Chronic pain after surgery: pathophysiology, risk factors and prevention

Chronic postsurgical pain following gastrointestinal surgery - A scoping review

BACKGROUND

Chronic postsurgical pain (CPSP) has a great impact on quality of life and socioeconomic status. The mechanisms behind CPSP remain poorly understood, however type of surgical intervention seems to play a role. Gastrointestinal surgeries are common procedures, yet research in CPSP following gastrointestinal surgery is limited. The objective of this scoping review was to map the current literature on CPSP following gastrointestinal surgery, identifying how CPSP have been investigated, and which evidence gaps exist.

METHODS

This scoping review followed a pre-published protocol and PRISMA-ScR guidelines. A search was carried out in Medline, Embase, CINAHL, Cochrane Central, Clinicaltrials.Gov, and Google Scholar. Eligible studies were original studies involving adults, undergoing gastrointestinal surgery, who had a pain assessment ≥30 days postoperatively. A two-phase screening process and data charting were done by two independent reviewers.

RESULTS

A total of 53 studies were included, published between 2001 and 2024, predominantly across Europe and Asia. The range of CPSP prevalence reported was 3.3%-46.1%. Only half the studies clearly defined CPSP, and the timing and manner of pain assessment varied considerably. Twenty-seven studies assessed risk factors for developing CPSP: preoperative pain and acute postoperative pain were consistently significant.

CONCLUSIONS

There was a wide consensus on CPSPs' negative impact on quality of life. CPSP following gastrointestinal surgery is prevalent and significantly impacts quality of life. Standardized definitions and methodologies to improve the comparability and reliability of the findings across studies are needed. Future research should focus on CPSP following specific surgical procedures to develop tailored prevention and treatment strategies.

A single epidural administration of butorphanol combined with patient-controlled intravenous analgesia relieves postpartum contraction pain after cesarean section: A randomized clinical trial

BACKGROUND

Numerous studies have shown that butorphanol exerts an inhibitory effect on visceral pain. The aim of this study was to observe the effects of a single epidural administration of butorphanol combined with patient-controlled intravenous analgesia on postpartum uterine contraction pain after cesarean section.

METHODS

We randomly allotted 121 women undergoing cesarean section surgery procedure to 3 groups: 31 cases were excluded; and 90 cases were divided into group S (blank control, n = 30), group I (intravenous butorphanol, n = 30), and group E (butorphanol administered into the epidural cavity, n = 30). We then observed changes in the indices of uterine contraction pain and intraoperative stretch pain for the 3 groups.

RESULTS

(1) In terms of the uterine contraction pain, the visual analog scale scores of group I were lower than those for group S at 10 minutes (P = .001), 20 minutes (P < .001), 30 minutes (P < .001), 1 hour (P < .001), 2 hours (P < .001), and 4 hours (P < .001) after the epidural administration. The visual analog scale scores of group E were lower than those of group I at 10 minutes (P < .001), 20 minutes (P < .001), 30 minutes (P < .001), 1 hour (P < .001), 2 hours (P < .001), 4 hours (P < .001), and 6 hours (P < .001) after the administration. (2) In terms of intraoperative traction reactions, sedation, and comfort during the operation, group E was superior to groups S and I at any time points (all P < .043).

CONCLUSIONS

Butorphanol single epidural administration combined with intravenous patient-controlled analgesia can effectively reduce the pain of uterine contraction and intraoperative traction reaction and improve perioperative comfort of the parturient.

Long term inguinal pain comparing TEP to Lichtenstein repair: the TEPLICH RCT 8 years follow-up

PURPOSE

To investigate long-term chronic postoperative inguinal pain (CPIP), QoL and recurrence in patients with a primary inguinal hernia comparing TEP to Lichtenstein.

MATERIAL AND METHODS

A questionnaire-based follow-up containing the Inguinal Pain Questionnaire (IPQ), the Cunningham Pain Scale and SF-36 was done 8 years after the TEPLICH RCT. The main objective was non-ignorable pain last week according to IPQ. A phone interview was performed with patients reporting new non-ignorable pain and those having a suspected recurrence. Records were scanned for long-term CPIP and recurrences. A lost to follow-up analysis was performed.

RESULTS

A total of 322 of 366 patients (88%) completed the follow-up of mean 7.94 years (5-10.75 years). Non-ignorable pain last week was reported by 7.6% in TEP and 6.7% in Lichtenstein (p < 0.73). New non-ignorable pain was reported by 5 patients. No difference in non-ignorable pain over time (1-8 years) was observed within groups. Moderate to severe pain, according to Cunningham, was reported by 3.8% in TEP and 5.5% in Lichtenstein (p < 0.48). QoL remained above the Swedish norm. No recurrences occurred after 3 years follow-up. The lost to follow-up analysis showed no difference in non-ignorable pain.

CONCLUSIONS

RCTs, comparing TEP to Lichtenstein repair with follow-up ≥ 5 years regarding CPIP are sparse with conflicting data. In this study, low frequencies of CPIP present at 3 years seem to persist at 8 years. Recurrences occured within the first 3 years. Patients need to be informed of the risk of long-term CPIP.

Comprehensive Pain Management in Total Joint Arthroplasty: A Review of Contemporary Approaches

Background: Total hip and knee arthroplasties are among the most effective and widely performed procedures in modern medicine, providing substantial benefits to patients with end-stage osteoarthritis. These surgeries have transformed the treatment of degenerative joint disease, significantly enhancing functionality and quality of life for patients. Despite considerable advancements in surgical techniques and postoperative care, managing postoperative pain remains a major challenge, impacting both clinical recovery and patient satisfaction. The persistence of postoperative pain as a barrier to recovery underscores the need for improved pain management strategies. Methods: A comprehensive narrative review of the literature was conducted, focusing on the physiological mechanisms underlying surgical pain, the role of anesthesia techniques, and the development of multimodal pain management approaches used in total joint arthroplasty. This review emphasizes the components of modern multimodal strategies, which combine multiple pharmacologic and non-pharmacologic methods to address the various mechanisms of postoperative pain. Results: Current pain management strategies employ a dynamic, multimodal approach that covers the perioperative period. These strategies aim to optimize pain control while minimizing side effects. They incorporate a range of methods, including nerve blocks, non-opioid analgesics, opioids, and non-pharmacologic techniques such as physical therapy. However, evidence regarding the efficacy and optimal combinations of these interventions varies widely across studies. Conclusions: This variation has led to inconsistent pain management practices across institutions. To standardize and improve care, this paper presents the authors' institutional pain management model, offering a potential framework for broader application and adaptation in the field of joint arthroplasty.

Efficacy of azasetron on postoperative chronic pain after pulmonary surgery: a randomized triple-blind controlled trial

BACKGROUND

Inhibition of 5-HT3 (5-Hydroxyl Tryptamine) receptors is known to enhance morphine analgesia in animal models. We tested the efficacy of azasetron, a 5-HT3 receptor antagonist, on postoperative chronic pain after pulmonary surgery in a randomized triple-blind controlled study.

METHODS

A total of 250 patients who were scheduled to receive pulmonary surgery were randomized to patient-controlled analgesia (PCA) using 200 µg sufentanil with normal saline or 200 µg sufentanil with 20 mg azasetron. The numerical rating scale of pain (NRS) was recorded at baseline, postoperative day (POD) 1, 2, 3, 90, and 180. Negative binomial regression was used to identify associated factors for postoperative NRS six months after surgery.

RESULTS

The results showed that azasetron did not affect the primary outcomes: the incidence of postoperative chronic pain on POD90 and 180. However, azasetron decreased postoperative NRS at rest and activity on POD1, 2, and 3. Furthermore, azasetron decreased postoperative nausea and vomiting on POD1 and 2. Univariate and multivariate negative binomial regression analysis identified preoperative pain, smoking, drinking and open surgery are risk factors of chronic pain six months after surgery.

CONCLUSIONS

Azasetron did not affect the incidence of chronic pain after pulmonary surgery. The presence of preoperative pain, smoking, drinking, and open surgery were found to be associated with chronic pain six months after surgery.

CLINICAL TRIAL REGISTRATION

The trial was registered prior to patient enrollment at the Chinese Clinical Trial Registry (ChiCTR2200060139), 20/05/2022; the site url is https://www.chictr.org.cn/ .

The efficacy and safety of ankle blocks for foot and ankle surgery: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Peripheral nerve blocks may be essential elements in a multimodal pain management regime following foot and ankle surgery. We assessed the effects of ankle blocks compared with no intervention/sham block or a sciatic nerve block in patients undergoing surgery of the foot or ankle.

METHODS

We searched CENTRAL, Medline, and Embase for randomised clinical trials comparing ankle block with no intervention/sham block or a sciatic nerve block for patients undergoing surgery of the foot or ankle. Our primary outcomes were duration of analgesia and cumulative 24-hour opioid consumption. We followed the recommendations of the Cochrane Handbook, and performed meta-analysis, Trial Sequential Analysis (TSA), and assessed the risk of bias and certainty of the evidence using the GRADE approach.

RESULTS

We included five trials (362 participants) comparing ankle block with no intervention/sham block and three trials (247 participants) comparing ankle block with a sciatic nerve block. Ankle block may increase the duration of analgesia when compared with no intervention/sham block (MD 431 min; 96.7% CI 208 to 654), but the evidence was very uncertain. Duration was decreased when compared with a sciatic nerve block (MD -410 min; 96.7% CI -462 to -358). The ankle block duration was probably important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain in both comparisons.

CONCLUSIONS

Ankle block may increase the duration of analgesia when compared with no intervention/sham block, but the evidence was very uncertain, and decrease the duration of analgesia when compared with a sciatic nerve block. The ankle block duration was probably clinically important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain.

Postoperative Pain Following Eye Enucleation: A Prospective Observational Study

Background and Objectives: Enucleation of an eye is the most invasive procedure in ophthalmologic surgery. It can be the result of various diseases (malignant/chronic/trauma/infection) and is nevertheless relatively rare, but leads to the loss of a strongly innervated neuronal organ. This study systematically evaluates postoperative pain levels following enucleation of the eye globe. Materials and Methods: This prospective single-center study enrolled twenty-four patients undergoing enucleation of the eye globe. Perioperatively all patients completed (preoperative day, day of surgery, 1st, 2nd, and 3rd day following surgery) standardized questionnaires concerning their pain experience and treatment-related side-effects (internal protocol, QUIPS, painDETECT®). Patients received usual pain therapy in an unstandardized individual manner. Results: Preoperatively, mean average pain intensity of all included patients was 3.29 ± 2.46 (range, 0-8), 3.29 ± 3.24 (range, 0-8) on the day of surgery, 4.67 ± 1.90 (range, 2-10) on day 1, 3.25 ± 1.39 (range, 1-6) on day 2, and 2.71 ± 1.30 (range, 1-6) on day 3 after surgery. Mean maximum pain intensity was 4.71 ± 3.28 (range, 0-10) preoperatively, 4.04 ± 3.78 (range, 0-10) on the day of surgery, 5.75 ± 2.01 (range, 2-10) on day 1, 4.25 ± 1.89 (range, 2-10) on day 2, and 3.88 ± 1.54 (range, 2-8) on day 3 after surgery. Nineteen patients (79.2%) stated that they would have preferred more pain therapy. Conclusions: Patients undergoing eye enucleation report pain sensations in need of intervention in this university hospital. Thus, effective standardized pain treatment concepts are now a high priority to be established in an interdisciplinary manner containing standardized regimens and continuous regional procedures. Awareness of this problem in the medical team should be sharpened through targeted training and information.

Mild Traumatic Brain Injury-Induced Augmented Postsurgical Pain Is Driven by Central Serotonergic Pain-Facilitatory Signaling

BACKGROUND

Individuals recovering from mild traumatic brain injury (mTBI) have increased rates of acute and chronic pain. However, the mechanism through which mTBI triggers heightened pain responses and the link between mTBI and postsurgical pain remain elusive. Recent data suggest that dysregulated serotonergic pain-modulating circuits could be involved. We hypothesized that mTBI triggers dysfunction in descending serotonergic pain modulation, which exacerbates acute pain and delays pain-related recovery after surgery.

METHODS

Using mouse models of mTBI and hindpaw incision for postsurgical pain in C57BL/6J mice, mechanical withdrawal thresholds were assessed throughout the postsurgical period. To determine whether mTBI leads to persistent alteration of endogenous opioid tone, mu-opioid receptors (MORs) were blocked with naloxone. Finally, the role of descending serotonergic signaling on postsurgical allodynia in animals with mTBI was examined using ondansetron (5-HT 3 receptor antagonist) or a serotonin-specific neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT), to ablate descending serotonergic fibers. The treatment effects on withdrawal thresholds were normalized to baseline (percentage of maximum possible effect, MPE%), and analyzed using paired t -test or 2-way repeated-measures ANOVA with post hoc multiple comparisons.

RESULTS

Post-mTBI mice demonstrated transient allodynia in hindpaws contralateral to mTBI, while no nociceptive changes were observed in sham-mTBI animals (mean difference, MD, MPE%, post-mTBI day 3: -60.9; 95% CI, -88.7 to -35.0; P < .001). After hindpaw incision, animals without mTBI exhibited transient allodynia, while mice with prior mTBI demonstrated prolonged postsurgical allodynia (MD-MPE% postsurgical day 14: -65.0; 95% CI, -125.4 to -4.5; P = .04). Blockade of MORs using naloxone transiently reinstated allodynia in mTBI animals but not in sham-mTBI mice (MD-MPE% post-naloxone: -69.9; 95% CI, -94.8 to -45.1; P < .001). Intrathecal administration of ondansetron reversed the allodynia observed post-mTBI and postincision in mTBI mice (compared to vehicle-treated mTBI mice, MD-MPE% post-mTBI day 3: 82.7; 95% CI, 58.5-106.9; P < .001; postsurgical day 17: 62.5; 95% CI, 38.3-86.7; P < .001). Both the acute allodynia after TBI and the period of prolonged allodynia after incision in mTBI mice were blocked by pretreatment with 5,7-DHT (compared to sham-mTBI mice, MD-MPE% post-mTBI day 3: 0.5; 95% CI, -18.5 to 19.5; P = .99; postsurgical day 14: -14.6; 95% CI, -16.7 to 45.9; P = .48). Similar behavioral patterns were observed in hindpaw ipsilateral to mTBI.

CONCLUSIONS

Collectively, our results show that descending serotoninergic pain-facilitating signaling is responsible for nociceptive sensitization after mTBI and that central endogenous opioid tone opposes serotonin's effects. Understanding brain injury-related changes in endogenous pain modulation may lead to improved pain control for those with TBI undergoing surgery.

Effect and safety profile of topical lidocaine on post-surgical neuropathic pain and quality of life: A systematic review and meta-analysis

STUDY OBJECTIVE

Post-surgical chronic pain with a neuropathic component is usually more severe and leads to worse quality of life. We conducted this systematic review to examine the evidence of topical lidocaine for post-surgical neuropathic pain.

DESIGN

Systematic review with meta-analysis.

SETTING

Published randomized controlled trials (RCTs) comparing topical lidocaine with placebo or no topical lidocaine for post-surgical neuropathic pain.

PATIENTS

Seven RCTs including 585 patients.

INTERVENTIONS

We systematically searched databases for randomized controlled trials (RCTs) investigating the effect and safety outcomes of topical lidocaine compared with placebo or no intervention.

MEASUREMENTS

We conducted meta-analyses to evaluate the effect of topical lidocaine on pain intensity, adverse events, and quality of life. Standardized mean difference (SMD) and relative risk (RR) with 95% CIs were effect measures for continuous and dichotomous outcomes, respectively. We assessed the risk of bias of included trials and the certainty of evidence for each outcome.

MAIN RESULTS

Our review included 7 studies with 585 participants. There is moderate certainty evidence that topical lidocaine may increase the likelihood of global pain relief, with a relative risk (RR) of 1.98 (95% confidence interval (CI): 1.04, 3.76; I2 = 70%, P = 0.04). Low certainty evidence suggested topical lidocaine may lead to more reduction in pain intensity (SMD: -0.70; 95% confidence interval: -1.46, 0.06; I2 = 93%, P = 0.07). High certainty evidence showed that topical lidocaine did not increase the adverse event risk (RR: 1.04; 95% CI: 0.93, 1.16; I2 = 0%, P = 0.51).

CONCLUSIONS

Topical lidocaine may lead to pain relief and is safe to use for patient with post-surgical pain, though its impact on quality of life is unclear. This review supports the use of topical lidocaine for patients with post-surgical pain, and reveals the evidence gap in topical lidocaine use. (Registration: PROSPERO CRD42021294100).

2-Hydroxybenzohydrazide as a novel potential candidate against nociception, inflammation, and pyrexia: in vitro, in vivo, and computational approaches

The current study was designed to evaluate the 2-hydroxybenzohydrazide (HBH) as a drug having efficacy against pyrexia, inflammation, and nociception. Besides, the therapeutic effects of HBH on oxidative stress and C-reactive proteins were also evaluated. The pharmacological studies on HBH (20-60 mg/kg) were conducted using nociception, inflammation, and pyrexia standard models. Naloxone antagonism was performed to assess the possible involvement of opioidergic mechanisms. The antioxidant study was conducted on ABTS and DPPH assays using gallic acid as a standard. Moreover, the binding capability of HBH with enzymes cyclooxygenase-I/II (COX-I/II) was determined using molecular modeling analysis. The findings indicated that the HBH dose-dependently inhibited pain, inflammation, and pyrexia. The HBH has significant anti-nociceptive and anti-inflammatory activities at 60 mg/kg (***p < 0.001), similar to the lower doses of diclofenac sodium (50 mg/kg) and tramadol (30 mg/kg). The HBH at 60 mg/kg reduced pyrexia as paracetamol (150 mg/kg). The HBH at 20-60 mg/kg doses declined the plasma C-reactive protein concentration. The mechanistic studies showed that the anti-nociceptive effect of HBH was antagonized by naloxone, indicating that the opioidergic mechanisms are involved. Furthermore, computational studies showed that the HBH exhibited an affinity for COX-I/II target receptors. The HBH significantly inhibited ABTS and DPPH radicals (IC50 = 33.81 and 26.74 μg/ml). These results proposed that the HBH has significant antipyretic, anti-inflammatory, and anti-nociceptive activities involving opioidergic mechanism.

Effectiveness of current perioperative telemonitoring on postoperative outcome in patients undergoing major abdominal surgery: A systematic review of controlled trials

BACKGROUND

Perioperative telemonitoring of patients undergoing major surgery might lead to improved postoperative outcomes. The aim of this systematic review is to evaluate the effectiveness of current perioperative telemonitoring interventions on postoperative clinical, patient-reported, and financial outcome measures in patients undergoing major surgery.

METHODS

For this systematic review, PubMed, CINAHL, and Embase databases were searched for eligible articles published between January 1, 2009 and March 15, 2021. Studies were eligible as they described: (P) patients aged 18 years or older who underwent major abdominal surgery, (I) perioperative telemonitoring as intervention, (C) a control group receiving usual care, (O) any type of postoperative clinical, patient-reported, or financial outcome measures, and (S) an interventional study design.

RESULTS

The search identified 2958 articles of which 10 were eligible for analysis, describing nine controlled trials of 2438 patients. Perioperative telemonitoring comprised wearable biosensors (n = 3), websites (n = 3), e-mail (n = 1), and mobile applications (n = 2). Outcome measures were clinical (n = 8), patient-reported (n = 5), and financial (n = 2). Results show significant improvement of recovery time, stoma self-efficacy and pain in the early postoperative phase in patients receiving telemonitoring. Other outcome measures were not significantly different between the groups.

CONCLUSION

Evidence for the effectiveness of perioperative telemonitoring in major surgery is scarce. There is a need for good quality studies with sufficient patients while ensuring that the quality and usability of the technology and the adoption in care processes are optimal.

Patient Satisfaction and Quality of Life After Mastectomy at King Abdulaziz Medical City, Jeddah

Background Overall well-being after surgical intervention is one of the most important aspects of assessing quality of life (QOL), yet it is not well explored in the literature. In this paper, it was necessary to involve the patient's perspective of the nature of their QOL. The burden of being diagnosed with breast cancer is an adaptation to a new lifestyle, having to deal with disease stigma, interpersonal relations problems, and being limited to specific clothing. This can be very challenging for patients. This study aims to identify which patient group, based on their treatment regimen, exhibits higher levels of satisfaction and dissatisfaction compared to other groups. Methods A retrospective, cross-sectional study analyzing the QOL among female breast cancer patients who underwent mastectomy, with or without breast reconstruction, in King Abdulaziz Medical City, Jeddah, between 2009 and 2022. Patients' demographics and phone numbers were obtained from each patient's medical record file in our hospital. Phone call-based interviews were conducted to contact patients to assess their QOL, satisfaction, and regrets after surgery. We excluded patients who do not speak Arabic, are illiterate, have memory disorders, patients who underwent lumpectomy or palliative mastectomy, patients with metastatic stage 4 cancer at the time of diagnosis, patients who are males, and patients who passed away. Results A total of 2,309 patients were screened during the period aforementioned; a total of 346 patients met our inclusion criteria. All of whom are female participants with a current mean age of 52.3 ± 11.5 years. There were 301 (86.99%) participants reported being satisfied, while only 45 (13.01%) participants reported being unsatisfied with surgery outcomes. Although the majority of participants were satisfied after mastectomy, many of them still struggled with psychological, social, and/or emotional challenges. These challenges can have a significant impact on a patient's overall well-being and QOL and must be addressed to provide patients with the highest quality of care possible. Conclusion The study findings highlight the significant impact of mastectomy on patients' lives. It is important to consider individual patient experiences and circumstances when evaluating treatment outcomes and patient satisfaction. We observed that patient satisfaction may vary depending on several factors, including patients' baseline satisfaction. Those factors may be psychological, such as body image issues, low self-esteem, the feeling of losing a body part, and fear of recurrence or metastasis. Other factors may be postoperative-related complications, including lymphedema, redundant skin, chronic pain, and operation scar. Additionally, factors may be socially related, such as loss of confidence, social withdrawal, embarrassment, inability to buy prostheses, being limited to specific clothes, and occupational impact.

Preoperatively assessed offset analgesia predicts acute postoperative pain following orthognathic surgery

OBJECTIVES

High intensity and longer duration of acute postoperative pain are generally associated with a higher risk of developing chronic postoperative pain. Therefore, it is important to identify the preoperative predictors for acute postoperative pain. Preoperative evaluation of offset analgesia (OA) and the Pain Catastrophising Scale (PCS) may be potential predictors for acute postoperative pain. This study aimed to investigate the relationship between preoperative OA, PCS, and acute postoperative pain following orthognathic surgery.

METHODS

Thirty patients (19 females) scheduled to undergo orthognathic surgery were included in this study. OA and PCS were evaluated preoperatively, and the patients reported their postoperative pain intensity using the visual analogue scale [0-100 mm] until it reached zero (number of days with pain). OA was induced on the dominant forearm via three consecutive painful heat pulses delivered for 5 s (T1=46 °C), 5 s (T2=47 °C), and 20 s (T3=46 °C). Subsequently, the associations between OA, PCS, and the number of days with pain were analysed.

RESULTS

The median duration of postoperative pain was 10.3 days. Multiple linear regression analysis showed a significant (p=0.0019) predictive value of OA (p=0.008) for the number of days with pain. The PCS-magnification component was positively correlated with the number of days with pain (R=0.369, p=0.045), with no predictive values of PCS-total and PCS-subscale scores observed.

CONCLUSIONS

Preoperative evaluation of OA may be a new individualised, predictive tool for the number of days with acute postoperative pain following orthognathic surgery; hence, a possible biomarker for the patient's vulnerability to developing chronic postoperative pain.

ETHICAL COMMITTEE NUMBER

The study was approved by the Ethics Committee of Meikai University (A1624, A2113).

TRIAL REGISTRY NUMBER

This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) Clinical Trial (Unique ID: UMIN000026719, UMIN000046957).

Prevalence and Risk Factors for Chronic Postsurgical Pain after Cardiac Surgery: A Single-center Prospective Cohort Study

BACKGROUND

Chronic postsurgical pain is a common complication of surgery. The role of psychologic risk factors like depression and anxiety is substantially understudied in cardiac surgery. This study sought to identify perioperative factors associated with chronic pain at 3, 6, and 12 months after cardiac surgery. The authors hypothesize that baseline psychologic vulnerabilities have a negative influence on chronic postsurgical pain.

METHODS

The authors prospectively collected demographic, psychologic, and perioperative factors in a cohort of 1,059 patients undergoing cardiac surgery at the Toronto General Hospital between 2012 and 2020. Patients were followed and completed chronic pain questionnaires at 3, 6, and 12 months after surgery.

RESULTS

The study included 767 patients who completed at least one follow-up questionnaire. The incidence of postsurgical pain (more than 0 out of 10) at 3, 6, and 12 months after surgery was 191 of 663 (29%), 118 of 625 (19%), and 89 of 605 (15%), respectively. Notably, among patients reporting any pain, the incidence of pain compatible with a neuropathic phenotype increased from 56 of 166 (34%) at 3 months to 38 of 97 (39%) at 6 months and 43 of 67 (64%) at 12 months. Factors associated with postsurgical pain scores at 3 months include female sex, pre-existing chronic pain, previous cardiac surgery, preoperative depression, baseline pain catastrophizing scores, and moderate-to-severe acute pain (4 or more out of 10) within 5 postoperative days.

CONCLUSIONS

Nearly one in three patients undergoing cardiac surgery reported pain at 3 months of follow-up, with approximately 15% reporting persistent pain at 1 yr. Female sex, pre-existing chronic pain, and baseline depression were associated with postsurgical pain scores across all three time periods.

EDITOR’S PERSPECTIVE

Incidence of postoperative administration of opioids in dogs undergoing a tibial plateau leveling osteotomy after intra-operative liposomal bupivacaine administration with or without morphine epidural

OBJECTIVE

To determine the influence of two intraoperative pain management protocols on the need for additional opioids in patients receiving an epidural and periarticular liposomal bupivacaine (PLB) vs. PLB alone in the 12-24 h period after undergoing a TPLO.

STUDY DESIGN

Retrospective study.

ANIMALS

One hundred seventy-four dogs with cranial cruciate ligament tears presenting for TPLO.

METHODS

Medical records of dogs presenting for a unilateral or bilateral cranial cruciate ligament tear who had a TPLO performed were reviewed for signalment, weight, body condition score, and peri-operative pain management protocol. Dogs were divided into two groups: those who received an epidural and PLB, and those who received only PLB. Post-operative opioid administration was recorded for each group.

RESULTS

Patients who received an epidural and PLB received fewer postoperative opioids. There were 36% fewer opioid injections administered to dogs who received epidurals compared to dogs who did not receive epidurals (IRR) (95% CI) = 0.64 (0.45-0.92), P = 0.02). BCS was not a significant predictor of the post-operative opioid requirement (IRR (95% CI) = 1.3 (0.75-2.4), P = 0.38). When adjusting for BCS as a possible confounder, there were 39% fewer opioid injections in dogs who received epidurals than dogs without (IRR (95% CI) = 0.61 (0.42-0.88), P = 0.009).

CONCLUSIONS

The incidence of postoperative opioid administration was significantly diminished in patients receiving both an epidural and PLB.

CLINICAL SIGNIFICANCE

Administration of an epidural in addition to infiltration of PLB significantly decreased the incidence of postoperative opioid administration in dogs undergoing a TPLO.

Pre-Trauma Pain Is the Strongest Predictor of Persistent Enhanced Pain Patterns after Severe Trauma: Results of a Single-Centre Retrospective Study

Background and Objectives: Traumatic injuries are a significant public health issue worldwide, with persistent enhanced pain being a common complication following severe trauma. Persistent and chronic pain can have a profound impact on patients' quality of life, affecting physical, emotional, and social functioning. This study aimed to investigate the pain patterns of trauma patients before and after severe trauma, and identify the predictors of persisting pain after injury. Materials and Methods: A total of 596 patients of a level-one trauma centre with severe trauma were included in this study. The Trauma Outcome Profile Scale was used to assess pain severity before and after trauma, and a logistic regression analysis was performed to determine the most significant predictors of relevant pain after severe trauma. Results: The mean age of the included patients was 48.2 years, and 72% were males. The most frequent cause of injury was traffic accidents, and the mean Injury Severity Score was 17.6. Nearly half of the patients experienced reduced pain-related quality of life after trauma, with persisting pain predominantly occurring in the neck, spine, shoulder, pelvis, hip, knee, and feet. Even minor injuries led to increased pain scores. Preexisting pain before injury (OR: 5.43; CI: 2.60-11.34), older age (OR: 2.09, CI: 1.22-3.27), female gender (OR: 1.08, CI: 0.73-1.59), and high injury severity (OR: 1.80, CI: 1.20-2.69) were identified as significant predictors of enhanced pain. Conclusions: These findings highlight the importance of considering pre-existing pain, body area, and injury severity in assessing the risk of persistent pain in trauma patients.

Pre-emptive coinfiltration of dexamethasone palmitate emulsion with ropivacaine for postoperative pain in patients undergoing major spine surgery: a study protocol for a prospective, randomised controlled, multicentre trial

INTRODUCTION

Patients undergoing major spine surgery usually experience moderate-to-severe postoperative pain. It has been shown that dexamethasone as an adjunct to local anaesthesia (LA) infiltration presented a superior analgesic benefit compared with LA alone in various types of surgeries. However, a recent meta-analysis reported that the overall benefits of dexamethasone infiltration were marginal. Dexamethasone palmitate (DXP) emulsion is a targeted liposteroid. Compared with dexamethasone, DXP has a stronger anti-inflammatory effect, longer duration of action and fewer adverse effects. We hypothesised that the additive analgesic effects of DXP on local incisional infiltration in major spine surgery may have better postoperative analgesic effect, compared with local anaesthetic alone. However, no study has evaluated this so far. The purpose of this trial is to determine whether pre-emptive coinfiltration of DXP emulsion and ropivacaine at surgical site incision will further reduce postoperative opioid requirements and pain scores after spine surgery than that with ropivacaine alone.

METHODS AND ANALYSIS

This is a prospective, randomised, open-label, blinded endpoint, multicentre study. 124 patients scheduled for elective laminoplasty or laminectomy with no more than three levels will be randomly allocated in a 1:1 ratio into two groups: the intervention group will receive local incision site infiltration with ropivacaine plus DXP; the control group will receive infiltration with ropivacaine alone. All participants will complete a 3 months follow-up. The primary outcome will be the cumulative sufentanil consumption within 24 hours after surgery. The secondary outcomes will include further analgesia outcome assessments, steroid-related side effects and other complications, within the 3 months follow-up period.

ETHICS AND DISSEMINATION

This study protocol has been approved by the Institutional Review Board of Beijing Tiantan Hospital (KY-2019-112-02-3). All participants will provide a written informed consent. The results will be submitted for publication in a peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05693467.

Rat model of attention-deficit hyperactivity disorder exhibits delayed recovery from acute incisional pain due to impaired descending noradrenergic inhibition

Chronic pain and attention-deficit hyperactivity disorder (ADHD) frequently coexist. However, the common pathology is still unclear. Attenuated noradrenergic endogenous analgesia can produce acute pain chronification, and dysfunction of noradrenergic systems in the nervous system is relevant to ADHD symptoms. Noxious stimuli-induced analgesia (NSIA) is measured to estimate noradrenergic endogenous analgesia in spontaneously hypertensive rats (SHR) as an ADHD model and control. Recovery of pain-related behaviors after paw incision was assessed. Contributions of noradrenergic systems were examined by in vivo microdialysis and immunohistochemistry. The SHR showed attenuated NSIA and needed a more extended period for recovery from acute pain. These results suggest ADHD patients exhibit acute pain chronification due to pre-existing attenuated noradrenergic endogenous analgesia. Immunohistochemistry suggests abnormal noradrenaline turnover and downregulation of the target receptor (alpha2a adrenoceptor). Standard ADHD treatment with atomoxetine restored NSIA and shortened the duration of hypersensitivity after the surgery in the SHR. NSIA protocol activated the locus coeruleus, the origin of spinal noradrenaline, of both strains, but only the control exhibited an increase in spinal noradrenaline. This result suggests dysfunction in the noradrenaline-releasing process and can be recognized as a novel mechanism of attenuation of noradrenergic endogenous analgesia.

Incidence of Chronic Postsurgical Pain after Upper Extremity Surgery and its Correlation with Preoperative Pain

The incidence of chronic postsurgical pain (CPSP) after upper extremity surgery is not known. The goal was to study CPSP at 5 years postoperative and to investigate patient, surgical, and anesthetic risk factors.

Methods

Patients scheduled for elective upper extremity surgery were included, and numeric rating scale (NRS) score for pain was obtained preoperatively and at 5 years postoperatively. According to the International Association for the Study of Pain definition, CPSP was defined as an increase in NRS compared with preoperatively.

Results

A total 168 patients were contacted at 5 years postoperatively. Incidence of CPSP was 22%, and 35% had an NRS score of 4 or more. The number of patients with an NRS score of 0 and with an NRS score of 4 or more preoperatively was higher in the no-CPSP group, with P values of 0.019 and 0.008, respectively. Of the patients with no preoperative pain, 34% developed CPSP. Regional anesthesia was associated with a lower CPSP incidence (P = 0.001) and was more frequently applied in surgery on bony structures and in patients with a preoperative NRS score of 4 or more.

Conclusions

The incidence CPSP was 22%. Patients with no pain or an NRS score of 4 or more preoperatively were less likely to develop CPSP, but individual susceptibility to pain and success of the surgery may be of influence. One-third of the patients with no preoperative pain developed CPSP. More studies are needed to reveal the exact relation between brachial plexus anesthesia and CPSP.

Bloqueo supramaleolar de tobillo para cirugía de pie y tobillo. Estudio retrospectivo de casos de los últimos cinco años

Objetivo: Describir la técnica de bloqueo supramaleolar de tobillo y nuestra experiencia con este bloqueo en la cirugía de tobillo y pie. Materiales y Métodos: Se llevó a cabo un estudio observacional, retrospectivo de los últimos 5 años en pacientes con enfermedad de tobillo y pie, sometidos a un bloqueo supramaleolar de tobillo. Se excluyó a pacientes con cirugía previa, cirugías bilaterales, neuropatía periférica o enfermedad vascular, diabetes, infección activa o tabaquistas. Se realizó el bloqueo supramaleolar de tobillo con lidocaína al 2% y bupivacaína al 0,5%, teniendo en cuenta las referencias anatómicas. Se evaluaron la duración del bloqueo, la escala analógica visual de dolor a las 24 h de la cirugía, el tiempo hasta la toma del primer analgésico y el grado de satisfacción del paciente. Resultados: Se incluyó a 771 pacientes operados, todos tuvieron una analgesia completa por, al menos, 12 h (duración promedio 18 h). El puntaje promedio de la escala para dolor a las 24 h fue de 1,4. El tiempo promedio hasta la toma del primer analgésico fue de 16 h. El grado de satisfacción del paciente con el bloqueo y el dolor percibido en las primeras 24 h fue: muy satisfecho (89%), satisfecho (10%) y poco satisfecho (1%). No hubo casos de secuela neurológica permanente, toxicidad sistémica ni infección. Conclusión: El bloqueo supramaleolar de tobillo es un método simple, eficaz y seguro que puede realizar el traumatólogo para obtener una analgesia posquirúrgica prolongada.

Acupuncture as Part of Multimodal Analgesia for Chronic Pain

Background

Chronic pain is a multifactorial condition that is afflicting populations worldwide causing an increasing economic, physical, mental, and emotional burden. Treatments range from medications to interventional procedures to complementary and alternative medicine (CAM), such as acupuncture. This review aims to discuss the use of acupuncture in the treatment of chronic pain, proposed mechanisms, indications, and efficacy for various chronic pain conditions.

Results

Evidence is varied on the efficacy and quality of data on the use of acupuncture in the treatment of chronic pain. Recent studies have demonstrated promising results in the support of acupuncture for the use in the treatment of cancer, neck, and back pain, functional dyspepsia, and various chronic abdominal pain syndromes.

Conclusion

Acupuncture, deemed well-tolerated and safe to use, has been increasingly studied and is regarded as effective in clinical practice, but its efficacy is limited by the lack of well-conducted, high-quality clinical trials, lower quality evidence, and conflicting study results. Additionally, the exact analgesic mechanism of acupuncture remains to be fully elucidated. Increasing evidence supports the role of acupuncture as therapy in the treatment of cancer, neck, and back pain and functional dyspepsia. Further rigorous studies are needed to fully assess the use of acupuncture in various chronic pain conditions, determine its indications, and optimal treatment schedule. Overall, future studies could benefit from better designed experimental studies, larger groups, and more objectives ways to measure pain reduction and symptom improvement.

Effects of Thoracic Paravertebral Block on Postoperative Anxiety and Depression for Patients Undergoing Thoracoscopic Lung Cancer Radical Surgery

This study is aimed at investigating the effect of thoracic paravertebral block (TPVB) on the occurrence of chronic postoperative pain, postoperative anxiety, and depression in patients undergoing thoracoscopic radical lung cancer surgery. A total of 120 patients who underwent thoracoscopic radical lung cancer surgery in our hospital from June 2019 to March 2021 were included. There were 62 males and 58 females, with an age of 18-75 years old and a body mass index of 20-28 kg/m2. Patients were divided into two groups using the random number table method, TPVB group (n = 60) and normal saline group (control group, n = 60). Two-point nerve block was performed at T5-6 and T6-7 levels. Patients in the TPVB group received nerve block with 15 mL of 0.375% ropivacaine hydrochloride, while those in the control group received 5 mL of 0.9% normal saline. The numeric rating scale (NRS) scores at rest and during movement at 24 and 48 hours after surgery and the number of times the button on the patient-controlled analgesia pressed at 24 h after surgery in two groups were recorded. All patients were followed up by outpatient visits or phone visits at 1 year after surgery and assessed using Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale and Hospital Anxiety and Depression Scale (HADS). According to the inclusion, exclusion, and drop-out criteria, 108 patients were finally included, with 52 patients in the TPVB group and 56 patients in the control group. There was no statistically significant difference between the two groups in terms of age, sex, height, body weight, body mass index, ASA classification, and operation time (P > 0.05). NRS pain scores at 24 h (P = 0.0108) and 48 h (P = 0.0000) after surgery, the number of times pressing patient-controlled analgesia at 24 h after surgery (P = 0.0000), the LANSS scores (P = 0.0000), HADS anxiety score (P = 0.0000), and depression scores (P = 0.0000) at 1 year after surgery in the TPVB group were both significantly lower than those in the control group. To sum up, ultrasound-guided TPVB can effectively relieve pain at 48 hours after thoracoscopic lung cancer radical surgery and chronic postoperative pain at 6 months after V thoracoscopic lung cancer radical surgery.

The Application of Acupuncture Therapy for Postoperative Pain Over the Past 20 Years: A Bibliometric Analysis

PURPOSE

The purpose of this study is to analyze and visualize the research trends on acupuncture therapy for postoperative pain over the past 20 years to identify hotspots and frontiers, and provide new research ideas.

METHODS

A search of the Web of Science database, with a time frame of 2001-01-01 to 2022-02-28, was conducted to collect literatures related to acupuncture therapy for postoperative pain. A bibliometric analysis and visualization of results was performed using CiteSpace software for the volume of annual publications, journals, countries, institutions, authors, keywords, and references.

RESULTS

A total of 840 literatures were eventually included in the analysis. The number of publications has fluctuated upwards each year over the past 20 years and reached a peak in the latest three years. Evidence-Based Complementary and Alternative Medicine was the journal with the most relevant publications and Pain was the most frequently cited journal. The country with the highest volume of publications was China, and the USA contributed most to the international collaboration. The most prolific and influential authors were Inhyunk Ha and Han JS respectively. The most frequent keyword was "acupuncture". References with highest frequency or centrality were both systematic evaluations focusing on different acupuncture therapies for postoperative pain relief.

CONCLUSION

The field of acupuncture therapy for postoperative pain is currently in a period of high growth. China and the USA have made the largest contribution to the volume of publications. The most influential institutions and authors are mainly from China and South Korea. The overall collaborative network needs to be strengthened. Electroacupuncture and auricular acupuncture (therapeutic techniques), low back surgery (types of surgery), and "postoperative pain, nausea and vomiting" are research hotspots in this field. Improvement of postoperative life quality, proof of clinical efficacy and evidence-based evaluation are the current research trends and frontiers.

Predictive risk factors for persistent pain following total prosthetic temporomandibular joint replacement

The aim of this study was to determine the rate of persistent pain following total TMJ replacement and to identify potential predictive risk factors. A retrospective review of case notes treated by a single surgeon in a tertiary unit was performed. For each patient a number of variables were recorded including visual analogue pain scores (0 to 10) and opioid usage pre surgery and at 12 months or last follow up beyond 12 months. Persistent pain scores of 5 to 7 were regarded as moderate and 8 to 10 as severe. The mean pain score at last follow-up was significantly lower than preoperatively (2.1 vs. 6.3, p < 0.001) with a mean follow-up time of 40.1 months (range 12-44). 16.4% of the patients reported moderate to severe pain and 13.7% were still on regular opioids at the last follow-up. Therefore 15 patients (20.5%) suffered from chronic postoperative pain after TMJ replacement surgery. Patients reporting severe preoperative pain scores (p = 0.04), regular opioid use (p = 0.001) or multiple previous open TMJ surgeries (p = 0.03) were more likely to suffer from chronic persistent pain and these should be regarded as predictive risk factors. The identification of these factors allows for better risk stratification of patients, informed consent and the agreement of expected outcomes. Patients with true articular disease and a single failed surgery should be considered for early total TMJ replacement to minimise multifactorial persistent pain.

"Prevalence of chronic pain following resection of pelvic bone tumours: A single centre prospective observational survey"

Background

Hemipelvectomy is a major surgery most often performed for pelvic malignancy. These complex surgeries often involve dissection around major neurovascular bundle and resection of tumour being bone along with involved tissues. This may result in short and long term morbidities. There is very little literature about incidence of chronic pain after pelvic resections. We conducted a prospective study at a tertiary cancer hospital to assess the prevalence of chronic pain post hemipelvectomy.

Method

This is a single centre prospective observational study conducted over 30 months. Pain scores were recorded using Brief pain inventory (BPI) and pain detect questionnaire. The quality of life was assessed using musculoskeletal tumour society (MSTS) score. Intra-operative details like extent of surgical resection, nerves spared, details of intra-operative and post-operative analgesia were retrieved from the patient files. Data were analysed using SPSS 21 version.

Results

Neuropathic pain post hemipelvectomy was uncommon. The prevalence of mild to moderate somatic pain was around 30%. Functional limitation was minimal as assessed by BPI and MSTS score. A high incidence of numbness was seen to persist in and around the area of surgical incision (50%).

Conclusion

This is first study to report the incidence of chronic pain post hemipelvectomy done for pelvic tumour resections. Despite the extensive nature of resection involved, there is a low prevalence of neuropathic pain in this population. However, incidence of persistent somatic pain is high and there is a need for further studies for evaluating the causality.

Chronic postsurgical pain after minimally invasive adrenalectomy: prevalence and impact on quality of life

BACKGROUND

Minimally invasive adrenalectomy is the standard of care for small adrenal tumours. Both the transperitoneal lateral approach and posterior retroperitoneal approach are widely used and have been proven to be safe and effective. However, the prevalence of chronic postsurgical pain has not been specifically investigated in previous studies. The primary goal of this study was to identify the prevalence of chronic postsurgical pain after minimally invasive adrenalectomy.

METHODS

A cross-sectional study was performed among all consecutive patients who had undergone minimally invasive adrenalectomy in a single university medical centre. The primary outcome was the prevalence of chronic postsurgical pain. Secondary outcomes were the prevalence of localized hypoesthesia, risk factors for the development of chronic postsurgical pain, and the Health-Related Quality of Life. Three questionnaires were used to measure the prevalence and severity of chronic postsurgical pain, hypoesthesia, and Health-Related Quality of Life. Logistic regression analysis was performed to determine risk factors for development of chronic postsurgical pain.

RESULTS

Six hundred two patients underwent minimally invasive adrenalectomy between January 2007 and September 2019, of whom 328 signed informed consent. The prevalence of chronic postsurgical pain was 14.9%. In the group of patients with chronic postsurgical pain, 33% reported hypoesthesia as well. Young age was a significant predictor for developing chronic postsurgical pain. The prevalence of localized hypoesthesia was 15.2%. In patients with chronic postsurgical pain, Health-Related Quality of Life was significantly lower, compared to patients without pain.

CONCLUSIONS

The prevalence of chronic postsurgical pain following minimally invasive adrenalectomy is considerable. Furthermore, the presence of chronic postsurgical pain was correlated with a significant and clinically relevant lower Health-Related Quality of Life. These findings should be included in the preoperative counselling of the patient. In the absence of evidence for effective treatment in established chronic pain, prevention should be the key strategy and topic of future research.

The Epigenetic Mechanisms Involved in Chronic Pain in Rodents: A Mini- Review

Chronic pain is a common distressing neurological disorder and about 30% of the global population suffers from it. In addition to being highly prevalent, chronic pain causes a heavy economic and social burden. Although substantial progress has been achieved to dissect the underlying mechanism of chronic pain in the past few decades, the incidence and treatment of this neurological illness is yet not properly managed in clinical practice. While nerve injury-, chemotherapy- or inflammation-induced functional regulation of gene expression in the dorsal root ganglion and spinal cord are extensively reported to be involved in the pathogenic process of chronic pain, the specific mechanism of these altered transcriptional profile still remains unclear. Recent studies have shown that epigenetic mechanisms, including DNA/RNA methylation, histone modification and circular RNAs regulation, are involved in the occurrence and development of chronic pain. In this review, we provide a description of research on the role of epigenetic mechanism in chronic pain, summarize the latest clinical and preclinical advance in this field, and propose the potential directions for further research to elucidate the molecular mechanism underlying the pathogenesis of chronic pain.

Association Between Anxiety and Depressive Symptoms During Prehospitalization Waiting Period and Quality of Recovery at Postoperative Day 3 in Perioperative Cancer Patients

PURPOSE

Perioperative depressive symptoms are associated with poor postoperative quality of life (QOL), leading to prolonged hospital stays, and delayed return to society. Previous studies show that physical and mental states change on the third day after surgery, and there is a correlation between quality of recovery (QoR) on this day and QOL at 3 months after surgery. QoR after surgery is an important indicator of postoperative QOL. However, there are no reports on the association between depressive symptoms, and postoperative QoR. Therefore, the study purpose was to clarify the relationship between depressive symptoms in perioperative cancer patients during the prehospitalization waiting period, and QoR on the third postoperative day.

DESIGN

This was a prospective cohort study.

METHODS

We examined whether depressive symptoms during the prehospitalization waiting period were related to QoR on day 3 after surgery in perioperative cancer patients. Subjects were patients with primary tumors who underwent surgery under general anesthesia. Subjects completed self-administered questionnaires during the prehospitalization waiting period and on postoperative day 3. The presence and/or absence of depressive symptoms was measured using the Hospital Anxiety and Depression Scale. Subjects were divided into two groups: depressive symptoms or non-depressive symptoms. Postoperative QoR was determined using the QoR-40 questionnaire and we calculated the rate of change in QoR-40 global and dimension scores from preoperation to postoperation.

FINDINGS

231 individuals met the inclusion criteria and agreed to participate in the study. Of these, 173 were included in the analysis. Only the rate of change in emotional state differed significantly between groups (P = .022). Both global and dimension QoR-40 scores were lower in the depressive symptoms group than in the non-depressive symptoms group.

CONCLUSIONS

These findings demonstrate the need to provide both psychological and physical support continuously from the preoperative to early postoperative stage for cancer patients with depressive symptoms in the prehospitalization waiting period.

Prevalence and Predictors of Chronic Pain with Two-Year Follow-Up After Knee Arthroplasty

Background

Pain relief is the most important issue in the long-term outcome of arthroplasty surgery, with nearly one-third of patients still suffered persistent pain and caused dissatisfaction after the surgery.

Methods

A total of 713 patients underwent primary elective primary TKA and UKA were included consecutively between July 2018 and December 2019, using binary logistic method to analyze the data.

Results

The prevalence of CPSP at rest and on movement at 2-year was 12.1% and 37.7% respectively after primary knee arthroplasty and CPSP at rest factors included: age above 80 (odds ratio [OR]= 6.72, 95% confidence interval [CI] 1.58 to 28.56), BMI above 30 (2.339, 1.02 to 5.383), and moderate to severe pain variables: preoperative pain, (1.95, 1.11 to 3.41); APSP on movement, 4.9 (2.31–10.6); and follow-up contralateral knee pain-at-rest scores (12.6, 5.5 to 28.5). Factors associated with presence of CPSP on movement included: no smoking (2.59, 1.07 to 6.26); and moderate to severe pain variables: preoperative pain, (1.57, 1.073 to 2.30); APSP at rest, (1.85, 1.13 to 3.02); APSP on movement, 6.11 (3.82 to 9.78); and follow-up contralateral knee pain-on-movement scores, 3.22 (2.08 to 5.00). Factors to occurrence of moderate to severe CPSP on movement include: presence of COPD (12.20, 2.19 to 67.98); and moderate to severe pain variables: preoperative pain (2.36, 1.32 to 4.23); APSP on movement (4.68, 1.95 to 11.25); and follow-up contralateral knee pain-on-movement scores (2.71, 1.66 to 4.42).

Conclusion

Prevention strategies should be targeted to different types of pain, and the comorbidity of COPD undergoing knee arthroplasty should receive early identification and attention.

Multimodal prediction of pain and functional outcomes 6 months following total knee replacement: a prospective cohort study

BACKGROUND

Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence and impact around the globe. In the U.S., the rising prevalence of knee OA has been paralleled by an increase in annual rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, post-operative trajectories of pain and functional status vary substantially; a significant minority of patients report ongoing pain and impaired function following TKA. A number of studies have identified sets of biopsychosocial risk factors for poor post-TKA outcomes (e.g., comorbidities, negative affect, sensory sensitivity), but few prospective studies have systematically evaluated the unique and combined influence of a broad array of factors.

METHODS

This multi-site longitudinal cohort study investigated predictors of 6-month pain and functional outcomes following TKA. A wide spectrum of relevant biopsychosocial predictors was assessed preoperatively by medical history, patient-reported questionnaire, functional testing, and quantitative sensory testing in 248 patients undergoing TKA, and subsequently examined for their predictive capacity.

RESULTS

The majority of patients had mild or no pain at 6 months, and minimal pain-related impairment, but approximately 30% reported pain intensity ratings of 3/10 or higher. Reporting greater pain severity and dysfunction at 6 months post-TKA was predicted by higher preoperative levels of negative affect, prior pain history, opioid use, and disrupted sleep. Interestingly, lower levels of resilience-related "positive" psychosocial characteristics (i.e., lower agreeableness, lower social support) were among the strongest, most consistent predictors of poor outcomes in multivariable linear regression models. Maladaptive profiles of pain modulation (e.g., elevated temporal summation of pain), while not robust unique predictors, interacted with psychosocial risk factors such that the TKA patients with the most pain and dysfunction exhibited lower resilience and enhanced temporal summation of pain.

CONCLUSIONS

This study underscores the importance of considering psychosocial (particularly positively-oriented resilience variables) and sensory profiles, as well as their interaction, in understanding post-surgical pain trajectories.

Effects of Transcutaneous Electrical Nerve Stimulation on Mastectomy Pain, Patient Satisfaction, and Patient Outcomes

PURPOSE

Mastectomy is one of the most painful surgical procedures. Postoperative pain guidelines recommend transcutaneous electrical nerve stimulation (TENS) as a reliable non-pharmacological analgesic method. The aim of this study was to investigate the effects of TENS on postoperative pain and outcomes in patients undergoing modified radical mastectomy (MRM).

DESIGN

A single-center, single-blind, prospective, randomized-controlled study.

METHODS

This single-center, single-blind, randomized-controlled study included a total of 80 patients who underwent MRM at general surgery clinic of a tertiary center were included. The pain management of the patient outcomes were evaluated using the Turkish Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R-TR).

FINDINGS

The pain levels of the intervention group were lower than the control group. There were significant improvements in the patient outcomes such as mobilization, position, sleep, anxiety, and fear in the intervention group.

CONCLUSIONS

Our study results suggest that TENS reduces MRM pain. Thus, TENS can be recommended as a useful analgesic method in MRM.

The Frequency of Temporomandibular Disorders, Surgical Complications, and Self-Reported Mental Health Problems in Orthognathic Patients

OBJECTIVE

To evaluate the frequency of signs and symptoms of temporomandibular disorders (TMD), surgical complications, and patient's self-reported mental health problems during orthognathic treatment.

MATERIAL AND METHODS

The clinical records of 145 patients treated with orthognathic treatment were retrospectively studied. Variables regarding occlusal parameters, treatment duration, TMD symptoms, complications, and self-reported mental health status at time points of T0 (beginning of the treatment), T1 (before surgery), and T2 (final examination) were evaluated. The variables were statistically compared with significance level of P < 0.05.

RESULTS

A total of 51% (n = 74) of the patients had TMD symptoms at 1 or several time points, women having significantly more TMD signs and symptoms (P = 0.002). Temporomandibular disorder signs and symptoms decreased significantly after orthognathic treatment (P=0.001). At least 1 self-reported mental health-related factor during 1 or several time points (T0-T2) was recorded in 17.2% (n = 25) of the patients. There was no significant difference in frequency of self-reported mental health problems in patients with TMD signs and symptoms compared with patients without TMD signs and symptoms (P > 0.05). The frequency of postoperative complications was 39.3%, being significantly higher after Bilateral Sagittal Split Osteothomy (BSSO, 48.7%). There was no difference in treatment duration of patients with self-reported mental health problems compared with patients without (P > 0.05).

CONCLUSIONS

In this study population, TMD signs and symptoms seem to be typical both in patients with or without self-reported mental health problems. Women had significantly more TMD symptoms. Orthognathic surgery treatment seems to have a positive effect on TMD signs and symptoms.

Incidence and Influencing Factors of Chronic Postthoracotomy Pain in Lung Tumor Patients

OBJECTIVES

To estimate the incidence of chronic postthoracotomy pain (CPTP) in lung tumor patients and to explore the influencing factors of the intensity of CPTP.

METHODS

Lung tumor patients who underwent video-assisted thoracoscopic surgery (VATS) or thoracotomy were consecutively recruited from October 2016 to December 2017 at Yunnan Cancer Hospital. All the eligible patients were interviewed via telephone at the end of the third month after surgeries to identify the presence of CPTP. The potential influencing factors of CPTP, including pre-, intra-, and postoperative variables, were collected from medical records. A cumulative logit regression model was used to identify the independent influencing factors of the intensity of CPTP.

RESULTS

Three hundred and forty-three patients completed a telephone interview. The estimated overall incidence of CPTP was 67.6% (95% of confidence interval, 95% CI: 62.4%, 72.6%) in lung tumor patients; 70.8% (95% CI: 63.8%, 77.1%) in benign patients and 63.5% (95% CI: 55.2%, 71.3%) in malignant patients; and 78.1% (95% CI: 66.0%, 87.5%) in open chest and 65.2% (95% CI: 59.3%, 70.8%) in VATS. Cumulative logit regression models (intensity order, NRS, 0 ⟶ 1-3 ⟶ 4-) revealed independent influencing factors of CPTP to be patients with diabetes (OR = 0.32; 95% CI: 0.14, 0.76), usage of VATS (OR = 0.47; 95% CI: 027, 0.82), and the amount of intraoperative blood loss (OR = 1.09; 95% CI: 1.00, 1.19).

CONCLUSIONS

A high incidence of CPTP is detected in lung tumor patients following the thoracic operation. Patients with diabetes and using VATS are the independent protective factors of the intensity of CPTP, and the increasing amount of intraoperative blood loss is an independent risk factor of the intensity of CPTP.

fNIRS brain measures of ongoing nociception during surgical incisions under anesthesia

Significance: Functional near-infrared spectroscopy (fNIRS) has evaluated pain in awake and anesthetized states. Aim: We evaluated fNIRS signals under general anesthesia in patients undergoing knee surgery for anterior cruciate ligament repair. Approach: Patients were split into groups: those with regional nerve block (NB) and those without (non-NB). Continuous fNIRS measures came from three regions: the primary somatosensory cortex (S1), known to be involved in evaluation of nociception, the lateral prefrontal cortex (BA9), and the polar frontal cortex (BA10), both involved in higher cortical functions (such as cognition and emotion). Results: Our results show three significant differences in fNIRS signals to incision procedures between groups: (1) NB compared with non-NB was associated with a greater net positive hemodynamic response to pain procedures in S1; (2) dynamic correlation between the prefrontal cortex (PreFC) and S1 within 1 min of painful procedures are anticorrelated in NB while positively correlated in non-NB; and (3) hemodynamic measures of activation were similar at two separate time points during surgery (i.e., first and last incisions) in PreFC and S1 but showed significant differences in their overlap. Comparing pain levels immediately after surgery and during discharge from postoperative care revealed no significant differences in the pain levels between NB and non-NB. Conclusion: Our data suggest multiple pain events that occur during surgery using devised algorithms could potentially give a measure of "pain load." This may allow for evaluation of central sensitization (i.e., a heightened state of the nervous system where noxious and non-noxious stimuli is perceived as painful) to postoperative pain levels and the resulting analgesic consumption. This evaluation could potentially predict postsurgical chronic neuropathic pain.

Minimizing the Risk of Opioid Misuse and Abuse in the Surgical Setting

The misuse of opioids continues to be a public health problem. Acute post-surgical pain management requires a careful balance between the benefits and risks of opioids. Opioids should be part of a multimodal treatment plan, including the use of nonopioid and nonpharmacologic treatment options. Multimodal pain management allows for individualized treatment and improved patient satisfaction while limiting the risks inherent to opioids, including diversion. Surgeons should avoid overprescribing opioids and have a plan for decreasing the use of opioids in the postsurgical time frame. With careful consideration of the risks, opioids can be prescribed to treat acute postsurgical pain effectively. [Orthopedics. 2021;44(6):353-359.].

Evaluation on curative effects of gabapentin for the prevention of chronic pain in adults following surgery: A protocol for systematic review and meta-analysis

BACKGROUND

Chronic pain is a common postsurgery symptom. It has an adverse impact on patients' overall wellbeing. Chronic pain after an operation is caused by intricate mechanisms that have not been well understood. The predictability of most surgical methods has enabled scholars to conduct randomized controlled trials (RCTs) involving pharmacological interventions to prevent chronic pain after a surgery. Therefore, the present study aims to evaluate the curative effects of gabapentin to prevent chronic pain in adults after surgery.

METHODS

The authors will collect RCTs related to the use of gabapentin to prevent chronic pain in adults following surgery. Accordingly, a comprehensive search will be performed in 4 online databases to find English language articles, including Cochrane Library, EMBASE, Web of Science, and PubMed. In addition, the search also includes 3 Chinese language databases: VIP data, WanFang database, and China National Knowledge Infrastructure. Each of the RCT published from their inception to September 2021 will be considered. The authors will carry out a meta-analysis of RCTs after screening the studies. Subsequently, the authors will use RevMan (v 5.3) to perform an assessment of bias risk, data synthesis, and subgroup analysis, provided inclusion criteria are met.

RESULTS

The results will provide clinical evidence for the curative effects of gabapentin to prevent chronic pain in adults after surgery.

CONCLUSION

The summary provided in this systematic review will judge whether gabapentin intervention is effective and feasible to prevent chronic pain in adults following surgery.Registration number: 10.17605/OSF.IO/XG4CK.

Low-dose midazolam for anxiolysis for pregnant women undergoing cesarean delivery: a randomized trial

INTRODUCTION

Anxiety and fear are common among pregnant women undergoing cesarean delivery. In addition to psychologically unpleasant, they can elicit endocrine and metabolic changes. Administration of benzodiazepines in this patient group is uncommon and investigation focusing on the topic is rare. This study aimed to determine anxiolysis efficacy of low-dose midazolam administered preoperatively, right before cesarean delivery, and to evaluate whether its administration impacts neonatal vitality, maternal consciousness, and recall of the moment the baby was born.

METHODS

Fifty pregnant women with indication for cesarean delivery were included in this randomized, double-blind, placebo-controlled clinical study and allocated into two groups of 25 participants each (Midazolam and Control group). Midazolam (0.0125 mg.kg^-1) or a placebo solution was administered immediately before spinal anesthesia and the anxiolytic effect was assessed using a visual analogue scale before and after administration. We registered the Apgar score at 1 and 5 minutes, the Ramsay scale and recall of the moment of birth, that was assessed 90 minutes after birth.

RESULTS

Pregnant women from the Midazolam group presented a 1.3-point reduction in anxiety on the visual analogue scale, while the Control group showed virtually no change (p = 0.027). We observed no statistically significant changes in Apgar scores, level of maternal consciousness and recall of the moment of delivery.

CONCLUSIONS

Low-dose midazolam can provide anxiety management in pregnant women undergoing cesarean delivery with no significant undesirable effects.

Prevalence, Characteristics and Preoperative Predictors of Chronic Pain After Double-Lung Transplantation: A Prospective Cohort Study

OBJECTIVE

Data on chronic pain after lung transplantation are heterogeneous. This study prospectively explored the prevalence, characteristics, consequences, and preoperative predictors of pain in lung transplant recipients.

DESIGN

A prospective cohort study.

SETTING

The Foch University Hospital, Suresnes, France.

PARTICIPANTS

Patients registered on the waiting list for double-lung transplantation in the authors' institution from August 2008 to October 2013 and transplanted.

INTERVENTIONS

Database prospectively completed in real time during consultations with a pain-certified anesthesiologist before lung transplantation and six months after surgery.

MEASUREMENTS AND MAIN RESULTS

The assessments explored pain in three components: physical (intensity, location, neuropathic and sensory qualifications, treatments), mental (anxiety and depression), and quality of life. Seventy-two patients underwent all assessments. The prevalence of six-month postoperative pain was 68.0%. Among patients with pain, 83.3% reported mild average pain and 26.5% had neuropathic pain. All patients who responded to the questionnaire took analgesics frequently, but only 9.1% took opioids. Patients with pain reported higher levels of anxiety (p = 0.02) and depression (p = 0.01). Additionally, they presented with increased difficulty in ambulation (p = 0.03), work (p = 0.02), and sleep (p = 0.02). The maximum level of preoperative pain was an independent risk factor of six-month postoperative pain (p = 0.03).

CONCLUSIONS

The authors report a high prevalence of chronic pain with concomitant psychosocial repercussions despite a reported mild intensity. Perioperative measures, such as personalized and detailed management plans, could improve patient satisfaction.

Prevalence and predictors of chronic postsurgical pain after colorectal surgery: A prospective study

AIM

The aim was to investigate the incidence, characteristics and the potential predictors of chronic postsurgical pain (CPSP) after colorectal surgery.

METHOD

Patients who underwent colorectal surgery at our institution from July 2014 to December 2016 were prospectively enrolled in this study. Perioperative potential demographic, clinical and psychological predictors for CPSP were collected. The follow-up visits were conducted through telephone interviews at 3 and 6 months postoperatively. The interview questionnaire comprised items regarding pain intensity, frequency, site, analgesic administration and impact on activities of daily living.

RESULTS

A total of 624 patients completed the 6-month follow-up and were included in the analysis. CPSP was reported by 32.1% of these patients at 3 months and 21.8% at 6 months after colorectal surgery. The pain interfered with several activities of daily living in a considerable proportion of CPSP cases. At 3 months, the identified predictors of CPSP were young age, preoperative abdominal pain and pain elsewhere, preoperative anxiety and depression, longer duration of surgery, and high pain intensity on movement within 24 h after surgery. Predictors of CPSP at 6 months were young age, preoperative abdominal pain, preoperative anxiety, longer duration of surgery, and high pain intensity on movement within 24 h after surgery.

CONCLUSION

Chronic pain after colorectal surgery is a common complication associated with young age, preoperative abdominal pain and pain elsewhere, preoperative anxiety and depression, longer duration of surgery, and high pain intensity on movement within 24 h after surgery.

Year in Review 2020: Noteworthy Literature in Cardiothoracic Anesthesiology

The year 2020 was marred by the emergence of a deadly pandemic that disrupted every aspect of life. Despite the disruption, notable research accomplishments in the practice of cardiothoracic anesthesiology occurred in 2020 with an emphasis on optimizing care, improving outcomes, and expanding what is possible for patients undergoing cardiac surgery. This year's edition of Noteworthy Literature Review will focus on specific themes in cardiac anesthesiology that include preoperative anemia, predictors of acute kidney injury following cardiac surgery, pain management modalities, anticoagulation strategies after transcatheter aortic valve replacement, mechanical circulatory support, and future directions in research.

Adjuvant Drugs for Peripheral Nerve Blocks: The Role of NMDA Antagonists, Neostigmine, Epinephrine, and Sodium Bicarbonate

The potential for misuse, overdose, and chronic use has led researchers to look for other methods to decrease opioid consumption in patients with acute and chronic pain states. The use of peripheral nerve blocks for surgery has gained increasing popularity as it minimizes peripheral pain signals from the nociceptors of local tissue sustaining trauma and inflammation from surgery. The individualization of peripheral nerve blocks using adjuvant drugs has the potential to improve patient outcomes and reduce chronic pain. The major limitations of peripheral nerve blocks are their limited duration of action and dose-dependent adverse effects. Adjuvant drugs for peripheral nerve blocks show increasing potential as a solution for postoperative and chronic pain with their synergistic effects to increase the duration of action and decrease the required dosage of local anesthetic. N-methyl-d-aspartate (NMDA) receptor antagonists are a viable option for patients with opioid resistance and neuropathic pain due to their affinity to the neurotransmitter glutamate, which is released when patients experience a noxious stimulus. Neostigmine is a cholinesterase inhibitor that exerts its effect by competitively binding at the active site of acetylcholinesterase, which prevents the hydrolysis of acetylcholine and subsequently retaining acetylcholine at the nerve terminal. Epinephrine, also known as adrenaline, can potentially be used as an adjuvant to accelerate and prolong analgesic effects in digital nerve blocks. The theorized role of sodium bicarbonate in local anesthetic preparations is to increase the pH of the anesthetic. The resulting alkaline solution enables the anesthetic to more readily exist in its un-ionized form, which more efficiently crosses lipid membranes of peripheral nerves. However, more research is needed to show the efficacy of these adjuvants for nerve block prolongation as studies have been either mixed or have small sample sizes.

Thoracolumbar interfascial plane block for postoperative analgesia in spine surgery: A systematic review and meta-analysis

INTRODUCTION

Thoracolumbar interfascial plane (TLIP) block has been discussed widely in spine surgery. The aim of our study is to evaluate analgesic efficacy and safety of TLIP block in spine surgery.

METHOD

We performed a quantitative systematic review. Randomized controlled trials that compared TLIP block to non-block care or wound infiltration for patients undergoing spine surgery and took the pain or morphine consumption as a primary or secondary outcome were included. The primary outcome was cumulative opioid consumption during 0-24-hour. Secondary outcomes included postoperative pain intensity, rescue analgesia requirement, and adverse events.

RESULT

9 randomized controlled trials with 539 patients were included for analysis. Compared with non-block care, TLIP block was effective to decrease the opioid consumption (WMD -16.00; 95%CI -19.19, -12.81; p<0.001; I2 = 71.6%) for the first 24 hours after the surgery. TLIP block significantly reduced postoperative pain intensity at rest or movement at various time points compared with non-block care, and reduced rescue analgesia requirement ((RR 0.47; 95%CI 0.30, 0.74; p = 0.001; I2 = 0.0%) and postoperative nausea and vomiting (RR 0.58; 95%CI 0.39, 0.86; p = 0.006; I2 = 25.1%). Besides, TLIP block is superior to wound infiltration in terms of opioid consumption (WMD -17.23, 95%CI -21.62, -12.86; p<0.001; I2 = 63.8%), and the postoperative pain intensity at rest was comparable between TLIP block and wound infiltration.

CONCLUSION

TLIP block improved analgesic efficacy in spine surgery compared with non-block care. Furthermore, current literature supported the TLIP block was superior to wound infiltration in terms of opioid consumption.

Quality of Life in Vestibular Schwannoma Patients: A Longitudinal Study

OBJECTIVE

To examine differences in quality of life in patients with vestibular schwannoma following a single treatment modality: observation, stereotactic radiosurgery (SRS), or microsurgery.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary academic medical center.

PATIENTS

Patients diagnosed with sporadic vestibular schwannoma who had completed at least 2 Penn Acoustic Neuroma Quality of Life (PANQOL) surveys.

INTERVENTIONS

Treatment via SRS, microsurgery, or observation.

MAIN OUTCOME MEASURES

PANQOL total survey and subdomain scores.

RESULTS

One hundred and thirty-four patients (94 observations, 24 SRS, 16 microsurgeries) were included. The mean number of PANQOL surveys completed was 2.8 (range 2-5). The total PANQOL scores were significantly lower in the SRS group, but not the microsurgery group, compared with observation at the time of diagnosis (observation 550.4 ± 58.4; SRS 471.4 ± 37.4; microsurgery 492.6 ± 40.7; p = 0.03). Over time, there were no significant differences in the change of PANQOL scores across the 3 groups (SRS PANQOL score worsened 6.8/year compared with observation, p = 0.3; microsurgery PANQOL score worsened 7.8/year compared with observation, p = 0.5). Anxiety was the only subdomain that significantly worsened over time in the microsurgery group (microsurgery PANQOL score worsened 3.8/year compared with observation; p = 0.009).

CONCLUSION

Despite differences in PANQOL scores at baseline, changes in total PANQOL score over time were not found to be statistically significant, regardless of the treatment group chosen. Overall, these results hold implications for patient counseling when considering treatment choice and quality of life predictions.

Effectiveness of perioperative pain science education on pain, psychological factors and physical functioning: A systematic review

OBJECTIVE

To synthesize the evidence on the effectiveness of pain science education on pain, psychological factors and physical functioning in adults who underwent surgery.

DATA SOURCES

A systematic literature search of English articles using PubMed/Medline, Embase, Web of Science Core Collection, and Cochrane Library.

REVIEW METHODS

The search strategy was constructed as follows: (((pain) AND (education)) OR (pain education)) AND (surgery). Only controlled quantitative studies in adults reporting outcome(s) on pain, psychological factors and/or physical functioning were included. Risk of bias was assessed using the Cochrane risk of bias tools. P-values and corresponding effect sizes for interaction-effect (time × group) portrayed the difference in change over time between groups were of interest. The last search was conducted on February 28, 2021.

RESULTS

Nine papers (n = 1078) were deemed eligible for this review. Two randomized controlled trials showed significant interaction effects. Breast cancer patients who had received one preoperative pain science education session showed a significant increase in postoperative pain compared to controls (P-value = 0.0394). Furthermore, psychological factors (pain catastrophizing and kinesiophobia) decreased in participants who had received pain science education before total knee arthroplasty, while this was not the case in the control group (P-value < 0.001, ƞ2p:0.11).

CONCLUSIONS

Overall, pain science education did not result in any significant postoperative effects on pain, psychological factors and/or physical functioning compared to controls. There is currently no strong evidence for the implementation of pain science education in the perioperative period.Registration number: PROSPERO: ID 161267, registration number CRD42020161267.

Anesthetic considerations and postoperative pain management in radical penectomy: Case report

Radical penectomy (RP) is infrequently performed as it is reserved for specific cases of penile cancer, hence the paucity of reports regarding surgical and anesthetic considerations. Acute postoperative pain, chronic post-surgical pain, concomitant mood disorders as well as a profound impact on the patient’s quality of life have been documented. This case is of a patient with diabetes and coronary heart disease, who presented with advanced, overinfected penile cancer, depressive disorder and a history of pain of neuropathic characteristics. The patient underwent radical penectomy using a combined spinal-epidural technique for anesthesia. Preoperatively, the patient was treated with pregabalin and magnesium sulphate, and later received a blood transfusion due to intraoperative blood loss. Adequate intra and postoperative analgesia was achieved with L-bupivacaine given through a peridural catheter during one week. Recovery was good, pain was stabilized to preoperative levels and the patient received pharmacological support and follow-up by psychiatry and the pain team.

The role of regional anaesthesia and multimodal analgesia in the prevention of chronic postoperative pain: a narrative review

Effective prevention of chronic postoperative pain is an important clinical goal, informed by a growing body of studies. Peri-operative regional anaesthesia remains one of the most important tools in the multimodal analgesic toolbox, blocking injury-induced activation and sensitisation of both the peripheral and central nervous system. We review the definition and taxonomy of chronic postoperative pain, its mechanistic basis and the most recent evidence for the preventative potential of multimodal analgesia, with a special focus on regional anaesthesia. While regional anaesthesia targets several important aspects of the mechanistic pathway leading to chronic postoperative pain, evidence for its efficacy is still mixed, possibly owing to the heterogeneity of risk profiles within the surgical patient, but also to variation in techniques and medications reported in the literature.

Analysis of SCN9A Gene Variants for Acute and Chronic Postoperative Pain and Morphine Consumption After Total Hysterectomy

BACKGROUND

Single nucleotide polymorphisms (SNPs) of the voltage-gated sodium channel alpha subunit gene (SCN9A) have been associated with pain in various settings. The aim of this study was to investigate the association of the SNPs to evaluate the influence of common gene variants on chronic postoperative pain (CPSP) and other related pain variables in a cohort of patients who underwent a scheduled hysterectomy.

METHODS

DNA samples from a cohort of 1,075 patients who underwent a scheduled total hysterectomy in our hospital were genotyped for three common SCN9A SNPs using TaqMan assays. Multivariate logistic regression models were used to quantify the association between independent covariates such as pain threshold, pain endurance, pain scores, morphine use, and the presence of chronic pain.

RESULTS

Frequencies of the minor alleles were different between the different ethnic groups. There was a statistically significant association of rs16851799 with morphine consumption and self-reported postoperative pain for the 1,038 subjects genotyped, with the TT genotype reporting higher pain and using more morphine. For the subpopulation of 446 subjects with chronic pain data, there was a similar association with self-reported postoperative pain and tolerance of pressure pain. Univariate analysis also showed a statistically significant association of rs16851799 with CPSP, whereas multivariable analysis revealed a similar association of rs4387806 with this outcome. There were three haplotypes with different relative frequencies for the CPSP and non-CPSP groups.

CONCLUSIONS

Our results showed that SCN9A polymorphisms could play a role in acute pain perception and the susceptibility to chronic pain.

Ultrasound-Guided Rectus Sheath Block Combined with Butorphanol for Single-Incision Laparoscopic Cholecystectomy: What is the Optimal Dose of Ropivacaine?

Purpose

In recent years, ultrasound-guided rectus sheath block (RSB) has been widely used in postoperative analgesia of abdominal operation. However, there is no uniform standard for the optimal dose of local anesthetics (LA) under ultrasound-guided rectus sheath block. This study aimed to determine the dose of ropivacaine combined with butorphanol that is effective in 50% (ED50) and 95% (ED95) of subjects for successful pain-free ultrasound-guided RSB in single-incision laparoscopic cholecystectomy (SILC).

Patients and Methods

Twenty-four patients scheduled to undergo single-incision laparoscopic cholecystectomy received an ultrasound-guided RSB. The initial dose of ropivacaine injected was 1.7 mg/kg, which was subsequently increased or decreased by 0.2 mg/kg, depending on whether the previous patient was free from pain (numeric rating scale (NRS) score of incisional pain at rest within 12 h after operation ≤ 3). All patients were treated with butorphanol 0.02 mg/kg as preemptive analgesia. The ED50 and ED95 were calculated using a probit regression model.

Results

The ED50 and ED95 of ropivacaine combined with butorphanol in ultrasound-guided rectus sheath block for analgesia in SILC, which were calculated by the probit regression model, were 0.719 mg/kg (95% confidence interval (CI), 0.553 mg/kg−0.873 mg/kg) and 0.967 mg/kg (95% CI, 0.835 mg/kg−1.91 mg/kg), respectively.

Conclusion

As part of a multimodal analgesia strategy, a dose of 0.719 mg/kg ropivacaine provided successful RSB under ultrasound guidance in 50% of the patients who underwent SILC. A dose of 0.967 mg/kg would be successful in 95% of patients.