Hyperalgesia and Persistent Pain after Breast Cancer Surgery: A Prospective Randomized Controlled Trial with Perioperative COX-2 Inhibition

Effect of Preadministration of Nalmefene on Sufentanil-Induced Cough During Induction of General Anesthesia in Patients Undergoing Breast Surgery: A Double-Blind Randomized Controlled Trial

Purpose

This study was designed to investigate the effects of preadministration of nalmefene before general anesthesia induction on sufentanil-induced cough (SIC) in patients undergoing breast surgery.

Patients and Methods

A total of 105 patients scheduled for elective breast surgery under general anesthesia were selected and randomly assigned into three groups: normal saline (Group C), low-dose nalmefene 0.1 μg·kg-1 (Group LN), and high-dose nalmefene 0.25 μg·kg-1 (Group HN). Sufentanil 0.5 μg·kg-1 was injected intravenously within 2 s after 5 min of intervention. The count and severity of cough within 2 min after sufentanil injection, as well as the time to first cough, were recorded. In addition, we also collected intraoperative hemodynamic data, postoperative pain scores, the incidence of receiving rescue analgesics, and side effects up to 24 h after surgery.

Results

Compared to Group C, the incidence of SIC was significantly lower in Group LN and HN (64.7% vs 30.3% and 14.7%, respectively; P < 0.001), but no significant difference was observed between the two groups (P=0.126). Compared to Group C, the risk factors decreased by 53.4% (95% confidence interval [CI] =0.181-0.735, P=0.008) in Group LN and by 75.9% (95% CI=0.432-0.898, P=0.001) in Group HN. Of the patients with SIC, less frequent SIC within 2 min after induction and a lower proportion of severe coughs were observed than Group C (P < 0.05), and no difference was detected between Group LN and HN. Additionally, the onset time to the first SIC did not differ significantly between the groups. Intraoperative hemodynamic data, postoperative pain scores, and side effects in the first 24 h did not differ among the groups.

Conclusion

Preadministration of nalmefene prior to induction of general anesthesia effectively suppressed SIC in patients undergoing breast surgery, without affecting intraoperative hemodynamic fluctuation and postoperative pain intensity.

Effect of use of NSAIDs or steroids during the acute phase of pain on the incidence of chronic pain: a systematic review and meta-analysis of randomised trials

BACKGROUND

This study is the first to summarize the evidence on how the use of anti-inflammatory drugs during acute pain has an impact on the development of chronic pain.

METHODS

Randomized controlled trials retrieved from nine databases included anti-inflammatory drugs (NSAIDs or steroids) versus non-anti-inflammatory drugs in patients with acute pain and reported the incidence of chronic pain. No specified date, age, sex, or language restrictions. Subgroup analyses were performed according to pain classification, follow-up time, and medication. The GRADE method was used to evaluate quality of evidence.

RESULTS

A total of 29 trials (5220 patients) were included. Steroids or NSAIDs did not reduce the incidence of chronic nociceptive pain. Steroid use in acute phase significantly reduced the incidence of chronic neuropathic pain. In subgroup analysis, benefits were observed for methylprednisolone and dexamethasone, with some adverse effects. Steroids or NSAIDs were statistically significant in reducing pain intensity over 1 year, but the effect size was too small, and whether the long-term effect is clinically relevant needs to be further studied.

CONCLUSION

Quality of the evidence was low to moderate. No drug can be recommended to prevent chronic nociceptive pain. Injections of steroids (methylprednisolone or dexamethasone) during the acute phase reduce the incidence of chronic neuropathic pain, but most included studies also used local anesthetics. The results are indirect and need to be interpreted with caution. The pooled data effect sizes for pain intensity were small, so the clinical relevance was unclear. Study registration PROSPERO (CRD42022367030).

How to Modulate Peripheral and Central Nervous System to Treat Acute Postoperative Pain and Prevent Pain Persistence

Chronic postoperative pain (CPSP) is a major issue after surgery, which may impact on patient's quality of life. Traditionally, CPSP is believed to rely on maladaptive hyperalgesia and risk factors have been identified that predispose to CPSP, including acute postoperative pain. Despite new models of prediction are emerging, acute pain is still a modifiable factor that can be challenged with perioperative analgesic strategies. In this review we present the issue of CPSP, focusing on molecular mechanism underlying the development of acute and chronic hyperalgesia. Also, we focus on how perioperative strategies can impact directly or indirectly (by reducing postoperative pain intensity) on the development of CPSP.

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.

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.

Perioperative Breast Analgesia: a Systematic Review of the Evidence for Perioperative Analgesic Medications

PURPOSE OF REVIEW

Breast surgery is common and may result in significant acute as well as chronic pain. A wide range of pharmacologic interventions is available including opioids, non-steroidal anti-inflammatory drugs (NSAIDs), N-methyl-D-aspartate (NMDA) receptor antagonists, anticonvulsants, and other non-opioids with analgesic properties. We present a review of the evidence for these pharmacologic interventions. A literature search of the MEDLINE database was performed via PubMed with combined terms related to breast surgery, anesthesia, and analgesia. Articles were limited to randomized controlled trial (RCT) design, adult patients undergoing elective surgery on the breast (not including biopsy), and pharmacologic interventions only. Article titles and abstracts were screened, and risk of bias assessments were performed.

RECENT FINDINGS

The search strategy initially captured 7254 articles of which 60 articles met the full inclusion criteria. Articles were organized according to intervention: 6 opioid agonists, 14 NSAIDs and acetaminophen, 4 alpha-2 agonists, 7 NMDA receptor antagonists, 6 local anesthetics, 7 steroids, 15 anticonvulsants (one of which also discussed an NMDA antagonist), 1 antiarrhythmic, and 2 serotonin reuptake inhibitors (one of which also studied an anticonvulsant). A wide variety of medications is effective for perioperative breast analgesia, but results vary by agent and dose. The most efficacious are likely NSAIDs and anticonvulsants. Some agents may also decrease the incidence of chronic postoperative pain, including flurbiprofen, gabapentin, venlafaxine, and memantine. While many individual agents are well studied, optimal combinations of analgesic medications remain unclear.

"Post Mastectomy Pain Syndrome: A Systematic Review of Prevention Modalities"

Background

Post-mastectomy pain syndrome (PMPS) is a surgical complication of breast surgery characterized by chronic neuropathic pain. The development of PMPS is multifactorial and research on its prevention is limited. The objective of this systematic review is to synthesize the existing evidence on interventions for lowering the incidence of persistent neuropathic pain after breast surgery.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a comprehensive search of the electronic databases of MEDLINE, Cochrane Library, Embase, CINAHL, PsycINFO, Web of Science, and ClinicalTrials.gov using a combination of database-specific controlled vocabulary and keyword searches. Two reviewers independently screened all unique records. Publications on chronic (>3-month duration) pain after breast cancer-related surgery were included. Studies were classified by modality.

Results

Our literature search yielded 7092 articles after deduplication. We identified 45 studies that met final inclusion criteria for analysis, including 37 randomized-controlled trials. These studies revealed seven major intervention modalities for prevention of PMPS: physical therapy, mindfulness-based cognitive therapy, oral medications, surgical intervention, anesthesia, nerve blocks, and topical medication therapy.

Conclusion

High-quality data on preventative techniques for PMPS are required to inform decisions for breast cancer survivors. We present a comprehensive assessment of the modalities available that can help guide breast and reconstructive surgeons employ effective strategies to lower the incidence and severity of PMPS. Our review supports the use of multimodal care involving both a peripherally targeted treatment and centrally acting medication to prevent the development of PMPS.

Perioperative systemic nonsteroidal anti-inflammatory drugs (NSAIDs) in women undergoing breast surgery

BACKGROUND

Breast surgery encompasses oncologic, reconstructive, and cosmetic procedures. With the recent focus on the over-prescribing of opioids in the literature, it is important to assess the effectiveness and safety of non-opioid pain medication regimens including nonsteroidal anti-inflammatory drugs (NSAIDs) or NSAID pain medications. Clinicians have differing opinions on the safety of perioperative (relating to, occurring in, or being the period around the time of a surgical operation) NSAIDs for breast surgery given the unclear risk/benefit ratio. NSAIDs have been shown to decrease inflammation, pain, and fever, while potentially increasing the risks of bleeding complications.

OBJECTIVES

To assess the effects of perioperative NSAID use versus non-NSAID analgesics (other pain medications) in women undergoing any form of breast surgery.

SEARCH METHODS

The Cochrane Breast Information Specialist searched the Cochrane Breast Cancer Group (CBCG) Specialized Register, CENTRAL (the Cochrane Library), MEDLINE, Embase, The WHO International Clinical Trials Registry Platform (ICTRP) and Clinicaltrials.gov registries to 21 September 2020. Full articles were retrieved for potentially eligible trials.

SELECTION CRITERIA

We considered all randomized controlled trials (RCTs) looking at perioperative NSAID use in women undergoing breast surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies, extracted data and assessed risk of bias, and certainty of the evidence using the GRADE approach. The main outcomes were incidence of breast hematoma within 90 days (requiring reoperation, interventional drainage, or no treatment) of breast surgery and pain intensity 24 hours following surgery, incidence rate or severity of postoperative nausea, vomiting or both, bleeding from any location within 90 days, need for blood transfusion, other side effects of NSAID use, opioid use within 24 hours of surgery, length of hospital stay, breast cancer recurrence, and non-prescribed NSAID use. Data were presented as risk ratios (RRs) for dichotomous outcomes and standardized mean differences (SMDs) for continuous outcomes.

MAIN RESULTS

We included 12 RCTs with a total of 1596 participants. Seven studies compared NSAIDs (ketorolac, diclofenac, flurbiprofen, parecoxib and celecoxib) to placebo. Four studies compared NSAIDs (ketorolac, flurbiprofen, ibuprofen, and celecoxib) to other analgesics (morphine, hydrocodone, hydromorphone, fentanyl). One study compared NSAIDs (diclofenac) to no intervention. NSAIDs compared to placebo Most outcomes are judged to have low-certainty evidence unless stated otherwise. There may be little to no difference in the incidence of breast hematomas within 90 days of breast surgery (RR 0.33, 95% confidence interval (CI) 0.05 to 2.02; 2 studies, 230 participants; I² = 0%). NSAIDs may reduce pain intensity 24 (± 12) hours following surgery compared to placebo (SMD -0.26, 95% CI -0.49 to -0.03; 3 studies, 310 participants; I² = 73%). There may be little to no difference in the incidence rates or severities of postoperative nausea, vomiting, or both (RR 1.15, 95% CI 0.58 to 2.27; 4 studies, 939 participants; I² = 81%), bleeding from any location within 90 days (RR 1.05, 95% CI 0.89 to 1.24; 2 studies, 251 participants; I² = 8%), or need for blood transfusion compared to placebo groups, but we are very uncertain (RR 4.62, 95% CI 0.23 to 91.34; 1 study, 48 participants; very low-certainty evidence). There may be no difference in other side effects (RR 1.12, 95% CI 0.44 to 2.86; 2 studies, 251 participants; I² = 0%). NSAIDs may reduce opioid use within 24 hours of surgery compared to placebo (SMD -0.45, 95% CI -0.85 to -0.05; 4 studies, 304 participants; I² = 63%). NSAIDs compared to other analgesics There is little to no difference in the incidence of breast hematomas within 90 days of breast surgery, but we are very uncertain (RR 0.33, 95% CI 0.01 to 7.99; 1 study, 100 participants; very low-certainty evidence). NSAIDs may reduce pain intensity 24 (± 12) hours following surgery (SMD -0.68, 95% CI -0.97 to -0.39; 3 studies, 200 participants; I² = 89%; low-certainty evidence) and probably reduce the incidence rates or severities of postoperative nausea, vomiting, or both compared to other analgesics (RR 0.18, 95% CI 0.06 to 0.57; 3 studies, 128 participants; I² = 0%; moderate-certainty evidence). There is little to no difference in the development of bleeding from any location within 90 days of breast surgery or in other side effects, but we are very uncertain (bleeding: RR 0.33, 95% CI 0.01 to 7.99; 1 study, 100 participants; other side effects: RR 0.11, 95% CI 0.01 to 1.80; 1 study, 48 participants; very low-certainty evidence). NSAIDs may reduce opioid use within 24 hours of surgery compared to other analgesics (SMD -6.87, 95% CI -10.93 to -2.81; 3 studies, 178 participants; I² = 96%; low-certainty evidence). NSAIDs compared to no intervention There is little to no difference in pain intensity 24 (± 12) hours following surgery compared to no intervention, but we are very uncertain (SMD -0.54, 95% CI -1.09 to 0.00; 1 study, 60 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that NSAIDs may reduce postoperative pain, nausea and vomiting, and postoperative opioid use. However, there was very little evidence to indicate whether NSAIDs affect the rate of breast hematoma or bleeding from any location within 90 days of breast surgery, the need for blood transfusion and incidence of other side effects compared to placebo or other analgesics. High-quality large-scale RCTs are required before definitive conclusions can be made.

Post-Breast Surgery Pain Syndrome: Shifting a Surgical Paradigm

Post-mastectomy pain syndrome and the less well-described post-breast surgery pain syndrome are long-term neuropathic pain conditions that may affect more than 50% of patients after mastectomy and breast surgery. While the etiology, risk factors, and management have been reviewed in our literature, we offer here a focused outline that will gear the plastic surgeon with tools to lead a multidisciplinary, algorithmic approach to the care of patients with post-mastectomy pain syndrome/post-breast surgery pain syndrome. After reading this article, we hope the reader will have improved awareness of post-mastectomy pain syndrome/post-breast surgery pain syndrome, and thus be able to incorporate appropriate treatments and preventative steps into their primary surgical routine.

Effect of perioperative use of parecoxib on chronic post-surgical pain in elderly patients after hepatectomy: a prospective randomized controlled study

Background

Chronic post-surgical pain (CPSP) has a negative impact on the recovery, quality of life, and physical functioning of elderly patients. This study aimed to test the superiority of parecoxib vs. placebo in preventing chronic post-hepatectomy pain in elderly patients under combined general-epidural anesthesia.

Methods

A total of 105 elderly patients undergoing hepatectomy under combined general-epidural anesthesia were randomized into the parecoxib or placebo group. The primary outcome was the proportion of patients with CPSP 3 months postoperatively. The secondary outcomes included the Short-Form McGill Pain Questionnaire score in CPSP-positive responders, acute pain intensity, postoperative analgesic demand, inflammatory markers change, and postoperative complications within 28 days.

Results

The parecoxib group provided a non-significant absolute 9.1% reduction in the rate of CPSP compared to the placebo group (P = 0.34). The average chronic pain visual analog scale in the parecoxib group was lower than that in the placebo group (P = 0.04). Significantly less moderate-to-severe acute pain at rest (P = 0.04) and with coughing (P < 0.001), less patient-controlled epidural analgesia (PCEA) consumption (P = 0.01), and less rescue analgesia (P < 0.001) were observed in the parecoxib group compared to the placebo group. Furthermore, no between-group difference was observed in inflammatory markers (P > 0.05) and postoperative complications (P = 0.65).

Conclusions

Parecoxib reduced the prevalence of CPSP in elderly patients after hepatectomy under combined general-epidural anesthesia from 44.4 to 35.3% with no statistical significance. Moreover, significantly alleviated CPSP intensity and improved acute pain management were observed.

Trial registration

This study was retrospectively registered in the Chinese Clinical Trial Registry (URL: http://www.chictr.org.cn/edit.aspx?pid=56961&htm=4) on August 3, 2020 (ChiCTR-2,000,035,198).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-021-00501-1.

Pharmacotherapy for the Prevention of Chronic Pain after Surgery in Adults: An Updated Systematic Review and Meta-analysis

BACKGROUND

Chronic postsurgical pain can severely impair patient health and quality of life. This systematic review update evaluated the effectiveness of systemic drugs to prevent chronic postsurgical pain.

METHODS

The authors included double-blind, placebo-controlled, randomized controlled trials including adults that evaluated perioperative systemic drugs. Studies that evaluated same drug(s) administered similarly were pooled. The primary outcome was the proportion reporting any pain at 3 or more months postsurgery.

RESULTS

The authors identified 70 new studies and 40 from 2013. Most evaluated ketamine, pregabalin, gabapentin, IV lidocaine, nonsteroidal anti-inflammatory drugs, and corticosteroids. Some meta-analyses showed statistically significant-but of unclear clinical relevance-reductions in chronic postsurgical pain prevalence after treatment with pregabalin, IV lidocaine, and nonsteroidal anti-inflammatory drugs. Meta-analyses with more than three studies and more than 500 participants showed no effect of ketamine on prevalence of any pain at 6 months when administered for 24 h or less (risk ratio, 0.62 [95% CI, 0.36 to 1.07]; prevalence, 0 to 88% ketamine; 0 to 94% placebo) or more than 24 h (risk ratio, 0.91 [95% CI, 0.74 to 1.12]; 6 to 71% ketamine; 5 to 78% placebo), no effect of pregabalin on prevalence of any pain at 3 months (risk ratio, 0.88 [95% CI, 0.70 to 1.10]; 4 to 88% pregabalin; 3 to 80% placebo) or 6 months (risk ratio, 0.78 [95% CI, 0.47 to 1.28]; 6 to 68% pregabalin; 4 to 69% placebo) when administered more than 24 h, and an effect of pregabalin on prevalence of moderate/severe pain at 3 months when administered more than 24 h (risk ratio, 0.47 [95% CI, 0.33 to 0.68]; 0 to 20% pregabalin; 4 to 34% placebo). However, the results should be interpreted with caution given small study sizes, variable surgical types, dosages, timing and method of outcome measurements in relation to the acute pain trajectory in question, and preoperative pain status.

CONCLUSIONS

Despite agreement that chronic postsurgical pain is an important topic, extremely little progress has been made since 2013, likely due to study designs being insufficient to address the complexities of this multifactorial problem.

EDITOR’S PERSPECTIVE

Anaesthesia as an influence in tumour progression

Purpose

Tumour growth and the formation of metastases are essential elements in the progression of cancer. The centre of treatment is the surgical resection of primary solid tumours. But even if the tumour can be removed without microscopic residual cells, local recurrences and distant metastases occur and determine the patient’s fate. During the operation, tumour cells are shed from the primary tumour and released into the circulation. These circulating tumour cells might play an important role in the formation of new tumour sites. Therefore, a functional innate and adaptive immune system is essential, especially in this perioperative period. Anaesthesia influences consciousness and pain perception and interacts directly with the immune system and tumour cells.

Methods

Review of the current literature concerning intra- and postoperative anaesthetic decisions and tumour progression.

Results

There are beneficial aspects for patient survival associated with total intravenous anaesthesia, the use of regional anaesthetics and the avoidance of allogeneic red blood cell transfusions. Alternatives such as irradiated intraoperative blood salvage and preoperative iron supplementation may be advantageous in cases where transfusions are limited or not wanted. The immunosuppressive properties of opioids are theoretical, but strong evidence to avoid them does not exist. The application of nonsteroidal anti-inflammatory drugs and postoperative nausea and vomiting prophylaxis do not impair the patient’s survival and may even have a positive effect on tumour regression.

Conclusion

Anaesthesia does play an important part in the perioperative period in order to improve the cancer-related outcome. Further research is necessary to make more concrete recommendations.

Effects of a Single Myofascial Induction Session on Neural Mechanosensitivity in Breast Cancer Survivors: A Secondary Analysis of a Crossover Study

OBJECTIVES

The purpose of this study was to investigate the short-term effects of myofascial induction on mechanosensitivity of upper limb nerves.

METHODS

In this secondary analysis of a randomized, single-blind, placebo-controlled crossover study, 21 breast cancer survivors with stage I-IIIA cancer were randomly allocated to an experimental group (30 minutes of myofascial induction session) or placebo control group (unplugged pulsed 30 minutes of shortwave therapy), with a 4-week washout period between sessions that occurred in a physical therapy laboratory in the Health Science Faculty (University of Granada, Spain). Range of motion (universal goniometry), structural differentiation, symptoms (yes/no), and pressure pain thresholds (electronic algometry) were assessed during neurodynamic tests and attitude toward massage scale as covariate.

RESULTS

An analysis of covariance revealed significant time × group interactions for range of motion in affected upper limb nerves (median, P < .001; radial, P = .036; ulnar, P = .002), but not for nonaffected upper limb nerves (median, P = .083; radial, P = .072; ulnar, P = .796). A χ2 or Fisher exact test, as appropriate, also revealed a significant difference (P = .044) in sensitivity for the affected upper limb ulnar nerve in the experimental group, whereas the rest of the assessed nerves (affected and nonaffected upper limb nerves) showed no significant changes in either the experimental or control groups (P > .05). An analysis of covariance revealed no significant interactions on pressure pain thresholds over the nerves for affected (all P > .05) and nonaffected (all P > .05) upper limb nerves.

CONCLUSION

A single myofascial induction session may partially improve mechanosensitivity of median, radial, and ulnar nerves and yield positive effects on symptom mechanosensitivity, especially regarding the ulnar nerve in breast cancer survivors.

PROSPECT guideline for oncological breast surgery: a systematic review and procedure-specific postoperative pain management recommendations

Analgesic protocols used to treat pain after breast surgery vary significantly. The aim of this systematic review was to evaluate the available literature on this topic and develop recommendations for optimal pain management after oncological breast surgery. A systematic review using preferred reporting items for systematic reviews and meta-analysis guidance with procedure-specific postoperative pain management (PROSPECT) methodology was undertaken. Randomised controlled trials assessing postoperative pain using analgesic, anaesthetic or surgical interventions were identified. Seven hundred and forty-nine studies were found, of which 53 randomised controlled trials and nine meta-analyses met the inclusion criteria and were included in this review. Quantitative analysis suggests that dexamethasone and gabapentin reduced postoperative pain. The use of paravertebral blocks also reduced postoperative pain scores, analgesia consumption and the incidence of postoperative nausea and vomiting. Intra-operative opioid requirements were documented to be lower when a pectoral nerves block was performed, which also reduced postoperative pain scores and opioid consumption. We recommend basic analgesics (i.e. paracetamol and non-steroidal anti-inflammatory drugs) administered pre-operatively or intra-operatively and continued postoperatively. In addition, pre-operative gabapentin and dexamethasone are also recommended. In major breast surgery, a regional anaesthetic technique such as paravertebral block or pectoral nerves block and/or local anaesthetic wound infiltration may be considered for additional pain relief. Paravertebral block may be continued postoperatively using catheter techniques. Opioids should be reserved as rescue analgesics in the postoperative period. Research is needed to evaluate the role of novel regional analgesic techniques such as erector spinae plane or retrolaminar plane blocks combined with basic analgesics in an enhanced recovery setting.

Pressure Pain Tolerance Predicts the Success of Emotional Awareness and Expression Therapy in Patients With Fibromyalgia

OBJECTIVES

Quantitative sensory testing may help predict treatment responses in individuals with chronic pain. Our objective was to determine whether evoked pain sensitivity at baseline predicted preferential treatment responses to either emotional awareness and expression therapy (EAET) or cognitive behavioral therapy (CBT) in individuals with fibromyalgia (FM).

METHODS

This was a secondary analysis of a previous randomized clinical trial, in which individuals with FM were randomized to EAET, CBT, or Education as a control intervention. Only females who completed baseline and post-treatment assessments were analyzed (n=196). The primary outcome was change in overall clinical pain severity from pretreatment to posttreatment, and the primary predictor of interest was pressure pain tolerance at baseline.

RESULTS

Among patients with low pain tolerance at baseline (n=154), both EAET and CBT led to small but significant improvements in clinical pain severity (CBT mean=0.66, 95% confidence interval [0.24-1.07]; EAET mean=0.76 [0.34-1.17]). Conversely, in patients with normal pain tolerance (n=42), there was no significant improvement in clinical pain after CBT (0.13 [-0.88 to 1.14]), a small improvement after FM Education (0.81 [0.14-1.48]), but a much larger and statistically significant improvement after EAET (2.14 [1.23-3.04]).

DISCUSSION

Normal levels of pressure pain tolerance at baseline predicted greater improvement in clinical pain severity after EAET than CBT. Quantitative sensory testing may provide insights about individual responses to psychologically based therapies for individuals with chronic pain.

Incidence of contralateral neurosensitive changes and persistent postoperative pain 6 months after mastectomy: A prospective, observational investigation

Mirror image sensory dysfunction (MISD) after breast surgery has not yet been studied. This prospective observational study aimed to determine the incidence of MISD, persistent postoperative pain (PPP) and mirror image pain (MIP) during 6 months after total unilateral mastectomy.Visual analogue scale (VAS), Neuropathic Pain Symptom Inventory (NPSI), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), Life orientation test (LOT) and Quantitative Sensory Testing (QST) (in ipsi and contralateral breast, axilla and thigh) were recorded. VAS > 3 at 1, 3, and 6 postoperative months was considered PPP. Contralateral changes of QST at any time was considered indicative of MISD and spontaneous contralateral VAS ≥ 1 as MIP.Sixty-four patients were included. PPP at 1, 3 and 6 months was 18.8%, 56.2%, and 21.3%, respectively Ten patients presented MIP. MISD was detected in 79.7% patients in contralateral breast and 62.5% in contralateral axilla. Furthermore, changes in QST were present in 39.1% of patients in thigh. Electronic Von Frey (EVF) changes in both contralateral breast and axilla, and in thigh significantly diminished at all postoperative times. Changes of postoperative EVF ≥ 20% in contralateral breast were associated to higher VAS values. NPSI scores were significantly higher at all postoperative times. At 1 month, PCS, depression HADS subscale and LOT scores were significantly worse than all the other periods.MISD incidence was almost 80%, and 15.6% of patients showed spontaneous contralateral VAS ≥ 1. At 6 months 21.3% of patients manifested PPP. The worst alteration of factors related to PPP occurred at 1 postoperative month. Most consistent QST was EVF.

A clinically feasible method for the assessment and characterization of pain in patients with chronic pancreatitis

BACKGROUND AND AIMS

Pain is the primary symptom of chronic pancreatitis (CP), but methods for sensory testing and pain characterization have not previously been validated for clinical use. We present a clinically feasible method for the assessment and characterization of pain mechanisms in patients with CP based on quantitative sensory testing (QST).

METHODS

This was a cross-sectional, multicenter study of 122 control subjects without pancreatic disease and another 60 patients with painful CP. All subjects underwent standardized QST assessments including a cold pressor test, a conditioned pain modulation paradigm, repetitive pin-prick stimuli (temporal summation) and pressure stimulation of the upper abdominal (pancreatic) and control dermatomes. The effects of age and gender on QST assessment parameters were investigated and normative reference values based on quartile regression were derived and implemented in algorithms to categorize patients according to their patterns of central pain processing (normal vs. segmental sensitization vs. widespread sensitization).

RESULTS

Absolute pressure thresholds were subject to clinically relevant gender effects (all p < 0.001), while the remainder of QST parameters were unaffected by age and gender. The algorithm with the best discriminatory capacity showed good separation between patients and controls (p < 0.001); 50% of patients had normal central pain processing, 23% had evidence of segmental sensitization and 27% had evidence of widespread sensitization.

CONCLUSION

We show normative reference values for a clinically feasible method for assessment and characterization of pain mechanisms in patients with CP. Application of this method streamlines the evaluation of pancreatic pain and may be used to inform treatment. CLINICALTRIALS.

GOV ID

NCT03434392.

Associations Between Catecholaminergic and Serotonergic Genes and Persistent Arm Pain Severity Following Breast Cancer Surgery

Persistent arm pain is a common problem after breast cancer surgery. Little is known about genetic factors that contribute to this type of postsurgical pain. Study purpose was to explore associations between persistent arm pain phenotypes and genetic polymorphisms among 15 genes involved in catecholaminergic and serotonergic neurotransmission. Women (n = 398) rated the presence and intensity of arm pain monthly for 6 months after breast cancer surgery. Three distinct latent classes of patients were identified (ie, no arm pain [41.6%], mild arm pain (23.6%), and moderate arm pain (34.8%). Logistic regression analyses were used to evaluate for differences between genotype or haplotype frequencies and the persistent arm pain classes. Compared with the no arm pain class, 3 single nucleotide polymorphisms and 1 haplotype, in 4 genes, were associated with membership in the mild arm pain class: COMT rs4633, HTR2A haplotype B02 (composed of rs1923886 and rs7330636), HTR3A rs1985242, and TH rs2070762. Compared with the no arm pain class, 4 single nucleotide polymorphisms in 3 genes were associated with membership in the moderate arm pain class: COMT rs165656, HTR2A rs2770298 and rs9534511, and HTR3A rs1985242. Findings suggest that variations in catecholaminergic and serotonergic genes play a role in the development of persistent arm pain. PERSPECTIVE: Limited information is available on genetic factors that contribute to persistent arm pain after breast cancer surgery. Genetic polymorphisms in genes involved in catecholaminergic and serotonergic neurotransmission were associated with 2 persistent arm pain phenotypes. Findings may be used to identify patients are higher risk for this common pain condition.

Chronic postsurgical pain and cancer: the catch of surviving the unsurvivable

PURPOSE OF REVIEW

Chronic postsurgical pain (CPSP) is an important and well recognized cause of much long-term suffering, which in some cases may be preventable and affects many people living with cancer. Unfortunately, general consensus is lacking as to how best reduce the risk of developing CPSP.

RECENT FINDINGS

Cancer is now not always a short-lived, fatal disease and is now moving towards a chronic illness. Poorly managed perioperative pain is the greatest risk factor for CPSP. Recent trials have examined preventive strategies for CPSP associated with breast surgery and thoracotomy, two operations used in cancer treatment. Standard antinociceptive drugs, 5% lidocaine patches and ketamine do not prevent CPSP. The evidence for gabapentinoids is conflicting. Intravenous lidocaine and, separately, regional anaesthesia appear beneficial.

SUMMARY

Well-managed pain, irrespective of technique, reduces the risk of CPSP. The literature is inconclusive regarding an 'optimal approach.' Regional anaesthesia, intravenous lidocaine and the aggressive management of perioperative pain using multimodal analgesia including antineuropathic pain agents such as gabapentinoids and certain antidepressants are recommended. Clinicians should not rely on general anaesthesia, opioids, NSAIDs and ketamine to prevent CPSP. A blanket approach using gabapentinoids for all patients undergoing major surgery is not indicated. Instead, the presence of perioperative neuropathic pain should be checked for regularly.

Prevention and Treatment of Chronic Postsurgical Pain: A Narrative Review

Chronic postsurgical pain affects between 5 and 75% of patients, often with an adverse impact on quality of life. While the transition of acute to chronic pain is a complex process-involving multiple mechanisms at different levels-the current strategies for prevention have primarily been restricted to perioperative pharmacological interventions. In the present paper, we first present an up-to-date narrative literature review of these interventions. In the second section, we develop several ways by which we could overcome the limitations of the current approaches and enhance the outcome of our surgical patients, including the better identification of individual risk factors, tailoring treatment to individual patients, and improved acute and subacute pain evaluation and management. The third and final section covers the treatment of established CPSP. Given that evidence for the current therapeutic options is limited, we need high-quality trials studying multimodal interventions matched to pain characteristics.

A Quantitative Sensory Testing Paradigm to Obtain Measures of Pain Processing in Patients Undergoing Breast Cancer Surgery

Chronic pain following surgery, persistent postsurgical pain, is an important highly prevalent condition contributing to significant symptom burden and lower quality of life. Persistent postsurgical pain is relatively refractory to treatment hence generating a high need for preventive strategies and treatments. Therefore, the identification of patients at risk of developing persistent pain is an area of active ongoing research. Recently it was demonstrated that peri-operative disruptions in central pain processing may be able to predict persistent postsurgical pain at long term follow-up in breast cancer patients. The aim of the current report is to present a short protocol to obtain pain thresholds to different stimuli at multiple sites and a measure of endogenous analgesia in breast cancer patients. We have used this method successfully in a clinical context and detail some representative results from a clinical study.

Adding high-intensity interval training to conventional training modalities: optimizing health-related outcomes during chemotherapy for breast cancer: the OptiTrain randomized controlled trial

Purpose

Exercise training is an effective and safe way to counteract cancer-related fatigue (CRF) and to improve health-related quality of life (HRQoL). High-intensity interval training has proven beneficial for the health of clinical populations. The aim of this randomized controlled trial was to compare the effects of resistance and high-intensity interval training (RT–HIIT), and moderate-intensity aerobic and high-intensity interval training (AT–HIIT) to usual care (UC) in women with breast cancer undergoing chemotherapy. The primary endpoint was CRF and the secondary endpoints were HRQoL and cancer treatment-related symptoms.

Methods

Two hundred and forty women planned to undergo chemotherapy were randomized to supervised RT–HIIT, AT–HIIT, or UC. Measurements were performed at baseline and at 16 weeks. Questionnaires included Piper Fatigue Scale, EORTC-QLQ-C30, and Memorial Symptom Assessment Scale.

Results

The RT–HIIT group was superior to UC for CRF: total CRF (p = 0.02), behavior/daily life (p = 0.01), and sensory/physical (p = 0.03) CRF. Role functioning significantly improved while cognitive functioning was unchanged for RT–HIIT compared to declines shown in the UC group (p = 0.04). AT–HIIT significantly improved emotional functioning versus UC (p = 0.01) and was superior to UC for pain symptoms (p = 0.03). RT–HIIT reported a reduced symptom burden, while AT–HIIT remained stable compared to deteriorations shown by UC (p < 0.01). Only RT–HIIT was superior to UC for total symptoms (p < 0.01).

Conclusions

16 weeks of resistance and HIIT was effective in preventing increases in CRF and in reducing symptom burden for patients during chemotherapy for breast cancer. These findings add to a growing body of evidence supporting the inclusion of structured exercise prescriptions, including HIIT, as a vital component of cancer rehabilitation.

Trial registration

Clinicaltrials.gov Registration Number: NCT02522260.

Chronic postoperative pain: recent findings in understanding and management

Chronic postoperative pain is a poorly recognized potential outcome from surgery. It affects millions of patients every year, with pain lasting for months to years, resulting in patient suffering and ensuing economic consequences. The operations with the highest incidence of chronic postoperative pain are amputations, thoracotomies, cardiac surgery, and breast surgery. Other risk factors include preoperative pain, psychological factors, demographics, and the intensity of acute postoperative pain. Attempts to prevent chronic postoperative pain have often led to debatable results. This article presents data from recently published studies examining the incidence, risk factors, mechanisms, treatment options, and preventive strategies for chronic postoperative pain in adults. In summary, many of the previously identified risk factors for chronic postoperative pain have been confirmed and some novel ones discovered, such as the importance of the trajectory of acute pain and the fact that catastrophizing may not always be predictive. The incidence of chronic postoperative pain hasn’t changed over time, and there is limited new information regarding an effective preventive therapy. For example, pregabalin may actually cause more harm in certain surgeries. Further research is needed to demonstrate whether multimodal analgesic techniques have the best chance of significantly reducing the incidence of chronic postoperative pain and to determine which combination of agents is best for given surgical types and different patient populations.