Occurrence Of Chronic Pain Research Articles

Comparison of Intercostal Nerve Block and Serratus Anterior Plane Block for Perioperative Pain Management and Impact on Chronic Pain in Thoracoscopic Surgery: A Randomized Controlled Trial.

This study compares the analgesic efficacy of Intercostal Nerve Block (ICNB) under direct thoracoscopic visualization and Serratus Anterior Plane Block (SAPB) with ultrasound guidance during thoracoscopic surgery's perioperative period. Furthermore, it examines their impact on chronic pain and identifies potential risk factors associated with its development. In this prospective randomized controlled study, 74 thoracoscopic surgery patients were randomly assigned to ICNB or SAPB groups. Attending surgeons administered ICNB, while anesthesiologists performed SAPB, both using 20mL of 0.5% ropivacaine. Primary outcomes included Visual Analog Scale (VAS) scores for resting and coughing pain at 6, 12, 24, and 48 hours postoperatively, perioperative opioid and NSAID consumption, and chronic pain incidence at 3 months postoperatively. Secondary outcomes aimed to identify independent risk factors for chronic pain. The primary results reveal that SAPB group exhibited significantly lower VAS scores than ICNB group for postoperative coughing at 24 hours (P<0.001, 95% CI=[0.5, 1]) and for resting pain at 48 hours (P=0.001, 95% CI=[0.2, 1]). Conversely, ICNB group demonstrated reduced VAS score for resting pain at 6 hours compared to SAPB group (P=0.014, 95% CI=[-0.5, 0.5]). SAPB group required significantly less intraoperative sulfentanil (P<0.001, 95% CI=[2.5, 5]), remifentanil (P=0.005, 95% CI=[-0.4, -0.1]), and flurbiprofen ester (P=0.003, 95% CI=[0, 50]) than ICNB group. Chronic pain incidence was similar (P=0.572, 95% CI=[0.412, 1.279]), with mild pain in both ICNB and SAPB groups. Secondary findings indicate that resting VAS score at 12 hours (OR=7.59, P=0.048, 95% CI=[1.02, 56.46]), chest tube duration (OR=3.35, P=0.029, 95% CI=[1.13, 9.97]), and surgical duration (OR=1.02, P=0.049, 95% CI=[1.00, 1.03]) were significant predictors of chronic pain occurrence. ICNB and SAPB demonstrated comparable analgesic effects, with similar rates of chronic pain occurrence. Chronic pain independent risk factors included resting VAS score at 12 hours, chest tube duration, and surgical duration.

EP537 - Revolutionizing informed consent: A quantum leap in precision for chronic pain awareness in inguinal hernia operations through electronic consent

Abstract Aim The study aimed to assess the extent to which clinicians provide information to patients about the occurrence of chronic pain during consultations, recognizing it's significance as a prevalent postoperative complication following inguinal hernia repair. Methods Data were gathered by two teams at distinct time periods within the same trust. One team utilized the standard paper-based consenting method, while the other employed a recently introduced electronic consenting process. A comparison of these approaches was undertaken to derive the study's results, making it a retrospective and comparative analysis. Results An investigation on this subject conducted initially uncovered that 84% of patients were not informed about the risk of chronic pain and did not provide consent for this common occurrence via standard paper based method. Consequently, the study recommended the implementation of an e-consent facility in the Trust. This facility would feature a template encompassing all pertinent risks associated with inguinal hernia surgery. Following the introduction of e-consent later, we conducted a subsequent analysis on patients who underwent inguinal hernia surgery. The findings indicated a notable improvement, with 98% of patients having given their consent for chronic pain.Manner of consentingPatient who was informed about chronic pain during consentingPatient who wasn't informed about chronic pain during consentingPaper consent16%84%e-Consent982% Conclusion The incorporation of chronic pain as a potential complication in the consenting process for inguinal hernia surgery has seen improvement since the introduction of the e-consent software. However, to achieve full compliance, there is a need for further enhancement and increased utilization of the e-consent software.

FAILED BACK SURGERY SYNDROME (FBSS)

Failed Back Surgery Syndrome (FBSS) is a serious health problem and a term used to describe persistent or recurrent pain (limited or radiating to the lower limbs) of the lower back, occurring after one or more surgeries. According to various sources, it affects 10-44% of operated patients and, due to the constantly growing number of spine surgeries, it shows an upward trend. The etiology of FBSS can be surgical and non-surgical, but the mechanism of pain is complex. The most common causes include: intervertebral foramen stenosis, discogenic pain, pseudoarthrosis, and recurrent disc prolapse syndrome. The pain is neuropathic in nature with allodynia, hyperalgesia and dysesthesia. The aim of this work: FBSS in therapy is perceived as a huge challenge for both surgeons and other physicians, because due to the numerous causes and complex pathomechanism of pain, pain syndromes after unsuccessful spine surgeries often turn out to be resistant to treatment. As a result, it is important for a clinician to understand the problem and initiate appropriate treatment for a patient struggling with this syndrome. Methods: Selected articles from the Pubmed database and specialized literature were analyzed in detail. We focused on the characteristics of the pain occurring in this syndrome, its diagnosis and treatment. Conclusion: FBSS has various etiologies. Factors predisposing to the occurrence of chronic pain can be divided into preoperative, intraoperative and postoperative. Pain assessment is an important point in the decision-making process regarding management and treatment, which should be individual. The use of imaging tests is irreplaceable in diagnostics.

Longitudinal examination of associations with the onset of pediatric chronic pain at different pain locations.

Chronic pain is a frequent phenomenon in pediatrics. Little research explores whether there are factors that uniquely predict or accompany the onset of new chronic pain in different locations of the body. In this study, we report pediatric pain data for 3 location subsamples-headache, abdominal pain, and musculoskeletal pain-of a large secondary school sample (N = 2280). We distinguished between participants who experienced an onset of chronic pain and participants who had no chronic pain at the respective pain location within a 1-year period. We used regression and multilevel models to compare the 2 groups regarding factors previously associated with chronic pain. Our results indicate that irrespective of location, the onset of chronic pain is predicted by psychosocial factors, in particular, symptoms of depression (odds ratio [OR] = 1.13-1.17, P < 0.01) and anxiety (OR = 1.12-1.21, P < 0.05). Although the onset of headache is predicted by psychosocial factors only, the onsets of abdominal and musculoskeletal pain are additionally predicted by physiological factors such as level of physical activity. Many of the predictors were also accompanying factors. Regarding chronic abdominal pain, sleep deficiency did not predict pain onset but was a co-occurring phenomenon. Our findings underline the importance of mental health factors in the pain onset at all 3 body locations, whereas in chronic abdominal and musculoskeletal pain, physiological factors should also be considered. Measures of model fit, however, indicate that the occurrence of chronic pain is more complex and not well predicted by these factors alone.

Construction and validation of chronic pain prediction model after total knee arthroplasty.

To explore the risk factors of chronic pain after total knee arthroplasty (TKA) and to establish and verify a prediction model. As a retrospective observational study, medical records of 239 patients who underwent TKA in Affiliated Hospital of Jiangnan University from January 2020 to December 2022 were reviewed. Fifty four patients suffered from chronic pain after TKA surgery. Univariate and multivariate logistic regression were used to analyze factors associated with the occurrence of chronic pain after TKA. A nomogram prediction model was established based on the identified independent risk factors, and its predictive effectiveness was evaluated. Gender, postoperative 24-hourss numerical rating scale (NRS) and postoperative three months Hospital for Special Surgery Knee-Rating (HSS) scores were independent risk factors for chronic pain after TKA (p<0.05). The area of the receiver operating characteristic (ROC) of the nomogram model based on these factors was 0.904 (95% confidence interval [CI): 0.861-0.947), which indicates a good predictive value for the postoperative chronic pain. When the optimal cut off value was selected, the sensitivity and specificity of the model were 92.6% and 74.1%, respectively, indicating that the predictive model is effective. Gender, postoperative 24-hours NRS and postoperative three months HSS score are independent risk factors for chronic pain after TKA. The nomogram prediction model based on these factors is effective and can provide auxiliary reference for patients with chronic pain after TKA.

Effect of ultrasound-guided continuous erector spinae plane block on postoperative pain and inflammatory response in patients undergoing modified radical mastectomy for breast cancer: study protocol for a randomised controlled trial

BackgroundA single injection of local anaesthetic (LA) in the erector spinae plane block (ESPB) can reduce pain after modified radical mastectomy (MRM) surgery, but the duration of analgesia is affected by the duration of the LA. The aim of this study is to investigate the effect of continuous ESPB on acute and chronic pain and inflammatory response after MRM surgery.MethodsIn this prospective, randomised, controlled trial, we will recruit 160 patients, aged 18–80 years, scheduled for elective MRM surgery under general anaesthesia. They will be randomly assigned to two groups: a continuous ESPB group (group E) and a sham block group (group C). Both groups of patients will have a nerve block (group C pretended to puncture) and an indwelling catheter fixed prior to surgery. Electronic pumps containing LA are shielded. The primary outcome is the total consumption of analgesic agents. The secondary outcomes include the levels of inflammation-related cytokines; the occurrence of chronic pain (post-mastectomy pain syndrome, PMPS); static and dynamic pain scores at 2, 6, 12, 24 and 48 h postoperatively; and post-operative and post-puncture adverse reactions.DiscussionAnalgesia after MRM surgery is important and chronic pain can develop when acute pain is prolonged, but the analgesic effect of a nerve block with a single injection of LA is limited by the duration of drug action. The aim of this trial is to investigate whether continuous ESPB can reduce acute pain after MRM surgery and reduce the incidence of chronic pain (PMPS), with fewer postoperative analgesic drug-related complications and less inflammatory response. Continuous ESPB and up to 12 months of follow-up are two innovations of this trial.Trial registrationChinese Clinical Trial Registry (https://www.chictr.org.cn/) ChiCTR2200061935. Registered on 11 July 2022. This trial is a prospective registry with the following registry names: Effect of ultrasound-guided continuous erector spinae plane block on postoperative pain and inflammatory response in patients undergoing modified radical mastectomy for breast cancer.

Body Posture and Low Back Pain: Differences between Folk and Ballroom Dancers.

(1) Background: Dance is extremely diverse in its styles. Each of them presents different training, dynamics, and figures that may impact the body posture and the occurrence of low back pain. This observational study aimed to compare the sagittal curvatures and the range of motion (ROM) of the spine, as well as the low back pain occurrence and its intensity between folk and ballroom dancers. (2) Methods: Fifty-one participants took part in the study (nineteen folk dancers, fifteen ballroom dancers, and seventeen non-dancers) aged 18-32. Study groups did not differ in anthropometric parameters as well as in dancing experience and training frequency. Study procedures included a self-administered questionnaire and a physical examination of the sagittal spine curvatures and ROM. The questionnaire included questions about epidemiological data and the occurrence of chronic pain and its intensity using a Visual Analogue Scale (VAS). (3) Results: There was a significant difference in thoracic kyphosis angle between study groups (p = 0.02). The greatest angle was found in folk dancers and the lowest in ballroom dancers (40 vs. 33 respectively). We have found no significant differences in spine ROM, low back pain occurrence, and intensity between study groups (p > 0.05). We have found no correlation between low back pain and spine curvatures and ROM in dancers (p > 0.05), however, we found a very strong and negative correlation between thoracic spine range of motion and the pain intensity in non-dancers (R= -0.95, p = 0.003). The analysis also revealed that only in folk dancers, but not in ballroom dancers, the BMI correlates positively with dancing experience (R = 0.67, p = 0.002). (4) Conclusions: There are no differences in low back pain occurrence and pain intensity between folk and ballroom dancers, however, the prevalence of low back pain in dancers is very high. Folk dancers seem to have more flexed body posture compared to ballroom dancers.

Cell Reprogramming Strategies for Treating Osteoarthritis and Intervertebral Disc Degeneration.

Osteoarthritis (OA) and intervertebral disc degeneration (IVDD) are the most common degenerative bone and joint diseases, posing a major threat to patients' physical and mental health due to the occurrence of chronic pain and disability. Within this context, the absence of efficacious therapies has led to a growing interest in regenerative medicine. In particular, as a method that can erase the memory of differentiation and re-endow cells with pluripotency, cell reprogramming technologies have ushered in a new era of personalized therapy, which not only show great potential for the treatment of degenerative osteoarthropathies but also promise to achieve tissue regenerative and repair. However, compared to other areas of research, reprogramming technologies to treat OA and IVDD are still in the preliminary stages and require further investigation. This paper briefly introduces the characteristics of cell reprogramming; summarizes the pathological mechanisms of reprogramming to improves energy metabolism, aging, inflammation, oxidative stress, and immune imbalance in OA and IVDD under the background of microenvironment and immunity; highlights the significant advantages of reprogramming-derived cells compared to embryonic stem cells and mesenchymal stem cells, based on these advances, providing important strategies for its development and clinical application in OA and IVDD.

The Role and Mechanism of Spinal NF-κB-CXCL1/CXCR2 in Rats with Nucleus Pulposus-induced Radicular Pain.

Experimental study of the role and mechanism of spinal NFκB-CXCL1/CXCR2 in rats with nucleus pulposus-induced radicular pain. This study investigated the role and mechanism of spinal NFκB-CXCL1/CXCR2 in autologous nucleus pulposus-induced pain behavior in rats and to clarify the involvement and regulation of spinal NFκB as an upstream molecule of CXCL1 in autologous nucleus pulposus-induced radicular pain in rats. The inflammatory response of nerve roots is an important mechanism for the occurrence of chronic pain. NFκB-CXCL1/CXCR2 pathway plays an important role in the development of radicular pain, but its regulatory mechanism in the model of radicular pain induced by autologous nucleus pulposus is still unclear. We established a rat model of autologous medullary nucleus transplantation. We observed and recorded the changes in 50% mechanical withdrawal threshold and thermal withdrawal latency before and after the administration of CXCL1-neutralizing antibodies, CXCR2 inhibitor, and NFκB inhibitor in each group of rats and evaluated the expression of NFκB, CXCL1, and CXCR2 in the spinal dorsal horn using immunofluorescence and Western blot. To compare differences between groups in behavioral testing, analysis of variance was employed. Dunnett's method was used to compare differences at different time points within a group and between different groups at the same time point. A comparison of the relative concentration of protein, relative concentration of mRNA, and semiquantitative data from immunofluorescence staining was conducted utilizing one-way ANOVA and Dunnett's pairwise comparison. Autologous nucleus pulposus transplantation can induce radicular pain in rats and upregulate the expression of CXCL1, CXCR2, and NFκB in the spinal cord. CXCL1 is co-expressed with astrocytes, CXCR2 with neurons, and NFκB with both astrocytes and neurons. The application of CXCL1 neutralizing antibodies, CXCR2 inhibitors, and NFκB inhibitors can alleviate pain hypersensitivity induced by autologous nucleus pulposus transplantation in rats. Inhibitors of NFκB could downregulate the expression of CXCL1 and CXCR2. We found that spinal NFκB is involved in NP-induced radicular pain in rats through the activation of CXCL1/CXCR2, enriching the mechanism of medullary-derived radicular pain and providing a possible new target and theoretical basis for the development of more effective anti-inflammatory and analgesic drugs for patients with chronic pain following LDH.

Prognostic factors of poor surgical outcome after clitoral reconstruction in women with female genital mutilation/cutting.

Complications of surgical clitoral reconstruction for female genital mutilation/cutting (FGM/C) are a rare occurrence, but there has been reports of patients experiencing chronic pain or clitoral burial. This study aims to assess which factors are predictive of the occurrence of surgical complications in women who had surgical reconstruction for FGM/C (type 1, 2, or 3). This monocentric retrospective study was conducted among patients who underwent clitoral reconstruction after FGM/C from January 2016 to March 2020. Demographic and clinical data were abstracted from the medical records. The primary outcome was the occurrence of chronic pain (defined as occurrence or persistence of any clitoral pain >3 months after surgery), and the secondary outcome was the occurrence of clitoral burial. A total of 87 women were included in the analysis. Univariate analysis indicated significantly higher rates of a history of physical abuse in the group of women who experienced chronic pain after surgery (4 [100%] vs 2 [37.1%], P = .049). Patients with clitoral burial were significantly younger than the rest of the sample in univariate analysis (median [IQR],29.6 years [24.6-30.2] vs 33.8 [28.2-37.9]; P = .049). Surgical treatment of women who underwent FGM/C should include the entire history of the patient and especially a record of experiencing physical abuse. The study stands out for its originality, the extensive sample size gathered over nearly 4 years, the surgical clitoral reconstructions conducted by an experienced surgeon, and the minimal amount of missing data. However, because the occurrence of these complications was rare, the number of patients in the subgroups was extremely low, preventing a valid multivariate analysis to be conducted. The study suggests that women with a history of physical abuse could be at greater risk for chronic pain after surgery and that younger women tend to experience more clitoral burial.

Satellite glial cells in sensory ganglia play a wider role in chronic pain via multiple mechanisms.

Satellite glial cells are unique glial cells that surround the cell body of primary sensory neurons. An increasing body of evidence suggests that in the presence of inflammation and nerve damage, a significant number of satellite glial cells become activated, thus triggering a series of functional changes. This suggests that satellite glial cells are closely related to the occurrence of chronic pain. In this review, we first summarize the morphological structure, molecular markers, and physiological functions of satellite glial cells. Then, we clarify the multiple key roles of satellite glial cells in chronic pain, including gap junction hemichannel Cx43, membrane channel Pannexin1, K channel subunit 4.1, ATP, purinergic P2 receptors, and a series of additional factors and their receptors, including tumor necrosis factor, glutamate, endothelin, and bradykinin. Finally, we propose that future research should focus on the specific sorting of satellite glial cells, and identify genomic differences between physiological and pathological conditions. This review provides an important perspective for clarifying mechanisms underlying the peripheral regulation of chronic pain and will facilitate the formulation of new treatment plans for chronic pain.

Incidence of Chronic Pain following Oral Soft Tissue Biopsies: A Retrospective Study

Soft tissue oral biopsies (STOB) are commonly performed in the medical field to obtain tissue samples for diagnostic purposes. However, like all invasive procedures, these biopsies may carry risks, such as the development of chronic long-lasting neuropathic pain. This study aims to examine the occurrence of chronic pain following STOBs. A retrospective study was conducted on the medical records of 695 patients who underwent STOBs at the Maxillofacial Surgery Department of Hadassah Medical Center between the years 2013 and 2022. Demographic information, details of the procedure, histopathological diagnosis, and data related to post-procedure pain in the biopsy area were collected and analyzed. Out of the 695 patients, only 4 reports of chronic pain with mild intensity lasting more than three months following oral biopsy were documented, with incidence rate of 0.57%; all were females with a median age of 59 ± 2.0 years. The biopsies were taken from various sites and the common diagnoses were lichen planus, venous malformation, and fibromas. In conclusion, chronic pain after oral soft-tissue biopsies is rare, generally mild, and typically does not require extra therapy. These insights can aid clinicians and patients in making informed decisions about these procedures.

Socioeconomic and sex inequalities in chronic pain: A population-based cross-sectional study.

We investigated the impact of socioeconomic inequalities on chronic pain of older adults according to sex. This population-based cross-sectional study used survey data from the 2015 cohort of the SABE Study (Saúde, Bem-estar e Envelhecimento), Brazil. Socioeconomic status was examined at individual level (educational attainment, financial independence, and race/skin color) and contextual level (Human Development Index). We analyzed the association between variables using the chi-square test and the Rao & Scott correction. Logistic regression models were adjusted for risk factors. The study comprised 1,207 older adults representing 1,365,514 residents 60≥ years of age in the city of São Paulo. Chronic pain was more frequent in females (27.2%) than in males (14.5%) (p<0.001). Females evidenced the worst self-perception of pain, especially those of the most vulnerable socioeconomic strata. Social inequalities impacted chronic pain in different ways between sexes. Among females, unfavorable living conditions (OR = 1.59; 95%CI 1.07; 2,37) and Blacks/Browns females were most likely to have chronic pain (OR = 1.32; 95%CI 1.01; 1.74). Among males, only the individual aspects were significant for the occurrence of chronic pain, such as low educational attainment (OR = 1.88; 95%CI 1.16; 3.04) and insufficient income (OR = 1.63; 95%CI 1.01; 2.62). The potential for inequality was greater for females than for males reflecting structural factors inherent in a highly unequal society. Conclusions: Equity-oriented health policies are critical to preventing pain in human aging.

OC-005 COMPARISON OF POSTOPERATIVE PAIN: BIOLOGICAL VERSUS SYNTHETIC MESH SIX MONTHS AFTER LAPAROENDOSCOPIC HERNIA REPAIR – RESULTS OF THE RANDOMIZED, MULTICENTER, SELF-CONTROLLED BIOLAP TRIAL

Abstract Aim A remaining problem after hernia surgery is the occurrence of chronic pain. Up to now, the use of synthetic meshes is the standard procedure, but there is raising evidence that biological meshes could be advantageous concerning occurrence of chronic pain without the disadvantages of a life-long implant. The BIOLAP trial compares synthetic and biological meshes in laparoendoscopic inguinal hernia repair. To test the hypothesis that the use of biological meshes results in significantly less pain postoperatively than the use of synthetic meshes, without an increased recurrence rate, patients with bilateral primary inguinal hernias were included. Patients received biological mesh on one side and synthetic mesh on the other. Materials and Methods In 21 German hernia centres, 982 hernias were treated using TEP or TAPP techniques. In addition to the study endpoints (recurrence rate within 2 years, pain intensity after 6 months), demographic and perioperative data as well as intraoperative and postoperative complications were recorded. Results Recruitment was successfully completed in February 2021. Six month after laparoendoscopic hernia repair there is no significant difference in pain occurrence comparing biological to synthetic mesh implants. Furthermore general demographics of the patients with bilateral primary inguinal hernias are evaluated. Conclusion The study provides data from 982 hernia operations dependent of the mesh material used. According to the study protocol, at the current time pain intensity after 6 months comparing both mesh materials has been evaluated as the first endpoint. Further study endpoints will be evaluated after completion of the two-year follow-up phase.

MiR-26a-5p alleviates CFA-induced chronic inflammatory hyperalgesia through Wnt5a/CaMKII/NFAT signaling in mice.

Inflammation often leads to the occurrence of chronic pain, and many miRNAs have been shown to play a key role in the development of inflammatory pain. However, whether miR-26a-5p relieves pain induced by inflammation and its possible mechanism are still unclear. The complete Freund's adjuvant (CFA)-induced inflammatory pain mouse model was employed. Intrathecal or subcutaneous injection of miR-26a-5p agomir was performed after modeling to study its antinociceptive effect and the comparison of different administration methods. Bioinformatics analysis of miRNAs was performed to study the downstream mechanisms of miR-26a-5p. HE staining, RT-qPCR, Western blotting, and immunofluorescence were used for further validation. A single intrathecal and subcutaneous injection of miR-26a-5p both reversed mechanical hypersensitivity and thermal latency in the left hind paw of mice with CFA-induced inflammatory pain. HE staining and immunofluorescence studies found that both administrations of miR-26a-5p alleviated inflammation in the periphery and spinal cord. Bioinformatics analysis and dual-luciferase reporter gene analysis identified Wnt5a as a direct downstream target gene of miR-26a-5p. Wnt5a was mainly expressed in neurons and microglia in the spinal cord of mice with inflammatory pain. Intrathecal injection of miR-26a-5p could significantly reduce the expression level of Wnt5a and inhibit the downstream molecules of noncanonical Wnt signaling Camk2/NFAT, inhibiting the release of spinal cord inflammatory factors and alleviating the activation of microglia. In addition, miR-26a-5p could also inhibit lipopolysaccharide (LPS)-stimulated BV2 cell inflammation in vitro through a noncanonical Wnt signaling pathway. miR-26a-5p is a promising therapy for CFA-induced inflammatory pain. Both intrathecal and subcutaneous injections provide relief for inflammatory pain. miR-26a-5p regulated noncanonical Wnt signaling to be involved in analgesia partly through antineuroinflammation, suggesting a pain-alleviating effect via noncanonical Wnt signaling pathway in the CFA-induced inflammatory pain model in vivo.

Боль в спине у пожилых — современное состояние проблемы

The article discusses various aspects of chronic pain syndrome in general and chronic back pain in elderly patients. The frequency of chronic pain occurrence in the elderly, according to different authors, is up to 83.8%, chronic back pain ranges from 27 to 86%. The negative impact of chronic back pain on the life quality of elderly patients was shown. Correlations were found between chronic back pain and such conditions as an increased risk of falls, fractures, and the development of dementia. Chronic pain syndrome in people over 60 y. o. contributes to a risk of mortality increase by 57%. The reasons for the chronic back pain development are not only degenerative-dystrophic changes in the spine, but also changes in proprioception and locomotor function. The analysis of the literature substantiates the need for further research on chronic back pain in the elderly.

Effect of perioperative sciatic nerve block on chronic pain in patients undergoing below-knee amputation: A randomised controlled trial

Many pain syndromes such as chronic phantom limb pain (PLP) and stump pain (SP), involving nociceptive and neuropathic pain, develop after amputation. Recent literature suggests that the use of regional blocks reduces repeated stimulation of transected nerve roots and thus prevents central sensitisation. This randomised, double-blind study was conducted to evaluate the effect of pre-emptive ultrasound-guided single-shot lateral sciatic nerve block on the occurrence of chronic pain at six months after traumatic below-knee amputation. Thirty patients undergoing traumatic lower limb amputation under general anaesthesia were randomised into two groups: Group B received sciatic nerve block pre-emptively using ultrasound with 20 ml of 0.75% ropivacaine, whereas group C received 20 ml of normal saline. Follow-up of patients was done till six months post-amputation. The primary objective was to assess the occurrence of chronic pain at six months. Pain at 15 days and one month after surgery, post-operative morphine consumption and post-operative nausea and vomiting (PONV) were the secondary outcomes assessed. The occurrence of PLP at six months was comparable in the two groups, group B (46.7%) and C (66.7%). None of the patients developed SP at six months. Median intensities of phantom pain were 1.0 (range, 1-2.0) versus 1.0 (range, 1-2.0) (P = 0.36), and median intensities of SP 2 (range, 2-3.0) versus 3 (range, 2-3.0) (P = 0.39) at 1 month. Pre-emptive sciatic nerve block did not decrease the occurrence or severity of chronic pain after traumatic below-knee amputation.

Hyperalgesia and fentanyl dosing in on-pump coronary artery bypass grafting: a prospective, randomised, double-blinded clinical trial

Background: Chronic post-sternotomy pain after coronary artery bypass grafting (CABG) is an underestimated complication. Pain has a major impact on quality of life. Increasingly, low-dose or even opioid-free anesthesia has been shown to be feasible and in some cases beneficial. Different intraoperative analgesic treatment strategies may significantly impact occurrence of hyperalgesia and subsequent pain in cardiac surgery. Objective: To investigate whether different intraoperative dosing regimens of fentanyl during CABG influence the area of hyperalgesia 24 and 48 hours postoperatively. As secondary endpoints, we investigated whether acute postoperative pain measured by the numerical rating scale (NRS) scores at 24 and 48 hours and the occurrence of chronic pain after 3, 6 and 12 months were influenced by perioperative fentanyl dosing. Design: Prospective, randomized double-blind clinical trial. Setting: A preliminary analysis of a randomized multicenter study (University Hospital of Ghent and the University Hospital of Basel), including patients undergoing elective on-pump CABG in University Hospital of Ghent. Methods: We screened 80 patients, of whom 66 were included and randomized into three groups: a high fentanyl regimen (20 µg.kg-1 IBW (Ideal Body Weight)), a low dosing regimen (3 µg.kg-1 IBW), or a Shibutani continuous dosing regimen. When extubated and responsive, protocolized pin-pricking was performed at 24 and 48h to evaluate the surface area of hyperalgesia. Additionally, patients are asked to report the Numeric Rating Scale (NRS) at 24h, 48h, as well as the occurrence of persistent pain at 3, 6, and 12 months. Additional preoperative rescue fentanyl dosing and postoperative remifentanil dosing were taken into account as possible confounders. Results: Primary endpoint: the difference in the measured area of hyperalgesia between the randomization groups was not significantly different. At 24h a mean area of 88 cm2, 90 cm2 and 96 cm2 was found in the low, high and Shibutani groups, respectively. At 48h areas of 91 cm2, 96 cm2 and 103 cm2 were measured in the respective groups. Secondary endpoints: significantly higher NRS scores were recorded at 24 hours in the low-dose group. A higher NRS score was found at 6 months in the Shibutani group compared to the other groups in the longer term. Postoperative administration of remifentanil is was not found to be a confounding cause of hyperalgesia. Conclusion: More short-term pain was reported in patients administered lower doses of fentanyl intraoperatively. Other clinically relevant differences in outcomes were not found. Our findings suggest that the benefits of opioid low anesthesia may not be as relevant to cardiac surgery with median sternotomy. The total postoperative opioid dosing (including remifentanil) could be a possible cause of hyperalgesia. Trial registration: EudraCT (European Union Drug Regulating Authorities Clinical Trials Database), the European database for all interventional clinical trials on medicinal products authorized in the European Union. Eudra CT number: 2017-003278-15, AGO/2017/005.

Are Chronic Pain Syndromes the Reason for Statin-Associated Muscle Symptoms?

Background: Statin induced myalgia is defined as muscle pain without elevation of serum creatine phosphokinase levels, and is a well-known complaint among statin users. Chronic pain syndromes affect a high percentage of the population; and it may be possible that these pain syndromes confound the reports of statin induced myalgia. We sought to compare the occurrence of chronic pain among patients on statin therapy who developed myalgia with those who did not. Methods: This study included 112 statin-treated patients, followed up at the clinic of the Lipid Center in Sheba Medical Center. Fifty-six of the subjects had a diagnosis of statin associated muscle symptoms (SAMS) and 56 did not. Verified questionnaires were used to assess the diagnoses of fibromyalgia, pain intensity, functional impairment, anxiety and depression in the study population. Results: Patients with statin myalgia were more likely to fulfil the diagnostic criteria for fibromyalgia than patients without statin myalgia (11 (19.6%) vs. zero, respectively). Patients in the SAMS group also exhibited higher levels of anxiety and depression in comparison with the control group. Female sex, higher scores on the Brief Pain Inventory pain intensity scale, and a Hamilton rating scale level indicative of an anxiety disorder were found to be significant predictors for fibromyalgia in patients suffering from statin myalgia. Conclusion: A significant percentage of patients, diagnosed with statin myalgia actually fulfilled the diagnostic criteria for fibromyalgia, depression or anxiety disorder. Detection of these patients and treatment of their primary pain disorder or psychiatric illness has the potential to prevent unnecessary cessation of effective statin therapy.

Abnormal connectivity model of raphe nuclei with sensory-associated cortex in Parkinson's disease with chronic pain.

There are indicates that raphe nuclei may be involved in the occurrence of chronic pain in Parkinson's disease (PD). In the study, we investigated the functional connectivity pattern of raphe nuclei in Parkinson's disease with chronic pain (PDP) to uncover its possible pathophysiology. Fifteen PDP, who suffered from pain, lasted longer than 3months, sixteen Parkinson's disease patients with no pain (nPDP) and eighteen matched normal health controls (NCs) were recruited. All subjects completed the King's Parkinson's Pain Scale (KPPS) besides Parkinson-related scale and demographics. We performed a seed-based resting-state analysis of functional magnetic resonance imaging to explore whole-brain functional connectivity of the raphe nuclei. Multiple regression model was used to explore the related factors of pain including disease duration, disease severity, Hamilton Depression Rating Scale, age, sex, levodopa equivalent dose and the strength of network functional connectivity. Compared with the nPDP, the PDP group showed stronger functional connectivity between raphe nuclei and pain-related brain regions, including parietal lobe, insular lobe, cingulum cortex and prefrontal cortex, and the functional connectivity values of those areas were significantly positively correlated with KPPS independent of the clinical variables. Compared with NCs, the combined PD groups showed decreased functional connectivity including prefrontal cortex and cingulum cortex. Abnormal functional connectivity model of raphe nuclei may be partly involved in pathophysiological mechanism of pain in PD.