Clinical and Demographic Characteristics of Patients With Chronic Pain After Major Thoracotomy

Pain-related impairment in daily activities after lung cancer surgery: A 1-year prospective cohort study

BACKGROUND

Persistent postsurgical pain (PPSP) following thoracic surgery affects 40%-60% of patients undergoing lung resection due to malignancies. Postoperative pain-related symptoms are common, leading to limitations in activities of daily living (ADL) and deterioration in physical function, which significantly impacts quality of life. Pain-related limitations are of interest, as postsurgical pain may present as a target for intervention to improve postoperative rehabilitation. This study aimed to evaluate the association between PPSP and ADL limitations during the first 12 postoperative months after surgery for lung cancer.

METHODS

A total of 124 patients undergoing surgery for lung cancer were followed for 12 months. Every 2 months, participants reported ADL limitations attributed to PPSP. Cumulative pain impairment scores were calculated from reported limitations in 14 daily activities, and recovery trajectory patterns were analysed.

RESULTS

Daily activities most affected by PPSP were carrying bags, arm elevation, climbing stairs, cleaning floors and coughing, with >50% reporting limitations across all assessment times. Reported pain intensities were generally mild (NRS≤3), but still associated with significant impairment. Some recovery was observed in patients reporting pain at rest, but PPSP was consistently associated with higher cumulative pain impairment scores at all assessments during the 12-month follow-up period.

CONCLUSIONS

Findings indicate that persistent postsurgical pain, even of mild intensity, is associated with significant limitations in daily activities up to 12 months post-surgery. Some improvement in pain-related impairment was observed, although limitations remained significantly higher in patients reporting persistent postsurgical pain, as compared to pain-free patients.

SIGNIFICANCE

Surgery remains a cornerstone in the treatment of early-stage lung cancer. Despite advances in minimally invasive techniques and rehabilitation, persisting postsurgical pain and pain-related limitations in daily activities may endure. This study investigated specifically the pain-related limitations in activities of daily living and described recovery trajectories during the first 12 postoperative months. Patients with persistent postsurgical pain experienced multiple limitations compared to pain-free patients. Although partial recovery was observed, impairments remained significant for up to 12 months after surgery.

Postoperative acute pain trajectory and chronic postsurgical pain after abdominal surgery: a prospective cohort study and mediation analysis

BACKGROUND

This study aimed to investigate the trajectories of acute postoperative pain intensity during the initial 5 days after abdominal surgery, and to analyze their association with the risk of developing chronic postsurgical pain (CPSP).

METHODS

We enrolled patients with elective abdominal surgery with pain measurements taken across postoperative days 1 through 5. Since postoperative pain is often unavoidable and its initial intensity is closely related to the invasiveness of the surgery, focusing on the overall pain trajectory may be more meaningful than evaluating pain at a single time point. Therefore, the primary outcome of this study was to identify distinct pain trajectories. Secondary outcome was the incidence of CPSP between differences pain trajectories. Lastly, mediation analyses were performed to explore the mediating role of the quality of recovery and subacute pain on the studied associations.

RESULTS

The final analysis encompassed 1170 patients (36.75% female) with a median age of 55 years. Two distinct clusters were identified: with movement (high: 533 [45.56%]; low: 637 [54.44%]) and at rest (high: 363 [31.03%]; low: 807 [68.97%]). Patients in the high pain trajectory group (during movement [odds ratio [OR] 2.04, 95% CI 1.56-2.68] or at rest [OR 1.90, 95% CI 1.44-2.53]) exhibited nearly doubled risk of CPSP. Moreover, these patients exhibited a significantly poorer recovery quality. Mediation analyses revealed that the poor recovery quality at postoperative 5 days (17.62%-18.57%) and higher subacute pain at postoperative 1 month (29.46%-32.75%) were significant mediators in the association between adverse postoperative acute pain trajectory patterns and CPSP.

CONCLUSION

This study highlights the clinical significance of postoperative pain trajectory profiles in predicting the risk of CPSP, emphasizing postoperative acute pain trajectory as a critical indicator and subacute pain as a significant mediator. The findings underscore the potential for tailored pain management strategies targeting acute pain trajectories to reduce such risk.

Pain trajectories and neuropathic pain symptoms following lung cancer surgery: A prospective cohort study

BACKGROUND

Persistent postsurgical pain (PPSP) after lung cancer surgery is common and current definitions are based on evaluations at a single time point after surgery. Pain intensity and symptoms may however fluctuate and change over time, and be impacted by multiple and shifting factors. Studies of postoperative recovery patterns and transition from acute to chronic pain are needed for further investigation of preventive measures and treatments to modify unfavourable recovery paths.

METHODS

In this explorative study, 85 patients undergoing surgery due to either presumptive or confirmed lung cancer reported pain intensities bi-monthly for 12 months. Pain trajectories during recovery were investigated, using group-based trajectory modelling. Associations with possible risk factors for PPSP, including clinical variables and anxiety and depression score (HADS), were also explored.

RESULTS

A trajectory model containing three 12-month pain recovery groups was computed. One group without PPSP fully recovered (50%) within two to three months. Another group with mild-intensity PPSP followed a protracted recovery trajectory (37%), while incomplete recovery was observed in the last group (13%). Acute postoperative pain and younger age were associated with a less favourable recovery trajectory. More neuropathic pain symptoms were observed in patients with incomplete recovery.

CONCLUSIONS

Three clinically relevant recovery trajectories were identified, based on comprehensive pain tracking. Higher acute postoperative pain intensity was associated with an unfavourable pain recovery trajectory.

SIGNIFICANCE STATEMENT

Understanding the transition from acute to chronic postoperative pain and identifying preoperative risk factors is essential for the development of targeted treatments and the implementation of preventive measures. This study (1) identified distinct recovery trajectories based on frequent pain assessment follow-ups for 12 months after surgery and (2) evaluated risk factors for unfavourable postoperative pain recovery paths. Findings suggest that early higher postoperative pain intensity is associated with an unfavourable long-term recovery path.

Prevalence and Characteristics of Persistent Postoperative Pain After Thoracic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

A systematic review and meta-analysis was conducted to investigate the prevalence and characteristics of persistent (≥3 months) postoperative pain (PPP) after thoracic surgery.

METHODS

For this purpose, Medline, Embase, and CINAHL databases were searched for the prevalence and characteristics of PPP after thoracic surgery from their inception to May 1, 2022. Random-effect meta-analysis was used to estimate pooled prevalence and characteristics.

RESULTS

We included 90 studies with 19,001 patients. At a median follow-up of 12 months, the pooled overall prevalence of PPP after thoracic surgery was 38.1% (95% confidence interval [CI], 34.1-42.3). Among patients with PPP, 40.6% (95% CI, 34.4-47.2) and 10.1% (95% CI, 6.8-14.8) experienced moderate-to-severe (rating scale ≥4/10) and severe (rating scale ≥7/10) PPP, respectively. Overall, 56.5% (95% CI, 44.3-67.9) of patients with PPP required opioid analgesic use, and 33.0% (95% CI, 22.5-44.3) showed a neuropathic component.

CONCLUSIONS

One in 3 thoracic surgery patients developed PPP. There is a need for adequate pain treatment and follow-up in patients undergoing thoracic surgery.

Prognostic factors for chronic post-surgical pain after lung and pleural surgery: a systematic review with meta-analysis, meta-regression and trial sequential analysis

Chronic post-surgical pain is known to be a common complication of thoracic surgery and has been associated with a lower quality of life, increased healthcare utilisation, substantial direct and indirect costs, and increased long-term use of opioids. This systematic review with meta-analysis aimed to identify and summarise the evidence of all prognostic factors for chronic post-surgical pain after lung and pleural surgery. Electronic databases were searched for retrospective and prospective observational studies as well as randomised controlled trials that included patients undergoing lung or pleural surgery and reported on prognostic factors for chronic post-surgical pain. We included 56 studies resulting in 45 identified prognostic factors, of which 16 were pooled with a meta-analysis. Prognostic factors that increased chronic post-surgical pain risk were as follows: higher postoperative pain intensity (day 1, 0-10 score), mean difference (95%CI) 1.29 (0.62-1.95), p < 0.001; pre-operative pain, odds ratio (95%CI) 2.86 (1.94-4.21), p < 0.001; and longer surgery duration (in minutes), mean difference (95%CI) 12.07 (4.99-19.16), p < 0.001. Prognostic factors that decreased chronic post-surgical pain risk were as follows: intercostal nerve block, odds ratio (95%CI) 0.76 (0.61-0.95) p = 0.018 and video-assisted thoracic surgery, 0.54 (0.43-0.66) p < 0.001. Trial sequential analysis was used to adjust for type 1 and type 2 errors of statistical analysis and confirmed adequate power for these prognostic factors. In contrast to other studies, we found that age had no significant effect on chronic post-surgical pain and there was not enough evidence to conclude on sex. Meta-regression did not reveal significant effects of any of the study covariates on the prognostic factors with a significant effect on chronic post-surgical pain. Expressed as grading of recommendations, assessment, development and evaluations criteria, the certainty of evidence was high for pre-operative pain and video-assisted thoracic surgery, moderate for intercostal nerve block and surgery duration and low for postoperative pain intensity. We thus identified actionable factors which can be addressed to attempt to reduce the risk of chronic post-surgical pain after lung surgery.

Effect of acute postsurgical pain trajectories on 30-day and 1-year pain

Untreated pain after surgery leads to poor patient satisfaction, longer hospital length of stay, lower health-related quality of life, and non-compliance with rehabilitation regimens. The aim of this study is to characterize the structure of acute pain trajectories during the postsurgical hospitalization period and quantify their association with pain at 30-days and 1-year after surgery. This cohort study included 2106 adult (≥18 years) surgical patients who consented to participate in the SATISFY-SOS registry (February 1, 2015 to September 30, 2017). Patients were excluded if they did not undergo invasive surgeries, were classified as outpatients, failed to complete follow up assessments at 30-days and 1-year following surgery, had greater than 4-days of inpatient stay, and/or recorded fewer than four pain scores during their acute hospitalization period. The primary exposure was the acute postsurgical pain trajectories identified by a machine learning-based latent class approach using patient-reported pain scores. Clinically meaningful pain (≥3 on a 0–10 scale) at 30-days and 1-year after surgery were the primary and secondary outcomes, respectively. Of the study participants (N = 2106), 59% were female, 91% were non-Hispanic White, and the mean (SD) age was 62 (13) years; 41% of patients underwent orthopedic surgery and 88% received general anesthesia. Four acute pain trajectory clusters were identified. Pain trajectories were significantly associated with clinically meaningful pain at 30-days (p = 0.007), but not at 1-year (p = 0.79) after surgery using covariate-adjusted logistic regression models. Compared to Cluster 1, the other clusters had lower statistically significant odds of having pain at 30-days after surgery (Cluster 2: [OR = 0.67, 95%CI (0.51–0.89)]; Cluster 3:[OR = 0.74, 95%CI (0.56–0.99)]; Cluster 4:[OR = 0.46, 95%CI (0.26–0.82)], all p<0.05). Patients in Cluster 1 had the highest cumulative likelihood of pain and pain intensity during the latter half of their acute hospitalization period (48–96 hours), potentially contributing to the higher odds of pain during the 30-day postsurgical period. Early identification and management of high-risk pain trajectories can help in ascertaining appropriate pain management interventions. Such interventions can mitigate the occurrence of long-term disabilities associated with pain.

Multi-Site Observational Study to Assess Biomarkers for Susceptibility or Resilience to Chronic Pain: The Acute to Chronic Pain Signatures (A2CPS) Study Protocol

Chronic pain has become a global health problem contributing to years lived with disability and reduced quality of life. Advances in the clinical management of chronic pain have been limited due to incomplete understanding of the multiple risk factors and molecular mechanisms that contribute to the development of chronic pain. The Acute to Chronic Pain Signatures (A2CPS) Program aims to characterize the predictive nature of biomarkers (brain imaging, high-throughput molecular screening techniques, or "omics," quantitative sensory testing, patient-reported outcome assessments and functional assessments) to identify individuals who will develop chronic pain following surgical intervention. The A2CPS is a multisite observational study investigating biomarkers and collective biosignatures (a combination of several individual biomarkers) that predict susceptibility or resilience to the development of chronic pain following knee arthroplasty and thoracic surgery. This manuscript provides an overview of data collection methods and procedures designed to standardize data collection across multiple clinical sites and institutions. Pain-related biomarkers are evaluated before surgery and up to 3 months after surgery for use as predictors of patient reported outcomes 6 months after surgery. The dataset from this prospective observational study will be available for researchers internal and external to the A2CPS Consortium to advance understanding of the transition from acute to chronic postsurgical pain.

Presurgical distress about bodily sensations predicts chronic postsurgical pain intensity and disability 6 months after cardiothoracic surgery

ABSTRACT

Chronic postsurgical pain (CPSP) and disability after cardiothoracic surgery are highly prevalent and difficult to treat. Researchers have explored a variety of presurgical risk factors for CPSP and disability after cardiothoracic surgery, including one study that examined distress from bodily sensations. The current prospective, longitudinal study sought to extend previous research by investigating presurgical distress about bodily sensations as a risk factor for CPSP and disability after cardiothoracic surgery while controlling for several other potential psychosocial predictors. Participants included 543 adults undergoing nonemergency cardiac or thoracic surgery who were followed over 6 months postsurgically. Before surgery, participants completed demographic, clinical, and psychological questionnaires. Six months after surgery, participants reported the intensity of CPSP on a 0 to 10 numeric rating scale and pain disability, measured by the Pain Disability Index. Multinomial logistic regression analyses were conducted to evaluate the degree to which presurgical measures predicted pain outcomes 6 months after surgery. The results showed that CPSP intensity was significantly predicted by age and presurgical scores on the Symptom Checklist-90-Revised Somatization subscale (Nagelkerke R2 = 0.27, P < 0.001), whereas chronic pain disability was only predicted by presurgical Symptom Checklist-90-Revised Somatization scores (Nagelkerke R2 = 0.29, P < 0.001). These findings demonstrate that presurgical distress over bodily sensations predicts greater chronic pain intensity and disability 6 months after cardiothoracic surgery and suggest that presurgical treatment to diminish such distress may prevent or minimize CPSP intensity and disability.

New Thoracotomy Closure, a Simple Way to Decrease Chronic Post-Operative Pain in Selected Patients-Blinded Prospective Study

Background and Objectives: Chronic post-thoracotomy pain syndrome (PTPS) is a very common and uncomfortable complication, occurring frequently after thoracic operations, leading to the necessity of further medication and hospitalizations. One important risk factor in developing chronic pain is the chest closure technique, which can lead to chronic intercostal nerve damage. This study proposes an alternative nerve-sparring closure technique to standard peri-costal sutures, aimed toward minimizing the risk of chronic pain in selected patients. Materials and Methods: We performed a prospective randomized study on 311 patients operated for various thoracic pathology over a period of 12 months, evaluating incision types, chest closure technique, and number of drains with drainage duration. The patients were divided into three groups: peri-costal (PC), proposed extra-costal (EC), and simple (SC) suture, respectively. Pain was measured on day 1, 2, 5, 7, and at 6 months post-operatively using the Visual Analogic Scale. Results: No significant differences in pain level were recorded in the first two post-operative days between the PC and EC groups. However, a significant decrease in pain level was observed on day 5 and at 6 months post-operatively, with a mean level of 3.5 ± 1.8, 1.2 ± 1 for the EC group compared to a mean value of 5.3 ± 1.6, 3.2 ± 1.5, respectively. No significant differences were observed regarding other evaluated variables. Conclusions: The lower recorded pain scores in patients with extra-costal chest closure are a strong argument to use this technique. Its ease of use is similar to the classic peri-costal closure, and the time needed to perform it is not significantly increased. The association of this technique with less invasive procedures and short drainage duration limits chronic post-operative pain. This procedure may represent an option for decreasing healthcare costs associated with the management of PTPS.

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.

<p>Sonic Hedgehog Signaling Contributes to Chronic Post-Thoracotomy Pain via Activating BDNF/TrkB Pathway in Rats</p>

Purpose

Some patients undergoing thoracotomy may suffer from chronic post-thoracotomy pain (CPTP). Treatment of CPTP has been a clinical challenge and the underlying mechanisms of CPTP remain elusive. Recently, sonic hedgehog (Shh) signaling has been shown to be associated with various pain states but its role in the pathogenesis of CPTP is still unclear.

Methods

CPTP was induced in rats by thoracotomy. Rats were divided into CPTP group and non-CPTP group based on the mechanical withdrawal threshold (MWT). Rats were administered with Shh signaling inhibitor cyclopamine and activator smoothened agonist (SAG), and then evaluated by MWT and cold allodynia testing. The expressions of Shh signaling (Shh ligand, patched and smoothened receptor, Gli transcription factors), brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase receptor B (Trk-B), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) in rat T4-5 spinal cord dorsal horn (SDH) were detected by Western blotting and immunohistochemistry.

Results

The expression of Shh signaling significantly increased and the BDNF/TrkB pathway was activated in T4-5 SDH of CPTP rats. Cyclopamine attenuated hyperalgesia and down-regulated the expressions of Gil1, BDNF, p-TrkB, p-PI3K and p-Akt in CPTP rats. SAG induced hyperalgesia in non-CPTP rats and elevated the expressions of Gil1, BDNF, p-TrkB, p-PI3K and p-Akt.

Conclusion

Shh signaling may contribute to CPTP via activating BDNF/TrkB signaling pathway, and inhibition of Shh signaling may effectively alleviate CPTP.

Regional versus systemic analgesia in video-assisted thoracoscopic lobectomy: a retrospective analysis

Background

The optimal perioperative analgesic strategy in video-assisted thoracic surgery (VATS) for anatomic lung resections remains an open issue. Regional analgesic concepts as thoracic paravertebral or epidural analgesia were used as systemic opioid application. We hypothesized that regional anesthesia would provide improved analgesia compared to systemic analgesia with parenteral opioids in VATS lobectomy and would be associated with a lower incidence of pulmonary complications.

Methods

The study was approved by the local ethics committee (AZ 99/15) and registered (germanctr.de; DRKS00007529, 10th June 2015). A retrospective analysis of anesthetic and surgical records between July 2014 und February 2016 in a single university hospital with 103 who underwent VATS lobectomy. Comparison of regional anesthesia (i.e. thoracic paravertebral blockade (group TPVB) or thoracic epidural anesthesia (group TEA)) with a systemic opioid application (i.e. patient controlled analgesia (group PCA)). The primary endpoint was the postoperative pain level measured by Visual Analog Scale (VAS) at rest and during coughing during 120 h. Secondary endpoints were postoperative pulmonary complications (i.e. atelectasis, pneumonia), hemodynamic variables and postoperative nausea and vomiting (PONV).

Results

Mean VAS values in rest or during coughing were measured below 3.5 in all groups showing effective analgesic therapy throughout the observation period. The VAS values at rest were comparable between all groups, VAS level during coughing in patients with PCA was higher but comparable except after 8–16 h postoperatively (PCA vs. TEA; p < 0.004). There were no significant differences on secondary endpoints. Intraoperative Sufentanil consumption was significantly higher for patients without regional anesthesia (p < 0.0001 vs. TPVB and vs. TEA). The morphine equivalence postoperatively applicated until POD 5 was comparable in all groups (mean ± SD in mg: 32 ± 29 (TPVB), 30 ± 27 (TEA), 36 ± 30 (PCA); p = 0.6046).

Conclusions

Analgesia with TEA, TPVB and PCA provided a comparable and effective pain relief after VATS anatomic resection without side effects. Our results indicate that PCA for VATS lobectomy may be a sufficient alternative compared to regional analgesia.

Trial registration

The study was registered (germanctr.de; DRKS00007529; 10th June, 2015).

Skin/Muscle Incision and Retraction Induces Evoked and Spontaneous Pain in Mice

Background

Surgery is a frequent cause of persistent pain. Unrelieved chronic postsurgical pain causes unnecessary patient suffering and discomfort and usually leads to psychological complications. The rat model of skin/muscle incision and retraction (SMIR) with decreased paw withdrawal thresholds developed by Flatters was usually used to investigate the underlying mechanism of chronic postsurgical pain.

Objectives

The aim of our study was to develop a new mice model of SMIR for further investigation with transgenic mice and so on and to evaluate the analgesic effects of clonidine and gabapentin on pain behavior with this new mice model.

Methods

Male C57BL/6 mice were anesthetized, and a 1.0-1.3 cm incision was made in the skin of the medial thigh approximately 3 mm medial to the saphenous vein to reveal the muscle of the thigh. The paw withdrawal threshold (PWT) to mechanical stimuli and the paw withdrawal latency to heat stimuli were measured before and after SMIR. Furthermore, the PWT to mechanical stimuli and conditioned place preference (CPP) was measured before and after the systemic injection of clonidine and gabapentin.

Results

SMIR-evoked mechanical hypersensitivity in mice began on day 1 after the procedure, prominent between days 1 and 10 after the procedure, persisted at least until day 14, and disappeared on day 18 after the procedure. However, the mice model of SMIR did not evoke significant heat hypersensitivity. Systemic injection of clonidine and gabapentin raised the PWT in the SMIR mice dose-dependently. Compared with the mice that underwent the sham operation, mice of SMIR spent a longer time in the clonidine-paired chamber than those of NS, while the gabapentin-paired chamber has no difference with that of NS in the CPP paradigm.

Conclusion

These data suggested that the mice model of SMIR demonstrated a persistent pain syndrome, including evoked pain and spontaneous pain. Clonidine and gabapentin could relieve mechanical hypersensitivity dose-dependently simultaneously. However, clonidine but not gabapentin could alleviate the spontaneous pain of SMIR in the mice model.

Factors Associated With Acute Pain Estimation, Postoperative Pain Resolution, Opioid Cessation, and Recovery: Secondary Analysis of a Randomized Clinical Trial

Importance

Acute postoperative pain is associated with the development of persistent postsurgical pain, but it is unclear which aspect is most estimable.

Objective

To identify patient clusters based on acute pain trajectories, preoperative psychosocial characteristics associated with the high-risk cluster, and the best acute pain predictor of remote outcomes.

Design, Setting, and Participants

A secondary analysis of the Stanford Accelerated Recovery Trial randomized, double-blind clinical trial was conducted at a single-center, tertiary, referral teaching hospital. A total of 422 participants scheduled for thoracotomy, video-assisted thoracoscopic surgery, total hip replacement, total knee replacement, mastectomy, breast lumpectomy, hand surgery, carpal tunnel surgery, knee arthroscopy, shoulder arthroplasty, or shoulder arthroscopy were enrolled between May 25, 2010, and July 25, 2014. Data analysis was performed from January 1 to August 1, 2018.

Interventions

Patients were randomized to receive gabapentin (1200 mg, preoperatively, and 600 mg, 3 times a day postoperatively) or active placebo (lorazepam, 0.5 mg preoperatively, inactive placebo postoperatively) for 72 hours.

Main Outcomes and Measures

A modified Brief Pain Inventory prospectively captured 3 surgical site pain outcomes: average pain and worst pain intensity over the past 24 hours, and current pain intensity. Within each category, acute pain trajectories (first 10 postoperative pain scores) were compared using a k-means clustering algorithm. Fifteen descriptors of acute pain were compared as predictors of remote postoperative pain resolution, opioid cessation, and full recovery.

Results

Of the 422 patients enrolled, 371 patients (≤10% missing pain scores) were included in the analysis. Of these, 146 (39.4%) were men; mean (SD) age was 56.67 (11.70) years. Two clusters were identified within each trajectory category. The high pain cluster of the average pain trajectory significantly predicted prolonged pain (hazard ratio [HR], 0.63; 95% CI, 0.50-0.80; P < .001) and delayed opioid cessation (HR, 0.52; 95% CI, 0.41-0.67; P < .001) but was not a predictor of time to recovery in Cox proportional hazards regression (HR, 0.89; 95% CI, 0.69-1.14; P = .89). Preoperative risk factors for categorization to the high average pain cluster included female sex (adjusted relative risk [ARR], 1.36; 95% CI, 1.08-1.70; P = .008), elevated preoperative pain (ARR, 1.11; 95% CI, 1.07-1.15; P < .001), a history of alcohol or drug abuse treatment (ARR, 1.90; 95% CI, 1.42-2.53; P < .001), and receiving active placebo (ARR, 1.27; 95% CI, 1.03-1.56; P = .03). Worst pain reported on postoperative day 10 was the best predictor of time to pain resolution (HR, 0.83; 95% CI, 0.78-0.87; P < .001), opioid cessation (HR, 0.84; 95% CI, 0.80-0.89; P < .001), and complete surgical recovery (HR, 0.91; 95% CI, 0.86-0.96; P < .001).

Conclusions and Relevance

This study has shown a possible uniform predictor of remote postoperative pain, opioid use, and recovery that can be easily assessed. Future work is needed to replicate these findings.

Trial Registration

ClinicalTrials.gov Identifier: NCT01067144.

Local anaesthetics and regional anaesthesia versus conventional analgesia for preventing persistent postoperative pain in adults and children

BACKGROUND

Regional anaesthesia may reduce the rate of persistent postoperative pain (PPP), a frequent and debilitating condition. This review was originally published in 2012 and updated in 2017.

OBJECTIVES

To compare local anaesthetics and regional anaesthesia versus conventional analgesia for the prevention of PPP beyond three months in adults and children undergoing elective surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase to December 2016 without any language restriction. We used a combination of free text search and controlled vocabulary search. We limited results to randomized controlled trials (RCTs). We updated this search in December 2017, but these results have not yet been incorporated in the review. We conducted a handsearch in reference lists of included studies, review articles and conference abstracts. We searched the PROSPERO systematic review registry for related systematic reviews.

SELECTION CRITERIA

We included RCTs comparing local or regional anaesthesia versus conventional analgesia with a pain outcome beyond three months after elective, non-orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial quality and extracted data and adverse events. We contacted study authors for additional information. We presented outcomes as pooled odds ratios (OR) with 95% confidence intervals (95% CI), based on random-effects models (inverse variance method). We analysed studies separately by surgical intervention, but pooled outcomes reported at different follow-up intervals. We compared our results to Bayesian and classical (frequentist) models. We investigated heterogeneity. We assessed the quality of evidence with GRADE.

MAIN RESULTS

In this updated review, we identified 40 new RCTs and seven ongoing studies. In total, we included 63 RCTs in the review, but we were only able to synthesize data on regional anaesthesia for the prevention of PPP beyond three months after surgery from 39 studies, enrolling a total of 3027 participants in our inclusive analysis.Evidence synthesis of seven RCTs favoured epidural anaesthesia for thoracotomy, suggesting the odds of having PPP three to 18 months following an epidural for thoracotomy were 0.52 compared to not having an epidural (OR 0.52 (95% CI 0.32 to 0.84, 499 participants, moderate-quality evidence). Simlarly, evidence synthesis of 18 RCTs favoured regional anaesthesia for the prevention of persistent pain three to 12 months after breast cancer surgery with an OR of 0.43 (95% CI 0.28 to 0.68, 1297 participants, low-quality evidence). Pooling data at three to 8 months after surgery from four RCTs favoured regional anaesthesia after caesarean section with an OR of 0.46, (95% CI 0.28 to 0.78; 551 participants, moderate-quality evidence). Evidence synthesis of three RCTs investigating continuous infusion with local anaesthetic for the prevention of PPP three to 55 months after iliac crest bone graft harvesting (ICBG) was inconclusive (OR 0.20, 95% CI 0.04 to 1.09; 123 participants, low-quality evidence). However, evidence synthesis of two RCTs also favoured the infusion of intravenous local anaesthetics for the prevention of PPP three to six months after breast cancer surgery with an OR of 0.24 (95% CI 0.08 to 0.69, 97 participants, moderate-quality evidence).We did not synthesize evidence for the surgical subgroups of limb amputation, hernia repair, cardiac surgery and laparotomy. We could not pool evidence for adverse effects because the included studies did not examine them systematically, and reported them sparsely. Clinical heterogeneity, attrition and sparse outcome data hampered evidence synthesis. High risk of bias from missing data and lack of blinding across a number of included studies reduced our confidence in the findings. Thus results must be interpreted with caution.

AUTHORS' CONCLUSIONS

We conclude that there is moderate-quality evidence that regional anaesthesia may reduce the risk of developing PPP after three to 18 months after thoracotomy and three to 12 months after caesarean section. There is low-quality evidence that regional anaesthesia may reduce the risk of developing PPP three to 12 months after breast cancer surgery. There is moderate evidence that intravenous infusion of local anaesthetics may reduce the risk of developing PPP three to six months after breast cancer surgery.Our conclusions are considerably weakened by the small size and number of studies, by performance bias, null bias, attrition and missing data. Larger, high-quality studies, including children, are needed. We caution that except for breast surgery, our evidence synthesis is based on only a few small studies. On a cautionary note, we cannot extend our conclusions to other surgical interventions or regional anaesthesia techniques, for example we cannot conclude that paravertebral block reduces the risk of PPP after thoracotomy. There are seven ongoing studies and 12 studies awaiting classification that may change the conclusions of the current review once they are published and incorporated.

Local anaesthetics and regional anaesthesia versus conventional analgesia for preventing persistent postoperative pain in adults and children

BACKGROUND

Regional anaesthesia may reduce the rate of persistent postoperative pain (PPP), a frequent and debilitating condition. This review was originally published in 2012 and updated in 2017.

OBJECTIVES

To compare local anaesthetics and regional anaesthesia versus conventional analgesia for the prevention of PPP beyond three months in adults and children undergoing elective surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase to December 2016 without any language restriction. We used a combination of free text search and controlled vocabulary search. We limited results to randomized controlled trials (RCTs). We updated this search in December 2017, but these results have not yet been incorporated in the review. We conducted a handsearch in reference lists of included studies, review articles and conference abstracts. We searched the PROSPERO systematic review registry for related systematic reviews.

SELECTION CRITERIA

We included RCTs comparing local or regional anaesthesia versus conventional analgesia with a pain outcome beyond three months after elective, non-orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial quality and extracted data and adverse events. We contacted study authors for additional information. We presented outcomes as pooled odds ratios (OR) with 95% confidence intervals (95% CI), based on random-effects models (inverse variance method). We analysed studies separately by surgical intervention, but pooled outcomes reported at different follow-up intervals. We compared our results to Bayesian and classical (frequentist) models. We investigated heterogeneity. We assessed the quality of evidence with GRADE.

MAIN RESULTS

In this updated review, we identified 40 new RCTs and seven ongoing studies. In total, we included 63 RCTs in the review, but we were only able to synthesize data on regional anaesthesia for the prevention of PPP beyond three months after surgery from 41 studies, enrolling a total of 3143 participants in our inclusive analysis.Evidence synthesis of seven RCTs favoured epidural anaesthesia for thoracotomy, suggesting the odds of having PPP three to 18 months following an epidural for thoracotomy were 0.52 compared to not having an epidural (OR 0.52 (95% CI 0.32 to 0.84, 499 participants, moderate-quality evidence). Simlarly, evidence synthesis of 18 RCTs favoured regional anaesthesia for the prevention of persistent pain three to 12 months after breast cancer surgery with an OR of 0.43 (95% CI 0.28 to 0.68, 1297 participants, low-quality evidence). Pooling data at three to 8 months after surgery from four RCTs favoured regional anaesthesia after caesarean section with an OR of 0.46, (95% CI 0.28 to 0.78; 551 participants, moderate-quality evidence). Evidence synthesis of three RCTs investigating continuous infusion with local anaesthetic for the prevention of PPP three to 55 months after iliac crest bone graft harvesting (ICBG) was inconclusive (OR 0.20, 95% CI 0.04 to 1.09; 123 participants, low-quality evidence). However, evidence synthesis of two RCTs also favoured the infusion of intravenous local anaesthetics for the prevention of PPP three to six months after breast cancer surgery with an OR of 0.24 (95% CI 0.08 to 0.69, 97 participants, moderate-quality evidence).We did not synthesize evidence for the surgical subgroups of limb amputation, hernia repair, cardiac surgery and laparotomy. We could not pool evidence for adverse effects because the included studies did not examine them systematically, and reported them sparsely. Clinical heterogeneity, attrition and sparse outcome data hampered evidence synthesis. High risk of bias from missing data and lack of blinding across a number of included studies reduced our confidence in the findings. Thus results must be interpreted with caution.

AUTHORS' CONCLUSIONS

We conclude that there is moderate-quality evidence that regional anaesthesia may reduce the risk of developing PPP after three to 18 months after thoracotomy and three to 12 months after caesarean section. There is low-quality evidence that regional anaesthesia may reduce the risk of developing PPP three to 12 months after breast cancer surgery. There is moderate evidence that intravenous infusion of local anaesthetics may reduce the risk of developing PPP three to six months after breast cancer surgery.Our conclusions are considerably weakened by the small size and number of studies, by performance bias, null bias, attrition and missing data. Larger, high-quality studies, including children, are needed. We caution that except for breast surgery, our evidence synthesis is based on only a few small studies. On a cautionary note, we cannot extend our conclusions to other surgical interventions or regional anaesthesia techniques, for example we cannot conclude that paravertebral block reduces the risk of PPP after thoracotomy. There are seven ongoing studies and 12 studies awaiting classification that may change the conclusions of the current review once they are published and incorporated.

[A Comparative Study of Acute and Chronic Pain between Single Port and Triple Port Video-assisted Thoracic Surgery for Lung Cancer]

BACKGROUND

Through the comparative analysis of the acute and chronic pain postoperative between the single port and triple port video-assisted thoracic surgery to seek the better method which can reduce the incidence of acute and chronic pain in patients with lung cancer.

METHODS

Data of 232 patients who underwent single port -VATS (n=131) or triple port VATS (n=101) for non-small cell lung cancer (NSCLC) on January 1, 2016 to June 30, 2017 in our hospital were analyzed. The clinical and operative data were assessed, numeric rating scale (NRS) was used to evaluate the mean pain score on the 1th, 2th, 3th, 7th, 14th days, 3th months and 6th months postoperative.

RESULTS

Both groups were similar in clinical characteristics, there were no perioperative death in two groups. In the 1th, 2th, 7th, 14th days and 3th, 6th months postoperative, the NRS score of the single port group was superior, and the difference was significant compared with the triple port (P<0.05). There was no statistically significant difference between the two groups in operative time, blood loss, postoperative hospitalization time, duration of chest tube, the NRS scores in the 3 d (P>0.05). Univariate and multivariate analysis of the occurrence on the chronic pain showed that the operation time, surgical procedure and the 14th NRS score were risk factors for chronic pain (P<0.05).

CONCLUSIONS

The single port thoracoscopic surgery has an advantage in the incidence of acute and chronic pain in patients with non-small cell lung cancer. Shorter operative time can reduce the occurrence of chronic pain. The 14th day NRS score is a risk factor for chronic pain postoperative.

Erector spinae plane (ESP) block in the management of post thoracotomy pain syndrome: A case series

Background and aims

Post thoracotomy pain syndrome (PTPS) remains a common complication of thoracic surgery with significant impact on patients’ quality of life. Management usually involves a mul¬tidisciplinary approach that includes oral and topical analgesics, performing appropriate interventional techniques, and coordinating additional care such as physiotherapy, psychotherapy and rehabilitation. A variety of interventional procedures have been described to treat PTPS that is inadequately managed with systemic or topical analgesics. Most of these procedures are technically complex and are associated with risks and complications due to the proximity of the targets to neuraxial structures and pleura. The ultrasound-guided erector spinae plane (ESP) block is a novel technique for thoracic analgesia that promises to be a relatively simple and safe alternative to more complex and invasive techniques of neural blockade. We have explored the application of the ESP block in the management of PTPS and report our preliminary experience to illustrate its therapeutic potential.

Methods

The ESP block was performed in a pain clinic setting in a cohort of 7 patients with PTPS following thoracic surgery with lobectomy or pneumonectomy for lung cancer. The blocks were performed with ultrasound guidance by injecting 20–30mL of ropivacaine, with or without steroid, into a fascial plane between the deep surface of erector spinae muscle and the transverse processes of the thoracic vertebrae. This paraspinal tissue plane is distant from the pleura and the neuraxis, thus minimizing the risk of complications associated with injury to these structures. The patients were followed up by telephone one week after each block and reviewed in the clinic 4–6 weeks later to evaluate the analgesic response as well as the need for further injections and modification to the overall analgesic plan.

Results

All the patients had excellent immediate pain relief following each ESP block, and 4 out of the 7 patients experienced prolonged analgesic benefit lasting 2 weeks or more. The ESP blocks were combined with optimization of multimodal analgesia, resulting in significant improvement in the pain experience in all patients. No complications related to the blocks were seen.

Conclusion

The results observed in this case series indicate that the ESP block may be a valuable therapeutic option in the management of PTPS. Its immediate analgesic efficacy provides patients with temporary symptomatic relief while other aspects of chronic pain management are optimized, and it may also often confer prolonged analgesia.

Implications

The relative simplicity and safety of the ESP block offer advantages over other interventional procedures for thoracic pain; there are few contraindications, the risk of serious complications (apart from local anesthetic systemic toxicity) is minimal, and it can be performed in an outpatient clinicsetting. This, combined with the immediate and profound analgesia that follows the block, makes it an attractive option in the management of intractable chronic thoracic pain. The ESP block may also be applied to management of acute pain management following thoracotomy or thoracic trauma (e.g. rib fractures), with similar analgesic benefits expected. Further studies to validate our observations are warranted.

Ultrasound-Guided Interscalene Brachial Plexus Nerve Block With an Ultralow Volume of Local Anesthetic for Post-Thoracotomy Shoulder Girdle Pain

OBJECTIVES

To evaluate the efficacy of ultrasound-guided interscalene nerve block using an ultralow volume of local anesthetic (5 mL of ropivacaine, 0.75%) for the management of post-thoracotomy shoulder girdle pain.

DESIGN

Open-cohort, prospective, single-center study.

SETTING

University hospital.

INTERVENTIONS

Patients with post-thoracotomy shoulder girdle pain (visual analog scale [VAS] ≥5) received an ultrasound-guided interscalene nerve block.

MEASUREMENTS AND MAIN RESULTS

Thirty minutes after block implementation, the VAS was used to quantify pain across the shoulder girdle. The index (I) was calculated to indicate improvement of pain as follows: [Formula: see text] Nerve bocks resulting in I ≥75% were considered excellent. Total tramadol consumption 36 hours after nerve blocks, patients' satisfaction, and complications related to the procedure also were assessed. Patients were segregated in the following 2 groups: group A, which comprised patients with pain in the shoulder area (glenohumeral and acromioclavicular joints) (n = 30), and group B, which comprised patients with pain in the scapula (n = 17). I was significantly greater in group A (88.3% ± 14%) than in group B (43.2% ± 22%). In groups A and B, 90% and 11% of patients, respectively, demonstrated excellent pain control. Total tramadol consumption in group A, 25 (0-100) mg, was significantly less that of group B, 250 (150-500) mg. Patients' satisfaction also was significantly higher in group A compared with group B. No complications were recorded.

CONCLUSIONS

Ultrasound-guided interscalene nerve block can substantially alleviate post-thoracotomy pain in the shoulder but not in the scapular area.

Prevention of Chronic Post-Thoracotomy Pain in Rats By Intrathecal Resolvin D1 and D2: Effectiveness of Perioperative and Delayed Drug Delivery

Thoracotomy results in a high frequency of chronic postoperative pain. Resolvins are endogenous molecules, synthesized and released by activated immune cells, effective against inflammatory and neuropathic pain. Different resolvins have differential actions on selective neuronal and glial receptors and enzymes. This article examines the ability of intrathecal resolvin D1 and resolvin D2 to reduce chronic post-thoracotomy pain in rats. Thoracotomy, involving intercostal incision and rib retraction, resulted in a decrease in the mechanical force threshold to induce nocifensive behavior, an enlargement of the pain-sensitive area, and an increase in the fraction of rats showing nocifensive behavior, all for at least 5 weeks. The qualitative nature of the behavioral responses to tactile stimulation changed dramatically after thoracotomy, including the appearance of vigorous behaviors, such as turning, shuddering, and squealing, all absent in naive rats. Intrathecal delivery of resolvin D1 (30 ng/30 μL), at surgery or 4 days later, halved the spread of the mechanosensitive area, lowered by 60% the percent of rats with tactile hypersensitivity, and reduced the drop in threshold for a nocifensive response, along with a reduction in the occurrence of vigorous nocifensive responses. Resolvin D2's actions on threshold changes were statistically the same. These findings suggest that intrathecal resolvins, delivered preoperatively or several days later, can prevent chronic postoperative hyperalgesia.

PERSPECTIVE

In studies of rats, the injection of the proresolving compounds of the resolvin-D series into spinal fluid, before or just after thoracotomy surgery, prevents the occurrence of acute and chronic pain. If these chemicals, which have shown no side-effects, were used in humans it might greatly reduce chronic postoperative pain.

Acute Post Surgical Pain may result in chronic post surgical pain: A Systemic Review and Meta Analysis

Objective:

Chronic post surgical pain (CPSP) occurres frequently (from 10% to 50%) and has serious effects on the mood and activities of patients. This study was designed to evaluate the relationship between acute post surgical pain and chronic post surgical pain.

Methods:

Electronic search databases included PubMed, EMBASE, Cochrane database and web of science. 9-stars Newcastle-Ottawa Scale was used to evaluate the quality of included studies. The odds ratio was used as a summary statistic index. Heterogeneity was assessed with I².

Results:

We collected data from 4 case-control studies with or without chronic post surgical pain and compared those with patients who had acute post surgical pain or not. The age, sex was controlled as confounding factors. We collected 765 patients with chronic post surgical pain, of which 38.82% used to have acute post surgical pain. The risk ratio of patients with acute post surgical pain, as compared with no acute post surgical pain, was 3.10 for chronic post surgical pain (95% CI: 2.44, 3.96).

Conclusion:

Acute post surgical pain is a rick factor for chronic post surgical pain. We need to pay much attention to this phenomenon. However, more studies with high quality were still needed to confirm these findings.

Spontaneous Chronic Pain After Experimental Thoracotomy Revealed by Conditioned Place Preference: Morphine Differentiates Tactile Evoked Pain From Spontaneous Pain

Chronic pain after surgery limits social activity, interferes with work, and causes emotional suffering. A major component of such pain is reported as resting or spontaneous pain with no apparent external stimulus. Although experimental animal models can simulate the stimulus-evoked chronic pain that occurs after surgery, there have been no studies of spontaneous chronic pain in such models. Here the conditioned place preference (CPP) paradigm was used to reveal resting pain after experimental thoracotomy. Male Sprague Dawley rats received a thoracotomy with 1-hour rib retraction, resulting in evoked tactile hypersensitivity, previously shown to last for at least 9 weeks. Intraperitoneal injections of morphine (2.5 mg/kg) or gabapentin (40 mg/kg) gave equivalent 2- to 3-hour-long relief of tactile hypersensitivity when tested 12 to 14 days postoperatively. In separate experiments, single trial CPP was conducted 1 week before thoracotomy and then 12 days (gabapentin) or 14 days (morphine) after surgery, followed the next day by 1 conditioning session with morphine or gabapentin, both versus saline. The gabapentin-conditioned but not the morphine-conditioned rats showed a significant preference for the analgesia-paired chamber, despite the equivalent effect of the 2 agents in relieving tactile allodynia. These results show that experimental thoracotomy in rats causes spontaneous pain and that some analgesics, such as morphine, that reduce evoked pain do not also relieve resting pain, suggesting that pathophysiological mechanisms differ between these 2 aspects of long-term postoperative pain. Perspective: Spontaneous pain, a hallmark of chronic postoperative pain, is demonstrated here in a rat model of experimental postthoracotomy pain, further validating the use of this model for the development of analgesics to treat such symptoms. Although stimulus-evoked pain was sensitive to systemic morphine, spontaneous pain was not, suggesting different mechanistic underpinnings.

Effects of β2 agonists on post-thoracotomy pain incidence

BACKGROUND

Pre-clinical research has shown β2 -adrenoceptors to be essential for the antiallodynic action of antidepressant drugs in murine models of neuropathic pain and that sustained treatment with β2 -agonists has an antiallodynic action. Here, we clinically investigated whether chronic β2 -agonist treatments may influence the incidence of post-thoracotomy chronic pain, defined as pain that recurs or persists along a thoracotomy scar more than 2 months after surgery, either neuropathic or non-neuropathic.

METHODS

We conducted an epidemiological study on patients operated by thoracotomy. Demographic data, medical history and treatments concomitant to the surgery were recorded at a follow-up visit. Information on perioperative treatments was collected from the anaesthesia records and confirmed by the patients. In patients with pain at the surgery level, post-thoracotomy chronic pain was assessed by clinical examination and numeric scale. Physical examination and DN4 questionnaire were used to discriminate neuropathic and non-neuropathic chronic pain at scar level.

RESULTS

One hundred and eighty-nine patients were included. Eighty-one patients reported persisting thoracic pain, with neuropathic characteristics in 58 of them (30% of the 189 patients). The most common chronic drugs during the perioperative period were inhaled β2 -agonists (28.6%). The chronic use of β2 -agonists was an independent predictor of thoracic neuropathic pain (but not of non-neuropathic pain) and was associated with a five-fold decrease in the relative incidence of neuropathic pain [OR = 0.19 (0.06-0.45)].

CONCLUSIONS

These data suggest a possible influence of chronic β2 -agonist treatments on neuropathic pain secondary to thoracotomy. This apparent preventive effect of β2 -agonist treatments should warrant controlled clinical trials.

Managing post-thoracotomy pain: Epidural or systemic analgesia and extended care – A randomized study with an “as usual” control group

Background and aims

Thoracotomies can cause severe pain, which persists in 21–67% of patients. We investigated whether NSAID + intravenous patient-controlled analgesia (IV-PCA) with morphine is an efficacious alternative to thoracic epidural analgesia (TEA). We also wanted to find out whether an extended controlled pain management protocol within a clinical study can decrease the incidence of persistent post-thoracotomy pain.

Methods

Thirty thoracotomy patients were randomized into 3 intervention groups with 10 patients in each. G1: preoperative diclofenac 75mg orally+150 mg/24h IV for 44h, then PO; G2: valdecoxib 40mg orally+parecoxib 80mg/24h IV for 44h, then PO. IV-PCA morphine was available in groups 1 and 2 during pleural drainage, and an intercostal nerve block at the end of surgery was performed; G3: parac-etamol+patient controlled epidural analgesia (PCEA) with a background infusion of bupivacaine with fentanyl. After PCA/PCEA oxycodone PO was provided when needed. These patients were contacted one week, 3 and 6 months after discharge. Patients (N = 111) not involved in the study were treated according to hospital practice and served as a control group. The control patients’ data from the perioperative period were extracted, and a prospective follow-up questionnaire at 6 months after surgery similar to the intervention group was mailed.

Results

The intended sample size was not reached in the intervention group because of the global withdrawal of valdecoxib, and the study was terminated prematurely. At 6 months 3% of the intervention patients and 24%ofthe control patients reported persistent pain (p<0.01). Diclofenac and valdecoxib provided similar analgesia, and in the combined NSAID group (diclofenac+valdecoxib) movement-related pain was milder in the PCEA group compared with the NSAID group. The duration of pain after coughing was shorter in the PCEA group compared with the NSAID+IV-PCA group. The only patient with persistent painat6 months postoperatively had a considerably longer duration ofpain after coughing than the other Study patients. The patients with mechanical hyperalgesia had more pain on movement.

Conclusions

Both PCEA and NSAID+IV-PCA morphine provided sufficient analgesia with little persistent pain compared with the incidence of persistent pain in the control group. High quality acute pain management and follow-up continuing after discharge could be more important than the analgesic method per se in preventing persistent post-thoracotomy pain. In the acute phase the measurement of pain when coughing and the duration of pain after coughing could be easy measures to recognize patients having a higher risk for persistent post-thoracotomy pain.

Implications

To prevent persistent post-thoracotomy pain, the extended protocol for high quality pain management in hospital covering also the sub-acute phase at home, is important. This study also provides some evidence that safe and effective alternatives to thoracic epidural analgesia do exist. The idea to include the standard “as usual” care patients as a control group and to compare them with the intervention patients provides valuable information of the added value of being a study patient, and deserves further consideration in future studies.

Incidence and severity of chronic pain at 3 and 6 months after thoracotomy: meta-analysis

This systematic review was performed to determine the incidence and the severity of chronic pain at 3 and 6 months after thoracotomy based on meta-analyses. We conducted MEDLINE, Web of Science, and Google Scholar searches of databases and references for English articles; 858 articles were reviewed. Meta-regression analysis based on the publication year was used to examine if the chronic pain rates changed over time. Event rates and confidence intervals with random effect models and Freeman-Tukey double arcsine variance-stabilizing transformation were obtained separately for the incidence of chronic pain based on 1,439 patients from 17 studies at 3 months and 1,354 patients from 15 studies at 6 months. The incidences of chronic pain at 3 and 6 months after thoracotomy were 57% (95% confidence interval [CI], 51-64%) and 47% (95% CI, 39-56%), respectively. The average severity of pain ratings on a 0 to 100 scale at these times were 30 ± 2 (95% CI, 26-35) and 32 ± 7 (95% CI, 17-46), respectively. Reported chronic pain rates have been largely stable at both 3 and 6 months from the 1990s to the present.

PERSPECTIVE

This systematic review's findings suggest that reported chronic pain rates are approximately 50% at 3 and 6 months and have been largely stable from the 1990s to the present. The severity of this pain is not consistently reported. Chronic pain after thoracotomy continues to be a significant problem despite advancing perioperative care.

Persistent postsurgical pain

PURPOSE OF REVIEW

Persistent postsurgical pain (PPP) is an important cause of pain morbidity following surgery for almost any cause, but there is a greater evidence base for pain after cancer surgery. Historically, both patients and practitioners have struggled to recognize and accept this growing problem. This review will seek to highlight the awareness of this increasing epidemic and will discuss evidence base for diagnosis, risk factors and current strategies for prevention and treatment, especially after cancer surgery.

RECENT FINDINGS

Given the potential size of the problems of PPP, there is a relative paucity of recent data, especially as regards effective treatments. The review will synthesize current and existing evidence to give a balanced up-to-date view. There is a clear need for more high-quality randomized trials.

SUMMARY

An estimated 40,000 patients in the UK will develop PPP, of whom at least 5-10% will have severe pain. Lack of clear definition and lack of awareness have been barriers to diagnosis and access to treatment. Several risk factors associated with PPP have been identified and reduction of these factors may prevent its development. At present, there are large gaps in the evidence base and more large controlled trials are warranted.

Preoperatıve ultrasound-guıded suprascapular nerve block for postthoracotomy shoulder paın

BACKGROUND

Acute postthoracotomy pain is a well-known potential problem, with pulmonary complications, ineffective respiratory rehabilitation, and delayed mobilization in the initial postoperative period, and it is followed by chronic pain. The type of thoracotomy, intercostal nerve damage, muscle retraction, costal fractures, pleural irritation, and incision scar are the most responsible mechanisms.

OBJECTIVE

Our aim was to assess whether preoperative ultrasound suprascapular nerve block with thoracic epidural analgesia was effective for postthoracotomy shoulder pain relief.

METHODS

Thirty-six American Society of Anesthesiologist classification physical status I-III patients (2011-2012), with a diagnosis of lung cancer and scheduled for elective open-lung surgery, were prospectively included in the study. Eighteen of the patients received an ultrasound-guided suprascapular nerve block with 10-mL 0.5% levobupivacaine, using a 22-gauge spinal needle, 1 hour before operation (group S); 18 other patients had thoracic epidural analgesia only, and no nerve block was performed. Standard general anesthesia was administered. Degree of shoulder pain was assessed by a blinded observer when discharging patients from the recovery room, and thereafter at 1, 3, 6, 12, 24, 36, 48, and 72 hours on infusion at rest and 12, 24, 36, 48, and 72 hours on coughing. The same blinded observer also recorded the total amount of epidural levobupivacaine and fentanyl used by the 2 groups.

RESULTS

In the suprascapular block group, the total amount of levobupivacaine (P = 0.0001) and fentanyl (P = 0.005) used postoperatively was statistically lower than in the epidural group. Visual analogue scale measurements in the suprascapular group were statistically significantly lower at 0, 1, 3, 6, 12, 24, 36, and 48 hours than those in the epidural group, both at rest and coughing.

CONCLUSION

Postthoracotomy shoulder pain reduces patient function and postsurgical rehabilitation potential after thoracotomy, and various studies on explaining the etiology and management of postthoracotomy shoulder pain have been conducted. Theories of the etiology involved either musculoskeletal origin or referred pain. In this study, we concluded that preoperative ultrasound-guided suprascapular nerve block with thoracic epidural analgesia could achieve effective shoulder pain relief for 72 hours postoperatively, both at rest and coughing.

The Qualitative Hyperalgesia Profile: A New Metric to Assess Chronic Post-Thoracotomy Pain

Thoracotomy often results in chronic pain, characterized by resting pain and elevated mechano-sensitivity. This paper defines complex behavioral responses to tactile stimulation in rats after thoracotomy, shown to be reversibly relieved by systemic morphine, in order to develop a novel qualitative "pain" score. A deep incision and 1 hour of rib retraction in male Sprague-Dawley rats resulted in reduced threshold and a change in the locus of greatest tactile (von Frey filament) sensitivity, from the lower back to a more rostral location around the wound site, and extending bilaterally. The fraction of rats showing nocifensive responses to mild stimulation (10 gm) increased after thoracotomy (from a pre-operative value of 0/10 to 8/10 at 10 days post-op), and the average threshold decreased correspondingly, from 15 gm to ∼4 gm. The nature of the nocifensive responses to tactile stimulation, composed pre-operatively only of no response (Grade 0) or brief contractions of the local subcutaneous muscles (Grade I), changed markedly after thoracotomy, with the appearance of new behaviors including a brisk lateral "escape" movement and/or a 180° rotation of the trunk (both included as Grade II), and whole body shuddering, and scratching and squealing (Grade III). Systemic morphine (2.5 mg/kg, i.p.) transiently raised the threshold for response and reduced the frequency of Grade II and III responses, supporting the interpretation that these represent pain. The findings support the development of a Qualitative Hyperalgesic Profile to assess the complex behavior that indicates a central integration of hyperalgesia.

Natural variation in the μ-opioid gene OPRM1 predicts increased pain on third day after thoracotomy

OBJECTIVES

The mechanism whereby acute postsurgical pain can persist and become chronic remains unknown. Thoracotomy is a common procedure with a high incidence of long-term pain for which acute postsurgical pain is an established risk factor. Therefore, the genetic basis of elevations in acute postsurgical pain after thoracotomy was investigated.

METHODS

A cohort of thoracotomy patients participating in an ongoing trial of outcomes after cancer were enrolled. A standard combined general and epidural anesthetic and surgical approach were used. All patients received a standardized postoperative epidural analgesia regimen. Postoperatively, pain scores were determined and blood was collected for genotyping. Our a priori hypothesis was that variability of genes involved in nociception and analgesic therapy would predict pain score ≥3 of 10 on the third postoperative day.

RESULTS

Ninety patients with pain and genotyping data on postoperative day 3 were examined. We found no association between markers in COMT, COX1, COX2, and TRPV1 and postoperative pain. We demonstrated several statistically significant associations with 4 single nucleotide polymorphism markers in OPRM1 (odds ratio, 95% confidence intervals): rs634479 (0.4, 0.17, 0.97), rs499796 (0.35, 0.13, 0.92), rs548646 (0.47, 0.23, 0.97), and rs679987 (0.1, 0.01, 0.84). From these, we inferred 2 haplotype blocks in OPRM1 where both had a frequency of 9% and P=0.03 and 0.04. Previously published functional single nucleotide polymorphisms in OPRM1 and COMT were not associated with increased pain on the third postoperative day.

DISCUSSION

We identified previously unpublished haplotypes of the OPRM1 receptor that predicted increases in self-reported pain on the third postoperative day after thoracotomy. These findings require replication and further refinement before their impact on patient care can be determined.

Chronic postsurgical pain: still a neglected topic?

Background

Surgical injury can frequently lead to chronic pain. Despite the obvious importance of this problem, the first publications on chronic pain after surgery as a general topic appeared only a decade ago. This study tests the hypothesis that chronic postsurgical pain was, and still is, represented insufficiently.

Methods

We analyzed the presentation of this topic in journal articles covered by PubMed and in surgical textbooks. The following signs of insufficient representation in journal articles were used: (1) the lack of journal editorials on chronic pain after surgery, (2) the lack of journal articles with titles clearly indicating that they are devoted to chronic postsurgical pain, and (3) the insufficient representation of chronic postsurgical pain in the top surgical journals.

Results

It was demonstrated that insufficient representation of this topic existed in 1981–2000, especially in surgical journals and textbooks. Interest in this topic began to increase, however, mostly regarding one specific surgery: herniorrhaphy. It is important that the change in the attitude toward chronic postsurgical pain spreads to other groups of surgeries.

Conclusion

Chronic postsurgical pain is still a neglected topic, except for pain after herniorrhaphy. The change in the attitude toward chronic postsurgical pain is the important first step in the approach to this problem.

Local anaesthetics and regional anaesthesia for preventing chronic pain after surgery

BACKGROUND

Regional anaesthesia may reduce the rate of persistent (chronic) pain after surgery, a frequent and debilitating condition.

OBJECTIVES

To compare local anaesthetics and regional anaesthesia versus conventional analgesia for the prevention of persistent pain six or 12 months after surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 4), PubMed (1966 to April 2012), EMBASE (1966 to May 2012) and CINAHL (1966 to May 2012) without any language restriction. We used a combination of free text search and controlled vocabulary search. The results were limited to randomized controlled clinical trials (RCTs). We conducted a handsearch in reference lists of included trials, review articles and conference abstracts.

SELECTION CRITERIA

We included RCTs comparing local anaesthetics or regional anaesthesia versus conventional analgesia with a pain outcome at six or 12 months after surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data, including information on adverse events. We contacted study authors for additional information. Results are presented as pooled odds ratios (OR) with 95% confidence intervals (CI), based on random-effects models (inverse variance method). We grouped studies according to surgical interventions. We employed the Chi(2) test and calculated the I(2) statistic to investigate study heterogeneity.

MAIN RESULTS

We identified 23 RCTs studying local anaesthetics or regional anaesthesia for the prevention of persistent (chronic) pain after surgery. Data from a total of 1090 patients with outcomes at six months and of 441 patients with outcomes at 12 months were presented. No study included children. We pooled data from 250 participants after thoracotomy, with outcomes at six months. Data favoured regional anaesthesia for the prevention of chronic pain at six months after thoracotomy with an OR of 0.33 (95% CI 0.20 to 0.56). We pooled two studies on paravertebral block for breast cancer surgery; the pooled data of 89 participants with outcomes at five to six months favoured paravertebral block with an OR of 0.37 (95% CI 0.14 to 0.94).The methodological quality of the included studies was intermediate. Adverse effects were not studied systematically and were reported sparsely. Clinical heterogeneity, attrition and sparse outcome data hampered the assessment of effects, especially at 12 months.

AUTHORS' CONCLUSIONS

Epidural anaesthesia may reduce the risk of developing chronic pain after thoracotomy in about one patient out of every four patients treated. Paravertebral block may reduce the risk of chronic pain after breast cancer surgery in about one out of every five women treated. Our conclusions are significantly weakened by performance bias, shortcomings in allocation concealment, considerable attrition and incomplete outcome data. We caution that our evidence synthesis is based on only a few, small studies. More studies with high methodological quality, addressing various types of surgery and different age groups, including children, are needed.

Chronic preoperative pain and psychological robustness predict acute postoperative pain outcomes after surgery for breast cancer

BACKGROUND

Few epidemiological studies have prospectively investigated preoperative and surgical risk factors for acute postoperative pain after surgery for breast cancer. We investigated demographic, psychological, pain-related and surgical risk factors in women undergoing resectional surgery for breast cancer.

METHODS

Primary outcomes were pain severity, at rest (PAR) and movement-evoked pain (MEP), in the first postoperative week.

RESULTS

In 338 women undergoing surgery, those with chronic preoperative pain were three times more likely to report moderate to severe MEP after breast cancer surgery (OR 3.18, 95% CI 1.45-6.99). Increased psychological 'robustness', a composite variable representing positive affect and dispositional optimism, was associated with lower intensity acute postoperative PAR (OR 0.63, 95% CI 0.48-0.82) and MEP (OR 0.71, 95% CI 0.54-0.93). Sentinel lymph node biopsy (SLNB) and intraoperative nerve division were associated with reduced postoperative pain. No relationship was found between preoperative neuropathic pain and acute pain outcomes; altered sensations and numbness postoperatively were more common after axillary sample or clearance compared with SLNB.

CONCLUSION

Chronic preoperative pain, axillary surgery and psychological robustness significantly predicted acute pain outcomes after surgery for breast cancer. Preoperative identification and targeted intervention of subgroups at risk could enhance the recovery trajectory in cancer survivors.

Mild, moderate, and severe pain in patients recovering from major abdominal surgery

Pain interferes with various activities, such as coughing, deep breathing, and ambulation, designed to promote recovery and prevent complications after surgery. Determining appropriate cutpoints for mild, moderate, and severe pain is important, because specific interventions may be based on this classification. The purpose of this research was to determine optimal cutpoints for postoperative patients based on their worst and average pain during hospitalization and after discharge to home, and whether the optimal cutpoints distinguished patients with mild, moderate, or severe pain regarding patient outcomes. This secondary analysis consisted of 192 postoperative patients aged ≥60 years. Multivariate analyses of variance were used to stratify the sample into mild, moderate, and severe pain groups using eight cutpoint models for worst and average pain in the last 24 hours. One-way analyses of variance were conducted to determine whether patients experiencing mild, moderate, or severe pain were different in outcome. Optimal cutpoints were similar to those previously reported, with the boundary between mild and moderate pain ranging from 3 to 4 and the boundary between moderate and severe pain ranging from 5 to 7. Worst pain cutpoints were most useful in distinguishing patients regarding fatigue, depression, pain's interference with function, and morphine equivalent administered in the previous 24 hours. A substantial proportion of patients experienced moderate to severe pain. The results suggest a narrow boundary between mild and severe pain that interferes with function. The findings indicate that clinicians should seek to aggressively manage postoperative pain ratings greater than 3.

The development of an electronic database for Acute Pain Service outcomes

BACKGROUND

Quality assurance is increasingly important in the current health care climate. An electronic database can be used for tracking patient information and as a research tool to provide quality assurance for patient care.

OBJECTIVE

An electronic database was developed for the Acute Pain Service, University of Alberta Hospital (Edmonton, Alberta) to record patient characteristics, identify at-risk populations, compare treatment efficacies and guide practice decisions.

METHOD

Steps in the database development involved identifying the goals for use, relevant variables to include, and a plan for data collection, entry and analysis. Protocols were also created for data cleaning quality control. The database was evaluated with a pilot test using existing data to assess data collection burden, accuracy and functionality of the database. 

RESULTS

A literature review resulted in an evidence-based list of demographic, clinical and pain management outcome variables to include. Time to assess patients and collect the data was 20 min to 30 min per patient. Limitations were primarily software related, although initial data collection completion was only 65% and accuracy of data entry was 96%.

CONCLUSIONS

The electronic database was found to be relevant and functional for the identified goals of data storage and research.

The Transition from Acute to Chronic Post Surgical Pain

All chronic pain was once acute, but not all acute pain becomes chronic. The transition of acute postoperative pain to chronic post surgical pain is a complex and poorly understood developmental process. The manuscript describes the various factors associated with the transition from acute to chronic pain. The preoperative, intraoperative and postoperative surgical, psychosocial, socio-environmental and patient-related factors and the mechanisms involved are discussed and preventive (or limitation) strategies are suggested. In future, the increasing understanding of genetic factors and the transitional mechanisms involved may reveal important clues to predict which patients will go on to develop chronic pain. This may assist the development of appropriate interventions affecting not only the individual concerned, but also ultimately the community at large.

Consequences of persistent pain after lung cancer surgery: a nationwide questionnaire study

BACKGROUND

post-thoracotomy pain syndrome (PTPS) and its social consequences have been inconsistently investigated as most studies were either small sized, focused on a limited number of risk factors or included heterogeneous surgical procedures. The current objectives were to obtain detailed information on the consequences of PTPS after thoracotomy and video-assisted thoracic surgery (VATS) from homogenous unselected nationwide data, and to suggest mechanisms for the development of PTPS.

METHODS

data from 1327 patients were collected using a prospective national database and combined with a detailed questionnaire.

RESULTS

the response rate was 81.5%, resulting in 546 patients without prior thoracic surgery for the final analysis. Follow-up was 22 months (range 12-36). PTPS occurred in 33% thoracotomy patients and 25% VATS patients. Clinically relevant pain was present in 11-18% of the patients and severe pain in 4-12% depending on the level of physical activity. In PTPS patients, 64% also had pain from other locations on the body. Perceived sensory changes in the thoracic area were present in 63% of PTPS patients vs. 25% in pain-free patients (P<0.001). When comparing VATS with thoracotomy, no consistent differences in the prevalence, distribution of pain, sensory changes or effect of pain on daily activities were observed although clinically relevant and severe pain was reduced after VATS.

CONCLUSIONS

this nationwide study corroborates that PTPS is a clinically relevant problem influencing daily activities a long time after thoracotomy and VATS. Nerve injury and increased pain responsiveness may explain the majority of symptoms, the prevalence and distribution of pain including perceived sensory sensations.