Postoperative analgesic efficacy of ear acupuncture in patients undergoing abdominal hysterectomy: a randomized controlled trial

A scoping review of mechanisms of auricular acupuncture for treatment of pain

OBJECTIVES

Auricular acupuncture (AA) is becoming increasingly common in primary care clinics, emergency departments and peri-operatively for pain relief. Over the last decade, since the last comprehensive reviews were published, the literature has expanded. In this scoping review, we seek to document the efficacy of AA in treating both acute and chronic pain, describe the mechanism of action of AA in treating pain, and discuss how AA has been integrated into Western medicine to date.

METHODS

The authors performed a MEDLINE search inclusive of articles from 1966 to June 2023 including articles written in English identifying literature. We included human studies when more than 3 patients were included. Three hundred and fourteen unique articles were identified and 152 were selected by title screen. After abstract review, 117 were chosen for full-text review. Following full-text review, 33 articles were excluded and 21 added from references, totaling 105 articles included in our scoping review.

RESULTS

AA reduces pain severity in patients with both acute and chronic pain. The best studies in the acute settings have occurred in the peri-operative setting where sham AA is employed, multiple sessions of AA are given, and medication dosing is carefully monitored. In these cases, AA reduced pain and post-operative medications. In patients with chronic pain, multiple sessions of AA resulted not only in pain relief but also in improvements in function and disability. Literature suggests that AA works through multiple mechanisms with the most compelling data coupled to the autonomic nervous system and neuroendocrine system. Curriculums designed to teach AA and aid in implementation have been published.

CONCLUSION

AA is an accessible, effective means of pain relief. AA is relatively straightforward to learn, and protocols and curriculums exist to teach healthcare professionals this valuable skill. Overcoming implementation barriers, including patient education, are essential next steps.

Laser auriculotherapy associated with cupping therapy in chronic spinal pain: Randomized controlled clinical trial

BACKGROUND

Musculoskeletal spine disorders are common causes of chronic pain and impair functionality. Laser auriculotherapy and cupping has played a significant role in the treatment of chronic pain.

OBJECTIVE

to evaluate the effect of laser auriculotherapy associated with cupping at systemic acupuncture points on chronic spinal pain.

METHODS

Randomized controlled clinical trial. Volunteers underwent three evaluations: an initial evaluation, a final evaluation immediately after the last intervention session, and a 15-day follow-up. The pain was identified using the numeric pain scale. The pain threshold was also evaluated against mechanical stimulation using a Digital Dynamometer at specific points in the cervical, thoracic and lumbar regions. Fifty individuals with chronic spinal pain, randomized into groups: experimental (n = 25), submitted to 10 sessions of auriculotherapy with laser and cupping therapy and control (n = 25).

RESULTS

The experimental group achieved pain intensity reduction between pre and post and follow-up moments (p < 0.0001), of greatest pain in the last seven days among all moments (p < 0.0001), of least pain in the pre with post moment (p = 0.006) and follow-up (p = 0.002), and an increased pain threshold between pre and post (p = 0.023). The control group achieved a reduction in the nociceptive threshold between pre and post (p = 0.001) and follow-up (p < 0.0001). The experimental group showed reduced pain intensity (p = 0.027) and greater pain (p = 0.005) after intervention and in pain intensity (p = 0.018), greater (p < 0.0001) and less pain (p = 0.025) at follow-up, compared to the control group.

CONCLUSION

Auriculotherapy with laser associated with cupping therapy may effectively reduce pain intensity and increase the nociceptive threshold.

Cardiovascular effects of auricular stimulation -a systematic review and meta-analysis of randomized controlled clinical trials

Background

The number of randomized controlled trials using auricular stimulation (AS) such as transauricular vagus nerve stimulation, or other auricular electrostimulation or auricular acupuncture or acupressure, in experimental and clinical settings, has increased markedly over the last three decades. This systematic review focusses on cardiovascular effects of auricular stimulation.

Methods and analysis

The following databases were searched: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, and Scopus Database. RCTs were reviewed that had been published in English and European languages. Data collection and analysis was conducted by two reviewers independently. Quality and risk assessment of included studies was performed and the meta-analysis of the effect of the most frequently assessed biomarkers.

Results

Altogether, 78 trials were included. 38 studies assessed heart rate (HR), 19 studies analyzed heart rate variability (HRV), 31 studies analyzed blood pressure (BP) and 7 studies were identified that measured oxygen saturation (O2), 2 studies on baroreflex sensitivity and 2 studies on skin conductance were evaluated in this review. 26 studies contained continuous data and were eligible for meta-analysis, 50 trials reported non continuous data and were evaluated descriptively. The overall quality of the studies was moderate to low. AS leads to a significant reduction of HR, the changes though were not considered an adverse reaction. Furthermore, when looking at HRV, AS was able to reduce the LF/HF ratio significantly compared to control procedures. No other cardiovascular parameters (blood pressure, oxygen saturation, baroreflex sensitivity) were changed significantly. AS produced only minor side effects in all trials.

Conclusion

AS can lead to clinically safe reduction of HR and changes in the LF/HF ratio of the HRV, which is presumably via an increase in vagal activity. More research is needed to clarify whether AS can be used to modulate tachycardia or indications with autonomic imbalance.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=231885 PROSPERO, ID CRD42021231885.

Auricular bean embedding improves urination in epidural labor analgesia: A single center randomized controlled study

BACKGROUND

Acupoint buried beans on the auricle is a feasible method to prevent and treat postpartum urinary retention.

OBJECTIVE

This study investigated the effect of auricular acupoint buried beans on postpartum urination and maternal and fetal outcomes following epidural analgesia for labor.

METHODS

Two hundred forty primiparas underwent vaginal trial labor analgesia from May 2020 to January 2021 and were randomly placed into the intervention and control groups. Both groups received epidural labor analgesia. Maternal urination during labor, 2 h postpartum, and the time for first postpartum urination were recorded as primary outcomes, with maternal and infant outcomes documented as secondary results. Statistical analysis was performed using the independent sample t-test, non-parametric rank-sum, or chi-square test using the SPSS Statistics 25.0 software.

RESULTS

Two hundred eight study participants were subsequently included in the results, i.e., 105 patients in the intervention group and 103 in the control group. The intervention group comprised a significantly lower number of patients with excessive residual urine volume at cervical dilatation of 5-6 cm (P< 0.05). The total postpartum score of the intervention group was lower than in the control group (P< 0.01), and the time to first urination was shorter compared with the control group (P< 0.05). In the intervention group, the time of labor analgesia, the duration of the first stage of labor, and the total labor time were shorter compared with the control group (P< 0.01).

CONCLUSION

Auricular acupoint embedded beans can improve the urination status at cervical dilatation of 5-6 cm and 2 h postpartum, as well as significantly shorten the duration of labor.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Transcutaneous Electrical Nerve Stimulation in Rodent Models of Neuropathic Pain: A Meta-Analysis

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive therapeutic intervention that is typically used for many years to treat chronic pain in patients who are refractory to pain medications. However, evidence of the efficacy of TENS treatment for neuropathic pain is lacking in humans. To further understand the efficacy of TENS under various intervention conditions and illuminate the current circumstance and future research directions, we systematically reviewed animal studies investigating the efficacy of TENS in relieving pain in neuropathic pain rodent models. We searched the Cochrane Library, EMBASE, MEDLINE (via PubMed), and Web of Science and identified 11 studies. Two meta-analyses were performed. The first meta-analysis showed that a single TENS treatment was capable of temporarily ameliorating neuropathic pain when compared to control groups with a significant effect (standardized mean difference: 1.54; 95% CI: 0.65, 2.42; p = 0.0007; I² = 58%). Significant temporary alleviation in neuropathic pain intensity was also observed in the meta-analysis of repetitive TENS (standardized mean difference: 0.85; 95% CI: 0.31, 1.40; p = 0.002; I² = 75%). Subgroup analysis showed no effect of the timing of the application of TENS (test for subgroup difference, p = 0.47). Leave-one-out sensitivity analyses suggested that no single study had an outsized effect on the pooled estimates, which may partly prove the robustness of these findings. Other stratified analyses were prevented by the insufficient number of included studies. Overall, current data suggest that TENS might be a promising therapy to ameliorate neuropathic pain. However, the high risk of bias in the included studies suggests that cautions must be considered when interpreting these findings and it is not reasonable to directly generalize the results obtained from animal studies to clinical practice. Future studies should pay more attention to improving the quality of study design and reporting, thereby facilitating the understanding of mechanisms underlying TENS treatment, reducing more potentially unsuccessful clinical trials, and optimizing the efficacy of TENS for people with neuropathic pain.