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The mechanism of chronic knee osteoarthritis (OA) pain and postoperative pain due to knee arthroplasty has not been elucidated. This could be involved neuroplasticity in brain connectivity. To clarify the mechanism of chronic knee OA pain and postoperative pain, we examined the relationship between resting-state functional connectivity (rs-FC) and clinical measurements in knee OA before and after knee arthroplasty, focusing on rs-FCs with the anterior insular cortex (aIC) as the key region. Fifteen patients with knee OA underwent resting-state functional magnetic resonance imaging and clinical measurements shortly before and 6 months after knee arthroplasty, and 15 age- and sex-matched control patients underwent an identical protocol. Seed-to-voxel analysis was performed to compare the clinical measurements and changed rs-FCs, using the aIC as a seed region, between the preoperative and postoperative patients, as well as between the operative and control patients. In preoperative patients, rs-FCs of the aIC to the OFC, frontal pole, subcallosal area, and medial frontal cortex increased compared with those of the control patients. The strength of rs-FC between the left aIC and right OFC decreased before and after knee arthroplasty. The decrease in rs-FC between the left aIC and right OFC was associated with decreased subjective pain score. Our study showed a correlation between longitudinally changed rs-FC and clinical measurement before and after knee arthroplasty. Rs-FC between the aIC and OFC have the potential to elucidate the mechanisms of knee OA pain and postoperative pain due to knee arthroplasty., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: This study aimed to apply the International Association for the Study of Pain (IASP) grading system for identifying nociplastic pain in knee osteoarthritis (KOA) awaiting total knee arthroplasty (TKA) and propose criteria to fine-tune decision-making. In addition, the study aimed to characterize a "probable" versus "no or possible" nociplastic pain mechanism using biopsychosocial variables and compare both groups in their 1-year post-TKA response., Methods: A secondary analysis of baseline data of a longitudinal prospective study involving 197 patients with KOA awaiting total TKA in Belgium and the Netherlands was performed. Two approaches, one considering 4 and the other 3 pain locations (step 2 of the grading system), were presented. Linear mixed model analyses were performed to compare the probable and no or possible nociplastic pain mechanism groups for several preoperative biopsychosocial-related variables and 1-year postoperative pain. Also, a sensitivity analysis, comparing 3 pain mechanism groups, was performed., Results: Thirty (15.22%-approach 4 pain locations) and 46 (23.35%-approach 3 pain locations) participants were categorized under probable nociplastic pain. Irrespective of the pain location approach or sensitivity analysis, the probable nociplastic pain group included more woman, was younger, exhibited worse results on various preoperative pain-related and psychological variables, and had more pain 1-year post-TKA compared with the other group., Discussion: This study proposed additional criteria to fine-tune the grading system for nociplastic pain (except for discrete/regional/multifocal/widespread pain) and characterized a subgroup of patients with KOA with probable nociplastic pain. Future research is warranted for further validation., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

The aim of this randomized study was to investigate whether stripping massage (SM) of myofascial trigger points in the lower rhomboid muscle could alleviate chest pain in patients following thoracoscopic surgery. In addition, a literature review was conducted to assess the effectiveness of various pain management techniques. Sixty adult patients who reported a visual analog scale (VAS) score of 4 or higher were randomly assigned to receive conventional analgesics alone (conventional group) or combined with SM twice daily for 2 weeks (SM group). VAS scores and the use of additional analgesics were evaluated on postoperative days 1, 3, 7, 14, and 30. Using the PubMed and Cochrane Library databases, a review of current pain management techniques was carried out up to January 31, 2022. A subgroup analysis was also performed to examine the treatment effect during different surgical periods and techniques. Results showed that the SM group had significantly lower VAS scores on postoperative days 3, 7, 14, and 30 ( p  < 0.001), as well as a shorter hospitalization duration and reduced need for additional analgesics ( p  < 0.001). The literature review included a total of 20 studies (2,342 cases of chest pain relief after thoracoscopic surgery), which indicated that serratus anterior plane (SAP) blocks were commonly used as a perioperative approach to reduce pain and opioid consumption. SM and SAP can both serve as adjuvant treatments for chest pain in patients following thoracoscopic surgery, with SM being a safe and noninvasive pain control option after hospital discharge., Competing Interests: None declared., (Thieme. All rights reserved.)

Minipigs are widely used in biomedical research for translational studies. However, information about pain elicited by experimental procedures is lacking. Non-invasive methods as quantitative sensory testing and conditioned pain modulation are particularly attractive. Our overarching aim was to explore and refine these methods for assessing post-operative pain in minipigs after myocardial infarction. As first step, we aimed at defining mechanical and thermal thresholds in healthy adults Göttingen Minipigs, evaluating their reliability, and testing their modifications after the application of a conditioning stimulus. Thresholds were assessed at different body sites before and after a painful conditioning stimulus (CS) (cuffed tourniquet) and sham CS (uncuffed tourniquet) in eleven animals. Thresholds' reliability was assessed using interclass correlation coefficient (ICC). The effect of the CS was assessed calculating absolute change, percentage change of the thresholds and standard error of measurement. Baseline mechanical thresholds (Newton) were: left hindlimb 81 [73; 81]; left forearm 81 [72.1; 81]; right forearm 81 [76; 81]; left chest 80.5 [68; 81]; right chest 81 [76.5; 81]; left neck 81 [70.3; 81]; right neck 74.8 [62.3; 80.5]. Reliability of mechanical thresholds was good at right chest (ICC = 0.835) and moderate at left chest (ICC = 0.591), left hindlimb (ICC = 0.606) and left neck (ICC = 0.518). Thermal thresholds showed poor reliability in all the tested sites. A modulatory effect was present at right chest, but it was seen when both a painful CS and a sham CS was applied. Minipigs tendentially showed a pro-nociceptive profile (i.e. conditioning pain facilitation). The measured thresholds are a reference for future trials in this species. Mechanical thresholds showed to be more reliable and, therefore, more useful, than thermal ones. The pain facilitation might be explained by the phenomenon of stress induced hyperalgesia, but this finding needs to be further investigated with a stricter paradigm., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Petrucci et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Pain catastrophizing is an exaggerated focus on pain sensations. It may be an independent factor influencing pain and functional outcomes of knee arthroplasty. We aimed to evaluate the association between pre-operative pain catastrophizing with pain and function outcomes up to one year after knee arthroplasty. We used data from a cohort study of patients undergoing primary knee arthroplasty (either total or unicompartmental arthroplasty) for knee osteoarthritis. Pain catastrophizing was assessed pre-operatively using the Pain Catastrophizing scale (PCS). Other baseline variables included demographics, body mass index, radiographic severity, anxiety, depression, and knee pain and function assessed using the Western Ontario and McMaster University Index (WOMAC). Patients completed the WOMAC at 6- and 12-months after arthroplasty. WOMAC pain and function scores were converted to interval scale and the association of PCS and changes of WOMAC pain and function were evaluated in generalized linear regression models with adjustment with confounding variables. Of the 1136 patients who underwent arthroplasty (70% female, 84% Chinese, 92% total knee arthroplasty), 1102 and 1089 provided data at 6- and 12-months post-operatively. Mean (± SD) age of patients was 65.9 (± 7.0) years. PCS was associated with a change in WOMAC pain at both 6-months and 12-months (β = - 0.04, 95% confidence interval: - 0.06, - 0.02; P < 0.001) post-operatively after adjustment in multivariable models; as well as change in WOMAC function at 6-months and 12-months. In this large cohort study, pre-operative pain catastrophizing was associated with lower improvements in pain and function at 6-months and 12-months after arthroplasty., (© 2024. The Author(s).)

(1) Background: This study aimed to describe upper-limb (UL) movement quality parameters in women after breast cancer surgery and to explore their clinical relevance in relation to post-surgical pain and disability. (2) Methods: UL movement quality was assessed in 30 women before and 3 weeks after surgery for breast cancer. Via accelerometer data captured from a sensor located at the distal end of the forearm on the operated side, various movement quality parameters (local dynamic stability, movement predictability, movement smoothness, movement symmetry, and movement variability) were investigated while women performed a cyclic, weighted reaching task. At both test moments, the Quick Disabilities of the Arm, Shoulder, and Hand (Quick DASH) questionnaire was filled out to assess UL disability and pain severity. (3) Results: No significant differences in movement quality parameters were found between the pre-surgical and post-surgical time points. No significant correlations between post-operative UL disability or pain severity and movement quality were found. (4) Conclusions: From this study sample, no apparent clinically relevant movement quality parameters could be derived for a cyclic, weighted reaching task. This suggests that the search for an easy-to-use, quantitative analysis tool for UL qualitative functioning to be used in research and clinical practice should continue.

Background: The degree of postoperative pain and defecation function in colorectal cancer will affect patients' prognosis. Therefore, exploring the correlation between postoperative pain and defecation function, and analyzing the related factors, will help to improve the quality of patients' prognosis., Methods: A total of 94 patients with colorectal cancer admitted to our hospital from March 2022 to June 2023 were retrospectively selected for study. The visual analog scale (VAS) was used to evaluate the pain level of the patients. The low anterior resection syndrome (LARS) scale was used to evaluate bowel function of the patients, and the incidence of LARS was recorded. The patients were grouped according to whether or not they had the complications of LARS, and they were divided into the groups of concurrent LARS and non-concurrent LARS. The patients' anorectal pressure was measured, and the measurements included maximum tolerated volume (MTV), anorectal resting pressure (ARP), and maximum squeeze pressure (MSP). Pearson's correlation coefficient was used to test associations between anal defecation function and postoperative pain and anorectal manometry. Logistic regression was used to test predictors of concurrent LARS, and the value of each of the indices for prediction of LARS was examined using the receiver operating characteristic (ROC)., Results: Patients' VAS scores were positively correlated with LARS scores (p < 0.05). A total of 22 patients with VAS score ≥20 points were found to have a LARS incidence of 23.40% based on the LARS score. The VAS score was higher in the concurrent LARS group than in the non-concurrent LARS group (p < 0.05). The concurrent LARS group had a higher percentage of patients with age ≥60 years, body mass index ≥24 kg/m2, anastomotic position <5 cm from the anal verge, preoperative radiotherapy, and anastomotic fistula than the non-current LARS group (p < 0.05). The levels of MTV, ARP, and MSP were lower in patients in the concurrent LARS group than in the non-current LARS group (p < 0.05). Patients' LARS scores were negatively correlated with MTV (r = -0.420), ARP (r = -0.300) and MSP (r = -0.220) levels (p < 0.05). Logistic regression analysis showed that anastomotic position <5 cm from the anal verge, preoperative radiotherapy, anastomotic fistula, high VAS level, and low MTV level were all significant predictors of concurrent LARS. Anastomotic position, whether or not radiotherapy was administered preoperatively, anastomotic fistula, VAS score, and MSP level all had high sensitivity and specificity for prediction of concurrent LARS, and the combined area under the curve (AUC) of each index was 0.921, sensitivity was 0.818, and specificity was 0.944., Conclusion: LARS is strongly associated with the patient's pain level, and factors such as anastomotic position <5 cm from the anal verge, preoperative radiotherapy, anastomotic fistula, high VAS level, and low MTV level will increase the risk of concurrent LARS in patients.

Objective: To investigate the changes in vertebral function after minimally invasive surgery in patients with thoracolumbar spinal fractures and investigate the impact of percutaneous minimally invasive surgery on patients' quality of life by following up the patients in the long term., Methods: A retrospective analysis was performed to select 80 patients with thoracolumbar spinal fractures treated in our hospital from April 2013 to October 2018, and the patients were divided into a study group and a control group according to the difference in their choice of procedure. The two groups were compared in terms of perioperative wound pain, serum creatine kinase (CK) activity, and C-reactive protein (CRP) levels, and the two groups were followed up for 2 years to compare the changes in anterior vertebral body height and Cobb's angle during the follow-up period and to compare the differences in quality of life between the two groups., Results: (1) The pain level of patients in the study group was significantly lower than that of the control group at the 1st and 3rd postoperative days ( p < 0.05). (2) The CK activity and CPR level of patients in the study group were significantly lower than that of the control group at the 1st and 3rd postoperative days ( p < 0.05). (3) Compared with the preoperative period, the height of the anterior border of the vertebral body and the Cobb's angle in both groups showed significant changes at 7 d, 6 months, one year, and two years after surgery ( p < 0.05), suggesting that both procedures can significantly restore the height of the injured vertebra and improve the function of the vertebral body. (4) The somatic, physical, and psychological functions of patients in the study group were significantly greater than those in the control group at 6 months postoperatively ( p > 0.05)., Conclusion: Compared to traditional open surgery, minimally invasive percutaneous surgery for thoracolumbar fractures can significantly reduce perioperative pain and improve perioperative stress in patients, while achieving better surgical outcomes and a significantly improved quality of life in patients at long-term follow-up., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Bin Liu et al.)

Over 185,000 limb amputations are performed in the United States annually, many of which are due to the sequelae of peripheral vascular disease. Symptomatic neuromas remain a significant source of postamputation morbidity and contribute to both phantom limb (PLP) and residual limb pain (RLP). While many interventions have been proposed for the treatment of symptomatic neuromas, conventional methods lead to a high incidence of neuroma recurrence. Furthermore, these existing methods do not facilitate an ability to properly interface with myoelectric prosthetic devices. The Regenerative Peripheral Nerve Interface (RPNI) was developed to overcome these limitations. The RPNI consists of an autologous free muscle graft secured around the end of a transected nerve. The muscle graft provides regenerating axons with end organs to reinnervate, thereby preventing neuroma formation. We have shown that this simple, reproducible, and safe surgical technique successfully treats and prevents neuroma formation in major limb amputations. In this paper, we describe RPNI surgery in the setting of major limb amputation and highlight the promising results of RPNIs in our animal and clinical studies., (Copyright © 2021 Elsevier Inc. All rights reserved.)

BACKGROUND This single-center study compared the effect of combined thoracic paravertebral block (TPVB) and general anesthesia vs general anesthesia alone on postoperative stress and pain in patients undergoing laparoscopic radical nephrectomy. MATERIAL AND METHODS Patients undergoing laparoscopic radical nephrectomy were selected and randomized into a study group given TPVB combined with general anesthesia (n=43) and a reference group (n=43) given general anesthesia. The perioperative clinical indicators, blood pressure, pulse rate, visual analog scale (VAS) score, and adverse reactions were compared. RESULTS Perioperative clinical indicators of the study group (other than operation duration) were superior to those of the reference group (P<0.05). At 90 min in the operation, systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate were lower than before anesthesia (t=7.691, 10.017, and 7.728, P<0.05). SBP, DBP, and pulse rate at 90 minutes during operation were significantly lower in the study group than in the reference group (t=7.582, 8.754, and 6.682, P<0.01). The study group had lower VAS scores both during activity and at rest 48 h after the operation than in the reference group (t=5.171 and 6.025, P<0.001). The total incidence of adverse reactions in the study group was lower than in the reference group (χ²=5.018, P=0.024). CONCLUSIONS The findings from this study from a single center showed that TPVB combined with general anesthesia for patients undergoing laparoscopic radical nephrectomy significantly reduced postoperative pain and stress.

Objective: To evaluate the clinical effects and survival prognosis of radical gastrectomy assisted by external vision in gastric cancer., Methods: A total of 60 hospitalized gastric cancer patients from June 2016 to December 2018 were selected and divided into the observation group and control group according to different surgical procedures. The control group was treated with traditional open radical gastrectomy, while the observation group was treated with radical gastrectomy assisted by an external vision microscope. Relevant surgical indicators, visual analogue scale (VAS), postoperative complications, and life quality assessment were analyzed and compared between the two groups., Results: The incision length and intraoperative blood loss in the observation group were smaller than those in the control group, and the difference was statistically significant ( P < 0.05); compared with the control group, the observation group had significantly shorter hospital stay, earlier postoperative first exhaust time, and lower gastric fluid volume at the 3 rd day after surgery ( P < 0.05). The pain scores of the observation group at 1, 4, and 12 weeks after surgery were lower than those of the control group ( P < 0.05), and the difference was significant. The quality of life scores at the 1 st week and 12 th week after surgery showed that the dysphagia symptom scores of the observation group and the control group were significantly reduced but the two groups had significant differences in fatigue, physical function, pain score, postoperative pain, and overall quality of life. The observation group was significantly better than the control group ( P < 0.05). Follow-up studies showed no significant difference between mortality and cancer recurrence ( P > 0.05); the patients recovered well at postoperation, and the diet of the observation group was better than that of the control group ( P < 0.05); gastric reflux and knife pain were less than those of the control group ( P < 0.05)., Conclusion: Radical gastrectomy assisted by external vision for gastric cancer yields clinical benefits for gastric cancer patients, which not only dramatically shortened the length of hospital stay but also effectively ameliorated the quality of life of patients, all indicating that external vision-assisted surgery was significantly better than traditional gastrectomy in improving the postoperative quality of life of gastric cancer patients in the absence of increasing the risk of adverse events., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Jian Zheng et al.)

Background: As the population ages, the number of elderly people undergoing surgery increases. Literature on the incidence and intensity of postoperative pain in the elderly is conflicting. This study examines associations between age and pain-related patient reported outcomes and perioperative pain management in a dataset of surgical patients undergoing four common surgeries: spinal surgery, hip or knee replacement, or laparoscopic cholecystectomy. Based on the authors' clinical experience, they hypothesize that pain scores are lower in older patients., Methods: In this retrospective cohort, study data were collected between 2010 and 2018 as part of the international PAIN OUT program. Patients filled out the International Pain Outcomes Questionnaire on postoperative day 1., Results: A total of 11,510 patients from 26 countries, 59% female, with a mean age of 62 yr, underwent one of the aforementioned types of surgery. Large variation was detected within each age group for worst pain, yet for each surgical procedure, mean scores decreased significantly with age (mean Numeric Rating Scale range, 6.3 to 7.3; β = -0.2 per decade; P ≤ 0.001), representing a decrease of 1.3 Numeric Rating Scale points across a lifespan. The interference of pain with activities in bed, sleep, breathing deeply or coughing, nausea, drowsiness, anxiety, helplessness, opioid administration on the ward, and wish for more pain treatment also decreases with age for two or more of the procedures. Across the procedures, patients reported being in severe pain on postoperative day one 26 to 38% of the time, and pain interfered moderately to severely with movement., Conclusions: The authors' findings indicate that postoperative pain decreases with increasing age. The change is, however, small and of questionable clinical significance. Additionally, there are still too many patients, at any age, undergoing common surgeries who suffer from moderate to severe pain, which interferes with function, supporting the need for tailoring care to the individual patient., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

Introduction: More than 200 million women and girls have undergone genital mutilation. Clitoral reconstruction (CR) can improve the quality of life of some of them, but is accompanied by significant postoperative pain., Objective: Assess and describe the management of postoperative pain after CR, and the practices amongst specialists in different countries., Methods: Between March and June 2020, 32 surgeons in 14 countries (Germany, Austria, Belgium, Burkina Faso, Canada, Ivory Coast, Egypt, Spain, United States of America, France, the Netherlands, Senegal, Switzerland, Sweden) responded to an online questionnaire on care and analgesic protocols for CR surgery., Results: At day 7 post CR, 97% of the surgeons observed pain amongst their patients, which persisted up to 1 month for half of them. 22% of the participants reported feeling powerless in the management of such pain. The analgesic treatments offered are mainly step II and anti-inflammatory drugs (61%). Screening for neuropathic pain is rare (3%), as is the use of pudendal nerve block, used by 8% of the care providers and only for a small percentage of women., Conclusion: Pain after CR is frequent, long-lasting, and potentially an obstacle for the women who are willing to undergo clitoral surgery and also their surgeons. Most surgeons from different countries follow analgesic protocols that do not use the full available therapeutic possibilities. Early treatment of neuropathic pain, optimisation of dosing of standard analgesics, addition of opioids, use of acupuncture, and routine intraoperative use of pudendal nerve block might improve the management of pain after CR., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2021. Published by Elsevier Masson SAS.)

BACKGROUND The reasons for foot and ankle pain following total knee arthroplasty (TKA) for knee varus osteoarthritis are unknown. This retrospective study aimed to investigate the risk factors for postoperative foot and ankle pain in patients with varus osteoarthritis of the knee who underwent TKA. MATERIAL AND METHODS We enrolled 90 patients who underwent TKA for varus knee osteoarthritis. The visual analog scale (VAS) was used to evaluate patients' foot or ankle pain before and after surgery. The correlation between independent variables (eg, age, sex, body mass index [BMI], ankle osteoarthritis, and varus angle) and foot and ankle pain in patients with osteoarthritis of the knee was measured. Moreover, radiological changes were compared between the groups with and without worsened pain. RESULTS No significant difference in VAS was found between patients <60 and ≥60 years of age (P>0.05). Male sex and BMI <30 kg/m² were weakly correlated with preoperative foot or ankle pain. However, patients with varus of ≥6° and preexisting ankle osteoarthritis had a higher incidence of foot or ankle pain before surgery. Moreover, no significant differences in radiological changes were found between the groups with and without worsened foot or ankle pain after surgery (P>0.05). CONCLUSIONS In male patients with osteoarthritis of the knee, a BMI <30 kg/m², varus of <6°, and no preexisting ankle osteoarthritis were protective factors for foot and ankle pain. TKA corrected knee and ankle malalignment. Therefore, postoperative foot and ankle pain was not associated only with TKA surgery.

External humeral epicondylitis (EHE) is an inflammation and pain of the lateral tendons of the elbow with poor clinical efficacy. In this study, we aim to observe the effect of extra capsular arthroscopy (ECA) plus Traditional Chinese medicine (TCM) analgesic tincture in the treatment of EHE. A retrospective analysis was performed on the follow-up data of 58 patients with intractable EHE treated by ECA plus TCM analgesic tincture over 2 years from January 2017 to October 2018. All patients were followed up during the operation, with a mean follow-up duration of 17.6 months. There were no complications such as infection, nerve injury, wound nonunion and joint stiffness. The postoperative and pronation angles were statistically different from preoperative. The visual analogue scale (VAS) score during rest and movement of the elbow joint after operation was significantly different from that before operation. Postoperative Mayo elbow joint function score was significantly different from preoperative. Postoperative elbow joint function and brachial and shoulder dysfunction scores were statistically significant compared with those before surgery. Postoperative elbow joint function and brachial and shoulder dysfunction scores were statistically significant compared with those before surgery. The satisfaction rate of patients was 100%, with 52 cases of completely satisfied, 6 cases of basically satisfied and no dissatisfied cases. The curative effect of external capsular arthroscopy plus analgesic tincture in the treatment of external humeral epicondylitis was promising, which was worthy of clinical promotion.

Introduction: Opioids for managing postoperative pain are associated with side effects including opioid-induced respiratory depression (OIRD) and gastrointestinal complications. Opioids induce analgesia via G-protein signaling, while adverse effects are mediated by the β-arrestin pathway. Oliceridine is a biased ligand that preferentially activates G-protein signaling over β-arrestin, theoretically reducing adverse effects. Oliceridine has been approved by the Food and Drug Administration to treat acute pain severe enough to require intravenous opioid analgesics., Areas Covered: Preclinical and clinical trials demonstrate the analgesic efficacy of oliceridine. Available evidence suggests that oliceridine may have a lower risk of OIRD and gastrointestinal complications compared to conventional opioids., Expert Opinion: The analgesic efficacy of oliceridine has been evaluated in several clinical trials. However, safety data were obtained from an open-label observational study and studies assessing adverse effects as secondary outcomes, as post-hoc analyses, or from retrospective studies. These may be affected by gaps in detecting adverse events, heterogeneity in the original studies, and the limitations of retrospective studies. Prospective trials examining the safety of oliceridine versus conventional opioids are needed. Studies are also needed to assess the safety and efficacy of oliceridine in obstetric and pediatric populations, and in the context of multimodal analgesia and Enhanced Recovery after Surgery protocols.

Aims: Chronification of postoperative pain is a common clinical phenomenon following surgical operation, and it perplexes a great number of patients. Estrogen and its membrane receptor (G protein-coupled estrogen receptor, GPER) play a crucial role in pain regulation. Here, we explored the role of GPER in the rostral ventromedial medulla (RVM) during chronic postoperative pain and search for the possible mechanism., Methods and Results: Postoperative pain was induced in mice or rats via a plantar incision surgery. Behavioral tests were conducted to detect both thermal and mechanical pain, showing a small part (16.2%) of mice developed into pain persisting state with consistent low pain threshold on 14 days after incision surgery compared with the pain recovery mice. Immunofluorescent staining assay revealed that the GPER-positive neurons in the RVM were significantly activated in pain persisting rats. In addition, RT-PCR and immunoblot analyses showed that the levels of GPER and phosphorylated μ-type opioid receptor (p-MOR) in the RVM of pain persisting mice were apparently increased on 14 days after incision surgery. Furthermore, chemogenetic activation of GPER-positive neurons in the RVM of Gper-Cre mice could reverse the pain threshold of pain recovery mice. Conversely, chemogenetic inhibition of GPER-positive neurons in the RVM could prevent mice from being in the pain persistent state., Conclusion: Our findings demonstrated that the GPER in the RVM was responsible for the chronification of postoperative pain and the downstream pathway might be involved in MOR phosphorylation., (© 2021 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Background: Persistent postsurgical pain after total knee arthroplasty is a common problem and a major reason for patient dissatisfaction. This secondary analysis aimed to investigate the effects of anesthesia (spinal vs. general) and tourniquet use on persistent pain after total knee arthroplasty., Methods: In this secondary analysis of a previously presented parallel, single-center, randomized trial, 404 patients scheduled for total knee arthroplasty were randomized to spinal versus general anesthesia and no-tourniquet versus tourniquet groups. Patients assessed pain using the Brief Pain Inventory-short form preoperatively and 3 and 12 months postoperatively. The prespecified main outcome was the change in "average pain" measured with numerical 0 to 10 rating scale 1 yr postoperatively. The threshold for clinical importance between groups was set to 1.0., Results: The change in average pain scores 1 yr postoperatively did not differ between the spinal and general anesthesia groups (-2.6 [SD 2.5] vs. -2.3 [SD 2.5], respectively; mean difference, -0.4; 95% CI, -0.9 to 0.1; P = 0.150). The no-tourniquet group reported a smaller decrease in the average pain scores than the tourniquet group (-2.1 [SD 2.7] vs. -2.8 [SD 2.3]; mean difference, 0.6; 95% CI, 0.1 to 1.1; P = 0.012). After 1 yr, the scores concerning the mean of four pain severity variables (numerical rating scale) decreased more in the spinal than in the general anesthesia group (-2.3 [SD 2.2] vs. -1.8 [SD 2.1]; mean difference, -0.5; 95% CI, -0.9 to -0.05; P = 0.029) and less in the no-tourniquet than in the tourniquet group (-1.7 [SD 2.3] vs. -2.3 [SD 2.0]; mean difference, 0.6; 95% CI, 0.2 to 1.0; P = 0.005). None of the differences in pain scores reached the threshold for clinical importance., Conclusions: The type of anesthesia (spinal vs. general) or tourniquet use has no clinically important effect on persistent postsurgical pain after total knee arthroplasty., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

Chronic postsurgical pain (CPSP) is a serious problem. We developed a mouse model of CPSP induced by electrocautery and examined the mechanism of CPSP. In this mouse model, while both incision and electrocautery each produced acute allodynia, persistent allodynia was only observed after electrocautery. Under these conditions, we found that the mRNA levels of Small proline rich protein 1A (Sprr1a) and Annexin A10 (Anxa10), which are the key modulators of neuropathic pain, in the spinal cord were more potently and persistently increased by electrocautery than by incision. Furthermore, these genes were overexpressed almost exclusively in chronic postsurgical pain-activated neurons. This event was associated with decreased levels of tri-methylated histone H3 at Lys27 and increased levels of acetylated histone H3 at Lys27 at their promoter regions. On the other hand, persistent allodynia and overexpression of Sprr1a and Anxa10 after electrocautery were dramatically suppressed by systemic administration of GSK-J4, which is a selective H3K27 demethylase inhibitor. These results suggest that the effects of electrocautery contribute to CPSP along with synaptic plasticity and epigenetic modification., (© 2021. The Author(s).)

Background: Percutaneous peripheral nerve stimulation is an analgesic technique involving the percutaneous implantation of a lead followed by the delivery of electric current using an external pulse generator. Percutaneous peripheral nerve stimulation has been used extensively for chronic pain, but only uncontrolled series have been published for acute postoperative pain. The current multicenter study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent clinical trial and (2) estimate the treatment effect of percutaneous peripheral nerve stimulation on postoperative pain and opioid consumption., Methods: Preoperatively, an electrical lead was percutaneously implanted to target the sciatic nerve for major foot/ankle surgery (e.g., hallux valgus correction), the femoral nerve for anterior cruciate ligament reconstruction, or the brachial plexus for rotator cuff repair, followed by a single injection of long-acting local anesthetic along the same nerve/plexus. Postoperatively, participants were randomized to 14 days of either electrical stimulation (n = 32) or sham stimulation (n = 34) using an external pulse generator in a double-masked fashion. The dual primary treatment effect outcome measures were (1) cumulative opioid consumption (in oral morphine equivalents) and (2) mean values of the "average" daily pain scores measured on the 0 to 10 Numeric Rating Scale within the first 7 postoperative days., Results: During the first 7 postoperative days, opioid consumption in participants given active stimulation was a median (interquartile range) of 5 mg (0 to 30) versus 48 mg (25 to 90) in patients given sham treatment (ratio of geometric means, 0.20 [97.5% CI, 0.07 to 0.57]; P < 0.001). During this same period, the average pain intensity in patients given active stimulation was a mean ± SD of 1.1 ± 1.1 versus 3.1 ± 1.7 in those given sham (difference, -1.8 [97.5% CI, -2.6 to -0.9]; P < 0.001)., Conclusions: Percutaneous peripheral nerve stimulation reduced pain scores and opioid requirements free of systemic side effects during at least the initial week after ambulatory orthopedic surgery., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

To efficiently prolong analgesic effects, we developed osmotically balanced, large unilamellar liposomes (~ 6 μm in diameter) in which highly concentrated bupivacaine (up to 30 mg/mL) was encapsulated, and their sustained bupivacaine release was highly effective in relieving postoperative pain over 24 h in a rat model. Our reverse-phase evaporation method based on non-toxic alcohol, ethanol, enabled simple and cost-effective production of bupivacaine-loaded liposomes, of which osmotic pressure was readily balanced to improve the structural stability of the enlarged unilamellar liposomes along with extension of their shelf life (> a month). The in vitro release profile verified that the release duration of the bupivacaine-loaded liposomes extended up to 6 days. For the in vivo study, male Sprague-Dawley rats were used for the incisional pain model, simulating postoperative pain, and the mechanical withdrawal threshold (MWT) was measured using a von Frey filament. Compared to the control group that received intraplantar administration of normal saline, the group of liposomal bupivacaine showed that the initially increased MWT gradually decreased up to 24 h, and importantly, the analgesic effect of the liposomal bupivacaine was maintained 6 times longer than that of bupivacaine only, proving the potential of effective long-acting anesthetics.

Residual intra-peritoneal gas may be associated with post-laparoscopic shoulder pain (PLSP), which is a frequently and disturbance compliant after surgery. Herein, we aimed to examine whether expiring residual gas via a surgical drain reduces the frequency and intensity of PLSP in the first day after laparoscopic cholecystectomy. 448 participants were enrolled in this prospective cohort study. The incidence and severity of PLSP after surgery were recorded. Of these, the cumulative incidence of PLSP in the drain group was lower particularly at the 12th postoperative hour (18.3% vs. 27.6%; P = 0.022), 24th postoperative hour (28.8% vs. 38.1%; P = 0.039), and throughout the first postoperative day (P = 0.035). The drain group had less severe PLSP (crude Odds ratio, 0.66; P = .036). After adjustment using inverse probability of treatment weighting, the drain group also had a significant lower PLSP incidence (adjusted hazard ratio = 0.61, P < 0.001), and less severe PLSP (adjusted odds ratio = 0.56, P < 0.001). In conclusion, the maneuver about passive force to expel residual gas, surgical drain use, contributes to reduce the incidence and severity of PLSP, suggesting that to minimize residual gas at the end of surgery is useful to attenuate PLSP.

Introduction: Poorly controlled postoperative pain has been known to be characterized by longer post-operative care, longer hospital stays with increased readmission rates, and decreased patient satisfaction. Post-operative pain has been continuously addressed in the past three (3) to four (4) decades and has been shown that 20 to 80% of post-operative patients suffer ineffective pain management., Objective: The study was aimed at assessing the factors that may predict the satisfaction of patients with early postoperative pain management following abdominal surgeries at the Komfo Anokye Teaching Hospital, Kumasi., Methodology: A descriptive cross-sectional study was conducted among patients who had undergone abdominal surgeries between October 2019 and December 2019 at the Komfo Anokye Teaching Hospital. Structured questionnaires based on the IPO-Q were used to obtain responses from the patients. Descriptive and Inferential statistical analysis were employed in analyzing the data obtained from the respondents of the study., Results: 138 patients were involved in this study. The mean age of patients in the study was 45.81 (±16.81) years. A higher percentage, 58.7% of the patients were males. 39.1% had completed their tertiary level of education. The majority (50.7%) of the patients had had persistent pain for more than three (3) months. The satisfaction of the patients with the post-operative pain management received was generally high among a significant majority of the patients. Meanwhile, among the factors that influence the satisfaction of the patients with the post-operative pain management received, type of analgesia and pain relief methods (Pearson Coefficient = 0.523, p-value <0.05), patient's ability to request more pain relief, (Pearson Coefficient = 0.29, p-value <0.05), patient's access to information about their pain treatment options from the Nurses (Pearson coefficient = -0.22, p<0.05), were the only predictors of satisfaction in patients., Conclusion: This study found out that patients were generally satisfied with the post-operative pain management offered by their healthcare providers although the degree of satisfaction depended largely on the type of analgesia and pain relief methods, the ability to request for more pain relief, and access to information on pain treatment., Competing Interests: The authors have declared that no competing interests exist.

Background: Psychological factors such as depression, pain catastrophizing, kinesiophobia, pain anxiety, and more negative illness perceptions are associated with worse pain and function in patients at the start of treatment for de Quervain's tenosynovitis. Longitudinal studies have found symptoms of depression and pain catastrophizing at baseline were associated with worse pain after treatment. It is important to study patients opting for surgery for their condition because patients should choose surgical treatment based on their values rather than misconceptions. Psychological factors associated with worse patient-reported outcomes from surgery for de Quervain's tenosynovitis should be identified and addressed preoperatively so surgeons can correct any misunderstandings about the condition., Question/purpose: What preoperative psychosocial factors (depression, anxiety, pain catastrophizing, illness perception, and patient expectations) are associated with pain and function 3 months after surgical treatment of de Quervain's tenosynovitis after controlling for demographic characteristics?, Methods: This was a prospective cohort study of 164 patients who underwent surgery for de Quervain's tenosynovitis between September 2017 and October 2018 performed by 20 hand surgeons at 18 centers. Our database included 326 patients who underwent surgery for de Quervain's tenosynovitis during the study period. Of these, 62% (201 of 326) completed all baseline questionnaires and 50% (164 of 326) also completed patient-reported outcomes at 3 months postoperatively. We found no difference between those included and those not analyzed in terms of age, sex, duration of symptoms, smoking status, and workload. The mean ± SD age of the patients was 52 ± 14 years, 86% (141 of 164) were women, and the mean duration of symptoms was 13 ± 19 months. Patients completed the Patient-Rated Wrist Evaluation (PRWE), the VAS for pain and function, the Patient Health Questionnaire for symptoms of anxiety and depression, the Pain Catastrophizing Scale, the Credibility/Expectations Questionnaire, and the Brief Illness Perceptions questionnaire at baseline. Patients also completed the PRWE and VAS for pain and function at 3 months postoperatively. We used a hierarchical multivariable linear regression model to investigate the relative contribution of patient demographics and psychosocial factors to the pain and functional outcome at 3 months postoperatively., Results: After adjusting for demographic characteristics, psychosocial factors, and baseline PRWE score, we found that only the patient's expectations of treatment and how long their illness would last were associated with the total PRWE score at 3 months postoperatively. More positive patient expectations of treatment were associated with better patient-reported pain and function at 3 months postoperatively (ß = -2.0; p < 0.01), while more negative patient perceptions of how long their condition would last were associated with worse patient-reported pain and function (timeline ß = 2.7; p < 0.01). The final model accounted for 31% of the variance in the patient-reported outcome at 3 months postoperatively., Conclusion: Patient expectations and illness perceptions are associated with patient-reported pain and functional outcomes after surgical decompression for de Quervain's tenosynovitis. Addressing misconceptions about de Quervain's tenosynovitis in terms of the consequences for patients and how long their symptoms will last should allow patients to make informed decisions about the treatment that best matches their values. Prospective studies are needed to investigate whether addressing patient expectations and illness perceptions, with decision aids for example, can improve patient-reported pain and function postoperatively in those patients who still choose surgery for de Quervain's tenosynovitis., Level of Evidence: Level III, therapeutic study., Competing Interests: All remaining authors certify that neither he nor she, nor any member of his or her immediate family, has funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2020 by the Association of Bone and Joint Surgeons.)

Background: Evidence suggests that increased early postoperative pain (POP) intensities are associated with increased pain in the weeks following surgery. However, it remains unclear which temporal aspects of this early POP relate to later pain experience. In this prospective cohort study, we used wavelet analysis of clinically captured POP intensity data on postoperative days 1 and 2 to characterize slow/fast dynamics of POP intensities and predict pain outcomes on postoperative day 30., Methods: The study used clinical POP time series from the first 48 hours following surgery from 218 patients to predict their mean POP on postoperative day 30. We first used wavelet analysis to approximate the POP series and to represent the series at different time scales to characterize the early temporal profile of acute POP in the first 2 postoperative days. We then used the wavelet coefficients alongside demographic parameters as inputs to a neural network to predict the risk of severe pain 30 days after surgery., Results: Slow dynamic approximation components, but not fast dynamic detailed components, were linked to pain intensity on postoperative day 30. Despite imbalanced outcome rates, using wavelet decomposition along with a neural network for classification, the model achieved an F score of 0.79 and area under the receiver operating characteristic curve of 0.74 on test-set data for classifying pain intensities on postoperative day 30. The wavelet-based approach outperformed logistic regression (F score of 0.31) and neural network (F score of 0.22) classifiers that were restricted to sociodemographic variables and linear trajectories of pain intensities., Conclusions: These findings identify latent mechanistic information within the temporal domain of clinically documented acute POP intensity ratings, which are accessible via wavelet analysis, and demonstrate that such temporal patterns inform pain outcomes at postoperative day 30., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 International Anesthesia Research Society.)

Background: Pain after rotator cuff repair is commonly managed with opioid medications; however, these medications are associated with serious adverse effects. Relaxation exercises represent a potential nonpharmacologic method of pain management that can be easily implemented without substantial adverse effects; however, the effects of relaxation exercises have not been studied in a practical, reproducible protocol after arthroscopic rotator cuff repair., Questions/purposes: (1) Does performing relaxation exercises after arthroscopic rotator cuff repair (ARCR) decrease pain compared with standard pain management medication? (2) Does performing relaxation exercises after ARCR decrease opioid consumption? (3) What proportion of patients who used the relaxation techniques believed they decreased their pain level, and what proportion continued using these techniques at 2 weeks? (4) Does performing relaxation exercises after ARCR affect shoulder function?, Methods: During the study period, 563 patients were eligible for inclusion; however, only 146 were enrolled, randomized, and postoperatively followed (relaxation group: 74, control group: 72); 68% (384 of 563) of patients were not contacted due to patient and research staff availability. Thirty-three patients were unenrolled preoperatively or immediately postoperatively due to change in operative procedure (such as, only debridement) or patient request; no postoperative data were collected from these patients. Follow-up proportions were similar between the relaxation and control groups (relaxation: 80%, control: 81%; p = 0.90). The relaxation group received and reviewed educational materials consisting of a 5-minute video and an educational pamphlet explaining relaxation breathing techniques, while the control group did not receive relaxation education materials. Patients recorded their pain levels and opioid consumption during the 5 days after ARCR. Patients also completed the American Shoulder and Elbow Surgeons shoulder score preoperatively and 2, 6, 13, 18, and 26 weeks postoperatively. Linear mixed models were created to analyze postoperative pain, opioid consumption measured in morphine milligram equivalents (MMEs), and shoulder function outcomes. A per-protocol approach was used to correct for patients who were enrolled but subsequently underwent other procedures., Results: There was no difference in pain scores between the relaxation and control groups during the first 5 days postoperatively. There was no difference in pain scores at 2 weeks postoperatively between the relaxation and control groups (3.3 ± 3 versus 3.5 ± 2, mean difference -0.22 [95% CI -1.06 to 0.62]; p = 0.60). There was no difference in opioid consumption during the first 5 days postoperatively between the relaxation and control groups. The use of relaxation exercises resulted in lower 2-week narcotics consumption in the relaxation group than in the control group (309 ± 241 MMEs versus 442 ± 307 MMEs, mean difference -133 [95% CI -225 to -42]; p < 0.01). Sixty-two percent (41 of 66) of patients in the relaxation group believed the relaxation exercises decreased their pain levels. Fifty-two percent (34 of 66) were still performing the exercises at 2 weeks postoperatively. During the 6-month follow-up period, there was no difference in shoulder function between the relaxation and control groups., Conclusion: The preoperative administration of quick, basic relaxation exercises allowed patients to use appreciably lower opioid analgesic doses over the first 2 weeks after ARCR, without any worsening of pain scores. We consider this result promising but preliminary; it is possible that a more intense mindfulness intervention-the one we studied here was disseminated using only a 5-minute video-would deliver reductions in pain and further reductions in opioid usage., Level of Evidence: Level II, therapeutic study., Competing Interests: All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2021 by the Association of Bone and Joint Surgeons.)

Lesion or disease of the somatosensory system leads to the development of neuropathic pain. Peripheral neuropathic pain encompasses damage or injury of the peripheral nervous system. On the other hand, 10-15% of individuals suffer from acute postoperative pain followed by persistent pain after undergoing surgeries. Antidepressants, anticonvulsants, baclofen, and clonidine are used to treat peripheral neuropathy, whereas opioids are used to treat postoperative pain. The negative effects associated with these drugs emphasize the search for alternative therapeutics with better efficacy and fewer side effects. Curcumin, a polyphenol isolated from the roots of Curcuma longa, possesses antibacterial, antioxidant, and anti-inflammatory properties. Furthermore, the low bioavailability and fast metabolism of curcumin have led to the advent of various curcumin formulations. The present review provides a comprehensive analysis on the effects of curcumin and its formulations in preclinical and clinical studies of neuropathic and postoperative pain. Based on the positive outcomes from both preclinical and clinical studies, curcumin holds the promise of mitigating or preventing neuropathic and postoperative pain conditions. However, more clinical studies with improved curcumin formulations are required to involve its use as adjuvant to neuropathic and postoperative drugs.

Background: Short-length stems were developed to reduce bone loss of the proximal femur and potentially decrease the incidence of thigh pain after cementless THA. However, it remains unknown whether short stems indeed reduce bone loss or the frequency of thigh pain., Questions/purposes: Is there a difference between short- and standard-length stems in terms of: (1) the frequency or severity of thigh pain, (2) modified Harris hip scores, (3) implant loosening, or (4) bone mineral density as measured by dual-energy x-ray absorptiometry?, Methods: Between March 2013 and January 2014, three surgeons performed 205 primary THAs. To be eligible, patients needed to be at least 20 years of age, have not undergone previous history of hip surgery, and have no metabolic bone disease. A total of 100 patients were randomized to receive THA either with a short stem (n = 56) or with a standard-length stem (n = 44). Both stems were proximally coated, tapered, cementless stems. Compared with standard stems, short stems typically were 30- to 35-mm shorter. A total of 73% (41 of 56) and 77% (34 of 44) of those groups, respectively, were accounted for at a minimum of 5 years and were analyzed. The presence of thigh pain during activity was evaluated using a 10-point VAS, and the modified Harris hip score was calculated by research assistants who were blinded to the treatment groups. Plain radiographs were taken at 6 weeks, 6 months, and 12 months postoperatively, and every 1 year thereafter; loosening was defined as subsidence > 3 mm or a position change > 3° on serial radiographs. Radiological assessment was performed by two researchers who did not participate in the surgery and follow-up evaluations. Bone mineral density of the proximal femur was measured using dual-energy x-ray absorptiometry at 4 days, 1 year, 2 years, and 5 years postoperatively. The primary endpoint of our study was the incidence of thigh pain during 5-year follow-up. Our study was powered at 80% to detect a 10% difference in the proportion of patients reporting thigh pain at the level of 0.05., Results: With the numbers available, we found no difference between the groups in the proportion of patients with thigh pain; 16% (9 of 56) of patients in the short-stem group and 14% (6 of 44) of patients in the standard-stem group experienced thigh pain during the follow-up period (p = 0.79). In all patients, the pain was mild or moderate (VAS score of 4 or 6 points). Among the 15 available patients who reported thigh pain, there was no difference between the implant groups in mean severity of thigh pain (4.3 ± 0.8 versus 4.2 ± 0.7; p = 0.78). There were no between-group differences in the short versus standard-length stem groups in terms of mean modified Harris hip score by 5 years after surgery (89 ± 13 versus 95 ± 7 points; p = 0.06). No implant was loose and no hip underwent revision in either group. Patients in the short-stem group showed a slightly smaller decrease in bone mineral density in Gruen Zones 2, 3, and 5 than those in the standard-stem group did; the magnitude of the difference seems unlikely to be clinically important., Conclusion: We found no clinically important differences (and few differences overall) between short and standard-length THA stems 5 years after surgery in a randomized trial. Consequently, we recommend that clinicians use standard-length stems in general practice because standard-length stems have a much longer published track record in other studies, and short stems can expose patients to the uncertainty associated with novelty, without any apparent offsetting benefit., Level of Evidence: Level I, therapeutic study., Competing Interests: All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2020 by the Association of Bone and Joint Surgeons.)

Background: Bupivacaine and ropivacaine are the preferred long-acting local anesthetics for peripheral nerve blocks as they provide prolonged analgesia in the postoperative period. No studies have directly compared the analgesic duration of these commonly used local anesthetics in the setting of low-volume ultrasound-guided interscalene block (US-ISB). This study was designed to determine which local anesthetic and concentration provides superior analgesia (duration and quality) for low-volume US-ISB., Methods: Sixty eligible patients scheduled for arthroscopic shoulder surgery were randomized (1:1:1) to receive US-ISB (5 mL) with 0.5% bupivacaine with 1:200,000 epinephrine, 0.5% ropivacaine, or 1% ropivacaine. All individuals were blinded including study participants, anesthesiologists, surgeons, research personnel, and statistician. All participants received a standardized general anesthetic and multimodal analgesia. The primary outcome was duration of analgesia defined as the time from the end of injection to the time that the patients reported a significant increase in pain (>3 numeric rating scale [NRS]) at the surgical site., Results: The mean duration of analgesia for 0.5% bupivacaine with 1:200,000 epinephrine, 0.5% ropivacaine, or 1% ropivacaine was 14.1 ± 7.4, 13.8 ± 4.5, and 15.8 ± 6.3 hours, respectively (analysis of variance [ANOVA], P = .51). There were no observed differences in analgesic duration or other secondary outcomes between the 3 groups with the exception of a difference in cumulative opioid consumption up to 20h00 on the day of surgery in favor of ropivacaine 0.5% over bupivacaine of minimal clinical significance., Conclusions: In the context of single-injection low-volume US-ISB, we have demonstrated a similar efficacy between equal concentrations of ropivacaine and bupivacaine. In addition, increasing the concentration of ropivacaine from 0.5% to 1% did not prolong the duration of US-ISB., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2021 International Anesthesia Research Society.)

Background: Epidural block are often used for analgesia after open nephrectomy surgery. Subcostal anterior quadratus lumborum block may be an alternative. We therefore tested the hypothesis that the continuous subcostal anterior quadratus lumborum block is noninferior to epidural block for analgesia in patients having open partial nephrectomies., Methods: Adults having open partial nephrectomies were randomly allocated to epidural or unilateral subcostal anterior quadratus lumborum block. The joint primary outcomes were opioid consumption measured in morphine equivalents and pain measured on a numeric rating scale (0-10) from postanesthesia care unit (PACU) until 72 hours after surgery. The noninferiority deltas were 30% for opioid consumption and 1 point on a 0-10 scale for pain. Secondary outcomes included patient global assessment of pain management on the third postoperative day, the number of antiemetic medication doses through the third postoperative day, duration of PACU stay, and postoperative duration of hospitalization., Results: Twenty-six patients were randomized to anterior quadratus lumborum block and 29 to epidural analgesia. Neither pain scores nor opioid consumption in the quadratus lumborum patients were noninferior to epidural analgesia. At 72 hours, mean ± standard deviation pain scores in subcoastal anterior quadratus lumborum block and epidural group were 4.7 ± 1.8 and 4.1 ± 1.7, with an estimated difference in pain scores of 0.62 (95% confidence interval [CI], 0.74-1.99; noninferiority P = .21). The median [Q1, Q3] opioid consumption was more than doubled in quadratus lumborum patients at 70 mg [43, 125] versus 30 mg [18, 75] in the epidural group with an estimated ratio of geometric means of 1.69 (95% CI, 0.66-4.33; noninferiority P = .80). Patient global assessment and duration of PACU and hospital stays did not differ significantly in the 2 groups., Conclusions: We were unable to show that subcostal anterior quadratus lumborum block are noninferior to epidural analgesia in terms of pain scores and opioid consumption for open partial nephrectomies. Effectiveness of novel blocks should be rigorously tested in specific surgical setting before widespread adoption., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 International Anesthesia Research Society.)

Background: Acute postoperative pain plays an important role in the perioperative neurocognitive disorders (PND). The pathogenesis of PND is still unknown, but it is generally believed that peripheral and central nervous system inflammation play an important role, and acute postoperative pain is also thought to aggravate postoperative inflammatory response. The aim of the present study is to explore the effect of acute postoperative pain on peripheral and central nervous system inflammation and related cognitive impairment behaviour in elderly rats after surgery., Methods: Rats were assigned into four groups: control, surgery for internal fixation for tibial fracture, surgery with analgesia using intraperitoneal morphine, and morphine without surgery. Pain was assessed by the Subjective Pain Scale. The spatial memory of rats was assessed by the Morris water maze (delayed matching task) from the second day to the seventh day after surgery (POD2-POD7). In part of the rats, the pro-inflammatory cytokines TNF-α in plasma, the medial prefrontal cortex (mPFC), and the hippocampus were determined by ELISA on the POD2. The activation of microglia and the expression of c-Fos in the hippocampal CA1 regions and mPFC were detected by the immunohistochemical method on the POD2., Results: Acute postoperative pain and spatial memory impairment occurred after operation, and postoperative analgesia could significantly improve the both parameters. Additionally, on the POD2, the levels of TNF-α in plasma, hippocampus and mPFC were significantly increased, while the activation of microglia cells and the expression c-Fos in the hippocampal CA1 regions and mPFC were significantly increased. And postoperative analgesia with morphine significantly inhibited the above reactions., Conclusion: Our data suggest that acute postoperative pain increases the incidence of perioperative neurocognitive disorders. Peripheral and central nervous system inflammation may be involved in this cognitive impairment. And reducing the intensity of acute postoperative pain may be one of the main preventive strategies for PND.

Objective: To investigate the postoperative analgesic efficacy of ultrasound-guided lumbar erector spinae plane (ESP) blocks in patients undergoing posterior lumbar spinal surgery for lumbar spinal fractures., Methods: A total of 80 patients who were scheduled for posterior internal fixation for lumbar spinal fractures were divided into a patient-controlled analgesia (PCA) group or a combined ESP-PCA group. Numeric rating scale at rest and during movement, postoperative sufentanil consumption, and accumulative and effective bolus presses of PCA were recorded at 6, 12, 24, and 48 hours postoperatively. Numeric rating scale at rest and during movement was the primary outcome. Incidence of postoperative nausea and vomiting during the first 24-48 hours, pruritus and chronic postoperative pain, and dose of pethidine for rescue analgesia were also recorded., Results: Numeric rating scale at rest and during movement at 6, 12, and 24 hours was lower in the ESP-PCA group (P < 0.001, P < 0.001, P = 0.0016 at rest; all P < 0.001 during movement). Lumbar ESP blocks diminished accumulative bolus presses and effective bolus presses of PCA at 6, 12, 24, and 48 hours postoperatively. Besides, patients in the ESP-PCA group had fewer demands for sufentanil and pethidine. The incidence of postoperative nausea and vomiting in the ESP-PCA group was lower than that in PCA group., Conclusions: PCA combined with lumbar ESP blocks provided superior postoperative analgesia for patients with lumbar spinal fractures treated with posterior internal fixation. Lumbar ESP blocks decreased postoperative opioid consumption and incidence of postoperative nausea and vomiting, thereby enhancing postoperative recovery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Postoperative pain management is key for patient satisfaction. Pressure pain threshold (PPT) has been studied in some surgical cohorts but has not been studied in relationship to acute postoperative pain in short-stay patients undergoing anorectal surgery. We hypothesized that preoperative finger PPT measurements can identify respective patients with higher postoperative pain. Aiming to understand the relationship with subjective postoperative pain perception, we tested the hypotheses that preoperative PPT is associated with postoperative Visual Analog Scale (VAS) pain scores and correlates with postoperative analgesic consumption in short-stay patients undergoing anorectal surgery., Methods: We prospectively assessed preoperative PPT in a cohort undergoing anorectal surgery, known as a moderately to severely painful procedure. Linear mixed-effects models were used to assess the relationship with postoperative VAS pain scores at 1 and 3 days as well as 4 weeks postoperatively. Logistic regression was used to study the relationship with additional postoperative analgesic consumption., Results: We studied 128 patients and found that preoperative PPT is significantly associated with postoperative pain (P value for interaction = .025). Logistic regression modeling additionally revealed an association between the preoperative PPT and the need for additional postoperative analgesics, with odds of requiring additional analgesia decreasing by about 10% for each 1-point increase in PPT (odds ratio [OR] = 0.90; 95% confidence interval [CI], 00.81-0.98; P = .012)., Conclusions: Preoperative finger PPT is associated with postoperative pain and might help identify patients who are at risk of developing more severe postoperative pain on anorectal surgery. Especially in ambulatory and short-stay settings, this approach can help to address patients' high variability in pain sensitivity to facilitate appropriate postoperative analgesia, timely discharge, and prevent readmission., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Anesthesia Research Society.)

Background: The primary goal of this study was to evaluate patterns in acute postoperative pain in a mixed surgical patient cohort with the hypothesis that there would be heterogeneity in these patterns., Methods: This study included 360 patients from a mixed surgical cohort whose pain was measured across postoperative days 1 through 7. Pain was characterized using the Brief Pain Inventory. Primary analysis used group-based trajectory modeling to estimate trajectories/patterns of postoperative pain. Secondary analysis examined associations between sociodemographic, clinical, and behavioral patient factors and pain trajectories., Results: Five distinct postoperative pain trajectories were identified. Many patients (167 of 360, 46%) were in the moderate-to-high pain group, followed by the moderate-to-low (88 of 360, 24%), high (58 of 360, 17%), low (25 of 360, 7%), and decreasing (21 of 360, 6%) pain groups. Lower age (odds ratio, 0.94; 95% CI, 0.91 to 0.99), female sex (odds ratio, 6.5; 95% CI, 1.49 to 15.6), higher anxiety (odds ratio, 1.08; 95% CI, 1.01 to 1.14), and more pain behaviors (odds ratio, 1.10; 95% CI, 1.02 to 1.18) were related to increased likelihood of being in the high pain trajectory in multivariable analysis. Preoperative and intraoperative opioids were not associated with postoperative pain trajectories. Pain trajectory group was, however, associated with postoperative opioid use (P < 0.001), with the high pain group (249.5 oral morphine milligram equivalents) requiring four times more opioids than the low pain group (60.0 oral morphine milligram equivalents)., Conclusions: There are multiple distinct acute postoperative pain intensity trajectories, with 63% of patients reporting stable and sustained high or moderate-to-high pain over the first 7 days after surgery. These postoperative pain trajectories were predominantly defined by patient factors and not surgical factors., (Copyright © 2021, the American Society of Anesthesiologists, Inc. All Rights Reserved.)

Objectives: Our study will investigate the effect of ultrasound-guided thoracic paravertebral block (UG-TPVB) on postoperative pain, quality of life, and enhanced recovery in patients with non-small-cell lung cancer (NSCLC) undergoing lobectomy surgery., Methods: Our study included 100 patients aged 52 to 75 years who underwent lobectomy surgery with pathological diagnosis of NSCLC. Patients received ultrasound-guided thoracic paravertebral block or general anesthesia with tracheal intubation. Patients' pain score was recorded on a numeric rating scale (NRS) 24 hours post operation. The total postoperative dosage of tramadol hydrochloride, length of hospitalization, quality of life (QoL), and inflammation levels were recorded., Results: Compared with patients who received general anesthesia with tracheal intubation, patients in the UG-TPVB group had lower postoperative NRS scores at 24 h (1.8 vs. 3.5, P = 0.035); the average 24 h postoperative NRS score of the UG-TPVB group is lower than that of the general anesthesia with tracheal intubation (4.6 vs. 5.3, P = 0.012), thus receiving less dosage of tramadol hydrochloride (221 ± 45 vs. 250 ± 38 mg, P < 0.01). Patients in the UG-TPVB group had better EORTC QLQ-C30 scores compared with patients in the general anesthesia with tracheal intubation group. The difference of length of hospitalization, hs-CRP, and IL-6 between two groups did not reach statistical difference (length of hospitalization 6.2 vs. 6.9 days, P = 0.055; hs-CRP: 7.1 ± 1.9 vs. 10.4 ± 6.6, P = 0.095; and IL-6: 71.3 ± 7.2 vs. 68.9 ± 8.7, P = 0.529). Discussion . NSCLC patients undergoing lobectomy surgery who received UG-TPVB had less postoperative pain, used less dosage of tramadol hydrochloride, and had better QoL., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Cuijuan Zheng et al.)

Despite the need for safe and effective postoperative analgesia in neonates, research regarding pain management in neonatal rodents is relatively limited. Here, we investigate whether sustained release buprenorphine (Bup SR) effectively attenuates thermal hypersensitivity in a neonatal rat model of incisional pain. Male and female postnatal day 3 Sprague Dawley rat pups (n = 34) were randomly assigned to one of four treatment groups: 1) saline (control), 0.1 mL, once subcutaneously (SC); 2) buprenorphine HCl (Bup HCl), 0.05 mg/kg, once SC; 3) low dose Bup SR (low-SR), 0.5 mg/kg, once SC; 4) high dose Bup SR (high-SR), 1 mg/kg, once SC. Pups were anesthetized with sevoflurane and a 0.5-cm long skin incision was made over the left lateral thigh. The underlying muscle was dissected and closed using surgical glue. Thermal hypersensitivity testing was performed at 24 h prior to surgery and subsequently at 1, 4, 8, 24, and 48 h post-surgery using an infrared diode laser. Thermal hypersensitivity was attenuated at 1 h post-surgery in the Bup HCl group, while it was attenuated through the entire postoperative period in both low-SR and high-SR groups. This data suggests that a single dose of low-SR (0.5 mg/kg) or high-SR (1 mg/kg) effectively attenuates thermal hypersensitivity for at least 8 h in neonatal rat pups., Competing Interests: The authors have declared that no competing interests exist.

Electroencephalographic (EEG) activity is used to monitor the neurophysiology of the brain, which is a target organ of general anaesthesia. Besides its use in evaluating hypnotic states, neurophysiologic reactions to noxious stimulation can also be observed in the EEG. Recognising and understanding these responses could help optimise intraoperative analgesic management. This review describes three types of changes in the EEG induced by noxious stimulation when the patient is under general anaesthesia: (1) beta arousal, (2) (paradoxical) delta arousal, and (3) alpha dropout. Beta arousal is an increase in EEG power in the beta-frequency band (12-25 Hz) in response to noxious stimulation, especially at lower doses of anaesthesia drugs in the absence of opioids. It is usually indicative of a cortical depolarisation and increased cortical activity. At higher concentrations of anaesthetic drug, and with insufficient opioids, delta arousal (increased power in the delta band [0.5-4 Hz]) and alpha dropout (decreased alpha power [8-12 Hz]) are associated with noxious stimuli. The mechanisms of delta arousal are not well understood, but the midbrain reticular formation seems to play a role. Alpha dropout may indicate a return of thalamocortical communication, from an idling mode to an operational mode. Each of these EEG changes reflect an incomplete modulation of pain signals and can be mitigated by administration of opioid or the use of regional anaesthesia techniques. Future studies should evaluate whether titrating analgesic drugs in response to these EEG signals reduces postoperative pain and influences other postoperative outcomes, including the potential development of chronic pain., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: This RCT investigated the effect of opioid titration by three different nociception monitoring devices or clinical signs during general anaesthesia., Methods: Ninety-six patients undergoing radical retropubic prostatectomy with propofol/remifentanil anaesthesia were randomised into one of four groups to receive remifentanil guided by one of three nociception monitoring devices (surgical pleth index [SPI], pupillary pain index [PPI], or nociception level [NOL]) or by clinical judgement (control). Intraoperative remifentanil requirement was the primary endpoint, whereas recovery parameters and stress hormone levels were secondary endpoints., Results: The mean [95% confidence interval {CI}] remifentanil administration rate differed between the groups: control 0.34 (0.32-0.37), SPI 0.46 (0.38-0.55), PPI 0.07 (0.06-0.08), and NOL 0.16 (0.12-0.21) μg kg -1 min -1 (P<0.001). Intraoperative cessation of remifentanil administration occurred in different numbers (%) of patients: control 0 (0%), SPI 1 (4.3%), PPI 18 (75.0%), and NOL 11 (47.8%); P=0.002. The area under the curve analyses indicated differences in cumulative cortisol levels (mg L -1 min -1 ) amongst the groups: control 37.9 (33.3-43.1), SPI 38.6 (33.8-44.2), PPI 72.1 (63.1-82.3), and NOL 54.4 (47.6-62.1) (mean [95% CI]). Pairwise group comparison results were as follows: control vs SPI, P=0.830; control vs PPI, P<0.001; control vs NOL, P=0.001; SPI vs PPI, P<0.001; SPI vs NOL, P=0.002; and PPI vs NOL, P=0.009., Conclusions: The nociception monitoring devices and clinical signs reflect the extent of nociception differently, leading to dissimilar doses of remifentanil. Very low remifentanil doses were associated with an increase and higher remifentanil doses were accompanied by a decrease in serum cortisol concentrations. Use of nociception monitoring devices for guiding intra-operative opioid dosing needs further validation., Clinical Trial Registration: NCT03380949., (Copyright © 2020 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: Trigeminal neuralgia features jolts of pain along the distribution of the trigeminal nerve. If patients fail conservative management, microvascular decompression (MVD) is typically the next step in treatment. MVD consists of implanting a separating material, often Teflon, between the nerve and compressive lesions. A review found similar success and complication rates between Teflon and Ivalon, another commonly used material. The aim of this study was to analyze outcomes and complications associated with Teflon and Ivalon in MVD., Methods: We conducted a 2-center retrospective cohort study of trigeminal neuralgia treated with MVD between 2005 and 2019. Patients with no postoperative follow-up were excluded. Postoperative pain was graded using the Barrow Neurological Institute (BNI) pain intensity score. Relapse was defined as a BNI score of 4-5 during follow-up after initial pain improvement or an initial BNI score of 1-3., Results: The study included 221 MVD procedures in 219 patients. Ivalon was implanted in 121 procedures, and Teflon was implanted in 100 procedures. Multivariate analysis found that implant type had no effect on final BNI score (P = 0.305). Relapse rates were similar at 5- and 10-year follow-up (5-year: Ivalon 10.7%, Teflon 18.0%, P = 0.112; 10-year: Ivalon 11.6%, Teflon 19.0%, P = 0.123). There was no difference in postoperative immediate facial numbness (P = 0.125). Postoperative hearing difficulty was higher in the Ivalon cohort (8.4% vs. 1.0%; P = 0.016)., Conclusions: We found no significant difference in final BNI score or risk of relapse between Ivalon and Teflon. Complications were similar, although Ivalon was more associated with temporary postoperative hearing loss., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Consecutive exposure to high-dose remifentanil during anesthesia may induce remifentanil-induced postinfusion hyperalgesia (RPH). Dexmedetomidine, a highly selective α2-adrenergic receptor agonist, may have synergistic effects with opioids and aid in perioperative pain management. In this study, we hypothesized that an intraoperative bolus dose of intravenous dexmedetomidine could alleviate RPH in patients undergoing thyroidectomy under general anesthesia., Methods: Ninety patients undergoing thyroidectomy were randomly assigned to 1 of 3 groups: placebo, normal saline (group P); low-dose dexmedetomidine 0.2 μg·kg-1 (group LD); or high-dose dexmedetomidine 0.5 μg·kg-1 (group HD). Remifentanil was infused at a rate of 0.30 μg·kg-1·minute-1. Mechanical pain thresholds were measured using an Electronic von Frey device preoperatively and at 30 minutes, 6 hours, 24 hours, and 48 hours after surgery and were analyzed with 2-way repeated-measures analysis of variance (ANOVA) followed by Bonferroni post hoc comparison. We also recorded postoperative pain scores, the incidence of receiving rescue analgesics, and side effects up to 48 hours after surgery., Results: The mechanical pain thresholds around the skin incision were significantly higher in group LD compared to group P 30 minutes and 6 hours after surgery (mean ± standard deviation: [65.0 ± 25.2] vs [49.6 ± 24.4] g, mean difference [95% confidence interval]: 15.4 [0.3-30.5] g, P = .045 at 30 minutes; [65.9 ± 24.5] vs [49.3 ± 26.1] g, 16.6 [1.1-32.1] g, P = .032 at 6 hours). The pain thresholds around the skin incision were significantly higher in group HD compared to group P 30 minutes and 6 hours after surgery ([67.8 ± 21.7] vs [49.6 ± 24.4] g, 18.2 [3.1-33.3] g, P = .013 at 30 minutes; [68.3 ± 22.5] vs [49.3 ± 26.1] g, 19.0 [3.5-34.5] g, P = .011 at 6 hours). The incidence of hyperalgesia around the skin incision was lower in group HD than in group P 30 minutes and 6 hours after surgery (4 [13%] vs 14 [48%], P = .012 at 30 minutes, 4 [13%] vs 12 [41%], P = .045 at 6 hours), although no significant difference was observed between group LD and group P. Postoperative pain scores, the incidence of rescue analgesic demand, and postoperative side effects were not significantly different between the groups., Conclusions: An intraoperative intravenous bolus dose of dexmedetomidine 0.5 μg·kg-1 alleviates remifentanil-induced hyperalgesia in patients undergoing thyroidectomy without a significant difference in side effects., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 International Anesthesia Research Society.)

Abstract: The COVID-19 pandemic has had a tremendous impact, including on individuals with chronic pain. The social distancing policies necessary to slow the spread of SARS-CoV-2 have involved increased levels of social isolation. This cross-sectional survey study examined pain severity and interference among individuals with chronic pain during an early phase of social distancing mandates and identified characteristics of individuals who were most impacted. Approximately 4 to 8 weeks after social distancing mandates commenced in the state of Massachusetts, 150 patients with fibromyalgia, chronic spine, and postsurgical pain completed demographic, pain, social distancing, and validated psychosocial questionnaires. Patients self-reported an overall significant increase in pain severity and pain interference, compared with before social distancing, although both pain severity and interference were quite variable among individuals under conditions of social distancing. Several demographic, socioeconomic, and psychosocial factors were associated with greater pain severity and interference during social distancing. Multivariable linear regression demonstrated that female sex, nonwhite race, lower education, disability, fibromyalgia, and higher pain catastrophizing were independently associated with greater pain severity, while female sex and pain catastrophizing were independently associated greater pain interference. The findings suggest that individual differences among patients with chronic pain should be considered in the planning, development, and prioritization of interventions to improve pain care and to prevent worsening of symptoms during the continuing COVID-19 pandemic., (Copyright © 2020 International Association for the Study of Pain.)

Chronic post-thoracotomy pain is a debilitating condition after traumatic multiple rib fractures and surgery. We aimed to estimate the prevalence of chronic post-thoracotomy pain after traumatic multiple rib fractures in South Korea and explore factors associated with it. From October 2017 to June 2019, a cross-sectional survey of 100 adults, who had undergone thoracotomy due to traumatic fractures of two or more ribs 2 years to 3 months prior to the survey, was conducted in the regional trauma center in South Korea. In total, 80% and 65% patients reported any level and above moderate chronic pain, respectively. Quality of life was mostly below the normative value of the US general population. Forty-six percent patients had restrictive respiratory dysfunction, and 47% and 59% patients were classified as being at risk of above mild-level anxiety and depression, respectively. More than 70% of patients had a current opioid prescription. Multivariable logistic regression analysis showed weak evidence of association between acute, severe postoperative pain and chronic postsurgical pain (adjusted odds ratio 2.4, 95% confidence intervals 0.9 to 6.4). Collectively, chronic post-thoracotomy pain and associated incomplete recovery regarding respiratory, functional, and psychological outcomes were prevalent in patients with traumatic multiple rib fractures in South Korea.

Purpose of Review: We review the relevance of quantitative sensory testing (QST) in light of acute and chronic postoperative pain and associated challenges., Recent Findings: Predicting the occurrence of acute and chronic postoperative pain with QST can help identify patients at risk and allows proactive preventive management. Generally, central QST testing, such as temporal summation of pain (TSP) and conditioned pain modulation (CPM), appear to be the most promising modalities for reliable prediction of postoperative pain by QST. Overall, QST testing has the best predictive value in patients undergoing orthopedic procedures. Current evidence underlines the potential of preoperative QST to predict postoperative pain in patients undergoing elective surgery. Implementing QST in routine preoperative screening can help advancing traditional pain therapy toward personalized perioperative pain medicine.

Chronic postsurgical pain (CPSP) is a serious issue for many postoperative patients. Though there are numerous treatment options for the prevention of CPSP, none of them is optimal as the mechanisms of the transition from acute to chronic postoperative pain have not been elucidated. Ketamine and opioids have been administered for chronic postoperative pain treatment but induce severe adverse reactions and/or physical dependency. Here, we examined whether pre-administration of the nonselective N-methyl-d-aspartate (NMDA) receptor antagonist magnesium sulfate attenuates CPSP behavior and alters the expression of glutamate ionotropic receptor NMDA type subunit 1a (Grin1 mRNA) in a rat skin/muscle incision and retraction (SMIR) model. We assessed the effects of a single subcutaneous magnesium sulfate injection on nociceptive behaviors including guarding pain, mechanical hyperalgesia, and heat hypersensitivity in rats after SMIR surgery. We used reverse transcription-quantitative PCR (RT-qPCR) to evaluate Grin1 mRNA expression in the dorsal horn of the spinal cord on postoperative day 14. Compared with the vehicle, magnesium sulfate administration before SMIR surgery reduced mechanical hyperalgesia for 17 d Grin1 gene expression was significantly higher on the ipsilateral side than the contralateral side (P = 0.001) on postoperative day 14. The magnesium sulfate injection prevented Grin1 mRNA upregulation in the spinal cord dorsal horn. A single magnesium sulfate injection mitigated SMIR-induced mechanical hyperalgesia possibly by modulating Grin1 expression. Preoperative magnesium sulfate administration could prove to be a simple and safe CPSP treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The aim of this study was to assess whether the genotype of the serotonin transporter-linked polymorphic region (5-HTTLPR) in gastric cancer patients is associated with postoperative pain and pain threshold., Methods: We conducted a prospective cohort study of 251 patients scheduled for gastrectomy from May to September 2019. All patients enrolled in the study were asked to complete the Hospital Anxiety and Depression Scale questionnaire. Heat pain threshold (HPT), cold pain threshold (CPT) and Pressure pain threshold (PPT) were measured for all participants one day prior to surgery. Blood samples were collected for genetic testing. All patients were connected to a patient-controlled intravenous analgesia (PCIA) pump at the end of the surgery. After exclusion of 15 patients, the postoperative conditions of 236 patients were recorded., Results: Distribution of homozygous long (L/L), heterozygous (L/S), and homozygous short (S/S) 5-HTTLPR genotypes among participants were 26 (11.0%), 91 (38.6%), and 119 (50.4%), respectively. Heat pain threshold ( P  = 0.038) and Numerical rating scale (NRS) in the 1st postoperative 24 h ( P  = 0.026) were significantly different between long (L/L) and short (S/S) genotype carriers., Conclusions: In patients with gastric cancer, heat pain stimulation is associated with 5-HTTLPR polymorphism, and postoperative pain may be related to 5-HTTLPR polymorphism.

The aim was to compare short-term results of transvaginal hybrid-NOTES (NSR) with traditional laparoscopic technique in sigmoid resection (LSR) in cases of diverticulitis. Natural Orifice Transluminal Endoscopic Surgery has been evolved as a minimally invasive procedure to reduce the operative trauma due to the absence of specimen extraction through the abdominal wall causing less postoperative pain, and shorter hospital stay. Despite the increasing use and published case series of NSR for diverticulitis as a laparoscopic procedure with transvaginal stapling and specimen extraction, there are no studies comparing this procedure with LSR. Twenty NSR patients operated at the Cologne-Merheim Medical Center have been documented and compared with 20 female LSR patients matched for body mass index, American Society of Anesthesiologists-classification (ASA), Hansen/Stock classification, and age. To ensure comparability regarding peri- and postoperative care, only procedures performed by the same surgeon were included. Procedural time, intra- and postoperative complications, conversion rate, postoperative pain, the duration of an epidural catheter, analgesic consumption, and postoperative length of hospital stay were analyzed. There were no significant differences in the sum of pain levels (p = 0.930), length of procedure (p = 0.079), intra- and postoperative complications, as well as duration of an epidural catheter. On the contrary, there were significant positive effects for NSR on morphine requirement at day seven and eight (p = 0.019 and p = 0.035 respectively) as well as the postoperative length of hospital stay (p = 0.031). This retrospective study reveals significant positive effects for NSR compared to LSR regarding length of hospital stay as well as morphine consumption after removal of the epidural catheter, whereas there were no significant differences in complication rate and procedural time. In summary, NSR is an adequate alternative to traditional laparoscopic sigmoid resection considering the surgeons experience and the patient's personal preferences.

Background: There is currently no gold standard instrument for assessing pain in severely cognitively impaired adults who are unable to provide self-report., Aims: To determine interrater reliability of the PACSLAC and PAINAD in assessing pain behaviors in patients with the same pain stimulus, determine the consistency of the reliable changes between and within the instruments and assess nurse preference for either instrument., Design: A single-group, within-subjects repeated-measures design was implemented., Setting: The study took place in a small suburban hospital., Participants/subjects: Pain levels were observed at 24, 48, and 72 hours postsurgery using two instruments: Pain Assessment Checklist for Seniors with Limited Ability to Communicate (PACSLAC) and Pain Assessment in Advanced Dementia Scale (PAINAD). These instruments were selected because they are among the most commonly recommended tools for clinical use. Interrater reliability was analyzed along with reliable changes in pain for each period, and the study concluded with the nurse raters completing a preference survey., Methods: A convenience sample of 30 patients was used with a diagnosis of severe dementia rendering the patient unable to reliably express pain, 60+ years of age, recovering from hip fracture surgery., Results: Greater interrater reliability was found for the PACSLAC, with reliable change potentially affected by the type and level of pain medication. The nurses' preference for the tool was split., Conclusions: The results of this study indicate that the PACSLAC may be the more reliable tool over the PAINAD; however, rater training and familiarity with the tool is critical., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Loop electrosurgical excision procedure may be performed under local anesthesia or general anesthesia, and practice patterns differ worldwide. No randomized head-to-head comparison has been published to confirm or refute either practice., Objective: This study aimed to compare loop electrosurgical excision procedure under local anesthesia vs general anesthesia regarding patient satisfaction and procedure-related outcomes such as rates of involved margins, complications, pain, and blood loss., Study Design: Consecutive women referred to our colposcopy unit were recruited. Loop electrosurgical excision procedure was performed under local anesthesia with 4 intracervical injections of bupivacaine hydrochloride 0.5% or under general anesthesia with fentanyl, propofol, and a laryngeal mask with sevoflurane maintenance. The primary endpoint was patient satisfaction assessed on the day of surgery and 14 days thereafter using a Likert scale (score 0-100) and a questionnaire. Secondary endpoints included rates of involved margins, procedure-related complications, pain, blood loss, and surgeon preference. Results were compared using nonparametric and chi-square tests., Results: Between July 2018 and February 2020, we randomized 208 women, 108 in the local anesthesia arm and 100 in the general anesthesia arm. In the intention-to-treat analysis, patient satisfaction did not differ between the study groups directly after surgery (Likert scale 100 [90-100] vs 100 [90-100]; P=.077) and 14 days thereafter (Likert scale 100 [80-100] vs 100 [90-100]; P=.079). In the per-protocol analysis, women in the local anesthesia arm had significantly smaller cone volumes (1.11 cm 3 [0.70-1.83] vs 1.58 cm 3 [1.08-2.69], respectively; P<.001), less intraoperative blood loss (Δhemoglobin, 0.2 g/dL [-0.1 to 0.4] vs 0.5 g/dL [0.2-0.9]; P<.001), and higher satisfaction after 14 days (100 [90-100] vs 100 [80-100]; P=.026), whereas surgeon preference favored general anesthesia (90 [79-100] vs 100 [90-100], respectively; P=.001). All other secondary outcomes did not differ between groups (resection margin status R1, 6.6% vs 2.1% [P=.26]; cone fragmentation, 12.1% vs 6.3% [P=.27]; procedure duration, 151.5 seconds [120-219.5] vs 180 seconds [117-241.5] [P=.34]; time to complete hemostasis, 60 seconds [34-97] vs 70 seconds [48.25-122.25] [P=.08]; complication rate, 3.3% vs 1.1% [P=.59]). In a multivariate analysis, parity (P=.03), type of transformation zone (P=.03), and cone volume (P=.02) and not study group assignment, age, body mass index, and degree of dysplasia independently influenced the primary endpoint., Conclusion: Loop electrosurgical excision procedure under local anesthesia is equally well tolerated and offers patient-reported and procedure-related benefits over general anesthesia, supporting the preferred practice in some institutions and refuting the preferred practice in others., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Acid-sensing ion channel 3 (ASIC3) upregulation has been reported in dorsal root ganglion neurons after incision and contributes to postoperative nociception. This study hypothesized that upregulation of ASIC3 in incised tissues is induced by nerve growth factor through the phosphoinositide 3-kinase/protein kinase B signaling pathway., Methods: A plantar incision model was established in adult male and female Sprague-Dawley rats. ASIC3 was inhibited by APETx2 treatment, small interfering RNA treatment, or ASIC3 knockout. Sciatic nerve ligation was performed to analyze ASIC3 transport. A nerve growth factor antibody and a phosphoinositide 3-kinase inhibitor were used to investigate the mechanism by which nerve growth factor regulates ASIC3 expression., Results: Acid-sensing ion channel 3 inhibition decreased incisional guarding and mechanical nociception. ASIC3 protein levels were increased in skin and muscle 4 h after incision (mean ± SD: 5.4 ± 3.2-fold in skin, n = 6, P = 0.001; 4.3 ± 2.2-fold in muscle, n = 6, P = 0.001). Sciatic nerve ligation revealed bidirectional ASIC3 transport. Nerve growth factor antibody treatment inhibited the expression of ASIC3 (mean ± SD: antibody 2.3 ± 0.8-fold vs. vehicle 4.9 ± 2.4-fold, n = 6, P = 0.036) and phosphorylated protein kinase B (mean ± SD: antibody 0.8 ± 0.3-fold vs. vehicle 1.8 ± 0.8-fold, n = 6, P = 0.010) in incised tissues. Intraplantar injection of nerve growth factor increased the expression of ASIC3 and phosphorylated protein kinase B. ASIC3 expression and incisional pain-related behaviors were inhibited by pretreatment with the phosphoinositide 3-kinase inhibitor LY294002., Conclusions: Acid-sensing ion channel 3 overexpression in incisions contributes to postoperative guarding and mechanical nociception. Bidirectional transport of ASIC3 between incised tissues and dorsal root ganglion neurons occurs through the sciatic nerve. Nerve growth factor regulates ASIC3 expression after plantar incision through the phosphoinositide 3-kinase/protein kinase B signaling pathway., (Copyright © 2020, the American Society of Anesthesiologists, Inc. All Rights Reserved.)