Pain associated with breast cancer: etiologies and therapies

Pain associated with breast cancer is a prevalent problem that negatively affects quality of life. Breast cancer pain is not limited to the disease course itself but is also induced by current therapeutic strategies. This, combined with the increasing number of patients living with breast cancer, make pain management for breast cancer patients an increasingly important area of research. This narrative review presents a summary of pain associated with breast cancer, including pain related to the cancer disease process itself and pain associated with current therapeutic modalities including radiation, chemotherapy, immunotherapy, and surgery. Current pain management techniques, their limitations, and novel analgesic strategies are also discussed.

Prevalence and Predictors of Long-term Opioid Use After Pelvic Fractures

BACKGROUND

Opioids are effective in short-term pain treatment; however, their long-term effectiveness is unconfirmed. Many patients are exposed to opioids after pelvic injuries with little known about persistent use afterward. We assessed the prevalence and predictors of long-term opioid use following pelvic fractures.

MATERIALS AND METHODS

This retrospective study enrolled 277 patients with acute pelvic fractures over five years. Daily and total morphine milligram equivalents (MME) were calculated. The primary outcome was long-term opioid use (LOU) defined as ongoing opioid use 60-90 days post-discharge. The secondary outcome was intermediate-term opioid use (IOU) defined as ongoing opioid use 30-60 days post-discharge. Univariable and logistic regression analyses were performed.

RESULTS

Median (interquartile range) total inpatient opioid MME was 422 (157-1667) with a median daily MME of 69 (26-145). Long-term opioid use occurred in 16%, and IOU occurred in 29%. Univariable analysis found that total and daily inpatient opioid use were each significantly associated with LOU (median MME, 1241 vs 371; median MMEs, 127.7 vs 59.2, respectively) and IOU (median MME, 1140 vs 326; median MMEs, 111.8 vs 57.9, respectively). Logistic regression analysis found daily inpatient MME ≥50 (odds ratio [OR] 3.027, 95% confidence interval [CI] 1.059-8.652]) and pelvic fracture type (Tile B/C) (OR 2.992 [CI 1.324-6.763])were independent predictors of LOU.

CONCLUSION

Total and daily inpatient opioid use were significantly associated with LOU and IOU. Patients who received ≥50 MME/inpatient day had a higher likelihood of LOU. This study seeks to inform clinical decisions for pain management to prevent adverse outcomes.

Buprenorphine for acute post-surgical pain: A systematic review and meta-analysis

Our study was designed to evaluate the efficacy of buprenorphine for the management of acute post-surgical pain reported in published studies in the years 2015-2022. Comprehensive research was performed by using online resources like PUBMED and the Wiley Library database to gather the relevant literature. Two authors were assigned to independently collect the information. Cochran's Q-test and I square statistic were used to determine the heterogeneity across the studies. Publication bias was estimated by using the Egger regression analysis and found to be significantly present once the P value <0.05. In this review, 15 studies were included. The pooled ratio of pain reduction after 12 hours of surgery was reported as 11.2% with 97% heterogeneity. Day one shows 5.9 reductions in pain with 98% heterogeneity. The 3% more pain was reduced on day 2. The day 3 pooled pain reduction score was observed as 1.9%. The overall pool prevalence of pain reduction was noted as 6.2% at different time duration with significant heterogeneity of 100%. Buprenorphine transdermal and sublingual both have significant pain relief scores. The analgesic drug consumption was reduced at the end of the follow-up duration.

Real world experience with minimally invasive wireless percutaneous neuromodulation in a tertiary care centre

Background

Wireless percutaneous nerve stimulation (PNS) for chronic pain is rapidly evolving in the ever expanding neuromodulation paradigm. Safety and lower risks with a potential of long-term analgesia cannot be over emphasised especially with the ongoing opioid pandemic. PNS with an implanted pulse generator (IPG) has also been shown to provide good benefit, without often unpleasant widespread paraesthesia from conventional spinal cord stimulators.

Aim and Methods

We retrospectively extracted data on all wireless PNS implants in our highly specialised pain neuromodulation centre since initiation of wireless PNS service in August 2019. Patient demographics, pain history, analgesic intake and details on implant follow-up data within 1 year post-implant including pain relief, EuroQol-5 Dimension (EQ-5D) and Patients' Global Impression of Change (PGIC) scores were extracted. The cases are presented in a narrative format.

Result

A total of five patients were implanted with wireless (Stimwave^®) PNS from August 2019 to February 2020. Neuropathic pain was the most common presenting diagnosis. All patients showed >50% pain relief at 3 months. EQ-5D and PGIC did not show any improvement in the subjects. Two of the patients managed to decrease their analgesics after implantation. Similar sustained benefits could not be demonstrated after 1 year.

Discussion

PNS can provide analgesia in appropriately selected cases. Naivety of the technique and procedure might cause some degree of uncertainty. External pulse generator with wireless transmission avoids IPG and tunnelling related side effects, but requires individualised special wearable technology to power the lead. Minimally invasive nature of the technique might be attractive and preferable for patients with complex medical issues, nickel allergy and poor general health who may otherwise be unsuitable for Spinal Cord Stimulation (SCS) with conventional hardware. Robust prospective controlled studies and RCTs in future might provide further insights on utility in other neuropathic pain diagnosis, long-term outcomes and acceptability compared to conventional SCS.

Chronic Pain Prevalence and Factors Associated With High Impact Chronic Pain following Total Joint Arthroplasty: An Observational Study

Hip, knee, and shoulder arthroplasty are among the most frequently performed orthopaedic procedures in the United States. High impact and bothersome chronic pain rates following total joint arthroplasty (TJA) are unknown; as are factors that predict these chronic pain outcomes. This retrospective observational study included individuals that had a TJA from January 2014 to January 2020 (n = 2,638). Pre-operative and clinical encounter information was extracted from the electronic health record and chronic pain state was determined by email survey. Predictor variables included TJA location, number of surgeries, comorbidities, tobacco use, BMI, and pre-operative pain intensity. Primary outcomes were high impact and bothersome chronic pain. Rates of high impact pain (95% CI) were comparable for knee (9.8-13.3%), hip (8.3-11.8%) and shoulder (7.6-16.3%). Increased risk of high impact pain included non-white race, two or more comorbidities, age less than 65 years, pre-operative pain scores 5/10 or higher, knee arthroplasty, and post-operative survey completion 24 months or less. Rates of bothersome chronic pain (95% CI) were also comparable for knee (24.9-29.9%) and hip (21.3-26.3%) arthroplasty; but higher for shoulder (26.9-39.6%). Increased risk of bothersome chronic pain included non-white race, shoulder arthroplasty, knee arthroplasty, current or past tobacco use, and being female. PERSPECTIVE: In this cohort more than 1/3rd of individuals reported high impact or bothersome chronic pain following TJA. Non-white race and knee arthroplasty were the only two variables associated with both chronic pain outcomes.

Multimodal nonopioid pain protocol provides equivalent pain control versus opioids following arthroscopic shoulder labral surgery: a prospective randomized controlled trial

BACKGROUND

This study aimed to compare postoperative pain and patient satisfaction in patients undergoing primary arthroscopic labral surgery managed with either a nonopioid alternative pain regimen or a traditional opioid pain regimen.

METHODS

Sixty consecutive patients undergoing primary arthroscopic shoulder labral surgery were assessed for participation. In accordance with the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement, a prospective randomized controlled trial was performed. The 2 arms of the study were a multimodal nonopioid analgesic protocol as the experimental group and a standard opioid regimen as the control group. The primary outcome was postoperative pain scores (on a visual analog scale [VAS]) for the first 10 days postoperatively. Secondary outcomes included patient satisfaction, patient-reported outcomes, and complications. Randomization was performed with a random number generator, and all data were collected by blinded observers. Patients were not blinded.

RESULTS

Twelve patients did not meet the inclusion criteria or declined to participate. Thus, 48 patients were included in the final analysis: 24 in the nonopioid group and 24 in the opioid group. There was no significant difference in VAS or PROMIS (Patient-Reported Outcomes Measurement Information System) scores between patients in the 2 cohorts on any postoperative day (P > .05). When we controlled for confounding factors with repeated-measures mixed models, the nonopioid cohort reported significantly lower VAS and PROMIS (Patient-Reported Outcomes Measurement Information System) Pain Interference scores (P < .01) at all time points. No difference was found in reported adverse events (constipation, diarrhea, drowsiness, nausea, and upset stomach) between cohorts at any time point (P > .05).

CONCLUSION

This study found that a multimodal nonopioid pain regimen provided, at the minimum, equivalent pain control, an equivalent adverse reaction profile, and equivalent patient satisfaction when compared with a standard opioid-based regimen following arthroscopic shoulder labral surgery.

Reframe the Pain: A Randomized Controlled Trial of a Parent-Led Memory-Reframing Intervention

Negatively-biased pain memories (ie, recalling more pain as compared to earlier reports) are a robust predictor of future pain experiences. This randomized controlled trial examined the efficacy of a memory-reframing intervention to reframe children's pain memories. Sixty-five children (54% girls, M_age=5.35 years) underwent a tonsillectomy and reported their levels of post-surgical pain intensity and pain-related fear. 2 weeks post-surgery, children and 1 of their parents were randomized to the memory-reframing intervention or control group. Following control/intervention instructions, parents and children reminisced about the past surgery as they normally would (control) or using the memory-reframing strategies (intervention). Children recalled their post-surgical pain intensity and pain-related fear one week later. Parents reported the intervention's acceptability. Recruitment statistics were used to assess feasibility. Controlling for initial pain intensity ratings and using the Faces Pain Scale Revised, children in the intervention group reported more accurate/positively-biased memories for day 1 post-surgery pain intensity (M = 2.60/10; 95% CI, 1.62 to 3.68), compared to children in the control group (M = 4.11/10; 95% CI, 3.12 to 5.03), η_p² = .07, p = .040. The intervention was acceptable and feasible. Optimal parent-child reminiscing about a past pain experience resulted in children remembering their pain more accurately/positively. Clinicaltrials.gov:NCT03538730. PERSPECTIVE: This article presents results of the first randomized controlled trial examining the efficacy of parent-led memory-reframing intervention to change children's memories for pain. Children of parents who were taught and engaged in optimal reminiscing about a past surgery experience remembered their pain intensity more accurately/positively.

Surgery and opioids: evidence-based expert consensus guidelines on the perioperative use of opioids in the United Kingdom

There are significant concerns regarding prescription and misuse of prescription opioids in the perioperative period. The Faculty of Pain Medicine at the Royal College of Anaesthetists have produced this evidence-based expert consensus guideline on surgery and opioids along with the Royal College of Surgery, Royal College of Psychiatry, Royal College of Nursing, and the British Pain Society. This expert consensus practice advisory reproduces the Faculty of Pain Medicine guidance. Perioperative stewardship of opioids starts with judicious opioid prescribing in primary and secondary care. Before surgery, it is important to assess risk factors for continued opioid use after surgery and identify those with chronic pain before surgery, some of whom may be taking opioids. A multidisciplinary perioperative care plan that includes a prehabilitation strategy and intraoperative and postoperative care needs to be formulated. This may need the input of a pain specialist. Emphasis is placed on optimum management of pain pre-, intra-, and postoperatively. The use of immediate-release opioids is preferred in the immediate postoperative period. Attention to ensuring a smooth care transition and communication from secondary to primary care for those taking opioids is highlighted. For opioid-naive patients (patients not taking opioids before surgery), no more than 7 days of opioid prescription is recommended. Persistent use of opioid needs a medical evaluation and exclusion of chronic post-surgical pain. The lack of grading of the evidence of each individual recommendation remains a major weakness of this guidance; however, evidence supporting each recommendation has been rigorously reviewed by experts in perioperative pain management.

Evaluation of the need to prescribe opioid medication to control post-surgical pain of different periodontal/oral surgeries

BACKGROUND

To determine the level of perceived pain after different types of periodontal/oral surgical procedures, and the differences in patients' selection of pain management, over the counter (OTC) versus opioid, based on procedure type.

METHODS

Patients undergoing surgical procedures were asked to complete a pain questionnaire at four time points: 1) before surgery 2) first dose of analgesic at home, 3) 24 hours postoperatively, and 4) 72 hours postoperatively. The questionnaire consisted of numerical and descriptive scales to describe the perceived pain.

RESULTS

A total of 198 patients completed the questionnaire. All surgical procedures were grouped into five major categories: bone augmentation procedures (11% BAP), teeth extractions (26% EXT), surgical implant placement (25% IP), mucogingival surgeries (21% MGS), and pocket elimination procedures (17%). IP surgery was associated with significantly less pain compared with MGS and EXT (P <0.05). There was a statistically significant difference for taking any medication based on type of surgical procedure at 24 hours (P <0.05).

CONCLUSIONS

IP is associated with significantly lower perceived pain compared with EXT and MGS surgery. Analgesic consumption was generally parallel to pain perception. A considerable number of patients elected to control the post-surgical pain using OTC medication up to 72 hours. Periodontal/oral surgery procedures vary in the amount of perceived postoperative pain. Tailoring postoperative medications to the type of periodontal/oral surgery performed will help prevent overprescribing of opioids.

Pain complications of oral implants: Is that an issue?

The use of oral implants as a form of replacing missing teeth in partial or total edentulous patients is considered the gold standard in oral rehabilitation. Although considered a history of success in contemporary dentistry, surgical complications may occur, as excessive bleeding, damage to the adjacent teeth and mandibular fractures. Persistent pain and abnormal somatosensory responses after the surgery ordinary healing time are also potential problems and may lead to the development of a condition named posttraumatic trigeminal neuropathic pain (PTNP). Though relatively rare, PTNP has a profound impact on patient's quality of life. Appropriated previous image techniques, effective anaesthetic procedures and caution during the surgical procedure and implant installation are recommended for the prevention of this condition. In case of the PTNP, different management modalities, including antidepressant and membrane stabilizer medications, as well as peripheral strategies, as the use of topical medication and the botulin toxin are presented and discussed.

Evaluation of edonerpic maleate as a CRMP2 inhibitor for pain relief

We have previously reported that the microtubule-associated collapsin response mediator protein 2 (CRMP2) is necessary for the expression of chronic pain. CRMP2 achieves this control of nociceptive signaling by virtue of its ability to regulate voltage-gated calcium and sodium channels. To date, however, no drugs exist that target CRMP2. Recently, the small molecule edonerpic maleate (1 -{3-[2-(1-benzothiophen-5-yl)ethoxy]propyl}azetidin-3-ol maleate), a candidate therapeutic for Alzheimer’s disease was reported to be a novel CRMP2 binding compound with the potential to decrease its phosphorylation level in cortical tissues in vivo. Here we sought to determine the mechanism of action of edonerpic maleate and test its possible effect in a rodent model of chronic pain. We observed: (i) no binding between human CRMP2 and edonerpic maleate; (ii) edonerpic maleate had no effect on CRMP2 expression and phosphorylation in dorsal root ganglion (DRG) neurons; (iii) edonerpic maleate-decreased calcium but increased sodium current density in DRG neurons; and (iv) edonerpic maleate was ineffective in reversing post-surgical allodynia in male and female mice. Thus, while CRMP2 inhibiting compounds remain a viable strategy for developing new mechanism-based pain inhibitors, edonerpic maleate is an unlikely candidate.

Efficacy of erector spinae plane block for analgesia in breast surgery: a systematic review and meta-analysis

The erector spinae plane block is a new regional anaesthesia technique that provides truncal anaesthesia for breast surgery. This systematic review and meta-analysis was undertaken to determine if the erector spinae plane block is effective at reducing pain scores and opioid consumption after breast surgery. This study also evaluated the outcomes of erector spinae plane blocks compared with other regional blocks. PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov were searched. We included randomised controlled trials reporting the use of the erector spinae plane block in adult breast surgery. Risk of bias was assessed with the revised Cochrane risk-of-bias tool. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework was used to assess trial quality. Thirteen randomised controlled trials (861 patients; 418 erector spinae plane block, 215 no blocks, 228 other blocks) were included. Erector spinae plane block reduced postoperative pain compared with no block: at 0-2 hours (mean difference (95% CI) -1.63 (-2.97 to -0.29), 6 studies, 329 patients, high-quality evidence, I²  = 98%, p = 0.02); at 6 hours (mean difference (95% CI) -0.90 (-1.49 to -0.30), 5 studies, 250 patients, high-quality evidence, I²  = 91%, p = 0.003); at 12 hours (mean difference (95% CI) -0.46 (-0.67 to -0.25), 5 studies, 250 patients, high-quality evidence, I²  = 58%, p < 0.0001); and at 24 hours (mean difference (95% CI) -0.50 (-0.70 to -0.30), 6 studies, 329 patients, high-quality evidence, I²  = 76%, p < 0.00001). Compared with no block, erector spinae plane block also showed significantly lower postoperative oral morphine equivalent requirements (mean difference (95% CI) -21.55mg (-32.57 to -10.52), 7 studies, 429 patients, high-quality evidence, I²  = 99%, p = 0.0001). Separate analysis of studies comparing erector spinae plane block with pectoralis nerve block and paravertebral block showed that its analgesic efficacy was inferior to pectoralis nerve block and similar to paravertebral block. The incidence of pneumothorax was 2.6% in the paravertebral block group; there were no reports of complications of the other blocks. This review has shown that the erector spinae plane block is more effective at reducing postoperative opioid consumption and pain scores up to 24 hours compared with general anaesthesia alone. However, it was inferior to the pectoralis nerve block and its efficacy was similar to paravertebral block. Further evidence, preferably from properly blinded trials, is required to confirm these findings.

Botulinum Neurotoxins and Cancer-A Review of the Literature

Botulinum neurotoxins (BoNT) possess an analgesic effect through several mechanisms including an inhibition of acetylcholine release from the neuromuscular junction as well as an inhibition of specific pain transmitters and mediators. Animal studies have shown that a peripheral injection of BoNTs impairs the release of major pain transmitters such as substance P, calcitonin gene related peptide (CGRP) and glutamate from peripheral nerve endings as well as peripheral and central neurons (dorsal root ganglia and spinal cord). These effects lead to pain relief via the reduction of peripheral and central sensitization both of which reflect important mechanisms of pain chronicity. This review provides updated information about the effect of botulinum toxin injection on local pain caused by cancer, painful muscle spasms from a remote cancer, and pain at the site of cancer surgery and radiation. The data from the literature suggests that the local injection of BoNTs improves muscle spasms caused by cancerous mass lesions and alleviates the post-operative neuropathic pain at the site of surgery and radiation. It also helps repair the parotid damage (fistula, sialocele) caused by facial surgery and radiation and improves post-parotidectomy gustatory hyperhidrosis. The limited literature that suggests adding botulinum toxins to cell culture slows/halts the growth of certain cancer cells is also reviewed and discussed.

ANALGESIC EFFECT OF INTRAVENOUS ASCORBIC ACID VERSUS ACELCOFENAC POST-TRANSALVEOLAR EXTRACTION: A CASE-CONTROL STUDY

One of the most important aspects of postsurgical care is finding an efficient way for the management of pain. Third molar extractions/surgical impaction is one of the most frequent surgical procedures in dental hospitals, and it is most often associated with postoperative complications like severe pain, oedema and reduced mouth opening. This study was aimed to evaluate the efficacy of 2 g intravenous (IV) vitamin C compared to 100 mg aceclofenac on postsurgical pain, swelling and trismus after the surgical removal of third molars. A total of 101 patients were recruited for the study, and theywere divided into two treatment groups; group A (n = 51) received 2 g IV vitamin C and group B (n = 50) received 100 mg aceclofenac. Pain intensity, facial swelling and mouth opening were assessed till day 3 post-surgically. Statistical analysis of pain intensity revealed that IV vitamin C performed slightly better but not significantly different (p>0.05) from aceclofenac group at the end of day 3. No significant difference for facial swelling and mouth opening between the two treatment protocols was seen (p>0.05). Our results concluded that both treatment groups were overall similar in analgesic efficacy, postoperative oedema and reduction in mouth opening. It was also determined that the method devised administering 2 g IV vitamin C intravenously was well suited to the treatment of postoperative pain, swelling and trismus following the surgical extraction of impacted third molars.

Analysis of predictors of opioid-free analgesia for management of acute post-surgical pain in the United States

OBJECTIVES

Utilization of opioid-free analgesia (OFA) for post-surgical pain is a growing trend to counter the risks of opioid abuse and opioid-related adverse drug events (ORADEs). However, utilization patterns of OFA have not been examined. In this study, we investigated the utilization patterns and predictors of OFA in a surgical population in the United States.

METHODS

Analysis of the Cerner Health Facts database (January 2011 to December 2015) was conducted to describe hospital and patient characteristics associated with OFA. Baseline characteristics, such as age, gender, race, discharge status, year of admission and chronic comorbidities at index admission were collected. Hospital characteristics and payer type at index admission were collected as reported in the electronic health record database. Descriptive statistics and logistic regression were used to identify statistically significant predictors of OFA on patient and institutional levels.

RESULTS

The study identified 10,219 patients, from 187 hospitals, who received post-surgical OFA and 255,196 patients who received post-surgical opioids. OFA rates varied considerably by hospital. Patients more likely to receive OFA were older (OR = 1.06, 95% CI [1.03, 1.10]; p < .001), or had neurological disorders (OR = 1.24, 95% CI [1.10, 1.39]; p < .001), diabetes (OR = 1.20, 95% CI [1.08, 1.33]; p = .001) or psychosis (OR = 1.18, 95% CI [1.01, 1.37]; p = .030). Patients with obesity and depression were less likely to receive OFA (OR = 0.80, 95% CI [0.67, 0.95]; p = .010 OR = 0.85, 95% CI [0.73, 0.98]; p = .030, respectively).

CONCLUSIONS

Use of post-surgical OFA was limited overall and was not favored in some patient groups prone to ORADEs, indicating missed opportunities to reduce opioid use and ORADE incidence. A substantial proportion of OFA patients was contributed by a few hospitals with especially high rates of OFA, suggesting that hospital policies, institutional structure and cross-functional departmental commitment to reducing opioid use may play a large role in the implementation of OFA.

Persistent Post-Mastectomy Pain: Risk Factors and Current Approaches to Treatment

Persistent Post-Mastectomy Pain (PPMP) is a common condition that can follow surgeries for breast cancer, the most common cancer in women. Because of the frequency of PPMP and its potential severity, it has received increasing research attention. This manuscript reviews the recent research literature, beginning with a brief history and then relevant medical, surgical, demographic, and psychosocial risk factors. Subsequently, social, psychological, and functional sequelae that have been linked to PPMPS are considered, as is research on current pharmacological, psychological, and rehabilitative approaches to treatment. The review concludes with a discussion of directions for future research and treatment that might reduce the incidence and impact of PPMP on breast cancer survivors. PERSPECTIVE: This article describes current research literature involving mechanisms, risks, and treatments related to persistent post-mastectomy pain. Implications of research findings also are discussed for pre- and post-surgical approaches to pain management, current treatments, and promising research directions.

Distinct Analgesic Actions of DHA and DHA-Derived Specialized Pro-Resolving Mediators on Post-operative Pain After Bone Fracture in Mice

Mechanisms of pain resolution are largely unclear. Increasing evidence suggests that specialized pro-resolving mediators (SPMs), derived from fish oil docosahexaenoic acid (DHA), promote the resolution of acute inflammation and potently inhibit inflammatory and neuropathic pain. In this study, we examined the analgesic impact of DHA and DHA-derived SPMs in a mouse model of post-operative pain induced by tibial bone fracture (fPOP). Intravenous perioperative treatment with DHA (500 μg), resolvin D1 (RvD1, 500 ng) and maresin 1 (MaR1, 500 ng), 10 min and 24 h after the surgery, delayed the development of fPOP (mechanical allodynia and cold allodynia). In contrast, post-operative intrathecal (IT) administration of DHA (500 μg) 2 weeks after the surgery had no effects on established mechanical and cold allodynia. However, by direct comparison, IT post-operative treatment (500 ng) with neuroprotectin D1 (NPD1), MaR1, and D-resolvins, RvD1 and RvD5, but not RvD3 and RvD4, effectively reduced mechanical and cold allodynia. ELISA analysis showed that perioperative DHA treatment increased RvD1 levels in serum and spinal cord samples after bone fracture. Interestingly, sham surgery resulted in transient allodynia and increased RvD1 levels, suggesting a correlation of enhanced SPM levels with acute pain resolution after sham surgery. Our findings suggest that (1) perioperative treatment with DHA is effective in preventing and delaying the development of fPOP and (2) post-treatment with some SPMs can attenuate established fPOP. Our data also indicate that orthopedic surgery impairs SPM production. Thus, DHA and DHA-derived SPMs should be differentially supplemented for treating fPOP and improving recovery.

Does the number of veins ligated during microsurgical subinguinal varicocelectomy impact improvement in pain post-surgery?

Background

We examined the impact of the number of veins ligated during varicocelectomy on post-surgical improvement of pain in a group of men presenting with clinical varicocele and pain as an indication for surgery.

Methods

This is a retrospective study of patients presenting with clinical left varicocele to the male infertility unit at a teaching hospital in Qatar. Files of all patients who underwent sub-inguinal microsurgical varicocelectomy were retrieved and categorized into three groups indicating the number of spermatic veins ligated during varicocelectomy. The presence of pain was assessed during pre- and post-operation (at 3 and 6 months). Statistical analysis was performed using Kruskal-Wallis test (K) and Chi-square test (C).

Results

Out of 675 records, 207 (30.7%) patients did left varicocelectomy for pain. Their mean age was 35.3±9.2 years. Pain was assessed in 106/207 (51.2%) patients post operatively, of whom 89 (84%) reported complete resolution of symptoms. This improvement was maintained irrespective of the number of veins ligated during surgery (<5 veins: 90.0%, 5–10 veins: 81.5%, and >10 veins: 85.7%).

Conclusions

Microsurgical subinguinal varicocelectomy is a valid treatment method for patients with a symptomatic clinical varicocele. While a significant post-surgical (at 6 months) reduction of pain was detected, the number of veins ligated intraoperatively was not predictive of post-operative improvement of pain in this study population.

The safety of liposome bupivacaine 2 years post-launch: a look back and a look forward

The need for better post-surgical pain management continues to be unmet, despite clinicians' awareness and concern for many years. Opioids remain the standard of care because of their analgesic efficacy; however, opioid use is often associated with adverse effects and poor patient outcomes. Multimodal analgesic regimens have recently been endorsed as a way to provide adequate post-surgical pain control while reducing opioid consumption. Liposome bupivacaine is a liposomal formulation of bupivacaine indicated for a single administration into the surgical site. Based on the available clinical trial data compiled to date, as well as the author's review of publicly available post-marketing safety information, liposome bupivacaine may be a viable addition to currently available therapeutic options for post-surgical analgesia while reducing potential risks associated with use of opioid analgesics, and may represent a useful addition to the multimodal analgesic modalities currently used for post-operative pain management. The potential for its use in other areas is also being investigated. The purpose of this review is to examine the currently available post-marketing safety information on liposome bupivacaine.

Analgesic activity of the ethanolic extract of Shorea robusta resin in experimental animals

Aim:

Shorea robusta (Sal), an important traditional Indian medicinal plant used in various ailments and rituals and the indigenous use of the resin of this plant as a medicament for treatment of various inflammatory conditions is well documented in literature. In the present study, ethanolic extract of S. robusta resin (SRE) was evaluated for its analgesic activity by making use of different central and peripheral pain models.

Materials and Methods:

The analgesic activity of SRE was assessed by employing different pain models such as, i) hot plate and tail flick tests for central analgesia, ii) acetic acid- induced writhing (peripheral analgesic model), iii) formalin-induced hind paw licking (both central and peripheral model), iv) carrageenan-induced hyperalgesia (peripheral analgesic model) and v) post-surgical pain (peripheral analgesic model).

Results:

The extract produced significant central and peripheral analgesic effects, as is evident from increase in reaction time in hot plate and tail flick tests, inhibition in writhing counts in acetic acid-induced writhing test, inhibition of licking time in formalin-induced hind paw licking, increased pain threshold in paw withdrawal latency in carrageenan-induced hyperalgesia and increased paw withdrawal threshold in post-surgical pain.

Conclusion:

The results of the present study demonstrate marked antinociceptive effects of SRE.

Burrowing behavior as an indicator of post-laparotomy pain in mice

Detection of persistent pain of a mild-to-moderate degree in laboratory mice is difficult because mice do not show unambiguous symptoms of pain or suffering using standard methods of short-term observational or clinical monitoring. This study investigated the potential use of burrowing performance - a spontaneous and highly motivated behavior - as a measure of post-operative pain in laboratory mice. The influence of minor surgery on burrowing was investigated in adult C57BL/6J mice of both genders in a modified rodent burrowing test (displacement of food pellets from a pellet-filled tube) within the animal's home cage. Almost all (98%) healthy mice burrowed (mean latency 1.3 h, SEM 0.5 h). After surgery without pain treatment, latency of burrowing was significantly prolonged (mean Δ latency 10 h). Analgesic treatment using the anti-inflammatory drug carprofen (5 mg/kg bodyweight) decreased latency of burrowing after surgery (mean Δ latency 5.5 h) to the level found in mice that had been anesthetized (mean Δ latency 5.4 h) or had received anesthesia and analgesia (mean Δ latency 4.6 h). Analgesia during surgery was associated with a significantly earlier onset of burrowing compared to surgery without pain treatment. A distinct gradation in burrowing performance was found ranging from the undisturbed pre-operative status to the intermediate level following anesthesia/analgesia and surgery with analgesia, to the pronounced prolongation of latency to burrow after surgery without pain relief. In conclusion, post-surgical impairment of general condition, probably mainly attributable to pain, can be conveniently assessed in laboratory mice on the basis of the burrowing test.