Chronifizierung postoperativer Schmerzen

[Clinical efficacy of auricular vagus nerve stimulation in the treatment of chronic and acute pain : A systematic review]

BACKGROUND

Current guidelines recommend a personalized, multimodal, and interdisciplinary approach for the treatment of chronic pain. Already in the acute treatment of postoperative pain, it can be useful to minimize risk factors for chronification. Auricular vagus nerve stimulation (aVNS) could be an effective non-drug therapy for the treatment of chronic and acute pain.

AIM OF THE WORK

The aim of this systematic review is to evaluate the clinical efficacy of aVNS in chronic and acute pain as well as its effect on medication intake.

MATERIALS AND METHODS

A systematic literature search was carried out on the application of auricular electrical stimulation in chronic and acute pain. Studies were classified according to their level of evidence and evaluated via the Jadad scale as well as their scientific validity, and then analyzed in terms of indication, method, stimulation parameters, duration of treatment, efficacy, and safety.

RESULTS

Twenty studies on chronic pain indications, ten studies on acute postoperative pain, as well as seven studies on experimental acute pain were identified and analyzed. The search revealed a total of n = 1105 aVNS-treated patients. The best evidence on the efficacy of aVNS is available for the indications chronic low back pain, chronic cervical syndrome, chronic abdominal pain, and chronic migraine as well as acute postoperative pain in oocyte aspiration, laparoscopic nephrectomy, and open colorectal surgery. Additionally a significant reduction in analgesic or opiate intake was evident in most studies. In three randomized controlled trials in chronic pain patients, a sustainable pain reduction over a period of up to 12 months was shown. Overall, aVNS was very well tolerated.

CONCLUSION

This review indicates that aVNS can be a complementary and effective non-drug treatment for patients with chronic and acute postoperative pain. Future studies in these indications should focus on standardizing and optimizing treatment parameters, inclusion of quality-of-life outcome parameters, and longer follow-up periods to better understand the sustainable therapeutic effect of aVNS.

Pain chronification impacts whole-brain functional connectivity in women with hip osteoarthritis during pain stimulation

OBJECTIVE

Previous neuroimaging studies have shown that patients with chronic pain display altered functional connectivity across distributed brain areas involved in the processing of nociceptive stimuli. The aim of the present study was to investigate how pain chronification modulates whole-brain functional connectivity during evoked clinical and tonic pain.

METHODS

Patients with osteoarthritis of the hip (n = 87) were classified into 3 stages of pain chronification (Grades I-III, Mainz Pain Staging System). Electroencephalograms were recorded during 3 conditions: baseline, evoked clinical hip pain, and tonic cold pain (cold pressor test). The effects of both factors (recording condition and pain chronification stage) on the phase-lag index, as a measure of neuronal connectivity, were examined for different frequency bands.

RESULTS

In women, we found increasing functional connectivity in the low-frequency range (delta, 0.5-4 Hz) across pain chronification stages during evoked clinical hip pain and tonic cold pain stimulation. In men, elevated functional connectivity in the delta frequency range was observed in only the tonic cold pain condition.

CONCLUSIONS

Across pain chronification stages, we found that widespread cortical networks increase their synchronization of delta oscillations in response to clinical and experimental nociceptive stimuli. In view of previous studies relating delta oscillations to salience detection and other basic motivational processes, our results hint at these mechanisms playing an important role in pain chronification, mainly in women.

[Reflexology in patient rehabilitation with postoperative pain. (Literature review)]

Postoperative pain is a pressing medical problem, as it significantly reduces the quality of life of patients after surgical treatment. Chronic postoperative pain further disables patients and impairs their functional activity. Being a widespread interdisciplinary problem, postoperative pain requires the integration of various pain management methods in complex multimodal pain management in the acute period and treatment programs for its chronicity. The paper examines the possibilities of reflexology methods for the relief of acute and treatment of chronic postoperative pain. Integration of reflex effects from the first days after surgery makes it possible to more effectively and safely solve the problems of acute and chronic postoperative pain.

[Resolution of the Federal Joint Committee on the mandatory introduction and implementation of acute pain management concepts-Importance and consequences for ophthalmology]

Patient-centered and adequate postoperative pain management is an important part of a modern treatment concept and should also be standard in ophthalmology. Due to the "Regulation on the mandatory introduction and implementation of acute pain management concepts for adequate postoperative pain therapy" prescribed by the Federal Joint Committee of the German statutory healthcare system (G-BA), hospitals and outpatient facilities have been required to have regulations on pain management in place since 9 December 2020. It is very likely that the need of pain management in ophthalmic surgery has been systematically underestimated so far and studies on postoperative pain hardly exist. In the opinion of the authors, the decision represents an opportunity to pay more attention to the topic and to develop standards for ophthalmology as well. This article explains the G‑BA decision and the resulting consequences for ophthalmic surgical institutions.

Pain Management Program in Cardiology: A Template for Application of Normalization Process Theory and Social Marketing to Implement a Change in Practice Quality Improvement

Quality improvement plays a major role in healthcare, and numerous approaches have been developed to implement changes. However, the reasons for success or failure of the methods applied often remains obscure. Normalization process theory, recently developed in sociology, provides a flexible framework upon which to construct quality improvement. We sought to determine if examination of a successful quality improvement project, using normalization process theory and social marketing, provided insight into implementation. We performed a retrospective analysis of the steps taken to implement a pain management program in an electrophysiology clinic. We mapped these steps, and the corresponding social marketing tools used, to elements of normalization process theory. The combination of mapping implementation steps and marketing approaches to the theory provided insight into the quality-improvement process. Specifically, examination of the steps in the context of normalization process theory highlighted barriers to implementation at individual, group, and organizational levels. Importantly, the mapping also highlighted how facilitators were able to overcome the barriers with marketing techniques. Furthermore, integration with social marketing revealed how promotion of tangibility of benefits aided communication and how process co-creation between stakeholders enhanced value. Our implementation of a pain-management program was successful in a challenging environment composed of several stakeholder groups with entrenched initial positions. Therefore, we propose that the behavior change elements of normalization process theory combined with social marketing provide a flexible framework to initiate quality improvement.

Preventing Pediatric Chronic Postsurgical Pain: Time for Increased Rigor

Chronic postsurgical pain (CPSP) results from a cascade of events in the peripheral and central nervous systems following surgery. Several clinical predictors, including the prior pain state, premorbid psychological state (e.g., anxiety, catastrophizing), intraoperative surgical load (establishment of peripheral and central sensitization), and acute postoperative pain management, may contribute to the patient’s risk of developing CPSP. However, research on the neurobiological and biobehavioral mechanisms contributing to pediatric CPSP and effective preemptive/treatment strategies are still lacking. Here we evaluate the perisurgical process by identifying key problems and propose potential solutions for the pre-, intra-, and postoperative pain states to both prevent and manage the transition of acute to chronic pain. We propose an eight-step process involving preemptive and preventative analgesia, behavioral interventions, and the use of biomarkers (brain-based, inflammatory, or genetic) to facilitate timely evaluation and treatment of premorbid psychological factors, ongoing surgical pain, and postoperative pain to provide an overall improved outcome. By achieving this, we can begin to establish personalized precision medicine for children and adolescents presenting to surgery and subsequent treatment selection.

Pain after upper limb surgery under peripheral nerve block is associated with gut microbiome composition and diversity

Gut microbiota play a role in certain pain states. Hence, these microbiota also influence somatic pain. We aimed to determine if there was an association between gut microbiota (composition and diversity) and postoperative pain. Patients (n = 20) undergoing surgical fixation of distal radius fracture under axillary brachial plexus block were studied. Gut microbiota diversity and abundance were analysed for association with: (i) a verbal pain rating scale of < 4/10 throughout the first 24 h after surgery (ii) a level of pain deemed "acceptable" by the patient during the first 24 h following surgery (iii) a maximum self-reported pain score during the first 24 h postoperatively and (iv) analgesic consumption during the first postoperative week. Analgesic consumption was inversely correlated with the Shannon index of alpha diversity. There were also significant differences, at the genus level (including Lachnospira), with respect to pain being "not acceptable" at 24 h postoperatively. Porphyromonas was more abundant in the group reporting an acceptable pain level at 24 h. An inverse correlation was noted between abundance of Collinsella and maximum self-reported pain score with movement. We have demonstrated for the first time that postoperative pain is associated with gut microbiota composition and diversity. Further work on the relationship between the gut microbiome and somatic pain may offer new therapeutic targets.

Predictive Factors for Access-Site Pain Chronicity after Percutaneous Coronary Intervention via Radial Artery Access

Objectives

The aim of this study is to assess the prevalence and predictive factors for developing chronic access-site (A-S) pain after percutaneous coronary intervention (PCI) via radial artery access.

Methods

Data of selected patients (n = 161) who underwent elective PCI were collected prospectively and analysed in 2020. Verbal analogue scale was used to evaluate pain intensity after 12, 24, and 48 h and 3 months after PCI. The univariate logistic regression analysis was used.

Results

Pain prevalence decreased from 29% straight after PCI and 54% two hours later to 3.7% following 3 months after procedure. The predictors for A-S pain chronicity are diabetes (OR = 5.77 95% CI (1.07–31.08), p = 0.041), hematoma (OR = 6.48, 95% CI (1.06–39.66), p = 0.043), A-S hand neuropathy (OR = 19.93 95% CI (1.27–312.32), p = 0.033), A-S pain immediately after PCI (OR = 14.60 95% CI (1.63–130.27), p = 0.016), after 12 h (OR = 17.2 95% CI (1.60–185.27), p = 0.019), 24 h (OR = 48 95% CI (4.87–487), p = 0.01), and 48 h (OR = 23.46 95% CI (3.81–144.17), p = 0.001), and pain intensity immediately after procedure (OR = 3.30 95% CI (1.65–6.60), p = 0.001), after 2 h (OR = 2.56 95% CI (1.15–5.73), p = 0.022), after 12 h (OR = 3.02 95% CI (1.70–5.39), p < 0.001), after 24 h (OR = 3.58 95% CI (1.90–6.74), p < 0.001), and after 48 h (OR = 2.89 95% CI (1.72–4.87), p < 0.001). Pain control was performed with Ketoprofen and Ibuprofen as most used NSAIDs. 10 mg of Morphine intravenously was the choice from strong opioids if necessary.

Conclusions

The prevalence of chronic A-S pain is 3.7%. Main predictive factors for the A-S pain chronicity are diabetes, hematoma, and persistent pain and pain intensity during 48 h period after PCI.

[Current aspects of pain management during and after dermatologic surgery]

The project "Pain-free Hospital" was the first attempt to improve the level of postoperative care by standardizing pain therapy standards (concepts) in the individual surgical disciplines. Dermatosurgery is no exception. In addition to drug therapy, it is also important to consider biopsychosocial aspects of the symptom pain, as this is the only way to prevent chronification of acute pain in the further course of a disease. Drug therapy should not only be adapted to the classic WHO system (only considering pain intensity), but should also address aspects of pain quality. In this article, we discuss these aspects in more detail and present our treatment concept for dermatosurgery.

Anesthesia and Chronic Pain Management

The reasons for development of chronic pain are poorly understood. Chronic postoperative pain is linked to severe acute postoperative pain. Head and neck pain is often a complex phenomenon that requires meticulous diagnosis and treatment. Institution of early multimodal analgesic regimens by multidisciplinary teams may attenuate chronic pain formation and propagation in the otolaryngologic patient.

Psychophysical and psychological predictors of acute pain after breast surgery differ in patients with and without pre-existing chronic pain

The prediction of acute postoperative pain would be of great clinical advantage, but results of studies investigating possible predictors are inconsistent. Here, we studied the role of a wide variety of previously suggested predictors in 74 patients undergoing breast surgery. Preoperatively, patients filled out the Pain Sensitivity Questionnaire (PSQ) and a set of psychological questionnaires (the Beck Depression Inventory [BDI], State-Trait Anxiety Inventory [STAI], and Pain Catastrophizing Scale [PCS]) and participated in an experimental pain testing session, including assessment of conditioned pain modulation (CPM), temporal summation, and responses to heat, pinprick, and pressure pain. Postoperatively, patients reported pain intensity. Stepwise linear regression analysis was used to test for prediction of maximal pain on postoperative day 1 in the whole cohort and in the subgroups of patients with and without pre-existing chronic pain. In the total group, linear regression identified only the expectation of postoperative pain intensity as significant predictor (F[1,65] = 6.5, P < 0.05), explaining 9% of the variance. In patients without pre-existing chronic pain, a smaller CPM effect predicted more postoperative pain, explaining 17% of the variance (F[1,48] = 9.9, P < 0.01). In patients with pre-existing chronic pain, higher PSQ and PCS scores predicted more postoperative pain, together explaining 54% of the variance (F[2,19] = 11.1, P < 0.001). In conclusion, prediction of acute postoperative pain in the whole group was limited. This might be due to differing predictors in specific subgroups of patients. Although CPM predicted pain in patients without pre-existing chronic pain, PSQ and PCS predicted pain in patients with pre-existing chronic pain.

Risk stratification for the development of chronic postsurgical pain

Risk stratification for the development chronic postsurgical pain is an important tool, which may permit preventive measures or appropriate advice for patients at high risk.

Treatment for chronic low back pain: the focus should change to multimodal management that reflects the underlying pain mechanisms

Chronic low back pain: Chronic pain is the most common cause for people to utilize healthcare resources and has a considerable impact upon patients' lives. The most prevalent chronic pain condition is chronic low back pain (CLBP). CLBP may be nociceptive or neuropathic, or may incorporate both components. The presence of a neuropathic component is associated with more intense pain of longer duration, and a higher prevalence of co-morbidities. However, many physicians' knowledge of chronic pain mechanisms is currently limited and there are no universally accepted treatment guidelines, so the condition is not particularly well managed.

DIAGNOSIS

Diagnosis should begin with a focused medical history and physical examination, to exclude serious spinal pathology that may require evaluation by an appropriate specialist. Most patients have non-specific CLBP, which cannot be attributed to a particular cause. It is important to try and establish whether a neuropathic component is present, by combining the findings of physical and neurological examinations with the patient's history. This may prove difficult, however, even when using screening instruments. Multimodal management: The multifactorial nature of CLBP indicates that the most logical treatment approach is multimodal: i.e. integrated multidisciplinary therapy with co-ordinated somatic and psychotherapeutic elements. As both nociceptive and neuropathic components may be present, combining analgesic agents with different mechanisms of action is a rational treatment modality. Individually tailored combination therapy can improve analgesia whilst reducing the doses of constituent agents, thereby lessening the incidence of side effects.

CONCLUSIONS

This paper outlines the development of CLBP and the underlying mechanisms involved, as well as providing information on diagnosis and the use of a wide range of pharmaceutical agents in managing the condition (including NSAIDs, COX-2 inhibitors, tricyclic antidepressants, opioids and anticonvulsants), supplemented by appropriate non-pharmacological measures such as exercise programs, manual therapies, behavioral therapies, interventional pain management and traction. Surgery may be appropriate in carefully selected patients.

[Neglect-like symptoms after operations on the upper extremities]

BACKGROUND

Neglect-like symptoms (NLS) describe the experience of perceiving a limb as foreign and could be detected in chronic pain disorders as well as after knee joint replacement. The aim of the present study was to find out whether patients with and without NLS after surgery of the upper extremities differ with respect to pain intensity and psychosocial variables and if NLS are associated with chronic postoperative pain (CPSP).

METHODS

In this study 241 patients were interviewed using a validated questionnaire preoperatively as well as 1 day, 4 weeks, 3 months and 6 months postoperatively. Patients with and without NLS were compared using the χ²-test or Mann-Whitney U‑test. The level of significance was adjusted for multiple testing.

RESULTS

The NLS could be found to a slight extent throughout the entire study period. Patients with NLS showed significantly higher maximum pain scores at every measurement time point: average difference (∆ = 3, adjusted p < 0.005), a higher impairment due to pain (∆ = 15, adjusted p < 0.005), more anxiety (∆ = 3, adjusted p < 0.005), depression (∆ = 3, average adjusted p < 0.003) and kinesiophobia (∆ = 4, preoperative not significant, average postoperative adjusted p = 0.004). Preoperatively, more stressful life events (p = 0.002) and higher stress values (p < 0.001) were reported. In patients with CPSP, NLS occurred significantly more often (74%) than in patients without clinically relevant pain (17.5%. p < 0.001).

CONCLUSION

The occurrence of NLS is associated with higher pain scores, more impairment due to pain and a higher psychosocial burden and they are more frequent in patients with CPSP. Further investigations are needed to show if NLS are an independent risk factor for the chronification of pain and if NLS play an independent role in the pathogenesis of pain.

Improving the management of post-operative acute pain: priorities for change

Poor management of post-operative acute pain can contribute to medical complications including pneumonia, deep vein thrombosis, infection and delayed healing, as well as the development of chronic pain. It is therefore important that all patients undergoing surgery should receive adequate pain management. However, evidence suggests this is not currently the case; between 10% and 50% of patients develop chronic pain after various common operations, and one recent US study recorded >80% of patients experiencing post-operative pain. At the first meeting of the acute chapter of the Change Pain Advisory Board, key priorities for improving post-operative pain management were identified in four different areas. Firstly, patients should be more involved in decisions regarding their own treatment, particularly when fateful alternatives are being considered. For this to be meaningful, relevant information should be provided so they are well informed about the various options available. Good physician/patient communication is also essential. Secondly, better professional education and training of the various members of the multidisciplinary pain management team would enhance their skills and knowledge, and thereby improve patient care. Thirdly, there is scope for optimizing treatment. Examples include the use of synergistic analgesia to target pain at different points along pain pathways, more widespread adoption of patient-controlled analgesia, and the use of minimally invasive rather than open surgery. Fourthly, organizational change could provide similar benefits; introducing acute pain services and increasing their availability towards the 24 hours/day ideal, greater adherence to protocols, increased use of patient-reported outcomes, and greater receptivity to technological advances would all help to enhance performance and increase patient satisfaction. It must be acknowledged that implementing these recommendations would incur a considerable cost that purchasers of healthcare may be unwilling or unable to finance. Nevertheless, change is under way and the political will exists for it to continue.

Perioperative Pain Correlates and Prolonged Postoperative Pain Predictors: Demographic and Psychometric Questionnaires

Introduction

Perioperatively, patients are near-guaranteed to experience acute pain by virtue of the surgical tissue insult. The transition of acute pain to pathological chronic pain is a complex and poorly understood process. To study this, the prevalence of pain was examined preoperatively, and at 6 weeks and 3 months postoperatively.

Methods

Fifty-four patients undergoing moderate-major gynaecological surgery at Christchurch Women’s Hospital (Christchurch, New Zealand) were recruited over a period of 11 weeks. Follow-up by telephone was conducted at 6 weeks and 3 months following surgery. Demographic information including age, gender, ethnicity, work, and education status were collected, as well as aspects of medical history. Participants were subjected to psychometric questionnaires at each time-point.

Results

Of the participants, 15.7% experienced significant pain at 6 weeks postoperatively; 8.2% of participants experienced significant pain at 3 months postoperatively. The psychometric questionnaires used found differences between those experiencing pain and those not experiencing pain at given observation points. Only the Brief Illness Perception Questionnaire (BIPQ) appeared predictive of developing prolonged postoperative pain. The mean difference (7.4 on a 0–50) scale should assist in clinical decision-making regarding analgesia.

Conclusion

Only the BIPQ was predictive of developing prolonged postoperative pain. While none of the demographic factors observed significantly predicted the development of ‘prolonged pain’, the not significant data followed expected trends. Several relationships were detected in this study that should further efforts in developing preoperative predictors to promote the secondary prevention of postoperative pain states.

Electronic supplementary material

The online version of this article (doi:10.1007/s40122-015-0037-7) contains supplementary material, which is available to authorized users.

Treatment of peripheral neuropathic pain by topical capsaicin: Impact of pre-existing pain in the QUEPP-study

Background

This study evaluates the impact of the duration of pre-existing peripheral neuropathic pain on the therapeutic response to the capsaicin 8% cutaneous patch.

Methods

The non-interventional QUEPP (QUTENZA – safety and effectiveness in peripheral neuropathic pain) study evaluated the effectiveness of Qutenza™ in 1044 non-diabetic patients with peripheral neuropathic pain, who received a single application. Follow-up visits were scheduled at weeks 1–2, 4, 8 and 12. A pre-defined co-analysis of changes in average pain intensity was performed based on the duration of pre-existing pain.

Results

In patients with pre-existing pain for <6 months, the mean relative change of the numeric pain rating scale score on days 7–14 to week 12 versus baseline was −36.6% [4.6 standard error of the mean (SEM); n = 105], −25.1% (1.9 SEM; n = 311) in patients with pain duration of 6 months to 2 years, −22.3% (1.6 SEM; n = 391) in patients with pain for >2–10 years, and −19.2% (2.6 SEM; n = 99) in patients with pain for >10 years. Thirty percent and 50% responder rates were 61.7% and 39.3% in patients with pre-existing pain for <6 months, 42.3% and 23.3% in patients with pain for 6 months to 2 years, 40.9% and 21.6% in patients with pain for >2–10 years, and 32.3% and 14.1% in patients with pain for >10 years.

Conclusions

The highest treatment response to the capsaicin 8% cutaneous patch was observed in patients with a history of pre-existing peripheral neuropathic pain of less than 6 months, suggesting that early initiation of topical treatment might be indicated.