Prevention and Treatment of Chronic Postsurgical Pain: A Narrative Review

An in-depth analysis of postoperative insomnia in elderly patients and its implications on rehabilitation

OBJECTIVES

(1) Assess the prevalence of postoperative insomnia; (2) identify the risk factors for postoperative insomnia before exposure to surgery; (3) explore the impact of postoperative insomnia on rehabilitation.

METHODS

A study was conducted with 132 participants aged ≥ 65 undergoing spine interbody fusion. We collected the basic demographic data, Numeric Rating Scales (NRS), Pittsburgh Sleep Quality Index (PSQI), Geriatric Depression Scale (GDS), and Beck Anxiety Inventory (BAI). We measured Quality of Recovery 40 (QoR-40), GDS, BAI, NRS, and PSQI on the first and third nights post-surgery, followed by QoR-40 and NRS assessments two weeks after surgery.

RESULTS

The cases of postoperative insomnia on the first and third nights and after two weeks were 81 (61.36%), 72 (54.55%), and 64 (48.48%), respectively, and the type of insomnia was not significantly different (P = 0.138). Sleep efficiency on the first night was 49.96% ± 23.51. On the first night of postoperative insomnia, 54 (66.67%) cases were depression or anxiety, and the PSQI was higher in this group than in the group without anxiety or depression (P < 0.001). PSQI, GDS, and the time of surgery were related factors for postoperative insomnia (PPSQI < 0.001, PGDS = 0.008, and PTime = 0.040). Postoperative rehabilitation showed differences between the insomnia and non-insomnia groups (P < 0.001).

CONCLUSIONS

The prevalence of postoperative insomnia in the elderly was high, and postoperative insomnia had a significant correlation with postoperative rehabilitation. Interventions that target risk factors may reduce the prevalence of postoperative insomnia and warrant further research.

CLINICAL TRIAL REGISTRATION

Multivariate analysis of postoperative insomnia in elderly patients with spinal surgery and its correlation with postoperative rehabilitation ( https://www.chictr.org.cn/bin/project/edit?pid=170201 ; #ChiCTR2200059827).

Transitional Pain Service: An Update

PURPOSE OF REVIEW

Chronic Postsurgical Pain (CPSP) and the risk for long-term opioid dependency are known complications following major surgery. The idea of Transitional Pain Service (TPS) has been introduced as an interdisciplinary setting to manage pain in the perioperative continuum. We expand on the basic framework and principles of TPS and summarize the current evidence of the TPS and possible interventions to adress postoperative pain. Areas of future work in TPS-related research are discussed.

RECENT FINDINGS

Several studies support the effectiveness of TPS in reducing opioid consumption in the perioperative period and following discharge. Some studies also show an improvement in functional outcome with TPS with patients reporting lower pain severity and pain interference. The TPS aims to halt the progress of acute postoperative pain to CPSP by providing longitudinal support with patient-centered care. While some studies suggest a positive impact of TPS implementation in terms of reduction in postoperative opioid consumption and improvement of some functional outcomes, direct evidence in terms of reduction in the incidence of CPSP is still missing. The cost-effectiveness of TPS and the expansion of TPS through e-health services and digital applications also need to be evaluated.

Chronic Postsurgical Pain Following Lung Transplantation: Characteristics, Risk Factors, Treatment, and Prevention: A Narrative Review

Chronic pain after lung transplantation (LTx) can substantially reduce quality of life (QoL), yet current consensus guidelines say little about how to prevent or manage it. Research on pain after LTx has tended to focus on acute rather than chronic pain, and it has not extensively examined the factors associated with onset or resolution of chronic pain, which differ from factors influencing chronic pain after general thoracic surgery. This narrative review explores what is known about the epidemiology and risk factors of chronic pain after LTx, as well as effective ways to treat or prevent it. The review identifies key questions and issues that should be the focus of future research.

Mechanisms inherent in acute-to-chronic pain after surgery - risk, diagnostic, predictive, and prognostic factors

PURPOSE OF REVIEW

Pain is an expected consequence of a surgery, but it is far from being well controlled. One major complication of acute pain is its risk of persistency beyond healing. This so-called chronic post-surgical pain (CPSP) is defined as new or increased pain due to surgery that lasts for at least 3 months after surgery. CPSP is frequent, underlies a complex bio-psycho-social process and constitutes an important socioeconomic challenge with significant impact on patients' quality of life. Its importance has been recognized by its inclusion in the eleventh version of the ICD (International Classification of Diseases).

RECENT FINDINGS

Evidence for most pharmacological and non-pharmacological interventions preventing CPSP is inconsistent. Identification of associated patient-related factors, such as psychosocial aspects, comorbidities, surgical factors, pain trajectories, or biomarkers may allow stratification and selection of treatment options based on underlying individual mechanisms. Consequently, the identification of patients at risk and implementation of individually tailored, preventive, multimodal treatment to reduce the risk of transition from acute to chronic pain is facilitated.

SUMMARY

This review will give an update on current knowledge on mechanism-based risk, prognostic and predictive factors for CPSP in adults, and preventive and therapeutic approaches, and how to use them for patient stratification in the future.

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

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

The 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.

Protocol for Development and Validation of Multivariable Prediction Models for Chronic Postsurgical Pain Following Video-Assisted Thoracic Surgery

Purpose

Chronic postsurgical pain (CPSP) is a common complication after thoracic surgery and associated with long-term adverse outcomes. This study aims to develop two prediction models for CPSP after video-assisted thoracic surgery (VATS).

Methods and Analysis

This single-center prospective cohort study will include a total of 500 adult patients undergoing VATS lung resection (n = 350 for development and n = 150 for external validation). Patients will be enrolled continuously at The First Affiliated Hospital of Soochow University in Suzhou, China. The cohort for external validation will be recruited in another time period. The outcome is CPSP, which is defined as pain with the numerical rating scale score of 1 or higher 3 months after VATS. Univariate and multivariable logistic regression analyses will be performed to develop two CPSP prediction models based on patients' data of postoperative day 1 and day 14, respectively. For internal validation, we will use the bootstrapping validation technique. For external validation, the discrimination capability of the models will be assessed using the area under the receiver operating characteristic curve, and the calibration will be evaluated using the calibration curve and Hosmer-Lemeshow goodness-of-fit statistic. The results will be presented in model formulas and nomograms.

Conclusion

Based on the development and validation of the prediction models, our results contribute to early prediction and treatment of CPSP after VATS.

Trial Registration

Chinese Clinical Trial Register (ChiCTR2200066122).

Identifying risk factors for chronic postsurgical pain and preventive measures: a comprehensive update

INTRODUCTION

Chronic postsurgical pain (CPSP) is a prevalent condition that can diminish health-related quality of life, cause functional deficits, and lead to patient distress. Rates of CPSP are higher for certain types of surgeries than others (thoracic, breast, or lower extremity amputations) but can occur after even uncomplicated minimally invasive procedures. CPSP has multiple mechanisms, but always starts as acute postsurgical pain, which involves inflammatory processes and may encompass direct or indirect neural injury. Risk factors for CPSP are largely known but many, such as female sex, younger age, or type of surgery, are not modifiable. The best strategy against CPSP is to quickly and effectively treat acute postoperative pain using a multimodal analgesic regimen that is safe, effective, and spares opioids.

AREAS COVERED

This is a narrative review of the literature.

EXPERT OPINION

Every surgical patient is at some risk for CPSP. Control of acute postoperative pain appears to be the most effective approach, but principles of good opioid stewardship should apply. The role of regional anesthetics as analgesics is gaining interest and may be appropriate for certain patients. Finally, patients should be better informed about their relative risk for CPSP.

Transitional Pain Medicine; New Era, New Opportunities, and New Journey

Chronic postsurgical pain (CPSP), also known as persistent postsurgical pain (PPSP), is pain that develops or increases in intensity after a surgical procedure and lasts more than 3 months. Transitional pain medicine is the medical field that focuses on understanding the mechanisms of CPSP and defining risk factors and developing preventive treatments. Unfortunately, one significant challenge is the risk of developing opioid use dependence. Multiple risk factors have been discovered, with the most common, and modifiable, being uncontrolled acute postoperative pain; preoperative anxiety and depression; and preoperative site pain, chronic pain, and opioid use.

Acute and subacute postsurgical pain in women with breast cancer: incidence and associations with biopsychosocial predictors-a secondary analysis of a randomized controlled trial

Introduction

Women who undergo breast cancer surgery risk suffering from postsurgical pain long after their surgery. Still, research on postsurgical pain in the subacute phase has been neglected.

Objective

This study aims to investigate the incidence, intensity, unpleasantness, and presurgical predictors of acute and subacute postsurgical pain after breast cancer surgery.

Methods

The study used an observational design through secondary analyses of the control group in a randomized controlled trial. Data from 102 women undergoing breast cancer surgery were included. Levels of acute and subacute pain intensity and unpleasantness were measured using 100 mm Visual Analogue Scales on the day of surgery and 4 weeks postsurgery. Linear regression analyses were performed to identify presurgical biopsychosocial predictors of acute and subacute postsurgical pain.

Results

Average levels of postsurgical pain intensity and unpleasantness were as follows: 22.7 mm for acute pain intensity, 19.0 mm for acute pain unpleasantness, 10.3 mm for subacute pain intensity, and 11.7 mm for subacute pain unpleasantness. Pain expectancy predicted acute pain intensity (R² = 0.04, p = 0.047) and acute unpleasantness (R² = 0.06, p = 0.02). Perceived social support inversely predicted acute pain unpleasantness (R² = 0.04, p = 0.014).

Conclusion

Mild and moderate acute pain intensity and unpleasantness are common after breast cancer surgery, whereas levels of subacute pain intensity and unpleasantness are low. Pain expectancy predicts acute postsurgical pain intensity and unpleasantness, whereas expected social support inversely predicts acute postsurgical pain unpleasantness.

Change in perioperative neutrophil-lymphocyte ratio as a potential predictive biomarker for chronic postsurgical pain and quality of life: an ambispective observational cohort study

Introduction

Accurate and accessible predictors of chronic postsurgical pain (CPSP) to identify high-risk postsurgical patients are prerequisite for preventive and interventional strategies. We investigated the incidence and risk factors of CPSP after abdominal surgery, with a focus on plasma immunological markers.

Materials and methods

This was a retrospective analysis of patients who underwent abdominal surgery under general anesthesia at a tertiary center between January 2021 and January 2022. The preoperative demographics, laboratory test data, and surgical factors of the participants were collected from the electronic medical record system. Postoperative pain intensity and living conditions at 1 year after discharge from the hospital were assessed via a phone survey. Univariate and multivariate analyses were used to explore independent risk factors associated with CPSP.

Results

A total of 968 patients were included, and 13.53% (n = 131 of 968) of patients reported CPSP 1 year after surgery. Patients with older age, open surgery, higher American Association of Anesthesiologists classification, patient-controlled intravenous analgesia application, longer surgery duration, higher postoperative absolute neutrophil count, and neutrophil-lymphocyte ratio (NLR), lower postoperative absolute lymphocyte count, and higher white blood cell count, were more likely to suffer from CPSP. A changed ratio of NLR (postoperative to preoperative) ≥ 5 significantly correlated with CPSP, moderate to severe pain, maximum numeric rating score since discharge from the hospital, and affected quality of life.

Discussion

The changed ratio of NLR could be used for the early identification of patients at risk for CPSP and affect the quality of life to alert the clinician to undertake further assessment.

The impact of a postoperative multimodal analgesia pathway on opioid use and outcomes after cardiothoracic surgery

OBJECTIVE

The Enhanced Recovery after Surgery Cardiac Society recommends using multimodal analgesia (MMA) for postoperative pain however, evidence-based guidelines have yet to be established. This study examines the impact of a standardized postoperative MMA pathway in reducing opioid consumption and related complications after cardiothoracic surgery (CTS).

METHODS

Within a multicenter healthcare system, a postoperative MMA pathway was developed and implemented at two CTS intensive care units (ICU) while the other CTS ICU opted to maintain the existing opioid-based pathway. A retrospective chart review was conducted on patients admitted to a CTS ICU within this healthcare system after conventional coronary artery bypass grafting and/or valve surgery from September 1, 2018, to June 30, 2019. Comparative analysis was conducted on patients prescribed MMA versus those managed with an opioid-based pathway. The primary outcome was total opioid consumption, converted to morphine milligram equivalents, 72-h post-surgery. Secondary outcomes included mobility within one-day post-surgery, ICU length of stay (LOS), time to first bowel movement (BM), and time to first zero Richmond Agitation-Sedation Scale (RASS).

RESULTS

Seven hundred sixty-two adults were included for final analysis. The MMA group had a higher body mass index, higher percentage of females, were more likely classified as African American and had higher scores for risk-adjusted complications. General Linear Model analysis revealed higher opioid consumption in the MMA group (Est. 0.22, p < 0.0009); however, this was not statistically significant after adjusting for differences in fentanyl usage. The MMA group was more likely to have mobility within one-day post-surgery (OR 0.44, p < 0.0001), have longer time to first BM (OR 1.93, p = 0.0011), and longer time to first zero RASS (OR 1.62, p = 0.0071). The analgesia groups were not a predictor for ICU LOS.

CONCLUSIONS

Opioid consumption was not reduced secondary to this postoperative MMA pathway. The MMA group was more likely to have mobility within one-day post-surgery. Patients in the MMA group were also more likely to have prolonged time to first BM and first zero RASS. Development and evaluation of a perioperative MMA pathway should be considered.

Photobiomodulation enhanced endogenous pain modulation in healthy volunteers

To examine the effects of photobiomodulation (PBM) in healthy volunteers using photonic stimulation of acupuncture points on conditioned pain modulation (CPM), temporal summation of pain (TSP), and offset analgesia (OA), which reflect some aspects of endogenous pain modulation. We included 15 men and 15 women (age, 31.5 [27.3-37.0], body mass index, 25.7 [24.4-27.1], Fitzpatrick skin typing, II: 20, III: 8, IV: 2). CPM, TSP, and OA were evaluated after a sham procedure (control session) and after acupuncture point stimulation (LI4 and LI10 on the non-dominant forearm) using linear polarized near-infrared light irradiation (LPNILI; wavelengths peaked at approximately 1000 nm, output: 1.4 W/cm2, spot diameter: 10 mm, spot size: 1.02 cm2, maximum temperature: 40.5 °C, pulse width: 1 s, frequency: 0.2 Hz) (PBM session). Differences in CPM, TSP, and OA between the two sessions were evaluated by the paired t-test and Fisher's exact test (statistical significance: p < 0.05). Values indicate median [interquartile range]. LPNILI significantly increased CPM in all participants (control session: 12.1 [-4.5-37.4], PBM session: 23.9 [8.3-44.8], p < 0.05) and women (control session: 16.7 [-3.4-36.6], PBM session: 38.7 [24.6-52.1], p < 0.05). The CPM effect increment was significantly higher in women than in men (p = 0.0253). LPNILI decreased TSP in participants with higher TSP ratios (p = 0.0219) and increased OA in participants with lower OA scores (p = 0.0021). LPNILI enhanced endogenous pain modulation in healthy volunteers, particularly in women, as evaluated using CPM. CPM, TSP, and OA evaluations are potentially useful for discriminating PBM responders from non-responders.

Group-based trajectory analysis of postoperative pain in epidural analgesia for video-assisted thoracoscopic surgery and risk factors of rebound pain

BACKGROUND

The current study aimed to investigate the patterns of postoperative pain trajectories over time and their associated risk factors in patients receiving video-assisted thoracoscopic surgery (VATS) and epidural analgesia (EA) for non-small cell lung cancer (NSCLC).

METHODS

This retrospective study was conducted at a tertiary medical center and included patients undergoing VATS for stage I NSCLC between 2011 and 2015. Maximal pain intensity was recorded daily during the first postoperative week. Group-based trajectory analysis was performed to categorize variations in pain scores over time. Associations between pain trajectory classification and amount of EA administered and length of hospital stay (LOS) after surgery were also evaluated.

RESULTS

A total of 635 patients with 4647 pain scores were included in the analysis, and 2 postoperative pain trajectory groups were identified: group 1, mild pain trajectory (78%); and group 2, rebound pain trajectory (22%). Risk factors for rebound pain trajectory were a surgical time longer than 3 hours (odds ratio [OR], 1.97; 95% CI, 1.27-3.07), female sex (OR, 1.62; 95% CI, 1.04-2.53), and higher pain score on postoperative day 0 (OR, 1.21; 95% CI, 1.08-1.36; linear effect). Although group 2 had a longer LOS (p < 0.001), they did not receive more EA than group 1 (p = 0.805).

CONCLUSION

Surgical time, sex, and pain intensity after surgery were major determinants of rebound pain trajectory, and more aggressive pain control strategies should be considered in high-risk patients.

Developmental Mechanisms of CPSP: Clinical Observations and Translational Laboratory Evaluations

Understanding mechanisms that underly the transition from acute to chronic pain and identifying potential targets for preventing or minimizing this progression have specific relevance for chronic postsurgical pain (CPSP). Though it is clear that multiple psychosocial, family, and environmental factors may influence CPSP, this review will focus on parallels between clinical observations and translational laboratory studies investigating the acute and long-term effects of surgical injury on nociceptive pathways. This includes data related to alterations in sensitivity at different points along nociceptive pathways from the periphery to the brain; age- and sex-dependent mechanisms underlying the transition from acute to persistent pain; potential targets for preventive interventions; and the impact of prior surgical injury. Ongoing preclinical studies evaluating age- and sex-dependent mechanisms will also inform comparative efficacy and preclinical safety assessments of potential preventive pharmacological interventions aimed at reducing the risk of CPSP. In future clinical studies, more detailed and longitudinal peri-operative phenotyping with patient- and parent-reported chronic pain core outcomes, alongside more specialized evaluations of somatosensory function, modulation, and circuitry, may enhance understanding of individual variability in postsurgical pain trajectories and improve recognition and management of CPSP.

Predictors of Chronic Postsurgical Pain in Elderly Patients Undergoing Hip Arthroplasty: A Multi-Center Retrospective Cohort Study

Background

Identifying patients at high risk of developing chronic postsurgical pain (CPSP) is of extreme importance in order to help launch appropriate therapeutic strategies and intensive initiation of pain management.

Aim

In this study, we aimed to conduct a multi-center retrospective cohort study to establish a prognostic model and a nomogram to predict the risks of CPSP in elderly patients who underwent hip arthroplasty at 6 months postoperatively.

Methods

We collected data from 736 patients aged >65 years who had undergone hip arthroplasty from October 1, 2016 to September, 30, 2018 at multiple tertiary referral centers in Guangzhou, China. All data were randomly stratified into a training set and a testing set at a ratio of 8:2. Data were analyzed via multiple logistic regression analysis with receiver operating characteristic (ROC) curves and areas under the curve. This model was further validated by estimating calibration and discrimination. A nomogram was ultimately developed.

Results

A total of 736 eligible patients were enrolled, 27.20% of whom developed CPSP within 6 months postoperatively. Preoperative pain in the surgical area (OR=2.456, 95% CI:1.814–3.327, P<0.001), preoperative depression state (OR=1.256, 95% CI:1.146–1.378, P<0.001), surgical type (OR=7.138, 95% CI:3.548–14.364, P<0.001), acute postoperative numerical rating scale score (OR=5.537, 95% CI:3.607–8.499, P<0.001) and analgesic type (patient-controlled epidural analgesia: OR=0.129, 95% CI:0.055–0.299, P<0.001; patient-controlled intravenous analgesia: OR=0.033, 95% CI:0.011–0.097, P<0.001) were identified as independent significant factors associated with CPSP. A prognostic model was established and further validated. An ROC curve confirmed the predictive ability of this model with a high sensitivity value of 92.12% (95% CI:86.90–95.74) and specificity value of 91.72% (95% CI:88.77–94.11). A nomogram was developed to simplify the use of the predictive model in clinical practice.

Conclusion

This prognostic model could be of great value in clinical practice, serving as the basis for early personalized analgesic management of elderly patients undergoing hip arthroplasty.

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Chronic postoperative pain: ubiquitous and scarcely appraised: narrative review

The International Association for the Study of Pain chose pain prevention as the theme for the 2020 Global Year. Chronic postoperative pain is one the many types of pain that can be potentially prevented. It develops or increases in severity after a surgery, persists for at least three months, even after ruling out all other possible causes of pain. To perform the present narrative review, the authors searched the PubMed database using the following keywords “postoperative pain” OR “postsurgical pain” AND “chronic” OR “persistent”. The present review focused on the incidence, pain development and chronification, and predisposing factors. It also discusses prevention, diagnosis, and treatment of chronic postoperative pain. Awareness of occurrence of chronic postoperative pain and recognizing risk factors is crucial for the day-to-day practice of the anesthesiologist. Hence, numerous surgical patients can have their outcome improved by preventing chronic postoperative pain, a condition scarcely identified and without a well-established treatment.

Capsaicin 8% Patch and Chronic Postsurgical Neuropathic Pain

(1) Background: Surgery is a frequent cause of persistent pain, defined chronic post-surgical pain (CPSP). The capsaicin 8% patch (Qutenza^®) is approved for the treatment of postherpetic neuralgia (PHN) and for diabetic peripheral neuropathy (DPN) of the feet. We propose a review of the literature on use of the capsaicin 8% patch to treat neuropathic pain associated with surgery; (2) Methods: We identified the articles by searching electronic databases using a combination of such terms as “capsaicin 8% patch”, “Qutenza^®”, and “chronic postsurgical pain”; (3) Results: We identified 14 selected studies reporting on a total of 632 CPSP cases treated with capsaicin 8% patch. Treatment with the capsaicin 8% patch significantly reduced the average pain intensity. Only 5 studies reported adverse events (AEs) after the patch application. The most common AEs were erythema, burning sensation and pain; (4) Conclusions: Our review indicate that capsaicin 8% patch treatment for CPSP is effective, safe and well tolerated, but randomized controlled trials on efficacy, safety and tolerability should be conducted.

Persistent Pain After Cardiac Surgery: Prevention and Management

Persistent postoperative pain (PPP) after cardiac surgery is a significant complication that negatively affects patient quality of life and increases health care system burden. However, there are no standards or guidelines to inform how to mitigate these effects. Therefore, in this review, we will discuss strategies to prevent and manage PPP after cardiac surgery. Adequate perioperative analgesia may prove instrumental in the prevention of PPP. Although opioids have historically been the primary analgesic approach to cardiac surgery, an opioid-sparing strategy may prove advantageous in reducing side effects, avoiding secondary hyperalgesia, and decreasing risk of PPP. Implementing a multimodal analgesic plan using alternative medications and regional anesthetic techniques may offer superior efficacy while reducing adverse effects.

A randomized controlled trial of oxycodone/acetaminophen versus acetaminophen alone for emergency department patients with musculoskeletal pain refractory to ibuprofen

BACKGROUND

Use of oral opioids does not result in more pain relief than nonopioid alternatives when administered to patients as first-line treatment for acute musculoskeletal pain. This study compared the efficacy of oxycodone/acetaminophen to that of acetaminophen alone as second-line treatment for patients with acute musculoskeletal pain who were administered prescription-strength ibuprofen and reported insufficient relief 1 h later.

METHODS

A randomized, double-blind study was conducted in two urban emergency departments. Opioid-naïve patients ≥ 18 years with an acute musculoskeletal injury were administered ibuprofen 600 mg as part of the study protocol. Those who reported insufficient relief 1 h later were randomized (1:1 ratio) to oxycodone 10 mg/acetaminophen 650 mg or acetaminophen 650 mg. The primary outcome was improvement in 0 to 10 pain scale between randomization and 2 h later. We also assessed medication-associated adverse events. A sample size calculation, built around a minimum clinically important difference of 1.3 units, determined the need for 154 patients.

RESULTS

We screened 924 patients and enrolled 393. All 393 received ibuprofen. A total of 159 (40%) patients reported inadequate relief after 1 h had elapsed. A total of 154 of these were randomized, 77 to oxycodone/acetaminophen and 77 to acetaminophen. Baseline characteristics were comparable. Among patients randomized to oxycodone/acetaminophen, mean (±SD) improvement in 0 to 10 pain scale was 4.0 (±2.6) versus 2.9 (±2.4) in the acetaminophen arm. The 95% confidence interval (CI) for the mean difference of 1.1 was 0.3 to 1.9. Among patients who received oxycodone/acetaminophen, 26 of 76 (34%) reported any medication-related adverse event versus seven of 74 (9%) participants who received acetaminophen. The 95% CI for the between-group difference of 25% was 12% to 37%).

CONCLUSION

Among patients with acute musculoskeletal pain refractory to oral ibuprofen, oxycodone/acetaminophen resulted in slightly greater pain relief than acetaminophen, but this was associated with more medication-related adverse events.

Increasing the use of multimodal analgesia during adult surgery in a tertiary academic anaesthesia department

Objective

Multimodal analgesia pathways have been shown to reduce opioid use and side effects in surgical patients. A quality improvement initiative was implemented to increase the use of multimodal analgesia in adult patients presenting for general anaesthesia at an academic tertiary care centre. The aim of this study was to increase adoption of a perioperative multimodal analgesia protocol across a broad population of surgical patients. The use of multimodal analgesia was tracked as a process metric. Our primary outcome was opioid use normalised to oral morphine equivalents (OME) intraoperatively, in the postanaesthesia care unit (PACU), and 48 hours postoperatively. Pain scores and use of antiemetics were measured as balancing metrics.

Methods

We conducted a quality improvement study of a multimodal analgesia protocol implemented for adult (≥18 and≤70) non-transplant patients undergoing general anaesthesia (≥180 min). Components of multimodal analgesia were defined as (1) preoperative analgesic medication (acetaminophen, celecoxib, diclofenac, gabapentin), (2) regional anaesthesia (peripheral nerve block or catheter, epidural catheter or spinal) or (3) intraoperative analgesic medication (ketamine, ketorolac, lidocaine infusion, magnesium, acetaminophen, dexamethasone ≥8 mg, dexmedetomidine). We compared opioid use, pain scores and antiemetic use for patients 1 year before (baseline group—1 July 2018 to 30 June 2019) and 1 year after (implementation group—1 July 2019 to 30 June 2020) project implementation.

Results

Use of multimodal analgesia improved from 53.9% in the baseline group to 67.5% in the implementation group (p<0.001). There was no significant difference in intraoperative OME use before and after implementation (β₀=44.0, β₂=0.52, p=0.875). OME decreased after the project implementation in the PACU (β₀=34.4, β₂=−3.88, p<0.001) and 48 hours postoperatively (β₀=184.9, β₂=−22.59, p<0.001), while pain scores during those time points were similar.

Conclusion

A perioperative pragmatic multimodal analgesic intervention was associated with reduced OME use in the PACU and 48 hours postoperatively.

[Prediction and prevention of chronic postoperative pain]

Chronic postoperative pain has been identified as a major medical and socioeconomic problem. A prevention of the chronification processes is potentially possible and preventive treatment could start early (e.g. preoperatively). So far, however, evidence for the effectiveness of preventive strategies is basically low. Important reasons for this dilemma are the lack of appropriate risk assessment as well as effective and mechanism-based preventive (procedure-sepcific) strategies for the chronification process, a lack of stratification of treatment approaches and a so far barely investigated combination of various treatment approaches. In this review article recent findings on the appropriate identification of patients at risk for developing postoperative chronic pain are presented, predictive models for the valid estimation of the individual risk of patients are assessed and studies on pharmaceutical and regional analgesia techniques influencing the pain chronification process are discussed. As a chronification process is, however, extremely complex and dynamic and also necessitates adaptation of the prevention during the course of the process, only combinations of treatment, interdisciplinary and if necessary even longer term approaches might be successful. Future studies are needed to address with which preventive treatment strategies and in which patients chronic pain after surgery can effectively be prevented.

Postoperative Pain Management in Pediatric Spinal Fusion Surgery for Idiopathic Scoliosis

This article reviews and summarizes current evidence and knowledge gaps regarding postoperative analgesia after pediatric posterior spine fusion for adolescent idiopathic scoliosis, a common procedure that results in severe acute postoperative pain. Inadequate analgesia may delay recovery, cause patient dissatisfaction, and increase chronic pain risk. Despite significant adverse effects, opioids are the analgesic mainstay after scoliosis surgery. However, growing emphasis on opioid minimization and enhanced recovery has increased adoption of multimodal analgesia (MMA) regimens. While opioid adverse effects remain a concern, MMA protocols must also consider risks and benefits of adjunct medications. We discuss use of opioids via different administration routes and elaborate on the effect of MMA components on opioid/pain and recovery outcomes including upcoming regional analgesia. We also discuss risk for prolonged opioid use after surgery and chronic post-surgical pain risk in this population. Evidence supports use of neuraxial opioids at safe doses, low-dose ketorolac, and methadone for postoperative analgesia. There may be a role for low-dose ketamine in those who are opioid-tolerant or have chronic pain, but the evidence for preoperative gabapentinoids and intravenous lidocaine is currently insufficient. There is a need for further studies to evaluate pediatric-specific optimal MMA dosing regimens after scoliosis surgery. Questions remain regarding how best to prevent acute opioid tolerance, opioid-induced hyperalgesia, and chronic postsurgical pain. We anticipate that this timely update will enable clinicians to develop efficient pain regimens and provide impetus for future research to optimize recovery outcomes after spine fusion.

Preoperative Factors Associated with Remote Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: Post Hoc Analysis of a Perioperative Gabapentin Trial

Background

Preoperative patient-specific risk factors may elucidate the mechanisms leading to the persistence of pain and opioid use after surgery. This study aimed to determine whether similar or discordant preoperative factors were associated with the duration of postoperative pain and opioid use.

Methods

In this post hoc analysis of a randomized, double-blind, placebo-controlled trial of perioperative gabapentin vs active placebo, 410 patients aged 18–75 years, undergoing diverse operations underwent preoperative assessments of pain, opioid use, substance use, and psychosocial variables. After surgery, a modified Brief Pain Inventory was administered over the phone daily up to 3 months, weekly up to 6 months, and monthly up to 2 years after surgery. Pain and opioid cessation were defined as the first of 5 consecutive days of 0 out of 10 pain or no opioid use, respectively.

Results

Overall, 36.1%, 19.8%, and 9.5% of patients continued to report pain, and 9.5%, 2.4%, and 1.7% reported continued opioid use at 3, 6, and 12 months after surgery. Preoperative pain at the future surgical site (every 1-point increase in the Numeric Pain Rating Scale; HR 0.93; 95% CI 0.87–1.00; P=0.034), trait anxiety (every 10-point increase in the Trait Anxiety Inventory; HR 0.79; 95% CI 0.68–0.92; P=0.002), and a history of delayed recovery after injury (HR 0.62; 95% CI 0.40–0.96; P=0.034) were associated with delayed pain cessation. Preoperative opioid use (HR 0.60; 95% CI 0.39–0.92; P=0.020), elevated depressive symptoms (every 5-point increase in the Beck Depression Inventory-II score; HR 0.88; 95% CI 0.80–0.98; P=0.017), and preoperative pain outside of the surgical site (HR 0.94; 95% CI 0.89–1.00; P=0.046) were associated with delayed opioid cessation, while perioperative gabapentin promoted opioid cessation (HR 1.37; 95% CI 1.06–1.77; P=0.016).

Conclusion

Separate risk factors for prolonged post-surgical pain and opioid use indicate that preoperative risk stratification for each outcome may identify patients needing personalized care to augment universal protocols for perioperative pain management and conservative opioid prescribing to improve long-term outcomes.

A Randomized Controlled Trial of Music for Pain Relief after Arthroplasty Surgery

PURPOSE

Effective pain management for patients undergoing orthopedic surgery, using pharmacological and nonpharmacological strategies, is essential. This pilot study evaluated music as an adjuvant therapy with prescribed analgesics to reduce acute pain and analgesic use among patients undergoing arthroplasty surgery.

DESIGN

Prospective randomized controlled trial of 50 participants scheduled for arthroplasty surgery at a large university-affiliated hospital.

METHODS

Participants were randomly assigned to treatment (music and analgesic medication; n = 25) or control (analgesic medication only; n = 25) groups. The intervention consisted of listening to self-selected music for 30 minutes, three times per day postoperatively in hospital and for 2 days postdischarge at home. Participants rated pain intensity and distress before and after music listening (treatment group) or meals (control group). Analgesic medication use was assessed via medical records in hospital and self-report logs postdischarge.

RESULTS

Forty-seven participants completed the study. Participants who listened to music after surgery reported significantly lower pain intensity and distress in hospital and postdischarge at home. There were no statistically significant differences in analgesic medication use after surgery between groups.

CONCLUSIONS

Study findings provide further evidence for the effectiveness of music listening, combined with analgesics, for reducing postsurgical pain, and extend the literature by examining music listening postdischarge. Music listening is an effective adjuvant pain management strategy. It is easy to administer, accessible, and affordable. Patient education is needed to encourage patients to continue to use music to reduce pain at home during the postoperative recovery period.

Parents' management of adolescent patients' postoperative pain after discharge: A qualitative study

Background: Short hospital admission periods following pediatric inpatient surgery leave parents responsible for managing their child’s postoperative pain in the community following discharge. Little is known about the experiences of parents caring for their child’s postoperative pain after discharge home following inpatient surgery. Research examining parental postoperative pain management following their child’s day surgery has found that parents are challenged in their pain management knowledge and practices.

Aims: This interpretative phenomenological analysis study sought to understand parents’ experiences caring for their child’s postoperative pain at home.

Methods: Semistructured telephone interviews were conducted with seven parents between 2 weeks and 6 months after their child’s discharge from hospital.

Results: Identified themes were coming home without support, managing significant pain at home, and changes in the parent–child relationship.

Conclusions: Parents could potentially benefit from nurses optimizing educational interventions, from receiving ongoing support of transitional pain teams, and from assistance with return to school planning.

Evidence-Based Strategies for the Prevention of Chronic Post-Intensive Care and Acute Care-Related Pain

Chronic pain is prevalent in intensive care survivors and in patients who require acute care treatments. Many adverse consequences have been associated with chronic post-intensive care and acute care-related pain. Hence, interest in interventions to prevent these pain disorders has grown. To improve the understanding of the mechanisms of action of these interventions and their potential impacts, this article outlines the pathophysiology involved in the transition from acute to chronic pain, the epidemiology and consequences of chronic post-intensive care and acute care- related pain, and risk factors for the development of chronic pain. Pharmacological, nonpharmacological, and multimodal preventive interventions specific to the targeted populations and their levels of evidence are presented. Nursing implications for preventing chronic pain in patients receiving critical and acute care are also discussed.

Adolescent Patients' Management of Postoperative Pain after Discharge: A Qualitative Study

BACKGROUND

Adolescents are typically admitted for a short period of time after inpatient surgery, leaving much of their recovery to occur at home. Pain, and thus pain management, is a major component of recovery at home. Research among pediatric outpatient surgical patients has found that pain experienced in the community setting after discharge is often severe and is related to knowledge deficits resulting in inadequate pain management. However, there is little research on community pain management after inpatient surgery.

AIM

This study aimed to explore the pain experiences of seven adolescents who underwent inpatient surgery.

DESIGN

This study used Interpretative Phenomenological Analysis as a methodology.

SETTING

This study took place at a pediatric tertiary care hospital in Canada.

PARTICIPANTS

7 adolescents participated, all of whom underwent inpatient surgery with admission between 2-14 days in length.

METHODS

Semi-structured interviews were conducted 2 to 6 weeks post-discharge.

RESULTS

Three themes were identified that described their experiences, including managing severe pain at home with minimal preparation, changes in the parent-child relationship, and difficulties returning to school and regular activities.

CONCLUSIONS

Involving adolescents directly in discharge education, particularly with the use of novel interventions and coaching, may improve outcomes.

KEY PRACTICE POINTS

Adolescent patients experience significant pain after discharge from hospital after inpatient surgical procedures. Adolescents are in need of adolescent-specific pain management education to increase skill and knowledge and address pain management-related misconceptions. Greater emphasis on involving adolescents in their own pain care and novel intervention could prove useful in improving outcomes.

Ketamine relieves depression-like behaviors induced by chronic postsurgical pain in rats through anti-inflammatory, anti-oxidant effects and regulating BDNF expression

RATIONALE

Clinically, chronic postsurgical pain (CPSP) is very common. Many CPSP patients may experience depression. Thus far, little is known about the mechanism of the comorbidity of CPSP and depression. Ketamine has been confirmed to possess analgesic and rapid antidepressant effects, but it is unclear whether ketamine can relieve the comorbidity of CPSP and depression.

OBJECTIVES

The present study evaluated the effects of ketamine in rats with the comorbidity of CPSP and depression.

METHODS

We induced CPSP in rats by thoracotomy and screened for rats with or without depression-like phenotype by hierarchical cluster analysis based on the results of depression-related behavioral experiments. Subsequently, rats were intraperitoneally injected with ketamine (20 mg/kg) and were evaluated by mechanical withdrawal threshold, cold hyperalgesia test, sucrose preference test, forced swimming test, and open field test. The inflammatory-related cytokines (IL-1, IL-6, TNF-α, nuclear factor-kappaB), oxidative stress parameters (superoxide dismutase, malondialdehyde, glutathione, catalase), and brain-derived neurotrophic factor (BDNF) in rat hippocampus were detected.

RESULTS

In the hippocampus of rats with the comorbidity of CPSP and depression, IL-1, IL-6, TNF-α, nuclear factor-kappaB, and malondialdehyde were significantly increased, while superoxide dismutase, glutathione, catalase, and BDNF were significantly decreased. Ketamine relieved depression but did not attenuate hyperalgesia in CPSP rats. Additionally, ketamine reduced proinflammatory cytokines, inhibited oxidative stress, and elevated BDNF levels in rat hippocampus.

CONCLUSIONS

Ketamine can rapidly relieve CPSP-induced depression in rats, which may be related to the reduction of proinflammatory cytokines, regulating oxidative stress and increasing BDNF in the hippocampus.

Strategies aimed at preventing chronic opioid use in trauma and acute care surgery: a scoping review protocol

INTRODUCTION

Globally every year, millions of patients sustain traumatic injuries and require acute care surgeries. A high incidence of chronic opioid use (up to 58%) has been documented in these populations with significant negative individual and societal impacts. Despite the importance of this public health issue, optimal strategies to limit the chronic use of opioids after trauma and acute care surgery are not clear. We aim to identify existing strategies to prevent chronic opioid use in these populations.

METHODS AND ANALYSIS

We will perform a scoping review of peer-reviewed and non-peer-reviewed literature to identify studies, reviews, recommendations and guidelines on strategies aimed at preventing chronic opioid use in patients after trauma and acute care surgery. We will search MEDLINE, EMBASE, PsycINFO, CINHAL, Cochrane Central Register of Controlled Trials, Web of Science, ProQuest and websites of trauma and acute care surgery, pain, government and professional organisations. Databases will be searched for papers published from 1 January 2005 to a maximum of 6 months before submission of the final manuscript. Two reviewers will independently evaluate studies for eligibility and extract data from included studies using a standardised data abstraction form. Preventive strategies will be classified according to their types and targeted trauma populations and acute care surgery procedures.

ETHICS AND DISSEMINATION

Research ethics approval is not required as this study is based on the secondary use of published data. This work will inform research and clinical stakeholders on the required next steps towards the uptake of effective strategies aimed at preventing chronic opioid use in trauma and acute care surgery patients.

Multimodal Anesthesia via Opioid-Free Analgesia and Erector Spinae Plane Block

Multimodal anesthesia, which combines general and epidural anesthesia, is used in surgical cases in which a large or painful incision is anticipated. However, both epidural blocks and opioid-based analgesia have limitations in application. Here, we present a case of supra-infraumbilical laparotomy in a patient whose history of neurostimulator use and marked scoliosis discouraged the placement of an epidural catheter and whose prior adverse response to opioids prohibited their use. The intraoperative and postoperative management of this patient consisted of a combination of analgesia without opioids and erector spinae plane block. Adequate analgesia was achieved, and intraoperative or postoperative opioids were not required. This case illustrates the importance of mastering alternative and multimodal analgesia techniques that can be used in place of classical analgesia techniques when classical analgesia techniques are not appropriate.

Musculoskeletal pain: determination of clinical phenotypes and the rational treatment approach

Personalized treatment is one of the basic principles of modern medicine. When administering a treatment, one should consider individual patient characteristics, comorbidities and, what is most important, the prevailing symptoms, as well as the clinical phenotype of a disease. This is directly related to chronic musculoskeletal pain (MSP), which occurs with underlying most prevalent joint and vertebral disorders. At present, MSP is considered to be an independent clinical syndrome.Predominant mechanisms of MSP pathophysiology allow for determination of its special phenotypes: “inflammatory”, “mechanical”, related to enthesopathy and central sensitization. Treatment strategies for MSP phenotypes should obviously be differentiated and based on a tailored and pathophysiologically sound of medical agents and non-medical measures with different mechanisms of pharmacological effects. Effective treatment of the “inflammatory” phenotype requires the use of non-steroidal anti-inflammatory drugs, topical glucocorticoids, disease modifying anti-inflammatory agents. The “mechanical” phenotype necessitates the correction of biomechanical abnormalities, the use of hyaluronic acid containing agents, whereas the “enthesopathic” phenotype is treated with local therapy. Treatment of the phenotype with central sensitization is performed with agents effective for neuropathic pain (anticonvulsants, anti-depressants).

'You wouldn't do that to an animal, would you?' Ethical issues in managing pain in patients with substance dependence

In this article, we present a secondary analysis of a descriptive phenomenological study that we conducted in the United Kingdom exploring nurses' experiences of working with patients with substance dependence and pain. Our aim was to focus upon the ethical issues that emerged in the empirical data and so we used the Four Principles of Biomedical Ethics plus attention to scope to guide and inform our analysis. We present six key themes: trust, paternalism, coercion, failure to respect autonomy, advocacy and withholding. We discuss how these themes intersect with the four principles plus scope to illuminate practice and the ethical issues that emerge when managing this patient population's pain. We recommend that clinicians adopt a collaborative approach to managing pain for patients with substance dependence that they remain aware of the power differentials inherent within the clinical setting and ensure that communication and teamwork remain at the forefront of decisions. Clinicians need access to ethical guidance to inform their practice decisions and clinical ethics support services could provide one solution.

Chronic postsurgical pain: From risk factor identification to multidisciplinary management at the Toronto General Hospital Transitional Pain Service

Background: Chronic postsurgical pain is a highly prevalent public health problem associated with substantial emotional, social, and economic costs. Aims: (1) To review the major risk factors for chronic postsurgical pain (CPSP); (2) to describe the implementation of the Transitional Pain Service (TPS) at the Toronto General Hospital, a multiprofessional, multimodal preventive approach to CPSP involving intensive, perioperative psychological, physical, and pharmacological management aimed at preventing and treating the factors that increase the risk of CPSP and related disability; and (3) to present recent empirical evidence for the efficacy of the TPS. Methods: The Toronto General Hospital TPS was specifically developed to target patients at high risk of developing CPSP. The major known risk factors for CPSP are perioperative pain, opioid use, and negative affect, including depression, anxiety, pain catastrophizing, and posttraumatic stress disorder-like symptoms. At-risk patients are identified early and provided comprehensive care by a multidisciplinary team consisting of pain physicians, advanced practice nurses, psychologists, and physical therapists. Results: Preliminary results from two nonrandomized, clinical practice-based trials indicate that TPS treatment is associated with improvements in pain, pain interference, pain catastrophizing, symptoms of anxiety and depression, and opioid use. Almost half of opioid-naïve patients and one in four opioid-experienced patients were opioid free by the 6-month point. Conclusions: These promising results suggest that the TPS benefits patients at risk of CPSP. A multicenter randomized controlled trial of the TPS in several Ontario hospitals is currently underway.

Chronic pain and central sensitization in immuno-inflammatory rheumatic diseases: pathogenesis, clinical manifestations, the possibility of using targeted disease modifying antirheumatic drugs

Chronic pain is one of the main manifestations of immuno-inflammatory rheumatic diseases (IIRD), such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA), which determines the severity of suffering, reduced quality of life and disability of patients. Unfortunately, the use of synthetic and biological disease modifying antirheumatic drugs, as well as non-steroidal anti-inflammatory drugs does not always provide sufficient control of pain in IIRD, even when it is possible to achieve a significant reduction in inflammatory activity. The reason for this is the complex mechanism of chronic pain. It includes not onlystimulation of pain receptors caused by damage of the elements of the musculoskeletal system, but also a change in the perception of pain associated with the phenomenon of central sensitization (CS). CS is characterized by a significant and persistent increase in the sensitivity of nociceptive neurons to pain and nonpain stimuli. One of the main theories of the CS development consider this phenomenon as an inflammatory reaction of the neuronenvironmentthe activation of astrocytes and microglial cells, local hyperproduction of cytokines, inflammatory mediators and neurotrophic factors. Factors contributing to the development of CS in IIRD are obesity, depression and anxiety, damage of the somatosensory system, insufficient relief of pain in the onset of the disease. Clinical manifestations of CS in IIRD is hyperalgesia, allodinia, «expanded pain» and secondary fibromyalgia. An important role in the development of chronic pain and CS plays the intracellular inflammatory pathway JAK-STAT. Therefore, JAK inhibitors, such as tofacitinib, used in RA and PsA, can also be considered as an effective means of controlling chronic pain in these diseases.