Morphological and functional brain changes in chronic cancer-related pain: A systematic review

The purpose of this study was to perform a systematic review of the available literature on morphological and functional brain changes measured by modern neuroimaging techniques in patients suffering from chronic cancer-related pain. A systematic search was conducted in PubMed, Embase, and Web of Science using different keyword combinations. In addition, a hand search was performed on the reference lists and several databases to retrieve supplementary primary studies. Eligible articles were assessed for methodological quality and risk of bias and reviewed by two independent researchers. The search yielded only four studies, three of which used MRI and one PET-CT. None of the studies measured longitudinal morphological (i.e., gray or white matter) changes. All studies investigated functional brain changes and found differences in specific brain regions and networks between patients with chronic cancer-related pain and pain-free cancer patients or healthy volunteers. Some of these alterations were found in brain networks that also show changes in non-cancer populations with chronic pain (e.g., the default mode network and salience network). However, specific findings were inconsistent, and there was substantial variation in imaging methodology, analysis, sample size, and study quality. There is a striking lack of research on morphological brain changes in patients with chronic cancer-related pain. Moreover, only a few studies investigated functional brain changes. In the retrieved studies, there is some evidence that alterations occur in brain networks also involved in other chronic non-cancer pain syndromes. However, the low sample sizes of the studies, finding inconsistencies, and methodological heterogeneity do not allow for robust conclusions.

Postoperative Symptom Burden in Patients Undergoing Lung Cancer Surgery

CONTEXT

Previous studies on quality of life (QOL) after lung cancer surgery have identified a long duration of symptoms postoperatively. We first performed a systematic review of QOL in patients undergoing surgery for lung cancer. A subgroup analysis was conducted focusing on symptom burden and its relationship with QOL.

OBJECTIVE

To perform a qualitative review of articles addressing symptom burden in patients undergoing surgical resection for lung cancer.

METHODS

The parent systematic review utilized search terms for symptoms, functional status, and well-being as well as instruments commonly used to evaluate global QOL and symptom experiences after lung cancer surgery. The articles examining symptom burden (n = 54) were analyzed through thematic analysis of their findings and graded according to the Oxford Centre for Evidence-based Medicine rating scale.

RESULTS

The publication rate of studies assessing symptom burden in patients undergoing surgery for lung cancer have increased over time. The level of evidence quality was 2 or 3 for 14 articles (cohort study or case control) and level of 4 in the remaining 40 articles (case series). The most common QOL instruments used were the Short Form 36 and 12, the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire, and the Hospital Anxiety and Depression Score. Thematic analysis revealed several key findings: 1) lung cancer surgery patients have a high symptom burden both before and after surgery; 2) pain, dyspnea, cough, fatigue, depression, and anxiety are the most commonly studied symptoms; 3) the presence of symptoms prior to surgery is an important risk factor for higher acuity of symptoms and persistence after surgery; and 4) symptom burden is a predictor of postoperative QOL.

CONCLUSION

Lung cancer patients undergoing surgery carry a high symptom burden which impacts their QOL. Measurement approaches use myriad and heterogenous instruments. More research is needed to standardize symptom burden measurement and management, with the goal to improve patient experience and overall outcomes.

Comparison of Chronic Postsurgical Pain Between Single-Port and Multi-Port Video-Assisted Thoracoscopic Pulmonary Resection: A Prospective Study

Background  Little is known about the prevalence of chronic postsurgical pain (CPSP) among patients receiving single-port video-assisted thoracic surgery (SP-VATS) compared with those undergoing multi-port VATS (MP-VATS). This study aimed to compare the incidence of CPSP between SP-VATS and MP-VATS lung resection and assess how the pain affected the daily living activities of this patient population.

Methods  We prospectively collected data regarding the demographic features, clinical factors during surgery, the intensity of acute postoperative pain, and complications after surgery among patients receiving elective SP-VATS or MP-VATS lung resection at our institution between June 2015 and August 2018. At 3-, 6-, and 12-months following surgery, the patients were followed up through a telephonic interview. The Brief Pain Inventory-Short Form was adopted to assess the incidence, severity and location of the CPSP, analgesic consumption, as well as the interference of pain with daily activities.

Results  In total, 476 patients were screened for eligibility, 411 patients were followed up for 12 months and included in final analysis. Among these, 190 patients had undergone an SP-VATS pulmonary resection and 221 had an MP-VATS pulmonary resection. At both 3 and 6 months, the incidence of CPSP in the SP-VATS group was lower than that in the MP-VATS group (25.3 vs. 38.0%, p  = 0.006; 11.1 vs. 19.0%, p  = 0.026, respectively). At 12 months after surgery, the prevalence of CPSP was comparable between groups (4.7 vs, 9.0%, p  = 0.089). In addition, the SP-VATS technique alleviated pain interference with the daily living activities of patients with CPSP in several domains, including sleep, mood, and enjoyment of life compared with the MP-VATS technique. The two predictive factors for CPSP at postoperative 3 months were the MP-VATS technique (odds ratio [OR] = 1.792, p  = 0.019) and postoperative chemotherapy (OR = 1.718, p  = 0.033).

Conclusions  This study indicated that the SP-VATS technique reduced the prevalence of CPSP at 3- and 6-months post-pulmonary resection compared with the MP-VATS technique. The SP-VATS technique also significantly alleviated pain interference with the daily living activities of the patients.

Bony Decompression of a Chronically Painful Intercostal Nerve Yields Immediate and Long-Lasting Pain Relief: A Case Report

CASE

The case of an active 16-year-old adolescent girl who presented with rib malunion and 1 year of unremitting intercostal nerve pain after sustaining multiple rib fractures is presented. She underwent successful bony and soft-tissue decompression of her eighth and ninth intercostal nerves to relieve neurogenic symptoms.

CONCLUSION

When conservative treatment fails, chronic intercostal nerve pain due to chest wall trauma may be effectively managed with surgical bony decompression of the offending intercostal bundle(s). Anatomic knowledge of the intercostal nerve and a critical history and physical examination were critical for accurate diagnosis and surgical decompression of the patient's intercostal nerve.

Risk factors for persistent pain after breast and thoracic surgeries: a systematic literature review and meta-analysis

ABSTRACT

Persistent postsurgical pain (PPSP) is common after breast and thoracic surgeries. Understanding which risk factors consistently contribute to PPSP will allow clinicians to apply preventive strategies, as they emerge, to high-risk patients. The objective of this work was to systematically review and meta-analyze the literature on risk factors of PPSP after breast and thoracic surgeries. A systematic literature search using Ovid Medline, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO, and Scopus databases was conducted. Study screening with inclusion and exclusion criteria, data extraction, and risk of bias assessment was performed independently by 2 authors. The data for each surgical group were analyzed separately and meta-analyzed where possible. The literature search yielded 5584 articles, and data from 126 breast surgery and 143 thoracic surgery articles were considered for meta-analysis. In breast surgery, younger age, higher body mass index, anxiety, depression, diabetes, smoking, preoperative pain, moderate to severe acute postoperative pain, reoperation, radiotherapy, and axillary lymph node dissection were the main factors associated with higher risk of PPSP. In thoracic surgery, younger age, female sex, hypertension, preoperative pain, moderate to severe acute postoperative pain, surgical approach, major procedure, and wound complications were associated with PPSP. This systematic review demonstrated certain consistent risk factors of PPSP after breast and thoracic surgeries, as well as identified research gaps. Understanding the factors that increase susceptibility to PPSP can help selectively allocate resources to optimize perioperative care in high-risk patients and help develop targeted, risk-stratified interventions for PPSP prevention.

Persistent and acute postoperative pain after cardiac surgery with anterolateral thoracotomy or median sternotomy: A prospective observational study

OBJECTIVE

The primary objective of this study was to compare the association between cardiac surgical approach (thoracotomy vs. sternotomy) and incidence of persistent postoperative pain at 3 months. Secondary objectives were the incidence and intensity of persistent pain at 6 and 12 months, acute postoperative pain, analgesic requirement and its side effects.

DESIGN

Single-center, prospective, observational study. Recruitment between December 2017 and August 2018.

SETTING

Perioperative care at university-affiliated tertiary care centre.

PATIENTS

202 adults scheduled for cardiac surgery. Patients with chronic pain or behavioural disorder were excluded.

INTERVENTIONS

Thoracotomy (n = 106) and sternotomy (n = 96).

MEASUREMENTS

Pain scores and pain medication requirements from extubation until hospital discharge. Persistent postoperative pain was assessed using a telephone questionnaire.

MAIN RESULTS

Incidence and intensity of pain was not significantly different between thoracotomy or sternotomy either in the short- or in the long-term follow-up. Incidence of persistent postoperative pain showed no differences between groups (30.2 vs 22.9% at 3 months (p = 0.297), 10.4 vs 7.3% at 6 months (p = 0.364) and 7.5 vs 7.3% at 12 months (p = 0.518) in thoracotomy and sternotomy group). A significant decrease of pain incidence was observed between 3 and 6 months (p < 0.001) but not between 6 and 12 months (p = 0.259) in both groups. ANOVA of repeated measures adjusted for confounding variable showed a decrease of acute pain intensity over time (p = 0.001) with no difference between groups (p = 0.145). Acute pain medication requirements were not different between the groups (p = 0.237 for piritramide and p = 0.743 for oxycodone) with no difference in their side effects.

CONCLUSIONS

Our study showed no difference in short- or long-term pain in patients undergoing anterolateral thoracotomy or median sternotomy. Both groups showed a decrease in persistent postoperative pain incidence between 3 and 6 months without any significant changes at 12 months.

Acupuncture against chronic postsurgical pain in non-small cell lung cancer patients: A protocol of randomized controlled trial

INTRODUCTION

Video-assisted thoracoscopic lobectomy is the prior recommended treatment for non-small cell lung cancer (NSCLC), with the advantages of small trauma, less postoperative pain, and quick recovery. However, a large number of patients may suffer chronic postsurgical pain (CPSP), which makes the patients unwilling to practice pulmonary exercises, and it would directly affect patient's cough, sputum expectoration, and mobility. Opioids could greatly improve the quality of postoperative analgesia and the quality of life after surgery, but it is accompanied with obvious side effects. A number of clinical studies have proved that acupuncture could improve postoperative pain and reduce opioid use. In this study, we try to conduct a randomized controlled study to evaluate the efficacy and safety of plum-blossom needle acupuncture combined with Tramadol in improving CPSP after lobectomy in NSCLC patients.

METHODS

Patients will be randomly divided into treatment group (acupuncture plus Tramadol) and control group (sham acupuncture plus Tramadol) with a random number table in 1:1 ratio. The patients, outcome assessor, and statistician will be blinded. The outcomes are changes of numerical rating scale, Karnofsky performance score, brief pain inventory, blood routine, liver and kidney function. The data will be analyzed by SPSS 22.0.

CONCLUSIONS

The results will help to evaluate the efficacy and safety of plum-blossom needle acupuncture in improving CPSP after lobectomy in NSCLC patients.

Effects of Polymorphisms in the Serotonin Transporter Promoter-Linked Polymorphic Region on Postthoracotomy Pain Severity

Purpose

Serotonin (5-HT) is highly associated with pain modulation. The human 5-HT transporter (5-HTT) gene (SLC6A4) features several polymorphisms in its promoter region (5-HTTLPR) that affect the 5-HTT expression. The S allele of 5-HTTLPR induces low 5-HT tone, and it may influence the modulation of chronic pain. Meanwhile, pain occurs in 40–50% of patients after thoracic surgery, and its mechanism remains under investigation. This study assessed the role of 5-HTTLPR polymorphisms in postthoracotomy pain severity.

Patients and Methods

A total of 178 patients undergoing pneumonectomy were enrolled. The genotypes of 5-HTTLPR were divided into two groups: S/S group and S/L or L/L group. Linear mixed-effects models were used to assess the association between 5-HTTLPR genotypes and the numerical rating scale (NRS) score change over time.

Results

Among the participants, data were obtained for 162 patients. The genotype distribution was as follows: S/S, 67.3%; S/L or L/L, 32.7%. No significant difference in patient characteristics was found between the genotype groups. There was no significant interaction between the 5-HTTLPR genotypes and the NRS score change over time (p = 0.842).

Conclusion

Polymorphisms in 5-HTTLPR were not associated with postthoracotomy pain severity.

Trajectories of Pain in Patients Undergoing Lung Cancer Surgery: A Longitudinal Prospective Study

CONTEXT

Lung cancer surgery is among the surgical procedures associated with the highest prevalence of pain, but prospective longitudinal studies after the pain trajectory are scarce.

OBJECTIVES

We aimed to describe the pain trajectory in patients undergoing surgery for primary lung cancer and investigate whether distinct groups of patients could be identified based on different pain trajectories.

METHODS

Patients (n = 264; 95% thoracotomies) provided data on the average and worst pain intensity, pain location, and comorbidities before, and at one month and five, nine, and 12 months after surgery. Pain profiles were analyzed by latent class mixed models.

RESULTS

The occurrence of any pain increased from 40% before surgery to 69% after one month and decreased to 56%, 57%, and 55% at five, nine, and 12 months, respectively. Latent class mixed models identified two classes both for average and worst pain; one class started low with high ratings after one month, then returning to a level slightly higher than baseline. The other class started higher with similar scores through the trajectory. Patients reporting no pain (8%) were placed in a separate class. Higher comorbidity score, preoperative use of both pain and psychotropic medicine characterized the class with overall highest pain for average and/or worst pain.

CONCLUSION

Pain was highly prevalent after surgery, and subgroups could be identified based on different pain trajectories. Patients reported both postoperative pain and pain from chronic conditions. Knowledge about vulnerable patients and risk factors for pain is important to tailor interventions and information about pain.

High Frequency, Low Background Rate Extrapleural Programmed Intermittent Bolus Ropivacaine Provides Superior Analgesia Compared with Continuous Infusion for Acute Pain Management Following Thoracic Surgery: A Retrospective Cohort Study

Background

Thoracic surgery often results in severe postoperative pain. Regional analgesia via surgically placed extrapleural local anaesthetic (LA) and continuous infusion (CI) is an effective technique, however usually requires supplemental opioid to achieve satisfactory patient analgesia. We hypothesized that high frequency, low background rate extrapleural programmed intermittent boluses (PIB) of LA by could achieve superior patient analgesia and reduced oral morphine equivalent daily dosage (OMEDD) requirements for up to 3 days after thoracic surgery vs. CI.

Methods

We retrospectively analysed data from 84 adult patients receiving extrapleural analgesia after thoracic surgery in a single tertiary teaching hospital. The primary outcome measure was the effect of PIB vs. CI on maximum daily 11-point numerical rating scale (NRS-11) ratings as determined by multivariate linear regression analysis, corrected for OMEDD use, total daily LA dose, surgery type, age, opioid type, and use of ketamine analgesia. Secondary outcome measures were the effect on OMEDD use, the effect of total ‘rescue’ LA boluses, and univariate analyses of the above outcomes and variables.

Results

PIB on day 0, and a higher proportion of LA given as rescue boluses on day 1 were associated with reduced maximum NRS-11 ratings [standardized/ [unstandardized] beta coefficient -0.34/ [-0.92 NRS-11 if PIB] (P = 0.007); and -0.26/ [-0.029 NRS-11 per mg/kg extrapleural ropivacaine] (P = 0.03)], respectively. Only patient age was associated with reduced OMEDD use [day 0: -0.58/ [-4.4 OMEDDs per year of age] (P ≤ 0.005); day 1: -0.49/ [-3.56 OMEDDs per year of age] (P ≤ 0.005); day 2: -0.32/ [-1.9 OMEDDs per year of age] (P = 0.04)]. OMEDD use on day 2, however, was associated with slightly higher maximum NRS-11 ratings [+0.28/ +0.006 NRS-11 per mg OMEDD (P = 0.036)]. On univariate analysis, PIB patients achieved the largest difference in OMEDD use [-98 mg (95% CI -73 to -123 mg)] and NRS-11 ratings [-1.1 (-0.4 to -1.8)] against CI patients on day 3.

Conclusions

Use of high frequency, low background rate PIB extrapleural LA after thoracic surgery appears to have a modest beneficial effect on acute pain, but not OMEDD use, over CI when adjusted for patient, surgical and other analgesic factors after thoracic surgery. Further work is required to elucidate the potential magnitude of effect that extrapleural LA given by PIB over CI can achieve.

Chronic pain after bilateral thoracotomy in lung transplant patients

Background and aims

The relative contribution of patient-related factors and intraoperative nerve damage for the development of chronic pain after surgery is unclear. This study aimed to examine chronic pain after bilateral thoracotomy. We hypothesized, that individual patient-related risk factors would be important resulting in an intraindividual uniformity of pain and hyperphenomena between the two sides of the thorax.

Methods

Twenty patients who had undergone lung transplantation via bilateral thoracotomy 6–12 months previously were included from the Danish Lung Transplant program, Rigshospitalet, Denmark, from October 2016 to August 2017. All patients answered questionnaires about pain in and around the scar, completed the Neuropathic Pain Symptom Inventory, and underwent bedside examination for hyperphenomena (brush- and cold-evoked allodynia, pinprick hyperalgesia) and pinprick hypoalgesia.

Results

Nine patients reported spontaneous pain bilaterally, five patients had pain on one side only, and six patients had no pain. Hyperphenomena were present on both sides of the thorax in 13 patients, on one side in four patients, and three patients had no hyperphenomena. The intraindividual uniformity of pain (p=0.029) and hyperphenomena (p=0.011) between the two sides of the thorax suggests that patient-related factors play an important role in the development of chronic pain.

Conclusions

The results of the present study provide support for the hypothesis of an individual predisposition for the development of chronic pain after thoracotomy.

Implications

Patient-related risk factors contribute to the development of chronic pain after thoracotomy. This result most likely can be transferred to chronic pain after other surgical procedures and therefore help us understand risk factors for chronic pain after surgery.

Pain-diminishing effects of Kinesio® taping after median sternotomy

BACKGROUND

Postoperative pain and severe side effects of opioid analgesics present a clinical challenge after cardio-thoracic surgery. In this study, the impact of Kinesio® taping on postoperative morbidity after median sternotomy was observed.

METHODS

Thirty-nine patients (mean age 66 ± 9 years, CI: 63.28; 68.98) who underwent median sternotomy between 09/2014 and 11/2014 participated in this prospective randomized controlled trial. Patients were assigned into a treatment on a non-treatment group. Patients in the treatment group were taped after leaving the intensive care unit. We assessed, pain, consumption of pain medication, the subjective estimation of patients' ability to breathe, radiologic and microbial abnormalities as well as adverse effects resulting from the tape use daily until discharge. To determine the patients' satisfaction a discharge questionnaire was offered after completion of data.

RESULTS

Patients who were treated with tape report significantly less pain (2.14 ± 0.5, CI: 1.1; 3.13) than patients from the control group (4.16 ± 0.6, CI: 2.92; 5.41, p = 0.01). The need for opioid pain medication, as assessed by total analgesic consumption per patient, was significantly less in the treatment group (1.2 ml ± 0.4 ml, CI: 0.40 ml; 2.01 ml) versus (3.1 ml ± 0.5 ml, CI: 2.0 ml; 4.2 ml, p = 0.01). The subjective estimation of patients' ability to breathe was significantly better (p < 0.001) and the satisfaction was higher in the Kinesio® tape group compared to the control group. Taped patients had a mean hospitalization of 10 ± 1 day (CI: 8.74 days; 11.78 days) untapped patients stayed for 11 ± 1 days (CI: 9.17 days; 11.83 days). Adverse effects from the tape treatment were not observed.

CONCLUSIONS

Kinesio® taping after median sternotomy is a low-risk, non-pharmacologic, cost effective, and promising method for improving patients' breathing conditions, reducing postoperative pain, pain medication consumption, and thus, potential adverse effects of analgesics.

Impact of pregabalin on early phase post-thoracotomy pain compared with epidural analgesia

Background

The purpose of this randomized study was to compare the effects of pregabalin with epidural analgesia on early phase post-thoracotomy pain.

Methods

This study was conducted on 90 adult patients who underwent thoracotomy. Patients were randomly divided into two groups, an epidural analgesia group, where 45 patients received 0.2% ropivacaine hydrochloride and fentanyl through a thoracic epidural catheter, and a pregabalin group, where 45 patients received 75 mg pregabalin orally twice daily. Both groups were also administered orally with celecoxib along with each treatment. Numerical rating scale (NRS) and sleep interference rate (SIR) were evaluated on the first day, third day, and fifth day after surgery. Anesthetic induction time, operation time, recovery time, the use of additional analgesic drugs and adverse effects were also examined.

Results

NRS and SIR were significantly lower in the pregabalin group at all time points (P<0.05). The number of patients requiring additional analgesic drugs within 24 hours after surgery showed no difference between the two groups; however, the number was significantly decreased in the pregabalin group after post-operative day 1 (P<0.001). Adverse effects including pneumonia, dysuria, constipation and nausea were identified among many patients in the epidural analgesia group (P<0.05). Operation time and recovery time were the same for both groups, while the epidural analgesia group showed a significantly longer anesthetic induction time (P<0.001).

Conclusions

Pregabalin is considered to be a safe and effective treatment method which is an alternative to epidural analgesia for acute post-thoracotomy pain.

Post-thoracotomy pain syndrome and sensory disturbances following thoracotomy at 6- and 12-month follow-ups

Background

Persistent pain affects a large proportion of patients after thoracotomy and is associated with sensory disturbances. The objective of this prospective study was to investigate the time course of pain and sensory disturbances over a 12-month period.

Methods

Patients scheduled for thoracotomy were recruited. Data were collected on the day before surgery, including baseline characteristics and the presence of any preoperative pain. At 6- and 12-month follow-ups, data on pain were collected using the Brief Pain Inventory-Short Form, and perceived sensory disturbances around the thoracotomy scar were recorded from a self-exploration test.

Results

At 12 months after surgery, 97 patients had complete data including baseline and 6-and 12-month measurements. Almost half of the patients reported post-thoracotomy pain at the follow-ups. However, 20% of the patients not reporting post-thoracotomy pain at 6 months did report it at 12 months. Between 40% and 60% of patients experienced some kind of sensory disturbance at 6 months. A small decline in some kind of sensory disturbance was reported by 20%–50% of patients at 12 months.

Conclusion

A proportion of patients experienced either resolved or delayed onset of pain. Sensory changes were strongly associated with post-thoracotomy pain syndrome, but were also present in a large proportion of patients without it.

[Management of delayed complications after esophagectomy]

Esophagectomy and subsequent reconstruction represent major physiological insults to the upper gastrointestinal (GI) tract, which as a consequence can lead to malnutrition, dysphagia and reflux. From a technical perspective, operative reconstruction involving gastric pull-up with a 2-3 cm wide tube and an anastomosis cranial to the azygos vein may minimize the symptoms. Overall, the problems tend to improve approximately 6 months after the operation. Newly occurring delayed physical functional impairments with previously known underlying malignant disease may be indicative of cancer relapse. Interventional techniques, such as stent placement or brachytherapy may be better suited for treatment of recurrent disease.

Update on Prevalence of Pain in Patients With Cancer: Systematic Review and Meta-Analysis

CONTEXT

Cancer pain has a severe impact on quality of life and is associated with numerous psychosocial responses. Recent studies suggest that treatment of cancer pain has improved during the last decade.

OBJECTIVES

The aim of this review was to examine the present status of pain prevalence and pain severity in patients with cancer.

METHODS

A systematic search of the literature published between September 2005 and January 2014 was performed using the databases PubMed, Medline, Embase, CINAHL, and Cochrane. Articles in English or Dutch that reported on the prevalence of cancer pain in an adult population were included. Titles and abstracts were screened by two authors independently, after which full texts were evaluated and assessed on methodological quality. Study details and pain characteristics were extracted from the articles with adequate study quality. Prevalence rates were pooled with meta-analysis; meta-regression was performed to explore determinants of pain prevalence.

RESULTS

Of 4117 titles, 122 studies were selected for the meta-analyses on pain (117 studies, n = 63,533) and pain severity (52 studies, n = 32,261). Pain prevalence rates were 39.3% after curative treatment; 55.0% during anticancer treatment; and 66.4% in advanced, metastatic, or terminal disease. Moderate to severe pain (numerical rating scale score ≥5) was reported by 38.0% of all patients.

CONCLUSION

Despite increased attention on assessment and management, pain continues to be a prevalent symptom in patients with cancer. In the upcoming decade, we need to overcome barriers toward effective pain treatment and develop and implement interventions to optimally manage pain in patients with cancer.

An exploratory study on the effectiveness of "Calmare therapy" in patients with cancer-related neuropathic pain: A pilot study

PURPOSE

Calmare therapy (CT) has been suggested as a novel treatment for managing chronic pain. Recently, it was reported to show a positive therapeutic outcome for managing neuropathic pain condition. We performed an exploratory prospective study on the effectiveness of CT in patients with various types of cancer-related neuropathic pain (CNP).

METHOD

We performed an open-labeled, single-arm, exploratory study on the effectiveness of CT in patients with various types of cancer-related neuropathic pain (CNP). The primary endpoint was a comparison of the 11-point Numerical Rating Scale (NRS) pain score at one month with the baseline score in each patient. Brief Pain Inventory (BPI) and consumption of opioid were also evaluated during follow-up period.

RESULTS

CT significantly decreased NRS pain score at one month from baseline (p < 0.001) in 20 patients with chemotherapy-induced peripheral neuropathy (n = 6), metastatic bone pain (n = 7), and post-surgical neuropathic pain (n = 7). It also improved overall BPI scores, decreased consumption of rescue opioid (p = 0.050), and was found satisfactory by a half of patients (n = 10, 50.0%).

CONCLUSIONS

Our preliminary results suggest that CT may be considered for cancer patients with various types of CNP. Large studies are necessary to confirm our findings and ascertain which additional CNP show positive response to CT.

Prevalence and predictors of persistent post-surgical pain 12 months after thoracotomy

BACKGROUND

Persistent post-surgical pain is recognised as a major problem. Prevalence after different surgical procedures has been reported to range from 5% up to 85%. Limb amputation and thoracotomy have the highest reported prevalence. Prediction of persistent post-surgical pain has over the last decade caught attention. Several factors have been investigated, but in-depth knowledge is still scarce. The purpose of this study was to investigate the prevalence of persistent post-surgical pain, and predictive factors for persistent post-surgical pain 12 months after thoracotomy.

METHODS

A prospective longitudinal study was conducted. One-hundred and seventy patients were recruited before scheduled thoracotomy, and asked to answer a questionnaire. One-hundred and six patients completed the same questionnaire at 12-month follow-up. Regression analysis was performed to explore variables assumed predictive of persistent post-surgical pain.

RESULTS

One-hundred and six patients (62%) filled out the questionnaire at both time points. Preoperative, 34% reported muscle-skeletal related chronic pain. At 12-month follow-up, 50% of the patients reported persistent post-surgical pain. Of the variables explored in the logistic regression model, only preoperative pain (P < 0.001) and dispositional optimism (P = 0.04) were statistically significant. In this study, preoperative pain was a predominant predictor for persistent postoperative pain (OR 6.97, CI 2.40-20.21), while dispositional optimism (OR 0.36, CI 0.14-0.96) seem to have protective properties.

CONCLUSION

Our results show that preoperative pain is a predominant predictor of future pain. This implies that patients presenting with a chronic pain condition prior to surgery should be assessed thoroughly preoperatively and have an individually tailored analgesic regimen.

Postthoracotomy Pain Syndrome Following Surgery for Lung Cancer: Symptoms and Impact on Quality of Life

Postthoracotomy pain syndrome (PTPS) is a common complication following thoracic surgery. Most studies examining the influence of PTPS on patient-reported symptoms include few patients managed using a minimally invasive approach. Associated sensory changes, potentially neuropathic in origin, are not well described. We therefore examined the symptoms and quality of life (QOL) of patients with and without PTPS who underwent a standard thoracotomy (n = 43) or minimally invasive surgery (n = 54). Patients in this prospective, cross-sectional study completed questionnaires to assess pain (McGill Pain Questionnaire), neuropathic symptoms (Neuropathic Symptom Questionnaire), symptom distress (Symptom Distress Scale), anxiety and depression (Hospital Anxiety and Depression Scale), and QOL (Functional Assessment Cancer Therapy–Lung). Excepting younger age (p = .009), no demographic or surgical characteristic differentiated patients with and without PTPS. Patients with PTPS described discomfort as pain only (15.1%), neuropathic symptoms only (30.2%) or pain and neuropathic symptoms (54.7%). Scores differed between patients with and without PTPS for symptom distress (p < .001), anxiety and depression (p < .001), and QOL (p = .009), with higher distress associated with PTPS. Despite new surgical techniques, PTPS remains common and results in considerable distress. A focused assessment is needed to identify all experiencing this condition, with referral to pain management specialists if symptoms persist.

Conditioned pain modulation and situational pain catastrophizing as preoperative predictors of pain following chest wall surgery: a prospective observational cohort study

BACKGROUND

Variability in patients' postoperative pain experience and response to treatment challenges effective pain management. Variability in pain reflects individual differences in inhibitory pain modulation and psychological sensitivity, which in turn may be clinically relevant for the disposition to acquire pain. The aim of this study was to investigate the effects of conditioned pain modulation and situational pain catastrophizing on postoperative pain and pain persistency.

METHODS

Preoperatively, 42 healthy males undergoing funnel chest surgery completed the Spielberger's State-Trait Anxiety Inventory and Beck's Depression Inventory before undergoing a sequential conditioned pain modulation paradigm. Subsequently, the Pain Catastrophizing Scale was introduced and patients were instructed to reference the conditioning pain while answering. Ratings of movement-evoked pain and consumption of morphine equivalents were obtained during postoperative days 2-5. Pain was reevaluated at six months postoperatively.

RESULTS

Patients reporting persistent pain at six months follow-up (n = 15) were not significantly different from pain-free patients (n = 16) concerning preoperative conditioned pain modulation response (Z = 1.0, P = 0.3) or level of catastrophizing (Z = 0.4, P = 1.0). In the acute postoperative phase, situational pain catastrophizing predicted movement-evoked pain, independently of anxiety and depression (β = 1.0, P = 0.007) whereas conditioned pain modulation predicted morphine consumption (β = -0.005, P = 0.001).

CONCLUSIONS

Preoperative conditioned pain modulation and situational pain catastrophizing were not associated with the development of persistent postoperative pain following funnel chest repair. Secondary outcome analyses indicated that conditioned pain modulation predicted morphine consumption and situational pain catastrophizing predicted movement-evoked pain intensity in the acute postoperative phase. These findings may have important implications for developing strategies to treat or prevent acute postoperative pain in selected patients. Pain may be predicted and the malfunctioning pain inhibition mechanism as tested with CPM may be treated with suitable drugs augmenting descending inhibition.