Efficacy of wearable transcutaneous electrical acupoint stimulation bracelet on moderate-to-severe postoperative nausea and vomiting in patients after general anesthesia: a study protocol for a multicenter randomized controlled trial

Abstract

Background
Postoperative nausea and vomiting (PONV) is the most common complication following general anesthesia. Currently, pharmaceutical therapy is the primary method of treatment, but it has reached a plateau, and it is accompanied by inherent adverse reactions and high costs. Stimulation of the wrist acupuncture point PC6 is recommended as an effective means of preventing PONV. Our previous study suggests that the wearable transcutaneous electrical acupoint stimulation (TEAS) bracelet can prevent PONV, but its effectiveness in treating moderate-to-severe PONV that has already occurred remains unknown. This trial aims to include female patients who have suffered from PONV after general anesthesia in real-world settings to investigate the therapeutic effect of the TEAS bracelet.

Methods
This trial will be conducted in Shanghai and Tianjin, China, with a total of 232 participants recruited from four academic hospitals. Participants will be randomly allocated into the TEAS group or the control group in a 1:1 ratio. Participants in the TEAS group will wear an EmeTerm bracelet and be injected with normal saline, while participants in the control group will wear a model bracelet and be injected with 10 mg of metoclopramide. Follow-up will be conducted 2 h later, and participants who do not experience relief will be randomly allocated into two groups and given cross-intervention. The primary outcome of the trial is the response rate of moderate-to-severe PONV after 2 h of intervention. Secondary outcomes include the recurrence rate of moderate-to-severe PONV within 24 h after intervention and the response rate of moderate-to-severe PONV at 2 h after cross-intervention in a population insensitive to the initial intervention.

Discussion
This multi-center randomized controlled trial aims to reveal the therapeutic effect of the wearable TEAS bracelet on PONV. It is expected that this bracelet will become an effective supplement for the clinical treatment of PONV, reducing medical expenditure and improving anesthesia quality and patient satisfaction.

Trial registration
Chinese Clinical Trial Registry ChiCTR2400084329. Registered on May 14, 2024.

Full text

Dingetal. Trials (2024) 25:805
https://doi.org/10.1186/s13063-024-08650-4
STUDY PROTOCOL Open Access
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Trials
Ecacy ofwearable transcutaneous
electrical acupoint stimulation bracelet
onmoderate-to-severe postoperative nausea
andvomiting inpatients aftergeneral
anesthesia: astudy protocol foramulticenter
randomized controlled trial
Peng Ding1,2†, Dong-yu Zheng1†, Hong-wei Zhu1†, Ming Gong1†, Yong-qiang Wang3, Ling-yan Jin4,
Guang-li Ren2*, Hui-jing Shi1* and Yong-hua Li1*
Abstract
Background Postoperative nausea and vomiting (PONV) is the most common complication following general
anesthesia. Currently, pharmaceutical therapy is the primary method of treatment, but it has reached a plateau,
and it is accompanied by inherent adverse reactions and high costs. Stimulation of the wrist acupuncture point PC6
is recommended as an effective means of preventing PONV. Our previous study suggests that the wearable transcuta-
neous electrical acupoint stimulation (TEAS) bracelet can prevent PONV, but its effectiveness in treating moderate-to-
severe PONV that has already occurred remains unknown. This trial aims to include female patients who have suffered
from PONV after general anesthesia in real-world settings to investigate the therapeutic effect of the TEAS bracelet.
Methods This trial will be conducted in Shanghai and Tianjin, China, with a total of 232 participants recruited
from four academic hospitals. Participants will be randomly allocated into the TEAS group or the control group in a 1:1
ratio. Participants in the TEAS group will wear an EmeTerm bracelet and be injected with normal saline, while partici-
pants in the control group will wear a model bracelet and be injected with 10 mg of metoclopramide. Follow-up will
be conducted 2 h later, and participants who do not experience relief will be randomly allocated into two groups
and given cross-intervention. The primary outcome of the trial is the response rate of moderate-to-severe PONV
after 2 h of intervention. Secondary outcomes include the recurrence rate of moderate-to-severe PONV within 24 h
†Peng Ding, Dong-yu Zheng, Hong-wei Zhu and Ming Gong contributed
equally to this work.
*Correspondence:
Guang-li Ren
rengl254@163.com
Hui-jing Shi
312654328@qq.com
Yong-hua Li
liyonghua1207@smmu.edu.cn
Full list of author information is available at the end of the article
Content courtesy of Springer Nature, terms of use apply. Rights reserved.

Page 2 of 8
Dingetal. Trials (2024) 25:805
after intervention and the response rate of moderate-to-severe PONV at 2 h after cross-intervention in a population
insensitive to the initial intervention.
Discussion This multi-center randomized controlled trial aims to reveal the therapeutic effect of the wearable TEAS
bracelet on PONV. It is expected that this bracelet will become an effective supplement for the clinical treatment
of PONV, reducing medical expenditure and improving anesthesia quality and patient satisfaction.
Trial registration Chinese Clinical Trial Registry ChiCTR2400084329. Registered on May 14, 2024.
Keywords Acupuncture point, Non-pharmacological therapy, Postoperative nausea and vomiting, Thyroidectomy,
Transcutaneous electrical stimulation
Administrative information
Note: the numbers in curly brackets in this protocol refer
to SPIRIT checklist item numbers. e order of the items
has been modified to group similar items (see http://
www. equat or- netwo rk. org/ repor ting- guide lines/ spirit-
2013- state ment- defin ing- stand ard- proto col- items- for-
clini cal- trials/).
Title {1} Efficacy of wearable transcutaneous
electrical acupoint stimulation bracelet
on moderate-to-severe postopera-
tive nausea and vomiting in patients
after general anesthesia: a study
protocol for a multicenter randomized
controlled trial
Trial registration {2a and 2b}. Chinese Clinical Trial Registry:
ChiCTR2400084329. May 14th, 2024.
Protocol version {3} 2023.12.25 version 2.0
Funding {4} The second round of the Shanghai
Shenkang Hospital Development
Center’s “Three Year Action Plan
to Promote Clinical Skills and Clini-
cal Innovation in Municipal Hospitals”
research-oriented physician innova-
tion and transformation ability training
project (SHDC2023CRD024), the Medical
Innovation Reasearch Project of Shang-
hai Science and Technology Commission
(22Y11904000), and Clinical research
projects initiated by researchers in dem-
onstration research wards (2023YJBF-
PY11)
Author details {5a} 1. Peng Ding, Dong-yu Zheng, Hong-wei
Zhu, Ming Gong, Hui-jing Shi, and Yong-
hua Li, Department of Anesthesiology,
Second Affiliated Hospital of Naval Medi-
cal University (Shanghai Changzheng
Hospital), Shanghai, China
2. Peng Ding and Guang-li Ren, Depart-
ment of Anesthesiology, PLA No.983
Hospital, Tianjin, China
3. Yong-qiang Wang, Department
of Anesthesiology, Shuguang Hospital,
Traditional Chinese Medicine University,
Shanghai, China;
4. Ling-yan Jin, Department of Anesthe-
siology, Shanghai Fifth People’s Hospital
affiliated to Fudan University, Shanghai,
China
Name and contact informa-
tion for the trial sponsor {5b} No sponsor was involved in the initiation
and management of this trial.
Role of sponsor {5c} The funding source had no role
in the design of this study and will
not have any role during its execution,
analysis, interpretation of the data,
or decision to submit results.
Introduction
Background andrationale {6a}
Postoperative nausea and vomiting (PONV) is the
most common complication following general anesthe-
sia, accounting for 43% of all inpatients, with an inci-
dence rate of 70–80% among high-risk patients [1, 2].
Severe cases can lead to wound dehiscence, incisional
hernia, aspiration pneumonia, asphyxia, and even
death [3]. Pharmaceutical therapy is currently the pri-
mary method, with commonly used drugs including
5-HT3 receptor antagonists, glucocorticoids, dopa-
mine receptor antagonists, substance P antagonists,
anticholinergics, and antihistamines [1]. e multi-
tude of drug types indicates the lack of a specific drug
against PONV. Pharmaceutical therapy has reached a
bottleneck, and the inherent adverse reactions of these
antiemetic drugs, such as headache, dizziness, and
arrhythmia, coupled with relatively high drug costs,
limit their widespread use. erefore, it is urgent to
explore clinically effective non-pharmaceutical thera-
pies [4, 5], including acupuncture, acupressure, and
transcutaneous electrical acupoint stimulation (TEAS).
However, these traditional methods have high person-
nel skills and equipment requirements. Our previous
randomized controlled trial using a wearable brace-
let device based on the principle of TEAS found that
it reduced the incidence of PONV in patients under-
going hysteroscopic surgeries [6]. Although previous
studies have suggested that the TEAS bracelet can pre-
vent PONV, its effectiveness on PONV that has already
occurred remains unknown. us, we aim to study the
therapeutic effect of the TEAS bracelet on patients who
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Dingetal. Trials (2024) 25:805
have suffered moderate-to-severe PONV after general
anesthesia in real-world settings.
Objectives {7}
e objective of this study is to evaluate the therapeu-
tic effect of the TEAS bracelet on moderate-to-severe
PONV in patients after general anesthesia. Our hypoth-
esis is that the wearable non-pharmaceutical device is
superior to metoclopramide treatment.
Trial design {8}
e trial is designed as a randomized, controlled, patient-
blinded, multicenter, superiority trial with two parallel
groups. e primary endpoint of the trial is symptom
relief during 2h after moderate-to-severe PONV. Rand-
omization will be performed using block randomization
with a 1:1 allocation ratio.
Methods: participants, interventions andoutcomes
Study setting {9}
e trial will be conducted in Shanghai and Tianjin,
China. A total of 232 participants will be recruited from
four academic hospitals: 82 participants from the Second
Affiliated Hospital of Naval Medical University in Shang-
hai, 50 participants from Shanghai Shuguang Hospital, 50
participants from Shanghai Fifth People’s Hospital, and
50 participants from PLA No.983 Hospital in Tianjin.
Eligibility criteria {10}
Female patients undergoing thyroidectomy or ante-
rior cervical surgery under general anesthesia will be
screened for participation.
Inclusion criteria
• Moderate to severe PONV (visual analog score ≥ 4)
within 24h after surgery
• Age 25–55years
• American Society of Anesthesiologists (ASA) physi-
cal status I–II
Exclusion criteria
• Patients with PONV within 24h before surgery
• Patients who received antiemetic drugs within 24h
before surgery
• Patients with severe hepatic/renal dysfunction
• Patients known to be allergic to metoclopramide
• Patients with unstable vital signs before enrollment
• Patients who have participated in other studies
within the last 3months
• Pregnant or lactating women
Who will take informed consent? {26a}
In this study, an anesthesiologist will approach patients
who are eligible for participation. After explaining the
general anesthesia procedure and obtaining consent,
patients will be informed about the TEAS approach or
medication to treat PONV. Patients will only be enrolled
in the study if they provide consent for both the general
anesthesia and the research. If a patient is unable to pro-
vide written consent, it will be obtained from their des-
ignated representative. Patients who refuse to participate
in the study will still receive the same quality of care as
participants. Participants have the right to withdraw
from the study at any time, in accordance with the Decla-
ration of Helsinki (2013 version).
Additional consent provisions forcollection anduse
ofparticipant data andbiological specimens {26b}
Not applicable. We will not collect any biological speci-
mens from participants, and we are not currently consid-
ering the use of these data for ancillary studies.
Interventions
Explanation forthechoice ofcomparators {6b}
e Fourth Consensus Guidelines for the Management of
PONV recommend the use of multimodal prophylaxis in
patients with one or more risk factors [1]. In this study,
both groups will be routinely treated with a combina-
tion of dexamethasone and dolasetron, which are the
two most commonly used classes of drugs: glucocorti-
coids and serotonin agonists. For participants who have
already developed PONV, repeated use or higher doses of
these drugs often have little benefit. erefore, we have
chosen a new type of antiemetic, metoclopramide, as the
comparative intervention in the control group. Metoclo-
pramide is a dopamine 2 (D2) receptor antagonist and
5-hydroxytryptamine 4 (5-HT4) receptor agonist and has
a mild inhibitory effect on the 5-HT3 receptor. It acts on
the dopamine receptor in the chemoreceptor trigger zone
of the medulla to increase the threshold of the chemore-
ceptor trigger zone and has a central antiemetic effect. It
is a drug recommended in the guidelines (Evidence A1)
and its price is relatively low, so we chose metoclopra-
mide 10mg as the comparative intervention in the con-
trol group.
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Dingetal. Trials (2024) 25:805
Intervention description {11a}
All enrolled patients in this study will be routinely
administered intravenously with dexamethasone 5 mg
at the induction of general anesthesia, and dolasetron
12.5mg at the end of surgery. Patients with moderate to
severe PONV (VAS score ≥ 4) will be allocated into either
the TEAS group or the control group.
In the TEAS group, patients with PONV (VAS
score ≥ 4) will wear an EmeTerm bracelet and be injected
with normal saline. ey will be followed up 2h later to
observe the response rate of PONV. If PONV is signifi-
cantly relieved (VAS ≤ 3), the intervention will be contin-
ued for 24h, and the recurrence rate of moderate and
severe PONV within 24h will be observed and the high-
est score will be recorded.
In the control group, patients will wear a model brace-
let (the light will flash normally, but there will be no
electrical stimulation) and will be injected with meto-
clopramide 10mg. Two hours later, the response rate of
moderate to severe PONV will be observed. If PONV was
significantly relieved (VAS ≤ 3), the recurrence rate of
moderate and severe PONV within 24h will be observed
and the highest score will be recorded.
In the TEAS group, patients who have no significant
relief after the intervention of the electrostimulation
bracelet (VAS score ≥ 4) will stop using the bracelet and
then be randomly divided into two groups. One group
will be injected with metoclopramide 10 mg and the
other with an equal-volume of normal saline. ey will
be followed up 2h later to observe the response rate of
moderate and severe PONV.
In the control group, patients who have no significant
relief after metoclopramide medication (VAS score ≥ 4)
will be randomly divided into two groups. One group
will wear the electrical stimulation bracelet and the other
will wear the model bracelet. ey will be followed up 2h
later to observe the response rate of moderate and severe
PONV.
Criteria fordiscontinuing ormodifying allocated
interventions {11b}
If the vital signs of a participant are unstable after enroll-
ment or if the participant does not cooperate with fol-
low-up, the intervention will be suspended. Furthermore,
any participant may withdraw from the trial at any time
without providing a reason.
Strategies toimprove adherence tointerventions {11c}
e control group’s intervention, which is a single intra-
venous injection of metoclopramide, has good com-
pliance. e intervention in the TEAS group, which
involves wearing a bracelet, typically does not affect the
participant’s activity and has a short duration of 2 h.
erefore, adherence to the intervention is expected to
be good. e investigators will ask the ward nurses to
monitor whether the patients are wearing the bracelet
properly during routine rounds.
Relevant concomitant care permitted orprohibited
duringthetrial {11d}
Participants in both groups received conventional
postoperative care. No additional antiemetics (5-HT3
receptor antagonists, glucocorticoids, dopamine recep-
tor antagonists, substance P antagonists, anticholiner-
gics, and antihistamines) will be given. Ondansetron
4 mg will be administered intravenously as rescue
medication.
Provisions forpost‑trial care {30}
e intervention in this trial involved the normal use
of a long-marketed product, while the control inter-
vention was clinical routine medication. Participants
are not expected to suffer harm from trial participa-
tion, and no special provisions for post-trial care are
required.
Outcomes {12}
e primary outcome is the response rate of moderate-
to-severe PONV after 2 h of intervention (including
complete response, defined as the disappearance of all
uncomfortable symptoms, and partial response, defined
as the transition from vomiting to nausea, or a signifi-
cant reduction in the degree of nausea). e secondary
outcome includes the following: the recurrence rate of
moderate-to-severe PONV within 24h after interven-
tion, the response rate of moderate-to-severe PONV at
2h after cross-intervention in a population insensitive
to the initial intervention.
e primary outcome of the trial is the response rate
of moderate-to-severe postoperative PONV after 2h of
intervention. is includes complete response, which
is defined as the disappearance of all uncomfortable
symptoms, and partial response, which is defined as
the transition from vomiting to nausea or a significant
reduction in the degree of nausea (VAS ≤ 3). e sec-
ondary outcomes include the recurrence rate of moder-
ate-to-severe PONV within 24h after intervention, as
well as the response rate of moderate-to-severe PONV
at 2h after cross-intervention in a population insensi-
tive to the initial intervention.
Participant timeline {13}
e overall schedule of enrolment, allocation, interven-
tion, and follow-up is presented as a schematic diagram
in Fig.1.
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Dingetal. Trials (2024) 25:805
Sample size {14}
e sample size for this trial was calculated based on
the primary outcome. We previously found that meto-
clopramide was routinely administered intravenously
in patients suffering from moderate-to-severe PONV,
and the effective response rate was 37.5% (6/16) after
2h of follow-up. We estimate that the effective rate will
be increased to 60% by using the TEAS bracelet. Based
on the primary outcome (37.5% vs. 60%), test power
(1-β = 90%), and bilateral significance level (α = 5%), a
minimum of 104 samples are required for each group
using PASS software. To account for a 10% dropout
rate, we plan to recruit 232 participants (116 in each
group) for this trial.
Recruitment {15}
Each center participating in the trial has a dedicated
anesthesiologist who is responsible for screening all
women undergoing thyroid and anterior cervical surgery,
particularly those with more than two Apfel’s PONV risk
factors. Participants are provided with detailed informa-
tion about the potential complications of PONV, current
mainstream treatments, and the potential benefits and
risks of participating in the trial. e number of subjects
enrolled in each center is determined based on the type
and number of operations performed at the center, ensur-
ing that the target sample size can be achieved across all
four centers by the end of the enrollment period.
Assignment ofinterventions: allocation
Sequence generation {16a}
Participants in the trial will be randomly assigned to
either the control group or the TEAS group in a 1:1 ratio
using sealed envelopes. Permuted block randomization
will be performed using variable block sizes ranging from
4 to 10. e random numbers will be generated using
SAS software to ensure the randomization process is
unbiased and reliable.
Concealment mechanism {16b}
Allocation concealment will be ensured by using sealed
opaque envelopes that will be kept by a research nurse.
e allocation of participants to either the control
group or the TEAS group remains unknown to both the
participants.
Implementation {16c}
e statistical expert from the main research center
(e Second Affiliated Hospital of Naval Medical Uni-
versity) will be responsible for generating the allocation
sequence, preparing the envelopes, and sending them
directly to the research nurses in each center. Participants
will be enrolled by the anesthesiologist who administered
the anesthesia and will be assigned to the interventions
by a specialized anesthesiologist who will be blinded to
the group allocation.
Fig. 1 Schematic diagram. Timepoint: − t1, before anesthesia; 0, allocation; t1, primary intervention (after PONV occurs and last for 2 h); t2, 2 h
after intervention; t3, cross intervention (last for 2 h); t4, 2 h after cross intervention
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Dingetal. Trials (2024) 25:805
Assignment ofinterventions: blinding
Who will be blinded {17a}
In this trial, both the patients and the follow-up
researcher will be kept blind about the group allocation
and interventions. A designated anesthesiologist will
be responsible for postoperative follow-up, but will not
interfere with clinical anesthesia and PONV treatment.
After the end of the trial, the data will be summarized
and sent to the full-time statistical personnel for analysis.
Procedure forunblinding ifneeded {17b}
Emergency unblinding is not involved in this trial
because the safety of the intervention has been fully vali-
dated and does not affect routine postoperative treat-
ment and rehabilitation.
Data collection andmanagement
Plans forassessment andcollection ofoutcomes {18a}
Independent investigators at each center will be respon-
sible for following up with the participants at 2 and 24h
after the intervention. ey will fill out case report files
and print them out for storage. e case report files from
each center will then be sent to the statistical expert of
the leader unit for further analysis.
Plans topromote participant retention andcomplete
follow‑up {18b}
Follow-up in this trial will generally be completed within
24 to 48h after surgery, during which time participants
are usually still hospitalized, so the investigator can eas-
ily conduct face-to-face follow-up. If a participant has
any concerns or wishes to discontinue participation, he
or she can contact his or her physician-in-charge or the
study administrator at any time for assistance.
Data management {19}
Case report files are filled out by an independent inves-
tigator and stored in a locked cabinet in each center, and
these documents are not seen by study administrators,
recruiters, allocation, and intervention implementers. A
research nurse enters the data into a computer and sends
it directly to a statistical expert.
Condentiality {27}
e case report files will be stored in a locked cabinet
accessible only to the investigators. Personal information
that may reveal the privacy of participants will not be
recorded in the file.
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.
Statistical methods
Statistical methods forprimary andsecondary outcomes
{20a}
e primary outcome will be analyzed according to the
intention-to-treat principle, and worst-case imputation
will be used when there are missing data. Data normal-
ity is measured using the Shapiro–Wilk test. e inter-
group differences are analyzed using the Student’s t-test
or Mann–Whitney U test according to the data distribu-
tion. Binary and categorical variables are analyzed using
Fisher’s exact tests. Ordinal data are analyzed using the
Wilcoxon signed-rank test. A two-sided P value less than
0.05 is considered statistically significant.
Interim analyses {21b}
No interim analyses are planned in the trial.
Methods foradditional analyses (e.g., subgroup analyses)
{20b}
Participants who are not sensitive to the initial interven-
tion will receive cross-intervention, and the additional
outcome is the remission rate of PONV at 2h after cross-
intervention, which will be analyzed using Fisher’s exact
tests.
Methods inanalysis tohandle protocol non‑adherence
andany statistical methods tohandle missing data {20c}
e primary outcome will be analyzed according to the
intention-to-treat principle, and worst-case imputation
will be used when there are missing data. A per-protocol
analysis will be performed to enhance the results.
Plans togive access tothefull protocol, participant‑level
data andstatistical code {31c}
is protocol is publicly available and the data sets gener-
ated/anal analyzed during the current study are available
from the corresponding authors on reasonable request.
Oversight andmonitoring
Composition ofthecoordinating center andtrial steering
committee {5d}
e trial is led by the Department of Anesthesiology of
the Second Affiliated Hospital of Naval Medical Univer-
sity and involves four participating centers. A senior pro-
fessor from the leading unit and the administrators of the
other three centers form a coordinating center that will
meet online once a week to coordinate the progress of
the trial, review the inclusion and exclusion criteria, and
oversee the consent, recruitment, and follow-up process,
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Dingetal. Trials (2024) 25:805
without knowing the allocation, intervention, and out-
comes of any specific participant.
Composition ofthedata monitoring committee, its role
andreporting structure {21a}
e trial does not require a data monitoring committee
because of the short duration and minimal known risks.
Adverse event reporting andharms {22}
Possible adverse events in this trial include numbness
in the palms and fingers, allergies to the electrodes or
silicone strap, allergies to metoclopramide or related
lethargy, irritability, and fatigue. ese adverse events
are usually mild and recover quickly after the interven-
tion. Adverse events and harms will be recorded by the
investigator and eventually included as categorical data
in the secondary outcome analysis.
Frequency andplans forauditing trial conduct {23}
Audit is not planned in this trial.
Plans forcommunicating important protocol amendments
torelevant parties (e.g., trial participants, ethical
committees) {25}
e trial will follow the latest version of the protocol.
Any changes to the protocol or informed consent will
be considered as amendments and version updates.
ese changes will be submitted for review to the Eth-
ics Committee of Shanghai Changzheng Hospital and
the ethics committees of the other three centers.
Dissemination plans {31a}
e results of this trial will be communicated through
conference presentation and publication of peer-
reviewed research article.
Discussion
is multi-center randomized controlled trial aims
to evaluate the therapeutic effect of a wearable TEAS
bracelet on moderate-to-severe PONV. e trial is
expected to provide valuable information about the
effectiveness of the TEAS bracelet as a supplement
for clinical treatment of PONV, and could potentially
reduce medical expenditure and improve anesthesia
quality and patient satisfaction.
It is important to note that the trial includes only
female participants, which may introduce gender
bias into the study. However, this decision was made
in order to enroll a sufficient number of participants
faster, as women are at higher risk for PONV.
It is also important to note that blinding through a
model bracelet may not be entirely reliable for some
participants, as some of them may find that they have
no sensation at all after wearing the bracelet. Addition-
ally, some participants may discover the true role and
experience of the bracelet through internet searches.
erefore, this may not be a very rigorous patient-
blinded trial and may be biased due to the subjective
feelings of some subjects. Despite these potential limi-
tations, the trial is still expected to provide valuable
information about the effectiveness of the TEAS brace-
let as a treatment for PONV.
Trial status
e protocol version 2.0 was approved by all authors
on Dec 25th, 2023. e first participant was enrolled at
e Second Affiliated Hospital of Naval Medical Uni-
versity on May 20th, 2024. Subsequent recruitment will
be conducted after approval by the Ethics Committee
of each center. e recruitment will be completed on
December 2024.
Abbreviations
PONV Postoperative nausea and vomiting
TEAS Transcutaneous electrical acupoint stimulation
VAS Visual analog score
ASA American Society of Anesthesiologists
Acknowledgements
Not applicable.
Authors’ contributions {31b}
PD, DYZ, HWZ, and MG contributed to the study concept, design, data man-
agement, and draft of the manuscript; YQW, LYJ, GLR, and HJS are the chief
investigators of each research center, and contributed to the study design,
data collection, and data management; YHL contributed to the study concept,
design, drafting, funding, and supervising project administration. All authors
read and approved the final manuscript.
Funding {4}
The second round of the Shanghai Shenkang Hospital Development Center’s
“Three Year Action Plan to Promote Clinical Skills and Clinical Innovation in
Municipal Hospitals” research-oriented physician innovation and transforma-
tion ability training project (SHDC2023CRD024), the Medical Innovation Rease-
arch Project of Shanghai Science and Technology Commission (22Y11904000),
and Clinical research projects initiated by researchers in demonstration
research wards(2023YJBF-PY11).
Data availability {29}
The data sets generated and analyzed during the current study are available
from the corresponding authors on reasonable request.
Declarations
Ethics approval and consent to participate {24}
The study protocol is approved by the Ethics Committee of the Second Affili-
ated Hospital of Naval Medical University (No.2023SL074). Written informed
consent to participate will be obtained from all participants.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.

Page 8 of 8
Dingetal. Trials (2024) 25:805
Consent for publication {32}
Not applicable.
Competing interests {28}
The authors declare that they have no competing interests.
Author details
1 Department of Anesthesiology, Second Affiliated Hospital of Naval Medical
University (Shanghai Changzheng Hospital), Shanghai, China. 2 Department
of Anesthesiology, PLA No.983 Hospital, Tianjin, China. 3 Department of Anes-
thesiology, Shuguang Hospital, Traditional Chinese Medicine University,
Shanghai, China. 4 Department of Anesthesiology, Shanghai Fifth People’s
Hospital Affiliated to Fudan University, Shanghai, China.
Received: 3 August 2024 Accepted: 24 November 2024
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