedures. Regression analyses of data of 2258 surgical in- and outpatients showed that independent predictors for APSP using the mean NRS-MEP over the first three days after surgery were hospital admittance, female sex, higher preoperative pain, younger age, pain catastrophizing, anxiety, higher score on functional disability, highest categories of expected pain, medical specialty, unknown wound size, and wound size > 10 cm compared to wound size ≤ 10 cm (RMSE = 2.11). For pain at three months, the only predictors were preoperative pain and a higher score on functional disability (RMSE = 1.69). Adding pain trajectories improved the prediction of pain at three months (RMSE = 1.37). Our clinically applicable prediction models can be used preoperatively to identify patients at risk, as well as in the direct postoperative period.

AAAPT Diagnostic Criteria for Acute Thoracic Surgery Pain

Patients undergoing thoracic surgery experience particular challenges for acute pain management. Availability of standardized diagnostic criteria for identification of acute pain after thoracotomy and video assisted thoracic surgery (VATS) would provide a foundation for evidence-based management and facilitate future research. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the United States Food and Drug Administration, the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) formed the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) initiative to address absence of acute pain diagnostic criteria. A multidisciplinary working group of pain experts was invited to develop diagnostic criteria for acute thoracotomy and VATS pain. The working group used available studies and expert opinion to characterize acute pain after thoracotomy and VATS using the 5-dimension taxonomical structure proposed by AAAPT (i.e., core diagnostic criteria, common features, modulating factors, impact/functional consequences, and putative mechanisms). The resulting diagnostic criteria will serve as the starting point for subsequent empirically validated criteria. PERSPECTIVE ITEM: This article characterizes acute pain after thoracotomy and VATS using the 5-dimension taxonomical structure proposed by AAAPT (ie, core diagnostic criteria, common features, modulating factors, impact and/or functional consequences, and putative mechanisms).

Systematic Review on Pain-Related Outcome Domains After Sternotomy: A First Step Toward the Development of a Core Outcome Set

OBJECTIVES

Pain after surgery has a major impact on acute and long-term recovery and quality of life, but its management is often insufficient. To enhance the quality of research and to allow for better comparability between studies, it is important to harmonize outcomes for assessing the efficacy and effectiveness of pain management interventions after surgery. As a first step in developing a core outcome set, this study aimed to systematically search for outcome domains assessed in research regarding acute pain management after sternotomy as an example of a typically painful surgical procedure.

METHODS

A systematic literature review was performed using MEDLINE, Embase, and CENTRAL. Eligibility criteria consisted of randomized controlled trials and observational trials targeting pain management after sternotomy in adults in the acute postoperative setting (≤2 weeks). After duplicate removal and title and abstract screening by 2 independent reviewers, study characteristics and outcome domains were identified, which were extracted from full texts and summarized qualitatively.

RESULTS

Of 1350 studies retrieved by database searching, 156 studies were included for full-text extraction. A total of 80 different outcome domains were identified: pain intensity, analgesic consumption, physiological function, and adverse events were the most frequent ones. Outcome domains were often not explicitly reported, and the combination of domains and assessment tools was heterogeneous. The choice of outcomes is commonly made within clinicians; patients' perspectives are not considered.

CONCLUSIONS

The wide variety of commonly applied outcome domains, the nonexplicit wording, and the heterogeneous combination of the domains indicating treatment benefit demonstrate the need for harmonization of outcomes assessing perioperative pain management after surgery.

Early Postoperative Pain After Total Knee Arthroplasty Is Associated With Subsequent Poorer Functional Outcomes and Lower Satisfaction

BACKGROUND

There are few studies investigating the effects of acute postoperative pain on functional outcomes after total knee arthroplasty (TKA). The aims of this study are to identify perioperative factors associated with increased early postoperative pain and investigate the effects of acute postoperative day 1 and 2 pain on outcomes at 6 months and 2 years post-TKA.

METHODS

1041 unilateral TKA patients were included in this retrospective cohort study. Patients were categorized into minor (visual analog scale: VAS <5) and major (VAS ≥5) pain groups based on postoperative day 1/2 VAS scores. Patients were assessed preoperatively, at 6 months and 2 years using Knee Society Knee Score and Function Scores (KSFS), Oxford Knee Score (OKS), SF-36 physical and mental component score (SF-36 PCS), expectation and satisfaction scores. Perioperative variables including age, gender, race, body mass index, American Society of Anesthesiologist status, type of anesthesia, and presence of caregiver were analyzed as predictors of postoperative acute pain. Wilcoxon two-sample test was used to analyze outcomes significantly associated with "major pain." Multiple logistic regression was used to identify predictors of "major pain."

RESULTS

Patients with "minor pain" had significantly better KSFS, Knee Society Knee Score, OKS, and SF-36 PCS scores at 6 months and significantly better KSFS, OKS, SF-36 PCS, and satisfaction at 2 years (P < .05). A significantly higher percentage of patients with "minor pain" met the minimal clinically important difference for SF-36 PCS at 6 months and KSFS at 2 years (P < .05). Women, Indian/Malay race, higher BMI, and use of general over regional anesthesia were independent predictors of getting "major pain" (P < .05).

CONCLUSION

Patients should be counseled about risk factors of postoperative pain to manage preoperative expectations of surgery. Patients should be managed adequately using multimodal pain protocols to improve subsequent functional outcomes while avoiding unnecessary opioid use.

Static and Dynamic Pain Sensitivity in Adults With Persistent Low Back Pain: Comparison to Healthy Controls and Associations With Movement-evoked Pain Versus Traditional Clinical Pain Measures

OBJECTIVES

Despite its impact, individual factors associated with persistent low back pain (LBP) remain poorly understood. This study investigated static and dynamic pain sensitivity in adults with persistent LBP versus pain-free controls; and investigated associations between pain sensitivity and 3 clinical pain measures: recalled, resting, and movement-evoked pain (MEP).

MATERIALS AND METHODS

A lifespan sample of 60 adults with persistent LBP and 30 age-matched/sex-matched controls completed 4 laboratory sessions. Static pain sensitivity (pressure pain threshold [PPT], heat pain threshold) and dynamic pain sensitivity (heat pain aftersensations [AS], temporal summation [TS] of second heat pain) were measured. Demographic and clinical factors collected were education, global cognition, and perceived health. Resting and recalled pain were measured via questionnaire, and MEP via the Back Performance Scale.

RESULTS

LBP participants demonstrated lower PPT remotely (hand; F1,84=5.34, P=0.024) and locally (low back; F1,84=9.55, P=0.003) and also had higher AS (F1,84=6.01, P=0.016). Neither static nor dynamic pain sensitivity were associated with recalled pain (P>0.05). However, static pain sensitivity (local PPT) explained an additional 9% variance in resting pain, while dynamic pain sensitivity (AS, TS) explained an additional 10% to 12% variance in MEP.

DISCUSSION

This study characterized pain sensitivity measures among individuals with persistent LBP and suggests static pain sensitivity plays a larger role in resting pain while dynamic pain sensitivity plays a larger role in MEP. Future studies will confirm these relationships and elucidate the extent to which changes in static or dynamic pain sensitivity predict or mediate clinical pain among adults with persistent LBP.

Assessing outcome in postoperative pain trials: are we missing the point? A systematic review of pain-related outcome domains reported in studies early after total knee arthroplasty

ABSTRACT

The management of acute postoperative pain remains suboptimal. Systematic reviews and Cochrane analysis can assist with collating evidence about treatment efficacy, but the results are limited in part by heterogeneity of endpoints in clinical trials. In addition, the chosen endpoints may not be entirely clinically relevant. To investigate the endpoints assessed in perioperative pain trials, we performed a systematic literature review on outcome domains assessing effectiveness of acute pain interventions in trials after total knee arthroplasty. We followed the Cochrane recommendations for systematic reviews, searching PubMed, Cochrane, and Embase, resulting in the screening of 1590 potentially eligible studies. After final inclusion of 295 studies, we identified 11 outcome domains and 45 subdomains/descriptors with the domain "pain"/"pain intensity" most commonly assessed (98.3%), followed by "analgesic consumption" (88.8%) and "side effects" (75.3%). By contrast, "physical function" (53.5%), "satisfaction" (28.8%), and "psychological function" (11.9%) were given much less consideration. The combinations of outcome domains were inhomogeneous throughout the studies, regardless of the type of pain management investigated. In conclusion, we found that there was high variability in outcome domains and inhomogeneous combinations, as well as inconsistent subdomain descriptions and utilization in trials comparing for effectiveness of pain interventions after total knee arthroplasty. This points towards the need for harmonizing outcome domains, eg, by consenting on a core outcome set of domains which are relevant for both stakeholders and patients. Such a core outcome set should include at least 3 domains from 3 different health core areas such as pain intensity, physical function, and one psychological domain.

Seven-year follow-up of persistent postsurgical pain in cardiac surgery patients: A prospective observational study of prevalence and risk factors

BACKGROUND

Our aim was to describe the long-term prevalence, risk factors and impact on quality of life of persistent postsurgical pain (PPP) following cardiac surgery.

METHODS

All patients undergoing sternotomy in a single centre over 6 months were prospectively interviewed by telephone at six months and seven years following surgery.

RESULTS

We analysed data from 174 patients at six months and 146 patients at seven years following surgery, revealing a PPP prevalence of 39.7% (n = 69) and 9.6% (n = 14) respectively. At six post-operative months, younger age, higher acute pain score, intraoperative remifentanil infusion and more prolonged surgery were associated with sternotomy-site PPP. These variables, in combination, predict PPP in this study group with area under the receiver operating curve of 0.91 (95% CI 0.86-0.94) at 6 months and 0.74 (95% CI 0.57-0.86) at 7 years. Quality of life scores were significantly lower with PPP (median change in EQ-5D score = -0.23 [-0.57, -0.09] compared to 0.00 [0-0.24] without PPP at 7 years, p < 0.001). At7 years, younger age, prolonged surgery and intraoperative remifentanil infusion were associated with sternotomy-site PPP.

CONCLUSIONS

To the best of our knowledge, this is the longest follow-up of PPP across all surgical specialities and certainly within cardiac surgery. Prevalence of PPP and impact on QOL after cardiac surgery are high and associated with young age, high acute pain score, use of remifentanil and long operative time. We present a predictive score to highlight patients at risk of developing PPP.

SIGNIFICANCE

Seven years after cardiac surgery, almost 10% of patients in this cohort described persistent pain in and around the incision. While higher than previous reports in the literature (limited to up to five post-operative years), this assessment was made following three maximal coughs and therefore is movement or function evoked. High incident of persistent postsurgical pain may adversely affect long-term quality of life which is measured using a validated tool.

Duloxetine reduces pain after Total hip arthroplasty: a prospective, randomized controlled study

BACKGROUND

Previous studies have demonstrated the efficacy of duloxetine in reducing postoperative pain and opioid consumption. However, the effect of duloxetine on total hip arthroplasty (THA) remains unclear. The objective of this study was to assess the efficacy of oral duloxetine in THA.

METHODS

We enrolled 96 patients in this randomized controlled trial. These patients were randomized (1,1) to either the duloxetine group or the placebo group and received daily doses of 60 mg duloxetine or placebo, respectively, from 2 d pre-operation to 14 d after surgery. The primary outcome was pain severity upon movement measured by a visual analogue scale (VAS). The secondary outcomes included VAS scores for resting pain, morphine consumption, Harris Hip Score, patient satisfaction at discharge, length of postoperative hospital stay, and adverse events.

RESULTS

Patients in the duloxetine group had significantly lower pain severity scores upon movement within 3 postoperative weeks (p < 0.05) while none of the differences met the minimum clinically important difference (MCID). Moreover, patients in the duloxetine group performed better in terms of resting pain (in 3 weeks after surgery), morphine requirements, and satisfaction level at discharge (all p < 0.05). There was no difference between groups in the prevalence of adverse events.

CONCLUSIONS

Although it did not result in a clinically meaning reduction in pain after total hip arthroplasty, perioperative administration of 60 mg of duloxetine daily significantly alleviated pain in the postoperative 3 weeks and morphine requirements during the postoperative 48 h. Therefore, duloxetine still shows promise in optimizing the multimodal pain-management protocols in total hip arthroplasty.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2000033606 , 06/06/2020.

Early post-immobilization pain at rest, movement evoked pain, and their ratio as potential predictors of pain and disability at six- and 12-months after distal radius fracture

Background

Removal of immobilization is a critical phase of distal radius fracture (DRF) rehabilitation, typically occurring by 2 months post injury. This study examined the extent to which pain at rest (PAR), movement evoked pain (MEP), or the ratio between those (MEPR) assessed at 2-months after DRF predicts the occurrence of chronic pain or disability at 6- and 12-months after the injury.

Methods

This secondary analysis of a prospective cohort study was done at the Hand and Upper Limb Centre (HULC), London, Ontario, Canada. A total of 229 patients with DRF (159 (69.4%) women) were included. Scores for the pain and function subscales of the Patient-Rated Wrist Evaluation (PRWE) were extracted for 2, 6 and 12 months after DRF. Logistic as well as nonlinear quartile regression examined whether PAR and MEP predicted the severity of chronic pain and disability at 6- and 12-months after DRF. Receiver Operating Characteristics Curve were plotted, where area under the curve (AUC) examined the accuracy of the PAR and MEP scores in classifying those who experienced chronic pain and disability.

Results

Scores of ≥3 (AUC of 0.77) for PAR or ≥ 6 (AUC of 0.78) for MEP at 2 months after DRF predicted moderate to severe wrist pain at 6-months, whereas scores of ≥7 (AUC of 0.79) for MEP at 2-months predicted ongoing wrist disability at 6-months after the injury. The MEPR of 2 ≤ or ≥ 8 at 2-months was associated with adverse pain at 6-months and functional outcomes at 6- and 12-months (R-square = 0.7 and 0.04 respectively), but prediction accuracy was very poor (AUC ≤ 0.50).

Conclusion

Chronic wrist-related pain at 6-months can be predicted by either elevated PAR ≥ 3/10) or MEP (≥ 6/10) reported at 2-months after the injury, while disability experienced at 6-months after DRF is best predicted by MEP (≥7/10) reported at 2-months. The ratio of these two pain indicators increases assessment complexity and reduces classification accuracy.

Challenges and opportunities in translational pain research - An opinion paper of the working group on translational pain research of the European pain federation (EFIC)

For decades, basic research on the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need. In this opinion paper bringing together pain researchers from very different disciplines, the opportunities and challenges of translational pain research are discussed. The many factors that may prevent the successful translation of bench observations into useful and effective clinical applications are reviewed, including interspecies differences, limited validity of currently available preclinical disease models of pain, and limitations of currently used methods to assess nociception and pain in non-human and human models of pain. Many paths are explored to address these issues, including the backward translation of observations made in patients and human volunteers into new disease models that are more clinically relevant, improved generalization by taking into account age and sex differences, and the integration of psychobiology into translational pain research. Finally, it is argued that preclinical and clinical stages of developing new treatments for pain can be improved by better preclinical models of pathological pain conditions alongside revised methods to assess treatment-induced effects on nociception in human and non-human animals. Significance: For decades, basic research of the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need.

Toward Understanding Movement-evoked Pain (MEP) and its Measurement: A Scoping Review

OBJECTIVE

Individuals with chronic pain conditions often report movement as exacerbating pain. An increasing number of researchers and clinicians have recognized the importance of measuring and distinguishing between movement-evoked pain (MEP) and pain at rest as an outcome. This scoping review maps the literature and describes MEP measurement techniques.

MATERIALS AND METHODS

The scoping review utilized 6 databases to identify original studies that targeted pain or movement-related outcomes. Our search returned 7322 articles that were screened by title and abstract by 2 reviewers. The inclusion criteria focused on the measurement of MEP before, during, and after movement tasks in adults with chronic pain. Studies of children below 18 years of age or with nonhuman animals, case studies, qualitative studies, book chapters, cancer-related pain, non-English language, and abstracts with no full publish text were excluded from the study.

RESULTS

Results from 38 studies revealed great variation in the measurement of MEP, while almost all of the studies did not provide an explicit conceptual or operational definition for MEP. In addition, studies collectively illuminated differences in MEP compared with rest pain, movement provocation methods, and pain intensity as the primary outcome.

DISCUSSION

These results have clinically significant and research implications. To advance the study of MEP, we offer that consistent terminology, standardized measurement (appropriate for pain type/population), and clear methodological processes be provided in research publications. On the basis of the findings, we have put forth a preliminary definition of MEP that may benefit from the continued scholarly dialog.

Determining the feasibility of a trial to evaluate the effectiveness of phototherapy versus placebo at reducing pain during physical activity for people with knee osteoarthritis: a pilot randomized controlled trial

BACKGROUND

Although practice guidelines recommend physical activity and exercise for the management of knee osteoarthritis, pain is a common barrier to participation. Phototherapy has been shown to reduce pain intensity for people with knee osteoarthritis, but it is unclear if it reduces pain during physical activity or contributes to improved rehabilitation outcomes.

OBJECTIVE

The aim of this study is to assess the feasibility of performing a fully powered randomized controlled trial (RCT) comparing an active phototherapy intervention versus placebo on pain during physical activity for people with knee osteoarthritis.

METHODS

A pilot RCT was conducted to test the feasibility of a trial comparing 8-sessions (4 weeks) of active phototherapy versus placebo. People were able to participate if they (1) were an English speaking adult (> 18 years of age), (2) had received a diagnosis of knee osteoarthritis from a physician, and (3) self-reported experiencing pain and disability related to their knee osteoarthritis for > 3 months. Primary outcomes were the feasibility of participant recruitment, retention, assessment procedures, and maintaining high treatment fidelity. Secondary outcomes piloted for a full trial included pain during physical activity (primary outcome of full trial); self-reported pain severity, physical function, stiffness, adherence to prescribed exercise, global rating of change, patient satisfaction, and adverse events; 6-min walk test; and pressure pain threshold.

RESULTS

Twenty participants (4 men; 16 women) with knee osteoarthritis and a mean age of 63.95 (SD: 9.27) years were recruited over a 3-week period (6.7 participants per week). Fifteen out of 20 (75%) of participants completed the primary outcome assessment at 4 weeks and 19/20 (95%) of participants were retained and completed the final 16-week assessment. Overall, 89% of all assessment items were completed by participants across all time-points. Fifteen out of 20 participants (75%) completed all 8 treatment sessions. Treatment fidelity was 100% for all completed treatment sessions. No adverse events were reported by participants in either group.

CONCLUSIONS

Results suggest that the trial methodology and intervention are feasible for implementation in a fully powered randomized controlled trial to determine the effectiveness of phototherapy at reducing pain during physical activity for people with knee osteoarthritis.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT04234685 , January 21, 2020-Retrospectively registered.