The Pharmacology of Visceral Pain

Comparing the efficacy of duloxetine and nortriptyline in alleviating the symptoms of functional dyspepsia - a randomized clinical trial

Aim

To compare the efficacy of Duloxetine and Nortriptyline in alleviating the symptoms of severity, anxiety, depression and quality of life in patients with functional dyspepsia (FD).

Material and method

We conducted a single-blinded 3-month trial of Duloxetine 20-30 mg daily in 20 patients and Nortriptyline 25 mg daily in 25 FD patients. The primary outcome measure was the severity of FD symptoms by Gastrointestinal symptoms rating scale. Secondary measures included Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, and Nepean Dyspepsia Index. the patients were measured in 3 stages.

Results

45 patients with FD with a mean age of 37.18 ± 10.62 years participated in the study. The severity of symptoms was significantly lower in the Nortriptyline group than in the Duloxetine group after three months (p = 0.031). The level of anxiety (p = 0.049), depression (p = 0.045) and quality of life (p = 0.046) improved significantly after three months in the Duloxetine group compared to Nortriptyline. Mediation analysis using linear regression revealed a significant mediator role for anxiety. This mediation analysis revealed a 21.13% reduction in anxiety in the Duloxetine group.

Conclusion

While both medications demonstrated efficacy, Nortriptyline appeared to be superior in symptom reduction. Duloxetine exhibited more advantages compared to Nortriptyline in addressing anxiety and depression and enhancing the overall quality of life. Also, Duloxetine may have a noteworthy impact, contributing to a 20% reduction in FD symptoms by lowering anxiety levels.

Clinical trial registration

https://en.irct.ir/trial/65512.

Role and therapeutic target of P2X2/3 receptors in visceral pain

Visceral pain (VP) is caused by internal organ disease. VP is involved in nerve conduction and related signaling molecules, but its specific pathogenesis has not yet been fully elucidated. Currently, there are no effective methods for treating VP. The role of P2X2/3 in VP has progressed. After visceral organs are subjected to noxious stimulation, cells release ATP, activate P2X2/3, enhance the sensitivity of peripheral receptors and the plasticity of neurons, enhance sensory information transmission, sensitize the central nervous system, and play an important role in the development of VP. However, antagonists possess the pharmacological effect of relieving pain. Therefore, in this review, we summarize the biological functions of P2X2/3 and discuss the intrinsic link between P2X2/3 and VP. Moreover, we focus on the pharmacological effects of P2X2/3 antagonists on VP therapy and provide a theoretical basis for its targeted therapy.

Piperidine Derivatives: Recent Advances in Synthesis and Pharmacological Applications

Piperidines are among the most important synthetic fragments for designing drugs and play a significant role in the pharmaceutical industry. Their derivatives are present in more than twenty classes of pharmaceuticals, as well as alkaloids. The current review summarizes recent scientific literature on intra- and intermolecular reactions leading to the formation of various piperidine derivatives: substituted piperidines, spiropiperidines, condensed piperidines, and piperidinones. Moreover, the pharmaceutical applications of synthetic and natural piperidines were covered, as well as the latest scientific advances in the discovery and biological evaluation of potential drugs containing piperidine moiety. This review is designed to help both novice researchers taking their first steps in this field and experienced scientists looking for suitable substrates for the synthesis of biologically active piperidines.

Olfactory Stimulation Successfully Modulates the Neurochemical, Biochemical and Behavioral Phenotypes of the Visceral Pain

Visceral pain (VP) is the organ-derived nociception in which increased inflammatory reaction and exaggerated activation of the central nucleus of the amygdala (CeA) may contribute to this deficiency. Considering the amygdala also serves as the integration center for olfaction, the present study aimed to determine whether olfactory stimulation (OS) would effectively depress over-activation and inflammatory reaction in CeA, and successfully relieve VP-induced abnormalities. Adult rats subjected to intraperitoneal injection of acetic acid inhaled lavender essential oil for 2 or 4 h. The potential benefits of OS were determined by measuring the pro-inflammatory cytokine level, intracellular potassium and the upstream small-conductance calcium-activated potassium (SK) channel expression, together with detecting the stress transmitters that participated in the modulation of CeA activity. Results indicated that in VP rats, strong potassium intensity, reduced SK channel protein level, and increased corticotropin-releasing factor, c-fos, and substance P immuno-reactivities were detected in CeA. Enhanced CeA activation corresponded well with increased inflammatory reaction and decreased locomotion, respectively. However, in rats subjected to VP and received OS, all above parameters were significantly returned to normal levels with higher change detected in treating OS of 4h. As OS successfully depresses inflammation and CeA over-activation, application of OS may serve as an alternative and effective strategy to efficiently relieve VP-induced deficiency.

Butorphanol as an Adjuvant to Ropivacaine for Adductor Canal Blocks in Total Knee Arthroplasty Patients: A Randomized, Double, Blind Study

Background

The objective of this study was to observe the effects of butorphanol as an adjuvant to ropivacaine for the adductor canal block (ACB) on postoperative analgesia in patients undergoing total knee arthroplasty (TKA).

Methods

Seventy-four patients undergoing TKA were included and randomly divided into two groups: Group BR received 20 ml of 0.33% ropivacaine plus 1 mg butorphanol and Group R received 20 ml of 0.33% ropivacaine plus 1 ml normal saline for ultrasound-guided adductor canal blocks. The primary outcomes were the duration of the sensory block and the pain visual analogue scale (VAS), and secondary outcomes included the number of PCIA attempts (patient-controlled intravenous analgesia) and the time to first pressing and rescue analgesia. Other outcomes included knee active range of motion (ROM), quadriceps strength, the time to first mobilization, the duration of postoperative hospital stay, Knee Society Score (KSS), and postoperative complications.

Results

Since two patients in each group rejected postoperative assessments, 35 patients were included in each group. Compared with Group R, Group BR had longer duration of sensory blocks (18.42 ± 3.46 vs. 15.36 ± 2.29 h, p < 0.01) and lower postoperative pain scores within 24 hours at rest and within 12 hours with activity (p < 0.01). The number of PCIA attempts decreased within 48 hours after surgery (4.5 ± 1.2 vs. 7.8 ± 1.5 times, p < 0.01), and the time to first pressing was later (20.31 ± 2.59 vs. 16.25 ± 2.31 h, p < 0.01). In addition, Group BR had bigger knee ROM at within 24 hours after the operation than Group R (68.37 ± 4.70°vs. 59.21 ± 6.41,85.67 ± 5.17 vs. 74.37 ± 4.68°, 97.62 ± 5.43 vs. 84.18 ± 4.49°, p < 0.01). There was no significant difference between the two groups (p > 0.05) in terms of rescue analgesia, quadriceps strength, the time to first mobilization, the duration of postoperative hospital stay, the KSS function scores, and postoperative complications.

Conclusions

Butorphanol plus ropivacaine ultrasound-guided adductor canal block can prolong the duration of sensory block, relieve early postoperative pain, and improve the range of motion of the knee joint, without affecting the occurrence of postoperative complications. Name of the Registry. Chinese Clinical Trial Registry. Trial Registration Number. ChiCTR2100041859. URL of Trial Registry Record. http://www.chictr.org.cn/edit.aspx?pid=119731&htm=4. Date of Registration. 08/01/2021 0:00:00.

Improving Clinician-Patient Communication Alleviates Stigma in Patients With Functional Dyspepsia Receiving Antidepressant Treatment

Background/Aims

Antidepressants are effective in patients with functional dyspepsia (FD). However, stigma associated with FD and antidepressants may affect treatment adherence. This study aims to explore possible communication strategies to alleviate stigma and improve adherence in patients with FD.

Methods

In this randomized, single-center, and single-blind trial, 160 patients with FD initiating antidepressant treatment were recruited. Different communication strategies were performed when prescribing antidepressants. Participants in Group 1 were told that brain is the “headquarters” of gut, and that antidepressants could act as neuromodulators to relieve symptoms of FD through regulating the functions of gut and brain. Participants in Group 2 were told that antidepressants were empirically effective for FD. Stigma scores, medication-related stigma, treatment compliance, and efficacy were analyzed.

Results

After 8-week antidepressant treatment, the proportion of patients with FD with decreased stigma scores in Group 1 was significantly higher than in Group 2 (internalized stigma 64.10% vs 12.00%; perceived stigma 55.13% vs 13.33%; P < 0.01). Medication-related stigma was lower in Group 1 than in Group 2 (P < 0.05 for 3 of 4 questions). Concurrently, patients in Group 1 had better treatment compliance (0.71 ± 0.25 vs 0.60 ± 0.25, P < 0.01) and efficacy. In Group 1, participants with decreased post-treatment stigma scores showed better treatment compliance and efficacy than those with non-decreased scores. Decrease in stigma scores positively correlated with treatment compliance.

Conclusion

Improving knowledge of patients with FD of the disease and antidepressants via proper communication may be an effective way to alleviate stigma and promote adherence.

Oxycodone versus morphine for analgesia after laparoscopic endometriosis resection

Background

The objective of this study was to compare the analgesic potency of oxycodone versus morphine after laparoscopic deep infiltrating endometriosis resection.

Methods

Fifty patients undergoing laparoscopic deep infiltrating endometriosis resection were randomized to receive oxycodone or morphine intravenous-PCA after surgery. The primary outcome was opioid consumption during the 24 h after surgery. Secondary outcomes included time to first request for analgesia, the number of bolus, pain, sedation, nausea, vomiting, respiratory depression, and bradycardia. The prominent pain that caused patients to press the analgesic device was also recorded.

Results

Oxycodone consumption (14.42 ± 2.83) was less than morphine consumption (20.14 ± 3.83). Compared with the morphine group, the total number of bolus (78 vs 123) was less and the average time to first request for analgesia (97.27 ± 59.79 vs 142.17 ± 51) was longer in the oxycodone group. The incidence of nausea was higher in the morphine group than in the oxycodone group at 0–2 h (45.45% vs 17.19%), 2–4 h (50% vs 17.19%),12–24 h (40.91% vs 13.04%) and 0–24 h (39.17% vs 19.13%). The overall incidence of vomiting was higher in the morphine group (27.27% vs 13.92%). There was no difference in visual analogue scale score, the incidence of respiratory depression, and bradycardia between groups. Of the three types of pain that prompted patients to request analgesia, the incidence of visceral pain was highest (59.9%, P < 0.01).

Conclusion

Oxycodone was more potent than morphine for analgesia after laparoscopic endometriosis resection, and oxycodone has fewer side effects than morphine.

Name of the registry: Chinese Clinical Trial Registry

Trial registration number: ChiCTR1900021870

URL of trial registry record:http://www.chictr.org.cn/edit.aspx?pid=35799&htm=4

Date of registration: 2019/3/13 0:00:00

Tetrodotoxin: A New Strategy to Treat Visceral Pain?

Visceral pain is one of the most common symptoms associated with functional gastrointestinal (GI) disorders. Although the origin of these symptoms has not been clearly defined, the implication of both the central and peripheral nervous systems in visceral hypersensitivity is well established. The role of several pathways in visceral nociception has been explored, as well as the influence of specific receptors on afferent neurons, such as voltage-gated sodium channels (VGSCs). VGSCs initiate action potentials and dysfunction of these channels has recently been associated with painful GI conditions. Current treatments for visceral pain generally involve opioid based drugs, which are associated with important side-effects and a loss of effectiveness or tolerance. Hence, efforts have been intensified to find new, more effective and longer-lasting therapies. The implication of VGSCs in visceral hypersensitivity has drawn attention to tetrodotoxin (TTX), a relatively selective sodium channel blocker, as a possible and promising molecule to treat visceral pain and related diseases. As such, here we will review the latest information regarding this toxin that is relevant to the treatment of visceral pain and the possible advantages that it may offer relative to other treatments, alone or in combination.

The impact of stigma on medication adherence in patients with functional dyspepsia

BACKGROUND

Psychological factors contribute to the pathogenesis of functional dyspepsia (FD). Antidepressant agents are beneficial in treatment of refractory FD. However, their efficacy is greatly hindered by the poor treatment adherence. Stigma is present in patients with chronic diseases or mental disorders and could affect adherence. The present study was aimed to evaluate stigma prevalence in FD patients and to explore the impact of stigma on treatment adherence to antidepressants.

METHODS

Functional dyspepsia patients unsatisfied with the regular first-line treatment and received newly initiated antidepressant medicine were recruited and subjected to antidepressant treatment for 8 weeks. Stigma scales and symptom scores of dyspepsia, depression, and anxiety were analyzed before and after treatment. Associations between stigma and medication adherence were evaluated.

KEY RESULTS

One hundred and ten of the enrolled 138 participants reported minimal disease-related internalized stigma, and 28 reported mild stigma before antidepressant therapy. Male gender, lower education, and higher scores of dyspepsia, depression, and anxiety were predictors of stigma before treatment. The mean stigma scores increased after 8-week antidepressant treatment. A proportion (36.4%-89.9%) of patients showed stigma attached to antidepressant therapy in the 4-question survey. Post-treatment stigma scores negatively correlated with treatment adherence and efficacy. Patients with decreased post-treatment stigma scores displayed better medication adherence and symptom improvement compared to those with elevated or unaltered post-treatment stigma scores.

CONCLUSIONS

Patients with refractory FD report stigma attached to the disease and antidepressants. It is an obstacle to treatment adherence and efficacy of antidepressant medication in FD therapy.

Antinociception and less gastric injury with the dexketoprofen-tapentadol combination in mice

The purpose of this study was to evaluate the antinociceptive interaction between dexketoprofen and tapentadol in three different dose ratios, as well as the ulcerogenic activity of this combination. Dose-response curves were carried out for dexketoprofen, tapentadol, and dexketoprofen-tapentadol combinations in the acetic acid-induced writhing test in mice. On the other hand, the gastric damage of all treatments was assessed after the surgical extraction of the stomachs. Intraperitoneal administration of dexketoprofen and tapentadol induced a dose-dependent antinociceptive effect, reaching a maximal effect of about 58% and 99%, respectively. Isobolographic analysis and the interaction index showed that the three proportions produced an analgesic potentiation (synergistic interaction). Interestingly, the 1:1 and 1:3 ratios of the drugs combination produced minor gastric injury in comparison with the 3:1 proportion. Our data suggest that all proportions of the dexketoprofen-tapentadol combination produced a synergistic interaction in the acetic acid-induced visceral pain model in mice with a low incidence of gastric injury.

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.

Omega-3 derivatives, specialized pro-resolving mediators: Promising therapeutic tools for the treatment of pain in chronic liver disease

The main causes of liver injury are associated with inflammation and permanent damage. They can cause chronic liver disease (CLD), which is mainly related to viral hepatitis, alcohol consumption and non-alcoholic steatohepatitis, leading to fibrosis, cirrhosis and hepatocellular carcinoma. These conditions prevent the liver from working normally and make it begin to fail, which in turn may prompt a liver transplant. CLD and cirrhosis are the eleventh cause of death worldwide. At present, there are no approved pharmacological treatments to prevent, treat or resolve liver fibrosis. The prevalence of pain in the hepatic disease is elevated with ranges between 30% and 40%. Most of the pain drugs require hepatic function; therefore, the suitable control of pain is still a clinical challenge. Specialized pro-resolving mediators (SPM): lipoxins, resolvins, protectins and maresins, are potent endogenous molecules (nM concentrations) that modulate inflammatory body responses by reducing neutrophil infiltration, macrophage activity and pain sensitization. SPM have anti-inflammatory properties, stimulate tissue resolution, repair and regeneration, and exhibit anti-nociceptive actions. Furthermore, SPM were tried on different cellular, animal models and human observational data of liver injury, improving the pathogenesis of inflammation and fibrosis. In the present work, we will describe recent evidence that suggests that SPM can be used as a therapeutic option for CLD. Additionally, we will examine the role of SPM in the control of pain in pathologies associated with liver injury.

A novel view of the problem of Osteoarthritis in experimental rat model

Introduction: The article presents the results of the functional tests to improve the assessment of MIA-induced osteoarthritis development and the effectiveness of NSAID therapy.

Materials and methods: In the study, 26 male SD rats were used. MIA-induced osteoarthritis was simulated in the right knee joint. After an intra-articular injection of MIA, the animals were treated with ibuprofen and meloxicam. Pain assessment was studied in the following functional tests: incapacitance (hind limb weight bearing) test, von Frey test (mechanical allodynia), grip strength test, and knee diameter measurement. At the end of the study, a histological analysis of the knee joint was performed.

Results and discussion: An intra-articular MIA injection reduced 1.5 times the paw withdrawal threshold. In the rats that suffered MIA-induced osteoarthritis, the difference between the diameters of the intact and injected joints was 1.05 mm, compared to 0.03 mm difference in the control group. Hind limb weight bearing asymmetry was 89.5% when simulating MIA-induced osteoarthritis. The muscular hind limb grip strength in rats with MIA-induced osteoarthritis was significantly reduced on 3rd and 7th days after simulating osteoarthritis. Ibuprofen and meloxicam showed significant efficacy in all the above tests, although ibuprofen effectiveness was more pronounced than that of meloxicam.

Conclusion: The following functional tests were identified as the most significant and sufficient to assess the development of MIA-induced osteoarthritis and analgesic efficacy of NSAIDs: incapacitance test, allodynia test (von Frey filaments), measurement of hind limb grip strength and measurement of the diameter of the inflamed knee joint. The histological analysis made it possible to confirm the correspondence of the physiological response and pathological changes in the knee joint.

Perioperative Analgesic Effects of Preemptive Ultrasound-Guided Rectus Sheath Block Combined with Butorphanol or Sufentanil for Single-Incision Laparoscopic Cholecystectomy: A Prospective, Randomized, Clinical Trial

Purpose

Pain after single-incision laparoscopic cholecystectomy (SILC), especially visceral pain, often troubles patients and doctors. Whether preemptive butorphanol can relieve visceral pain in patients undergoing SILC remains unknown. The goal of this study was to assess the efficacy of ultrasound-guided bilateral rectus sheath block (RSB) and butorphanol for perioperative analgesia in patients undergoing SILC.

Patients and Methods

Fifty-eight patients who met the criteria were randomly divided into two groups, both of which were given preemptive RSB. Patients were given either butorphanol 0.02mg/kg (group B, n=29) or sufentanil 0.1 µg/kg (group S, n=29) as preemptive analgesia. The primary outcome was the cumulative frequency of rescue analgesic request within 24 hours after operation. Secondary outcomes were numeric rating scale (NRS) scores (from 0 to 10) of incisional pain and visceral pain, the length of hospital stay and the incidence of postoperative adverse events.

Results

The frequency of postoperative rescue analgesic request of group S was significantly higher than that of group B (P=0.021). The NRS scores for visceral pain were lower in group B at 2, 6 and 12 hours after surgery than in group S (both P<0.001). The occurrence of postoperative nausea and vomiting (PONV) was significantly higher in group S. There were no significant differences between two groups for other outcomes.

Conclusion

Butorphanol can provide sufficient visceral pain treatment after SILC than the dose of sufentanil in equal analgesic effect.

Bulleyaconitine A Exerts Antianxiety and Antivisceral Hypersensitivity Effects

Visceral pain is one of the leading causes for abdominal pain in gastroenterological diseases and is still hard to treat effectively. Bulleyaconitine A (BAA) is an aconitine analog and has been used for the treatment of pain. Our previous work suggested that BAA exerted analgesic effects on neuropathic pain through stimulating the expression of dynorphin A in spinal microglia. Here, we investigated the inhibitory effect of BAA on visceral pain and examined whether the expression of dynorphin A in spinal microglia was responsible for its effects. We found that BAA produced significant antivisceral pain effect induced by acetic acid through stimulating dynorphin A expression in spinal microglia. In addition, anxiety and chronic visceral pain are highly prevalent comorbid conditions in clinical research, which is still a problem to be solved. We also aimed to evaluate the effects of BAA on anxiety. A comorbidity model with characteristics of both chronic visceral pain and anxiety was developed by colorectal injection of 2,4,6-trinitrobenzene sulfonic acid and the induction of heterotypic intermittent chronic stress protocol. In comorbid animals, BAA exerted great antianxiety effects. Meanwhile, the antianxiety mechanism of BAA was different with the antivisceral pain mechanism of BAA. In conclusion, our study demonstrated, for the first time, that BAA exerted marked antivisceral pain and antianxiety effects, which expands the analgesic spectrum and clinical application of BAA. Furthermore, it also it provides a better guidance for the clinical use of BAA.

Gastrointestinal pain

Gastrointestinal (GI) pain - a form of visceral pain - is common in some disorders, such as irritable bowel syndrome, Crohn's disease and pancreatitis. However, identifying the cause of GI pain frequently represents a diagnostic challenge as the clinical presentation is often blurred by concomitant autonomic and somatic symptoms. In addition, GI pain can be nociceptive, neuropathic and associated with cancer, but in many cases multiple aetiologies coexist in an individual patient. Mechanisms of GI pain are complex and include both peripheral and central sensitization and the involvement of the autonomic nervous system, which has a role in generating the symptoms that frequently accompany pain. Treatment of GI pain depends on the precise type of pain and the primary disorder in the patient but can include, for example, pharmacological therapy, cognitive behavioural therapies, invasive surgical procedures, endoscopic procedures and lifestyle alterations. Owing to the major differences between organ involvement, disease mechanisms and individual factors, treatment always needs to be personalized and some data suggest that phenotyping and subsequent individual management of GI pain might be options in the future.

Chronic abdominal pain and persistent opioid use after bariatric surgery

Background and aims

Bariatric surgery remains a mainstay for treatment of morbid obesity. However, long-term adverse outcomes include chronic abdominal pain and persistent opioid use. The aim of this review was to assess the existing data on prevalence, possible mechanisms, risk factors, and outcomes regarding chronic abdominal pain and persistent opioid use after bariatric surgery.

Methods

PubMed was screened for relevant literature focusing on chronic abdominal pain, persistent opioid use and pharmacokinetic alterations of opioids after bariatric surgery. Relevant papers were cross-referenced to identify publications possibly not located during the ordinary screening.

Results

Evidence regarding general chronic pain status after bariatric surgery is sparse. However, our literature review revealed that abdominal pain was the most prevalent complication to bariatric surgery, presented in 3–61% of subjects with health care contacts or readmissions 1–5 years after surgery. This could be explained by behavioral, anatomical, and/or functional disorders. Persistent opioid use and doses increased after bariatric surgery, and 4–14% initiated a persistent opioid use 1–7 years after the surgery. Persistent opioid use was associated with severe pain symptoms and was most prevalent among subjects with a lower socioeconomic status. Alteration of absorption and distribution after bariatric surgery may impact opioid effects and increase the risk of adverse events and development of addiction. Changes in absorption have been briefly investigated, but the identified alterations could not be separated from alterations caused solely by excessive weight loss, and medication formulation could influence the findings. Subjects with persistent opioid use after bariatric surgery achieved lower weight loss and less metabolic benefits from the surgery. Thus, remission from comorbidities and cost effectiveness following bariatric surgery may be limited in these subjects.

Conclusions

Pain, especially chronic abdominal, and persistent opioid use were found to be prevalent after bariatric surgery. Physiological, anatomical, and pharmacokinetic changes are likely to play a role. However, the risk factors for occurrence of chronic abdominal pain and persistent opioid use have only been scarcely examined as have the possible impact of pain and persistent opioid use on clinical outcomes, and health-care costs. This makes it difficult to design targeted preventive interventions, which can identify subjects at risk and prevent persistent opioid use after bariatric surgery. Future studies could imply pharmacokinetic-, pharmacodynamics-, and physiological-based modelling of pain treatment. More attention to social, physiologic, and psychological factors may be warranted in order to identify specific risk profiles of subjects considered for bariatric surgery in order to tailor and optimize current treatment recommendations for this population.

Intraperitoneal Tramadol in Abdominal Surgery: A Systematic Review

BACKGROUND

Multimodal analgesic regimes are required to treat pain. Intraperitoneal (IP) agents, such as local anesthetics (LAs), have been shown to reduce pain after abdominal surgery. Other IP analgesics have been tested in several randomized control trials (RCTs), but no reviews or guidelines have evaluated their use. Tramadol is an effective oral and intravenous analgesia with recent evidence supporting the use of IP tramadol (IPT). We aimed to review the efficacy of IPT as an adjunct to intraperitoneal local anesthetics (IPLAs) for pain relief after abdominal surgery.

MATERIALS AND METHODS

Relevant articles were identified by two independent reviewers from MEDLINE, EMBASE and PubMed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines up to January 2019. Only RCT comparing IPT + IPLA with IPLA alone were included. Outcomes recorded were the postoperative analgesic requirement, pain scores at 4 h and 24 h and adverse events. Data were analyzed with Review Manager, version 5.3.

RESULTS

A total of five RCTs (4× laparoscopic cholecystectomy and 1× abdominal hysterectomy) were included in this review from 419 studies screened. All doses were given as a single bolus. Pain relief requirements over the first 24 h weres less in the IPT + IPLA groups when compared with those in IPLA alone. Pain scores were less for IPT + IPLA groups at 4 h and 24 h. There were no significant differences in adverse events between groups.

CONCLUSIONS

In summary, IPT, in combination with IPLA, is effective in the management of acute postoperative pain and reduces the total amount of pain relief consumed in the first 24 h after surgery. Studies reporting the use of IPT + IPLA reported no toxicity or systemic adverse events. Further research into standardizing the dosing of IPT to optimize its effectiveness and further reduce the additional analgesic requirement is indicated.

Neuromodulators for Functional Gastrointestinal Disorders (Disorders of Gut-Brain Interaction): A Rome Foundation Working Team Report

BACKGROUND & AIMS

Central neuromodulators (antidepressants, antipsychotics, and other central nervous system-targeted medications) are increasingly used for treatment of functional gastrointestinal disorders (FGIDs), now recognized as disorders of gut-brain interaction. However, the available evidence and guidance for the use of central neuromodulators in these conditions is scanty and incomplete. In this Rome Foundation Working Team report, a multidisciplinary team summarized available research evidence and clinical experience to provide guidance and treatment recommendations.

METHODS

The working team summarized the literature on the pharmacology of central neuromodulators and their effects on gastrointestinal sensorimotor function and conducted an evidence-based review on their use for treating FGID syndromes. Because of the paucity of data for FGIDs, we included data for non-gastrointestinal painful disorders and specific symptoms of pain, nausea, and vomiting. This information was combined into a final document comprising a synthesis of available evidence and recommendations for clinical use guided by the research and clinical experience of the experts on the committee.

RESULTS

The evidence-based review on neuromodulators in FGID, restricted by the limited available controlled trials, was integrated with open-label studies and case series, along with the experience of experts to create recommendations using a consensus (Delphi) approach. Due to the diversity of conditions and complexity of treatment options, specific recommendations were generated for different FGIDs. However, some general recommendations include: (1) low to modest dosages of tricyclic antidepressants provide the most convincing evidence of benefit for treating chronic gastrointestinal pain and painful FGIDs and serotonin noradrenergic reuptake inhibitors can also be recommended, though further studies are needed; (2) augmentation, that is, adding a second treatment (adding quetiapine, aripiprazole, buspirone α2δ ligand agents) is recommended when a single medication is unsuccessful or produces side effects at higher dosages; (3) treatment should be continued for 6-12 months to potentially prevent relapse; and (4) implementation of successful treatment requires effective communication skills to improve patient acceptance and adherence, and to optimize the patient-provider relationship.

CONCLUSIONS

Based on systematic and selectively focused review and the consensus of a multidisciplinary panel, we have provided summary information and guidelines for the use of central neuromodulators in the treatment of chronic gastrointestinal symptoms and FGIDs. Further studies are needed to confirm and refine these recommendations.

Prospective analysis of pain and pain management in an emergency department

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BACKGROUND AND AIM OF THE WORK

The aim of pain management in the Emergency Department (ED) is to temporarily optimize patient quality of life by reducing acute discomfort. The goals of this study were to evaluate the intensity and location of pain experienced by patients in the ED, the time to analgesia administration in the ED, and the patient's satisfaction so to identify potential useful interventions to improve pain management.

METHODS

We prospectively collected data on the intensity of pain experienced by 137 patients during their ED stays using the Visual Analog Scale (VAS) and the Numeric Rating Scale (NRS). Patients were further stratified by pain intensity according to three categories, and by cause of pain.

RESULTS

NRS pain measurements were higher than VAS measurements. Patients who took pain medication within a few hours before their ED visit had a higher mean VAS score at arrival in comparison to patients who did not. Patients treated with pain medications, compared to the non-treated, had more pain at arrival; abdominal pain was treated earlier than non-abdominal pain, whereas no difference in timing of medication administration was noted between traumatic and non-traumatic pain. Among the  hospitalized patients, the chest was the most common location of pain; these patients had lower NRS scores than non-hospitalized patients. Patients with mild to moderate pain were more satisfied then those with severe pain.

CONCLUSIONS

The discrepancy between NRS and VAS scores suggests that pain intensity cannot be determined accurately according to pain scale data alone but should also incorporate clinical judgment.

[Clinical and emotional/behavioral characteristics of acute and chronic low-back pain]

AIM

To analyze clinical and emotional/behavioral characteristics of acute and chronic low-back pain that significantly affect quality-of-life.

MATERIAL AND METHODS

Fifty-three patients with pain syndromes were examined using the painDETECT questionnaire, the Visual Analog Scale for Pain, The McGill Pain Questionnaire and laboratory and instrumental methods of neurological assessment.

RESULTS AND CONCLUSION

A 'picture of the patient with acute and chronic pain' was built, a group of patients with neuropathic component of pain was described. The size of herniated discs was not correlated with VAS assessments and the neuropathic component had a mild effect on pain intensity. The significant correlation was found between the severity of pain and coping strategies for pain. The results indicate the importance of effective and safety pain stopping, in particular at the acute stage, to prevent pain chronification. A drug of choice in case of intensive pain and marked nociceptive component are highly effective and safe nonsteroidal anti-inflammatory drugs, in particular etoricoxib (Arcoxia), a selective COX-2 inhibitor.