Efficacy of perioperative transcutaneous electrical acupoint stimulation on postoperative pain and recovery in patients undergoing pancreatectomy: a study protocol for a randomized controlled trial

Abstract

Background

Movement-evoked pain following pancreatectomy is often severe and inadequately controlled by conventional analgesic regimens. Transcutaneous electrical acupoint stimulation (TEAS), a non-invasive technique derived from acupuncture, has shown promise in reducing postoperative pain and opioid consumption. However, the efficacy of extended perioperative TEAS—particularly its sustained application through the early postoperative period—has not been evaluated in patients undergoing pancreatectomy.

Methods

This will be a prospective, single-center, two-arm, randomised controlled trial. A total of 132 patients undergoing pancreatectomy will be randomised allocated to the TEAS and the Sham TEAS groups. The TEAS group will receive stimulation (5–30mA, the stimulation intensity will be adjusted in accordance with the maximal level tolerated by each patient, 2/100 Hz alternating, on the Neiguan (PC6), Zusanli (ST36), Hegu (LI4) and Waiguan (SJ5)) from 30 min before anesthesia for 30min and repeated on the first 1,2 and 3 days after surgery. The patients in the Sham TEAS group will receive electrodes applied, but will receive no stimulation. The primary outcome is the highest movement-evoked pain intensity during 72 h postoperatively, assessed by the numeric rating scale (NRS). The secondary outcomes include the highest movement-evoked pain at rest, morphine consumption, recovery quality, and sleep quality over 72 h postoperatively and levels of inflammatory factors. All statistical analyses will be performed based on the modified intention-to-treat principle.

Discussion

This study aims to evaluate whether continuous TEAS during perioperative period (administered from 30 min before induction of anesthesia through 72 h postoperatively) will reduce the movement-evoked pain during postoperative 72 h in patients undergoing pancreatectomy. The findings may offer evidence for an effective opioid reducing anesthesia strategy that enhances analgesia and supports recovery, with potential value for broader clinical application.

Trial registration

ClinicalTrials.gov, NCT06541561. Registered on 2 August 2024.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-025-09386-5.

Introduction

Background and rationale {6a}

Pancreatectomy remains the mainstay of treatment for pancreatic cancer. However, postoperative pain following pancreatectomy is often severe and persistent, particularly within the first 72 h after surgery [1, 2]. Movement-evoked pain, which provoked by deep breathing, coughing, or ambulation, is the most prominent and debilitating symptom [3]. This form of pain significantly impedes early mobilization and delays recovery, despite advances in surgical technique and perioperative care [4].

Numerous analgesic options are currently employed for abdominal surgery, including systemic opioids, regional anesthesia, and neuraxial techniques [5]. Among these, epidural analgesia has long been considered the first-line approach for upper abdominal surgery. Nevertheless, its clinical utility is frequently limited by a relatively high failure rate—approximately 28.5%—as well as risks of hemodynamic instability, infection and nerve injury [6]. Consequently, patient-controlled intravenous analgesia (PCIA) with opioids, often combined with peripheral nerve blocks or wound infiltration, has become the mainstay of postoperative pain control. Yet, systemic opioids demonstrate limited efficacy in relieving movement-evoked pain [7], and their dose-limiting side effects—including nausea, vomiting, pruritus, respiratory depression, and ileus—may compromise both analgesic quality and overall recovery [4]. Therefore, there is a growing demand for non-invasive, safe, and opioid-sparing analgesic strategies that can specifically and effectively target movement-evoked pain to enhance functional outcomes in patients undergoing pancreatectomy.

Transcutaneous electrical acupoint stimulation (TEAS), a modern, non-invasive adaptation of traditional acupuncture, delivers electrical stimulation to specific acupoints via surface electrodes without needle insertion. TEAS has shown promising results in reducing postoperative pain and opioid-related side effects in various surgical populations [8, 9]. For example,Liu and colleagues found that preoperative TEAS at Hegu (LI4), Waiguan (SJ5), and Zusanli (ST36) acupoints for 30 min reduced postoperative pain on day 1, decreased opioid requirements, and improved patient comfort [10]. Sun et al. Further showed that extending TEAS into the postoperative period enhanced its analgesic effect [11].

Objectives {7}

The main objective is to assess whether continuous TEAS during perioperative period (administered from 30 min before induction of anesthesia through 72 h postoperatively) in pancreatectomy will reduce the movement-evoked pain during postoperative 72 h in a prospective, double-blind, randomized controlled trial.

No formal patient or public involvement was implemented in the design, conduct, or reporting of this trial. The trial was designed with a primary focus on patient-reported outcomes.

Trial design {8}

This is a single-center, prospective, double-blind, randomized controlled trial including 132 patients aged 18–80 years who will be scheduled for elective pancreatectomy for pancreatic cancer. After obtaining informed consent, eligible patients will undergo a baseline assessment within one day and will be enrolled in the study. Participants will be randomized in a 1:1 ratio to either the TEAS group, which will receive TEAS treatment starting 30 min before anesthesia for 30 min and repeated on postoperative days 1, 2, and 3, or the Sham TEAS group, in which electrodes will be applied without delivering any stimulation. We will assess the effect of TEAS compared with Sham TEAS on the reduction of movement-evoked pain during the first 72 h postoperatively. The study will be conducted in accordance with international guidelines for interventional trials, and the randomization sequence will be computer-generated.

Methods: participants, interventions, and outcomes

Study setting {9}

The present study is a single-center, prospective double-blind, randomized controlled trial. This protocol is in accordance with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 statement [12]. We followed the SPIRIT checklist to address the recommended items in our clinical trial protocol and documents (see Reporting Checklist in Additional file 1). And all procedures in the trial will be conducted in accordance with the World Medical Association’s “Helsinki Declaration (version 19 October 2013)”. Ethics approval has been received from West China Hospital, Sichuan University. Approved No. of Ethics Committee: 2023–689. The trial has been registered at clinicaltrials.gov on 2 August 2024 (NCT06541561) and illustrated in Fig. 1.

Fig. 1.

Flow chart of the study protocol. TEAS, transcutaneous electrical acupoint stimulation; NRS, numeric rating scale; PONV, postoperative nausea and vomiting

Eligibility criteria {10}

Patients will be recruited from the Department of Pancreatic Surgery, at West China Hospital, Sichuan University. Potentially eligible subjects who are scheduled for pancreatectomy under general anesthesia for pancreatic cancer will be invited to participate. Patients will be referred from a pancreatic surgeon, and then a research assistant will approach the subjects in the general ward preoperation. Patients will then be screened and consented for the study.

Inclusion criteria

The inclusion criteria will be as follows: patients scheduled for elective pancreatectomy for pancreatic cancer, aged 18 to 80 years, American Society of Anesthesiologists (ASA) physical status I-III.

Exclusion criteria

Participants meeting one or more of the following criteria will be excluded: have a history of epilepsy; rash or local infection over the acupoint stimulation skin area; pregnancy or breastfeeding; mental retardation, psychiatric, or neurological disease; inability to comprehend the numeric rating scale (NRS); implantation of a cardiac pacemaker, cardioverter, or defibrillator; chronic opioid use; metastases in other organs; have a history of TEAS or electroacupuncture treatment in the past or recently.

Participants meeting one or more of the following criteria will be excluded: a history of epilepsy; rash or local infection over the acupoint stimulation area; pregnancy or breastfeeding; mental retardation or psychiatric or neurological disorders; inability to comprehend the numeric rating scale (NRS); implantation of a cardiac pacemaker, cardioverter, or defibrillator; chronic opioid use; presence of metastatic disease. Patients with recent exposure to TEAS or electroacupuncture will also be excluded to minimize expectation-related bias and to preserve blinding integrity.

Who will provide informed consent? {26a}

The principal investigators or their assigned delegates obtain written informed consent from the participants.

Additional consent provisions for collection and use of participant data and biological specimens {26b}

There is no biological specimens are collected in this trial. Regarding participant data, the consent procedure includes provisions for possible secondary use. Specifically, anonymized data obtained in this study may be used for ancillary analyses by the investigators or with other researchers for purposes such as replication or meta-analysis. Any such use will require prior approval by the relevant institutional ethics committee, and only data that cannot identify individual participants will be shared.

Interventions

Explanation for the choice of comparators {6b}

There is currently a lack of high-quality evidence to recommend the use of TEAS for reducing postoperative movement-evoked pain in patients undergoing pancreatectomy. As a result, the specific effect of TEAS compared with a sham procedure remains uncertain, and both TEAS and sham stimulation are feasible and considered in clinical practice.

Intervention description {11a}

This trial will include two groups: the TEAS group and the Sham TEAS.

The patients of the TEAS group will receive TEAS therapy in the perioperative period, and in the Sham TEAS group, pseudo therapy without actual electrical stimulation will be performed in the perioperative period. All acupuncture therapists involved have at least 5 years of experience and hold a Traditional Chinese Medicine (TCM) license. The detailed procedures for each group are shown in Table 1.

Table 1.

Locations and stimulation parameters of groups

Group	Acupoints	Locations	stimulation parameter
TEAS group	Neiguan (PC-6)	On the anterior aspect of the forearm, between the tendons of the palmaris longus and the flexor carpi radialis, approximately 2.5 inches proximal to the palmar wrist crease	(a) Frequency: 2/100 Hz alternating; (b) Intensity: 5–30 mA, the stimulation intensity will be adjusted in accordance with the maximal level tolerated by each patient
	Zusanli (ST-36)	On the anterior outer side of the calf, 3 inches below the calf nose point, one transverse finger (middle finger) away from the anterior tibial ridge
	Hegu (L14)	Between the first and second metacarpal bones on the dorsum of the hand, the midpoint of the radial side of the second metacarpal bone
	Waiguan (SJ5)	on the dorsal forearm, approximately 2.5 inches above the dorsal wrist crease, between the radius and ulna bones
Sham TEAS group	It is the same as the TEAS group		Frequency: 2/100 Hz alternating; Intensity: 0 mA

TEAS group

In the TEAS group, treatment will be bilaterally performed at two acupoint pairs: Neiguan (PC6), Zusanli (ST36), Hegu (L14) and Waiguan (SJ5) (Fig. 2) (Table 1) [13–15]. During the operation, 75% alcohol is needed to apply to the treated area to enhance electrical conductivity; then, the TEAS instrument (made by Dajia, China) is activated, electrical piece (45 × 60 mm) will be put in treatment points to induce stimulation for 30 min with 2/100 Hz alternating, dilatational wave, stimulation intensity ranges from 5 to 30 mA, which will be adjusted in accordance with the maximal level tolerated by each patient. Following the session, any unusual symptoms experienced by participants will be recorded. The treatment will consist of two phases: a 30-min stimulation administered 30 min before anesthesia induction, and a 30-min stimulation session once daily on postoperative days 1, 2, and 3.

Fig. 2.

The location of the Neiguan (PC6), Zusanli (ST6), Hegu (L14) and Waiguan (SJ5) acupoints

Sham TEAS group

No electrical stimulation will actually be performed in the Sham TEAS group (Table 1). In this group, pseudo-stimulation will be provided by intentionally connecting the electrodes to the incorrect output socket of the TEAS device, ensuring that no electric current will flow. Patients will observe the output light flashing, but no current will be transmitted throughout the procedure. They will be informed that the selected stimulation frequency will not be perceivable by humans.

Perioperative management

Anesthesia protocol

All patients will receive standardized anesthesia. After standard monitoring (electrocardiogram (ECG), pulse oximetry, blood pressure (BP), and the bispectral index (BIS)) and preoxygenation, anesthesia will be induced with propofol 1.5–2 mg/kg and midazolam 2 mg, sufentanil 0.2–0.3 μg/kg and cis-atracurium 0.2 mg/kg. Maintenance will involve desflurane or sevoflurane with remifentanil 0.1–0.2 μg/kg/min and FiO₂ 60%. Blood pressure will be maintained within 20% of baseline. Hypotension (MAP < 55 mm Hg) will be treated with intravenous phenylephrine. 0.25% ropivacaine 20 ml will be used for local wound infiltration. Patients will be extubated in the operating room after completion of the surgical procedure and admitted to the post-anesthesia care unit (PACU).

Postoperative management

Subjects will be monitored for noninvasive BP, ECG, and pulse oxygen saturation in the PACU for at least 30 min and until the modified Aldrete score was > 9 [16]. Pain will be assessed by the NRS every 10 min. If an NRS score > 3, sufentanil (0.1 μg kg⁻¹) will be administered. Non-steroidal anti-inflammatory drugs (NSAIDs) will be included as part of the multimodal postoperative analgesia regimen. Flurbiprofen axetil will be administered unless contraindicated (e.g., renal insufficiency, elevated bleeding risk, gastrointestinal ulceration). All NSAIDs administration—including dosing, timing, and any reasons for omission—will be recorded. Supplemental postoperative analgesia was provided with patient controlled intravenous analgesia pumps, analgesia was established with sufentanil (2.0 μg kg⁻¹) and granisetron (12 mg) diluted to 200 ml in 0.9% normal saline at a rate of 2 ml h⁻¹, with a bolus volume of 2 ml per press, and a lockout interval of 15 min.

Criteria for discontinuing or modifying allocated interventions {11b}

If a participant experiences significant discomfort from TEAS (e.g., severe pain or fainting) or any serious adverse event, the intervention will be stopped immediately, and appropriate medical care will be provided until stabilization. Participants with serious adverse events will be withdrawn from the trial and classified as dropouts.

Strategies to improve adherence to interventions {11c}

As TEAS and Sham TEAS are both feasible and well-tolerated in clinical practice, high adherence to the intervention protocol is expected. Before patient enrolment, the study team will review standard perioperative care procedures to ensure that the study interventions do not interfere with routine clinical practice. To ensure complete and accurate delivery of the interventions, a dedicated checklist will be used to document the timing, duration, and parameters of each TEAS or Sham TEAS session. Study staff will complete this standardized checklist for every session, and intervention delivery will be monitored regularly by the principal investigators.

Relevant concomitant care permitted or prohibited during the trial {11d}

To appropriately evaluate the efficacy of TEAS, concomitant care will be restricted during the study period. Participants will be allowed to continue their stable usual care, such as prescription medications or physical therapy, provided that the type, dosage, and administration remain unchanged. Participants will be asked not to initiate other complementary or interventional pain therapies, including other acupoint stimulation or clinical trials. If any change in usual care is medically necessary, it will take priority, and participants will be instructed to report the change at the next study visit. For participants receiving care from another physician or hospital, a written summary of the study requirements will be provided to ensure that usual care remains unchanged from enrollment until the post-assessment.

Provisions for post‑trial care {30}

TEAS in this study will be limited to the scheduled intervention sessions and will not continue after trial completion. Thereafter, participants will continue to receive usual care from their attending physicians. In the unlikely event of harm related to trial participation, appropriate medical treatment will be provided within the framework of routine clinical care. As this trial involves only minimal risk—TEAS is delivered as an adjunct to usual care and is not expected to cause serious adverse events—no financial compensation or additional allowances will be provided. Participants will be informed of these provisions in advance and will provide their consent accordingly.

Outcomes {12}

Primary outcomes

The primary outcome is the highest NRS pain score for movement-evoked pain (defined as deep breathing or forced coughing three times) during 72 h postoperatively.

Secondary outcomes

The secondary outcomes are: (1) the highest NRS pain score at rest during 72 h postoperatively; (2) Cumulative morphine consumption at 24, 48, and 72 h postoperatively (all opioid consumption will be standardized to morphine mg equivalents for comparison. Include intraoperative and postoperative opioids: morphine (iv) 10 mg = fentanyl(iv) 100 μg = remifentanil (iv) 100 μg = sufentanil (iv) 10 μg = tramadol (iv) 100 mg = pethidine (iv) 100 mg) [17]; (3) Incidence of postoperative nausea and vomiting (PONV) during the first 72 h postoperatively (any nausea or vomiting); (4)The incidence of a composite of postoperative pulmonary complications during hospitalization, defined as positive if any component developed before discharge after surgery; These complications included respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, bronchospasm, or aspiration pneumonitis (see Table S1 in Additional file 2 for definitions); The diagnoses of pleural effusion, atelectasis, and pneumothorax were based on chest x-rays and were adjudicated by assessors blinded to study group allocation [18]; (5) Quality of Recovery Scale Score at 24, 48, and 72 h after surgery, assessed using the QoR-15 scale (scores from 0 to 150), which includes five domains: physical comfort, emotional state, psychological support, physical independence, and pain, with higher scores indicating a better recovery quality [19]; (6) The postoperative sleep quality score at 24, 48, and 72 h after surgery, assessed using the AIS, Which consists of 8 items: waking up at night, sleep induction, final awakening, total sleep duration, sleep quality, well-being, functional ability, and daytime sleepiness. with higher scores indicating a poor sleep quality [20]; (7) The plasma levels of C-reactive protein (CRP), procalcitonin (PCT), beta-endorphin, serotonin (5-HT), interleukin-2 (IL-2), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) on the 1st, 3rd, and 5th postoperative days.

Participant timeline {13}

After surgery, subjects will be followed from postoperative Day 1 until hospital discharge. Movement-evoked pain intensity (pain scores will be assessed when subjects perform three forced coughs or deep breathing, with the highest NRS score recorded) and pain intensity at rest will be evaluated during the first three days after surgery [7]. Medications, including the consumption of study drugs and the use of supplemental analgesics, will also be recorded during this period. Patient schedules of the whole study are shown in Fig. 3

Fig. 3.

SPIRIT figure for the schedule of enrollment, interventions and assessments. Abbreviations: PACU, post-anesthesia care unit; TEAS, Transcutaneous electrical acupoint stimulation; PONV, postoperative nausea and vomiting; QoR-15, the Quality of Recovery-15 Scale; AIS, Athens Insomnia Scale

Sample size {14}

In our preliminary observation, the highest movement-evoked pain score (mean ± SD) during 72 h after pancreatectomy was 4.73 ± 1.61 in patients who received routine analgesia following pancreatectomy. We anticipated a clinically relevant reduction in NRS pain score was 1 point, which would require 56 patients per study arm (90% power; 2-tailed α = 0.05). We planned a total sample size of 132, allowing for 15% potential attrition. The calculation was performed with PASS version 15 software.

Recruitment {15}

Eligibility is assessed during the preoperative anesthetic consultation. Clinicians and clinical research staff review inclusion and exclusion criteria and document all assessments in the screening log.

Assignment of interventions: allocation

Sequence generation {16a}

The clinical research team will screen, enroll, and randomize participants. Randomization will be based on a computer-generated table of random numbers (www.randomizer.org) and performed by a senior anesthesiologist who will not be involved in subsequent conduct of the study. Participants will be assigned in a 1:1 ratio to the TEAS or Sham TEAS group.

Concealment mechanism {16b}

The allocation sequence will be concealed in sequentially numbered, opaque envelopes. Randomization will be performed independently of the data analysts and outcome assessors.

Implementation {16c}

Upon inclusion, participants will be randomly assigned to the TEAS or Sham TEAS group using the computer-generated randomization sequence. A clinical research assistant will communicate the allocated group to the investigator responsible for delivering the intervention, while maintaining blinding of outcome assessors.

Assignment of interventions: blinding

Who will be blinded {17a}

Trial participants, pancreatic surgeons, anesthesiologists (other than the designated TEAS operator), outcome assessors, and data analysts will be blinded to the treatment allocation to minimize potential sources of bias. Only the researcher of the anesthesiology department (having received specialized acupuncture training) will know the participants’ group allocations.

Procedure for unblinding if needed {17b}

In the event of an emergency, such as rapid deterioration in the participant’s clinical condition, clinicians will adjust or discontinue TEAS treatment. Unmasking will be permitted only when absolutely necessary.

Data collection and measurements

Plans for assessment and collection of outcomes {18a}

Before the trial begins, research personnel responsible for baseline data collection and follow-up assessments (JWW, JC) will be thoroughly trained to use assessment tools, including the NRS, the Quality of Recovery-15 (QoR-15) and Athens Insomnia Scale score. The following preoperative data will be collected: age, sex, height, weight, coexisting medical conditions, comorbidities, smoking and alcohol history, and preoperative laboratory tests (including hemoglobin, white blood cell count, platelet count, prothrombin time, activated partial thromboplastin time, international normalized ratio, alanine transaminase, total bilirubin, and albumin). Tumor size and location will also be recorded. Intraoperative data will include the surgical approach (open or laparoscopic), type of surgical incision, duration of surgery and anesthesia, volume of packed red blood cells transfused, volumes of crystalloids and colloids administered, estimated blood loss, total dose of remifentanil, and cumulative dose of sufentanil.

Plans to promote participant retention and complete follow-up {18b}

As the primary outcome—movement-evoked pain over the first 72 h postoperatively—will be assessed during the hospital stay, minimal loss to follow-up is anticipated. Participants will be monitored according to the study schedule, and any protocol deviations or missed assessments will be documented to ensure complete data collection.

Data management {19}

All study data will be recorded in an electronic case report form hosted on a secure, access-controlled server. All modifications, additions, and deletions will be automatically logged. Clinical trial data, including intervention records and outcome assessments, will be securely stored for at least 5 years following trial completion in accordance with institutional and regulatory requirements.

Confidentiality {27}

Participants will be identified using unique alphanumeric codes in the case report form to maintain confidentiality. Access to identifiable participant information will be restricted to authorized study personnel, and all data handling will comply with applicable privacy regulations.

Plans for collection, laboratory evaluation, and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}

No biological specimens will be collected in this trial, as the study focuses solely on clinical outcomes related to TEAS intervention and postoperative pain.

Statistical methods

Statistical methods for primary and secondary outcomes{20a}

Baseline balance will be assessed with absolute standardized differences. According to Austin’s method, baseline data with an absolute standardized difference ≥ 0.341 (i.e.,) will be considered imbalanced between groups and will be adjusted for [21].

A modified intention-to-treat approach will be used, in which all patients who will be randomly allocated to treatment and will receive any amount of the study treatment will be included. All data will first be tested for normality by evaluating a histogram of distributions, and a Shapiro–Wilk test will be used to determine normality. Two-sample t-tests will be used to compare differences when data are normally distributed, and Mann–Whitney U tests will be used for non-parametric data. Categorical variables will be compared with χ² or Fisher exact tests, with between-group differences expressed as relative risks and 95% confidence intervals (CI).

Continuous data will be presented as means and standard deviations (SD) for normally distributed variables, and medians and interquartile ranges (IQR) for non-parametric data. Categorical variables will be summarized using proportions. All tests will be two-sided, and a P-value < 0.05 will be considered to represent a significant difference. Statistical analyses will be conducted with SPSS 22.0 software (IBM Corp, Armonk, NY, USA).

Interim analyses {21b}

No interim analyses are planned, and no formal stopping guidelines have been established. This approach is based on the anticipated low risk associated with TEAS and the relatively modest sample size of the trial.

Methods for additional analyses (e.g., subgroup analyses) {20b}

Preplanned subgroup analyses are not powered and will therefore be exploratory only. If conducted, they will examine effect modification by prespecified baseline factors such as age, sex, surgical approach (open or laparoscopic). Generalized estimating equations will be used to account for repeated measures of pain scores, QoR-15 scores and AIS scores. These additional analyses will be exploratory and interpreted cautiously.

Methods in analysis to handle protocol nonadherence and any statistical methods to handle missing data {20c}

The primary analysis will follow the intention-to-treat principle, and protocol deviations will not result in exclusion. Missing outcome data will be imputed according to data type using appropriate statistical methods (e.g., mean/median imputation for continuous variables and mode or categorical imputation for discrete variables).

Plans to give access to the full protocol, participant‑level data, and statistical code {31c}

The protocol is available on ClinicalTrials.gov since August 2, 2024. The full study protocol will be made publicly available upon publication of the trial results. After completion of the trial, deidentified participant-level data and statistical code will be made available upon reasonable request, pending approval from the principal investigator and the Ethics Committee of West China Hospital, Sichuan University.

Oversight and monitoring

Composition of the coordinating center, trial steering committee and data and safety monitoring board {5d}

This single-center trial will be conducted at the Department of Anesthesiology of West China hospital. The principal investigator will be responsible for overall study oversight, including protocol implementation, staff training, and data quality assurance. A trial steering committee, consisting of the principal investigator and key members of the research team (including anesthesiologists, surgeons, and clinical research assistants), will meet approximately every 2 months to review recruitment status, protocol adherence, and any adverse events.

Because TEAS is a non-invasive, low-risk intervention, a formal independent Data and Safety Monitoring Board is not required. Safety oversight will be managed internally by the trial steering committee. Any serious adverse events will be promptly reported to the institutional ethics committee and reviewed by the committee to determine whether additional safety measures or protocol modifications are necessary.

Before patient enrollment begins, the research team will hold a preparatory meeting to ensure consistent understanding of all study procedures, including intervention delivery, data collection, and documentation requirements.

Composition of the data monitoring committee and its role and reporting structure {21a}

No independent data monitoring committee has been established for this trial because the intervention (TEAS) is a non-invasive therapy. In accordance with institutional and regulatory requirements, a formal external monitoring committee is not mandated for studies involving minimal-risk physiologic stimulation.

Instead, trial oversight and safety monitoring will be ensured through existing study governance structures. A Trial Steering Committee will meet approximately every 2 months to review recruitment progress, protocol adherence, adverse events, and data completeness. Any serious adverse event will be immediately communicated to all study team members through internal reporting channels, and appropriate medical and administrative actions will be coordinated without delay.

In addition, the principal investigator and data manager will regularly monitor the case report form for missing data, inconsistencies, or protocol deviations. The institutional ethics committee will oversee compliance with ethical standards, and site investigators will verify source documents, consent procedures, and data accuracy in accordance with institutional regulations.

Adverse event reporting and harms {22}

Adverse events—whether related to TEAS or not—will be systematically recorded in the case report form. Possible events include discomfort such as local pain, dizziness, or fainting, and serious adverse events such as hospitalization, life-threatening conditions, or death. Each event will be documented with its timing, duration, severity, management, outcome, and an assessment of its relationship to the intervention.

Serious adverse events will result in immediate withdrawal from the trial and appropriate medical care. All serious or unexpected adverse events will be reported to the institutional oversight system according to regulatory requirements and will be included in the final study report.

Frequency and plans for auditing trial conduct {23}

Because this study involves a non-invasive intervention (TEAS) with minimal associated risk, no independent external audit of trial conduct is planned. Oversight of the study will instead be ensured through regular meetings of the trial team held approximately every 2 months, during which trial progress, recruitment status, protocol adherence, and safety issues—including any adverse events or discontinuations—will be reviewed.

In addition, ongoing monitoring of data entry in the case report form will be performed to ensure accuracy and completeness. The principal investigator will periodically review source documents, consent procedures, and intervention records in accordance with institutional requirements. The institutional ethics committee will also review trial conduct as needed to ensure compliance with ethical and regulatory standards.

Plans for communicating important protocol amendments to relevant parties (e.g., trial participants, ethical committees) {25}

Any important protocol amendments will be reviewed and approved by the institutional ethics committees before implementation, updated in the trial registry, and communicated to all trial team members. The consent form will be modified accordingly, if needed.

Dissemination plans {31a}

The results of this study will be disseminated through presentations at scientific conferences and through publications in peer-reviewed journals.

Data management and monitoring

All original data will be recorded in case report forms. The study supervisor (Chunling Jiang) will supervise the conduct of the trial conduction and perform monthly audits of the trial.

Quality control

The chief surgeon of the pancreatic surgery department, the anesthetist to implement anesthetic management, the therapists of the Traditional Chinese Medicine department to carry out TEAS (having at least 5 years of experience and hold a TCM license.) as well as data recording personnel are fixed to avoid bias from human operations. Specialized acupuncture training mainly includes selection of acupoints and the TEAS operation standard and procedure.

Discussion

Previous studies have demonstrated that TEAS can effectively reduce postoperative pain and improve recovery outcomes. It offers distinct advantages over traditional electroacupuncture as it is non-invasive, easier to administer and more acceptable by patients. While earlier studies have confirmed the analgesic efficacy of preoperative or intraoperative TEAS across various surgical populations [22–25], few have addressed its sustained impact on movement-evoked pain in high-risk procedures such as pancreatectomy.

Pancreatectomy is associated with substantial postoperative pain, particularly movement-evoked pain during activities like coughing, deep breathing, or mobilization [1, 2]. This pain can significantly impair pulmonary function, delay ambulation, and increase the risk of complications, including pneumonia and thromboembolism [26]. Despite the adoption of multimodal analgesia regimens, current strategies—including epidural anesthesia and systemic opioids—have limitations [6, 27]. Thus, there is a pressing need for adjunctive, non-pharmacological interventions that improve dynamic pain control and support recovery.

Importantly, recent evidence suggested that the duration and continuity of TEAS application may influenced its analgesic efficacy [24, 28]. In patients undergoing supratentorial craniotomy, TEAS at combined acupoints before surgery was associated with decreased pain score and opioid consumptions after surgery [10]. TEAS has been applied to patients undergoing colonoscopy, and the results showed that TEAS can reduce abdominal pain score, which may be related to the brain–gut axis [29]. Moreover, Sun and colleagues reported that continuous TEAS from the preoperative period through postoperative recovery yielded better outcomes compared with preoperative TEAS alone [11]. Building upon these findings, our study extends the TEAS intervention across a 72-h postoperative window—the period when pain intensity typically peaks and recovery is most vulnerable to disruption. This approach represents a key innovation compared to previous TEAS trials, which were often limited to preoperative or single-session use.

In our protocol, stimulation is applied at four classical acupoints: PC6 (Neiguan) and ST36 (Zusanli), as well as LI4 (Hegu) and SJ5 (Waiguan). These points are recommended in national standards and widely recognized for their roles in analgesia, gastrointestinal regulation, and homeostatic modulation. PC6, associated with the Pericardium Meridian, is used to alleviate chest discomfort, regulate autonomic function, and reduce nausea. ST36, linked to the Stomach Meridian, enhances gastrointestinal motility, boosts immunity, and relieves abdominal pain. The combination of these acupoints aims to produce synergistic effects that support both pain relief and functional recovery [14, 15].

This randomized controlled trial will, for the first time, systematically evaluate the impact of extended TEAS (preoperative to 72 h postoperative) on movement-evoked pain following pancreatectomy. By targeting the high-incidence window of postoperative pain [2, 30], this study aims to provide robust clinical evidence on the timing, duration, and efficacy of TEAS as a perioperative analgesic adjunct. Positive findings could not only validate the sustained analgesic benefit of TEAS but also inform the development of enhanced recovery protocols that integrate acupuncture-based therapies.

If TEAS proves effective in reducing dynamic pain and opioid use, it could enhance early mobilization, improve quality of life, and shorten hospitalization. Moreover, as a non-pharmacological, low-risk intervention, TEAS may contribute to lowering the burden of opioid-related adverse effects and promote safer, more holistic pain management. Its integration into perioperative care could have important implications for healthcare systems seeking multimodal, patient-centered strategies that improve outcomes and reduce costs.

In summary, this study addresses a critical gap in perioperative pain management by evaluating the extended use of TEAS in a high-risk surgical population. The results will help determine whether prolonged TEAS administration offers superior benefits for movement-evoked pain and recovery following pancreatectomy, and may pave the way for broader adoption of acupuncture-derived therapies in enhanced recovery after surgery (ERAS) programs.

Trial status

The trial was registered at ClinicalTrials.gov on 2 August 2024 (NCT06541561). The study was approved by the ethics committee of the West China Hospital, Sichuan University (approval No. 2023–689). The first participant was recruited on 15 August 2024, and the anticipated completion date will be September 2026.

Abbreviations

PCIA

Patient controlled intravenous analgesia

PONV

Postoperative nausea and vomiting

SPIRIT

Standard Protocol Items Recommendations for Interventional Trials

ASA

American Society of Anesthesiologists

NRS

Numeric rating scale

BIS

Bispectral index

PACU

Post-anesthesia care unit

Authors’ contributions

JW and LZ: principal investigator, concept and idea generation; LZ: administrative support, ensured regulatory compliance and IRB approval; JC: data management and analysis; JW and LZ: technical Support and sample size calculations; all authors contributed to the writing and editing of the proposal, including drafting, revising, and proofreading.

Funding

This study is supported by the Sichuan Provincial Science and Technology Program (2025NSFSCR0135) and the Sichuan Provincial Administration of Traditional Chinese Medicine Science and Technology Special Research Project (25ZDIZX035)

Data availability

Not applicable.

Declarations

Ethics approval and consent to participate

The study design was registered in the clinicaltrials.gov on 2 August 2024 (NCT06541561), and was carried out in compliance with the ethical principles outlined in the Declaration of Helsinki. Ethical approval for this study was obtained from the West China Hospital, Sichuan University. Approved No. of Ethics Committee: 2023-689. Trial participants sign informed consent forms at baseline, and their personal information remains strictly confidential.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.