Effects and Mechanisms of Transcutaneous Electrical Acustimulation on Postoperative Recovery After Elective Cesarean Section

Accelerative Effects of Transcutaneous Electrical Acustimulation on Postoperative Recovery After Thoracolumbar Vertebral Fracture Associated With Suppressed Sympathetic Activity and Interleukin-6

OBJECTIVES

Gastrointestinal (GI) disturbance is a frequent complication in patients with thoracolumbar vertebral fracture (TVF). Transcutaneous electrical acustimulation (TEA) has been reported to effectively accelerate postoperative GI function recovery after abdominal surgery. This study aimed to investigate the effects of TEA on postoperative recovery and the associated mechanisms.

MATERIALS AND METHODS

A total of 81 patients with TVF who underwent elective posterior pedicle screw fixation surgery were randomized to receive TEA or sham-TEA. TEA at ST36 or sham-TEA at nonacupoints was performed for one hour twice daily, from 24 hours before surgery to postoperative day (POD) 3. The effects were then assessed in the form of a diary at different time points.

RESULTS

Compared with sham-TEA, TEA attenuated postoperative impairments associated with lower GI motility, including a reduction in time to defecation by 27.2% (p = 0.002 vs sham-TEA), time to first flatus by 17.2% (p = 0.027), an increase in the Bristol stool score (p = 0.014), and the number of spontaneous bowel movement (p = 0.009). TEA also relieved other GI symptoms including abdominal bloating on POD1 and POD4 (p < 0.001 and p = 0.001, respectively), straining during defecation (p < 0.001), and sensation of anorectal blockage during defecation (p = 0.02). Moreover, TEA reduced the visual analog scale wound pain score on POD1 (p = 0.026), POD2 (p < 0.001), and POD3 (p < 0.001), increased vagal activity, and decreased sympathetic activity (p < 0.001), in addition to suppressing the serum level of norepinephrine on both POD1 (p = 0.047) and POD4 (p = 0.036). TEA caused a higher decrease from POD1 to POD4 in serum interleukin-6 (p = 0.011, vs sham-TEA). The use of TEA was an independent predictor of shortened time to first defecation.

CONCLUSION

Noninvasive TEA at ST36, in comparison with sham-TEA, is effective in promoting postoperative recovery in patients with TVF by enhancing vagal and suppressing sympathetic activities.

CLINICAL TRIAL REGISTRATION

The study was retrospectively registered on www.chictr.org.cn (Chinese Clinical Trial Registry ChiCTR2300078195).

CiteSpace-based visual analysis on transcutaneous electrical acupoint stimulation of clinical randomized controlled trial studies and its mechanism on perioperative disorders

To systematically present an overview of randomized controlled trials on transcutaneous electrical acupoint stimulation (TEAS) using bibliometric methods, and describe the role and mechanisms of TEAS in most prevalent diseases. Relevant literature was searched in China National Knowledge Infrastructure, Wanfang Data, VIP, SinoMed, PubMed, and Web of Science. The literature was imported and screened into NoteExpress, screened according to inclusion and exclusion criteria, and analyzed using Excel and CiteSpace 6.3R1 software. A total of 1296 documents were included. The number of publications increased annually after 2012. Junlu Wang was the most prolific author. The main research institutions were Peking University, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Shuguang Hospital, and Tongde Hospital of Zhejiang Province. The research hotspots in this field include perioperative care, cancer, pain management, and stroke, primarily focusing on analgesia, immune enhancement, antihypertension, and reduction of gastrointestinal disorders. The main regulatory mechanisms of TEAS include the control of inflammation, oxidative stress, and regulation of the autonomic nervous system. TEAS is most widely used in the elderly, with PC6, ST36, and LI4 being the most frequently studied acupoints in clinical randomized controlled trials. The concept of accelerated rehabilitation is gradually being applied to TEAS, representing an emerging trend for future development. Clinical research on TEAS is rapidly developing, with a focus on applications in cancer and perioperative care. Future research should expand collaboration and conduct high-level clinical and mechanistic studies, which will contribute to the development of standardized protocols and clinical practice.

Effects of transcutaneous electrical acupoint stimulation on early postoperative pain and recovery: a comprehensive systematic review and meta-analysis of randomized controlled trials

Background

Previous studies have indicated beneficial outcomes of transcutaneous electrical acupoint stimulation (TEAS), but high-quality and comprehensive meta-analyses are lacking. The aim was to quantitatively analyze the efficacy and safety of perioperative TEAS on postoperative pain and recovery.

Methods

PubMed, Web of Science, EMBASE, and the Cochrane Library were searched through July 2022. Randomized controlled trials (RCTs) that examined the perioperative application of TEAS in adults compared with sham-TEAS and/or non-TEAS were eligible. Cumulative analgesic consumption within 24 h and rest pain scores at 2, 6, 12, and 24 h postoperatively were the two co-primary outcomes.

Results

Seventy-six RCTs (n = 9,665 patients) were included. Patients treated with TEAS experienced a reduction in clinical importance in cumulative analgesic (morphine equivalent) consumption (WMD: -14.60 mg, 97.5% CI: -23.60 to -5.60; p < 0.001) and a reduction in statistical importance in rest pain scores at multiple time points within the first 24 postoperative hours. The secondary outcome analysis also identified clinically significant recovery benefits to TEAS during the first 24 h after surgery. Furthermore, TEAS could effectively reduce opioid-related side effects and did not increase serious side effects.

Conclusion

This article describes current evidence about TEAS intervention on early postoperative pain and recovery. The results support the effectiveness of TEAS, but more high-quality evidence of clinical applicability is also needed.

Systematic review registration

PROSPERO (CRD42021249814).

Noninvasive Transcutaneous Auricular Vagal Nerve Stimulation Improves Gastric Slow Waves Impaired by Cold Stress in Healthy Subjects

BACKGROUND/AIMS

Stress is known to inhibit gastric motility. The aim of this study was to investigate the effects and autonomic mechanisms of transcutaneous auricular vagal nerve stimulation (taVNS) on cold stress (CS)-induced impairment in gastric motility that are relevant to the brain-gut interactions in healthy volunteers.

MATERIALS AND METHODS

Healthy volunteers (eight women; age 28.2 ± 1.8 years) were studied in four randomized sessions (control, CS, CS + taVNS, and CS + sham-electrical stimulation [sham-ES]). Each session was composed of 30 minutes in the fasting state and 30 minutes after a standard test meal. CS was induced during minutes 10 to 30 after the meal, whereas taVNS or sham-ES was performed during minutes 0 to 30 after the meal. The electrogastrogram and electrocardiogram were recorded for assessing gastric slow waves and autonomic functions, respectively.

RESULTS

First, CS decreased the percentage of normal gastric slow waves (59.7% ± 9.8% vs 85.4% ± 4.5%, p < 0.001 vs control); this impairment was dramatically improved by taVNS (75.5% ± 6.3% vs 58.4% ± 12.5%, p < 0.001 vs sham-ES). Second, CS increased the symptom score (22.0 ± 12.1 vs 39.3 ± 11.5, p = 0.001 vs control); taVNS, but not sham-ES, reduced the symptom score (26.0 ± 12.2 vs 38.3 ± 21.6, p = 0.026 vs sham-ES). Third, CS decreased vagal activity assessed from the spectral analysis of heart rate variability (0.21 ± 0.10 vs 0.26 ± 0.11, p < 0.05 vs control) and increased the sympathovagal ratio (4.89 ± 1.94 vs 3.74 ± 1.32, p = 0.048 vs control); taVNS normalized CS-induced suppression in vagal activity (0.27 ± 0.13 vs 0.22 ± 0.10, p = 0.049 vs sham-ES; p > 0.05 vs control) and CS-induced increase in the sympathovagal ratio (3.28 ± 1.61 vs 4.28 ± 2.10, p = 0.042 vs sham-ES; p > 0.05 vs control).

CONCLUSION

The noninvasive taVNS improves the CS-induced impairment in gastric pace-making activity, possibly by reversing the detrimental effect of CS on autonomic functions. taVNS may have a therapeutic potential for stress-induced gastric dysmotility.

Potential value of gastrointestinal myoelectrical activity in the diagnosis of anxiety-depression disorder: a population-based study

BACKGROUND

Depression and anxiety are frequently coexisted mental illness. The lack of solid objective diagnostic criteria has led to a high rate of suicide. The brain-gut axis bridges the gastrointestinal system with neuropsychiatric disorders. However, it is still not possible to reflect mental disease with gastrointestinal information. The study aimed to explore the auxiliary diagnostic value of gastrointestinal myoelectrical activity in anxiety-depression disorders (ADD) without gastrointestinal disturbance.

METHODS

A natural population cohort from 3 districts in Western China were established. The Patient Health Questionnaire-9 and the Generalized Anxiety Disorder-7 were used to assess ADD. Gastrointestinal myoelectrical activity of ADD were measured by multi-channel cutaneous electrogastroenterogram (EGEG). Then the parameters of EGEG between ADD and healthy controls were analyzed.

RESULTS

The average amplitude and response area of intestinal channel in ADD were significantly lower than those of controls (153.49 ± 78.69 vs. 179.83 ± 103.90, 57.27 ± 29.05 vs. 67.70 ± 38.32), which were shown to be protective factors for ADD (OR = 0.944 and 0.844, respectively). Further, the scale item scores related to the core symptoms of anxiety and depression were also associated with these two channels (p < 0.05), and the gastrointestinal electrical signals of ADD are significantly changed in the elderly compared to the young adults.

CONCLUSIONS

The intestinal myoelectrical activity has a certain auxiliary diagnostic value in psychiatric disorders and is expected to provide objective reference for the diagnosis of anxiety and depression.

Research Status and Prospects of Acupuncture in Perioperative Medicine Over the Past Decade: A Bibliometric Analysis

Background

Over the past decade, acupuncture in the perioperative period has attracted great interest, and a growing number of related literature has been published.

Purpose

To analyze the general information and identify the research hotspots and trends of acupuncture in perioperative medicine in the last 10 years by bibliometric analysis.

Methods

We searched the Web of Science Core Collection for publications on acupuncture in perioperative medicine from 2013 to 2023. The articles and reviews were collected with no language restriction. CiteSpace and VOSviewer software were used for bibliometric and visual analysis of relevant literature.

Results

A total of 814 bibliographic records were retrieved. Overall, the annual number of publications showed an increasing trend. China and its institutions were in a leading position regarding the publication number. With comparatively more scientific collaboration with China, the USA ranked second. Shanghai University of Traditional Chinese Medicine was the most prolific institution. Ha, In-Hyuk had the most publications, and Han JS and Lee A were the most cited authors. Medicine was the most popular journal and Journal of Clinical Oncology had the highest impact factor. "Acupuncture", "electroacupuncture" and "postoperative pain" were the top three keywords. The most popular topics were postoperative pain, postoperative ileus, and postoperative nausea and vomiting according to the keywords and references. And the clusters of postoperative cognitive dysfunction, anxiety, and breast cancer attracted relatively more attention recently.

Conclusion

This study summarized the research status, hotspots, and trends of acupuncture in perioperative medicine in the past decade, which may aid researchers in better understanding this field. The research hotspots primarily focused on postoperative pain management and postoperative gastrointestinal function. The research of acupuncture for postoperative cognitive dysfunction, cancer-related surgery, and psychological states were the main frontiers topics and may be the focus in the future.

Acceleration of postoperative recovery with brief intraoperative vagal nerve stimulation mediated via the autonomic mechanism

Introduction

Postoperative recovery is largely dependent on the restoration of gastrointestinal motility. The aim of this study was to investigate the effects and mechanisms of intraoperative vagus nerve stimulation (iVNS) on postoperative recovery from abdominal surgery in rats.

Methods

The Nissen fundoplication surgery was performed on two groups of rats: sham-iVNS group and iVNS group (VNS was performed during surgery). Animal's behavior, eating, drinking and feces' conditions were monitored at specific postoperative days. Gastric slow waves (GSWs) and electrocardiogram (ECG) were recorded; blood samples were collected for the assessment of inflammatory cytokines.

Results

(1) iVNS shortened initiate times to water and food intake (p = 0.004) and increased the number of fecal pellets (p < 0.05, vs. sham-iVNS) and the percentage of water content in fecal pellets (p < 0.05). (2) iVNS improved gastric pace-making activity at 6 h after surgery reflected as a higher percentage of normal slow waves (p = 0.015, vs. sham-iVNS). (3) iVNS suppressed inflammatory cytokines at 24 h after surgery compared to sham-iVNS (TNF-α: p = 0.001; IL-1β: p = 0.037; IL-6: p = 0.002). (4) iVNS increased vagal tone compared to sham-iVNS group at 6 h and 24 h after the surgery (p < 0.05). Increased vagal tone was correlated with a faster postoperative recovery to start water and food intake.

Conclusion

Brief iVNS accelerates postoperative recovery by ameliorating postoperative animal behaviors, improving gastrointestinal motility and inhibiting inflammatory cytokines mediated via the enhanced vagal tone.

Development of a Gastrointestinal-Myoelectrical-Activity-Based Nomogram Model for Predicting the Risk of Mild Cognitive Impairment

Mild cognitive impairment (MCI) is the prodromal stage and an important risk factor of Alzheimer's disease (AD). Interventions at the MCI stage are significant in reducing the occurrence of AD. However, there are still many obstacles to the screening of MCI, resulting in a large number of patients going undetected. Given the strong correlation between gastrointestinal function and neuropsychiatric disorders, the aim of this study is to develop a risk prediction model for MCI based on gastrointestinal myoelectrical activity. The Mini-Mental State Examination and electrogastroenterography were applied to 886 participants in western China. All participants were randomly assigned to the training and validation sets in a ratio of 7:3. In the training set, risk variables were screened using LASSO regression and logistic regression, and risk prediction models were built based on nomogram and decision curve analysis, then validation was performed. Eight predictors were selected in the training set, including four electrogastroenterography parameters (rhythm disturbance, dominant frequency and dominant power ratio of gastric channel after meal, and time difference of intestinal channel after meal). The area under the ROC curve for the prediction model was 0.74 in the training set and 0.75 in the validation set, both of which exhibited great prediction ability. Furthermore, decision curve analysis displayed that the net benefit was more desirable when the risk thresholds ranged from 15% to 35%, indicating that the nomogram was clinically usable. The model based on gastrointestinal myoelectrical activity has great significance in predicting the risk of MCI and is expected to be an alternative to scales assessment.

Efficacy and Safety of Transcutaneous Electrical Acupoint Stimulation for Postoperative Pain: A Meta-Analysis of Randomized Controlled Trials

Objective

This meta-analysis aims to evaluate the effectiveness and safety of transcutaneous electrical acupoint stimulation (TEAS) in treating post-operative pain.

Methods

This meta-analysis was registered in PROSPERO (CRD42021286753). We searched PubMed, Embase, and the Cochrane Library for relevant randomized controlled trials (RCTs) about TEAS in treating postoperative pain that were published before November 2021. The primary outcome was visual analogue scale (VAS) within 24 h after surgery. The secondary outcomes included postoperative opioid analgesic drug consumption and the occurrence of adverse reactions within the postoperative 24–72 h. Adverse reactions included dizziness, nausea, and vomiting. Continuous variables were analyzed using mean difference (MDs) or standardized mean difference (SMDs) and 95% CIs. Relative risk (RR) and 95% CI were used for dichotomous data. The data were pooled and analyzed by RevMan 5.4 and STATA15.0 software.

Results

Seventeen trials with 1375 participants were included. The current results suggested that application of TEAS showed obvious superiority in reducing VAS scores (SMD = −1.51, 95% CI = −2.20∼−0.82, I2 = 96%). Subgroup analysis was performed according to open surgery and minimally invasive surgery. VAS scores were decreased after surgery at 24 h (SMD = −0.84, 95% CI = −1.07∼−0.6, I2 = 96%; SMD = −0.88, 95% CI = −1.02∼−0.75, I2 = 96%). The incidence of postoperative dizziness and nausea and vomiting was significantly lower in the TEAS group within postoperative 24–72 h (RR = 0.48, 95% CI = 0.34∼0.68, I2 = 0%; RR = 0.66, 95% CI = 0.44∼1.01, I2 = 69%; and RR = 0.49, 95% CI = 0.24∼1.00, I2 = 51%). Postoperative opioid analgesics were also reduced in the TEAS group within 72 h after surgery (SMD = −2.10, 95% CI = −3.37∼−0.82, I2 = 96%).

Conclusions

TEAS can reduce postoperative pain as well as the incidence of dizziness, nausea, and vomiting and the number of analgesics used after surgery. TEAS is a reasonable modality to incorporate into a multimodal management approach for postoperative pain.

Transcutaneous auricular vagal nerve stimulation improves functional dyspepsia by enhancing vagal efferent activity

This study was designed to investigate whether transcutaneous auricular vagal nerve stimulation (taVNS) would be able to improve major pathophysiologies of functional dyspepsia (FD) in patients with FD. Thirty-six patients with FD (21 F) were studied in two sessions (taVNS and sham-ES). Physiological measurements, including gastric slow waves, gastric accommodation, and autonomic functions, were assessed by the electrogastrogram (EGG), a nutrient drink test and the spectral analysis of heart rate variability derived from the electrocardiogram (ECG), respectively. Thirty-six patients with FD (25 F) were randomized to receive 2-wk taVNS or sham-ES. The dyspeptic symptom scales, anxiety and depression scores, and the same physiological measurements were assessed at the beginning and the end of the 2-wk treatment. In comparison with sham-ES, acute taVNS improved gastric accommodation (P = 0.008), increased the percentage of normal gastric slow waves (%NSW, fasting: P = 0.010; fed: P = 0.007) and vagal activity (fasting: P = 0.056; fed: P = 0.026). In comparison with baseline, 2-wk taVNS but not sham-ES reduced symptoms of dyspepsia (P = 0.010), decreased the scores of anxiety (P = 0.002) and depression (P < 0.001), and improved gastric accommodation (P < 0.001) and the %NSW (fasting: P < 0.05; fed: P < 0.05) by enhancing vagal efferent activity (fasting: P = 0.015; fed: P = 0.048). Compared with the HC, the patients showed increased anxiety (P < 0.001) and depression (P < 0.001), and decreased gastric accommodation (P < 0.001) and %NSW (P < 0.001) as well as decreased vagal activity (fasting: P = 0.047). The noninvasive taVNS has a therapeutic potential for treating nonsevere FD by improving gastric accommodation and gastric pace-making activity via enhancing vagal activity.NEW & NOTEWORTHY Treatment of functional dyspepsia is difficult due to various pathophysiological factors. The proposed method of transcutaneous auricular vagal nerve stimulation improves symptoms of both dyspepsia and depression/anxiety, and gastric functions (accommodation and slow waves), possibly mediated via the enhancement of vagal efferent activity. This noninvasive and easy-to-implement neuromodulation method will be well received by patients and healthcare providers.