Effects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol.

Effects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol. Kamylla Caroline Santos, Mariana Arias Avila, Gilberto Inacio Cardoso Neto, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3946854/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 5 You are reading this latest preprint version Abstract ● Background : Breast augmentation is a surgical procedure that may result in postoperative pain. The use of analgesics to relieve pain may produce adverse effects and delay recovery. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological approach that can relieve pain by activating nerve fibers. However, the effectiveness of TENS in breast augmentation has yet to be investigated. The aim of this study was to assess the effects of TENS on pain intensity immediately after breast augmentation. The results have the potential to advance scientific and technological knowledge in the treatment of acute postoperative pain, using accessible non-pharmacological interventions that can improve patients’ experiences. ● Methods: A placebo-controlled, double-blind randomized clinical trial will be conducted with 52 participants submitted to breast augmentation following a rapid 24-hour recovery. Participants will be randomly allocated to two groups: active TENS and placebo TENS. Each participant will undergo a TENS treatment session. The primary outcome will be pain intensity assessed at rest and during movement, before and immediately after TENS. Secondary outcomes will include pain intensity one hour after treatment, respiratory muscle strength, satisfaction with the intervention and analgesic use in the first four hours after surgery. ● Discussion : The results of this study will provide important information on the effects of TENS in patients submitted to breast augmentation, contributing to improving ´postoperative pain. It is hoped that the findings of a non-pharmacological approach will contribute to developing more effective and less costly pain management strategies. This may result in a significant improvement in the experience of patients submitted to this surgical procedure. ● Trial registration : This study was prospectively registered in the Brazilian Clinical Trials Registry (ReBEC) on 01/02/2024 under registration number RBR-96h3k97. Pain Postoperative Acute Pain Mammaplasty Breast Implantation Transcutaneous Electrical Nerve Stimulation Study protocol Figures Figure 1 Figure 2 Administrative information * Note: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the items has been modified to combine similar items. Title {1} Effects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol. Trial registration {2a and 2b}. This study will be registered in the Brazilian Clinical Trials Registry (ReBEC). Protocol version {3} Version 1 from 01-02-2024. Funding {4} This study will be completely funded by the researchers themselves. Author details {5a} Kamylla Caroline Santos a , Mariana Arias Avila b , Gilberto Inacio Cardoso Neto c , Alexandre Fabricio Martucci d , Richard Eloin Liebano e,f * a Departamento de Fisioterapia, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luis, km 235, São Carlos, São Paulo, Brasil, CEP 13565-905. E-mail: [email protected] b Departamento de Fisioterapia, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luis, km 235, São Carlos, São Paulo, Brasil, CEP 13565-905. E-mail: [email protected] c Departamento de Medicina, Universidade Federal de Goiás (UFG), Avenida Esperança, s/n - Chácaras de Recreio Samambaia, Goiânia, Goiás, Brasil, CEP 74690-900. E-mail: [email protected] d Departamento de Medicina, Universidade Federal de Jatai (UFJ), Rodovia BR 364, KM 195. Setor Parque Industrial, nº 3800, Jataí, Goiás, CEP 75801-615. E-mail: [email protected] e Departamento de Fisioterapia, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luis, km 235, São Carlos, São Paulo, Brasil, CEP 13565-905. E-mail: [email protected] . f Department of Rehabilitation Sciences, University of Hartford, 200 Bloomfield Avenue, West Hartford, CT 06117. E-mail: [email protected] *Corresponding author: Tel.: +1 860.768.5181. Department of Rehabilitation Sciences, University of Hartford. Name and contact information for the trial sponsor {5b} This study has no sponsors Role of sponsor {5c} Not applicable Introduction Background and rationale {6a} Breast augmentation is widely used in plastic surgery, with high prevalence in Brazil and the world (1). Thus, as in other surgeries, it is performed under anesthesia, and pain management generally involves drug treatment (2,3). However, these drugs may cause a series of adverse effects, such as vomiting, nausea, urinary retention and sedation, which could compromise postoperative recovery, prolong hospital stays and hinder physical exercises during hospitalization (4–8). Postoperative exercise is widely recognized as safe and beneficial, in breast augmentation and other surgeries (6,9–11). Regular exercise contributes to reducing muscle atrophy, pulmonary complications and length of hospital stay, in addition to improving the functional capacity and quality of life of patients (12–14). On the other hand, the lack of postoperative exercises is related to complications such as anxiety, depression, increased pain intensity, muscle contractions and adhesive capsulitis (15–19). Surgical techniques that allow patients to return early to work and physical exercises are preferred by young women submitted to breast augmentation (20–22). In this respect, a breast augmentation protocol was developed to optimize surgeries, making them more efficient than previous procedures, favoring rapid patient recovery. This protocol proposes to reduce surgical trauma and intra postoperative drug therapy using refined techniques that recover up to 96% of patients in 24 hours, resulting in a return to normal life (23,24). Although surgery involving the rapid 24-hour recovery (R24R) protocol is less traumatic than traditional methods, it is important to underscore that it also causes pain and requires suitable relief (6,23,25,26). Postoperative analgesia should be incorporated into the patient recovery process, aimed at comprehensive improvement that goes beyond reducing pain intensity, including decreasing drug use and their possible side effects (2,3). In this respect, implementing non-pharmacological analgesic interventions is recommended as part of the therapeutic plan (6). One non-pharmacological option widely recognized to control postoperative pain is Transcutaneous Electrical Nerve Stimulation (TENS). This technique involves applying electrical stimuli through surface electrodes that activate nerve fibers and modulate pain perception, stimulating opioid receptor activation in the central and peripheral nervous system (27–31). TENS is considered a safe, accessible, and easy-to-use option (28,32,33), and can contribute to reducing hospital stays, relieving pain and allowing early mobilization via physical exercises in the immediate postoperative (26,34,35). Previous studies demonstrated the effectiveness of TENS in reducing pain intensity and analgesic consumption in different surgical procedures, such as lipoaspiration (36), mastectomy (32,37), orthopedic surgeries (38–40), thoracotomy (33,34), inguinal herniorrhaphy (35) and myocardial revascularization (41). However, to date, no studies have investigated the analgesic effectiveness of TENS in postoperative breast augmentation. Our hypothesis is that TENS, used as a non-pharmacological therapy, can play an important role in reducing pain after breast augmentation performed using the rapid 24-hour recovery protocol (R24R). Objectives {7} Hypothesis The study hypothesis is that applying a single TENS session would significantly reduce acute postoperative breast augmentation pain intensity when compared to the placebo group. Primary objective The primary objective of the study is to assess pain intensity at rest before, immediately after TENS intervention and during 90-degree shoulder flexion. Secondary objective The secondary objectives include assessing pain intensity at rest and during movement one hour after TENS intervention, respiratory muscle strength, satisfaction with the intervention and analgesia use 4 hours after surgery. Trial design {8} This is a double-blind, placebo-controlled randomized clinical trial (RCT), where participants and raters are blind to the intervention applied. The study will be reported following Consolidated Standards of Trial Reporting (CONSORT) guidelines (42) and was developed based on Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT). Participants will be randomly allocated to two groups: active TENS and placebo TENS, at a 1:1 ratio. Intention-to-treat analysis will be adopted, thereby ensuring the inclusion of all participants of the original groups, regardless of their complete study adherence. Allocation concealment and participant and rater blinding reduce expectation bias and increase internal study validity. This methodology aims at ensuring the quality and reliability of the results obtained in assessing the effects of TENS on acute postoperative breast augmentation pain. Methods: Participants, interventions, and outcomes Study setting {9} The study will be conducted at the UNIMED hospital in Jataí, Goiás state, Brazil. This location was selected because it provides ideal conditions to carry out the research, thereby guaranteeing the required ethical and quality standards. In addition, the infrastructure of the hospital is suitable for breast augmentation surgery and postoperative support, which will make it possible to obtain reliable and relevant results. Eligibility criteria {10} The eligibility criteria to participate in the study are established based on the specific characteristics of patients that seek breast augmentation surgery using the R24R technique at the private plastic surgery clinic of researcher 1 (described in item 16c), located in Jataí, Goiás, Brazil. These eligibility criteria are important to ensure participant homogeneity and result validity, in addition to guaranteeing patient safety during the TENS intervention and postoperative period. Inclusion criteria: Included will be women aged between 18 and 65 years, submitted to breast augmentation surgery using the fast 24-hour recovery protocol (R24R) (24). Participants reporting significant pain intensity greater than or equal to 3 points on the Numerical Pain Scale (NPS) in the immediate postoperative will also be included. Patients must be willing to be randomly allocated to one of the two study groups (active TENS or placebo TENS) and understand and accept the possible adverse effects related to the proposed treatments, which will be described on the informed consent form. Exclusion criteria: Excluded will be those with chronic pain, previous use of electric currents to relieve pain, illicit or psychotropic drug use, chronic opioid use, the presence of a pacemaker, neurological disorders that may interfere in their awareness level and inability to sustain shoulder elevation at 90 degrees. Who will take informed consent? {26a} Informed consent will be obtained by researcher 4, responsible for assessments, who will explain the research details to the participants. The informed consent form will be provided for reading and voluntary signing, guaranteeing that the participants are well informed about the procedures and that they may withdraw their consent at any time. Data collection will start after the informed consent form is signed. Additional consent provisions for collection and use of participant data and biological specimens {26b} There is no participant or biological specimen data collection in this study. Interventions Explanation for the choice of comparators {6b} No literature studies were found that compared the analgesic effectiveness of TENS with a TENS placebo in postoperative breast augmentation. In addition, the placebo TENS comparator was selected to guarantee the internal validity and robustness of the results, providing more reliable evidence on the effectiveness of TENS as a complementary pain management therapy after breast augmentation, in addition to minimizing expectation bias and controlling the placebo effect. Intervention description {11a} Preoperative Before surgery, participants will be submitted to individual sessions with a qualified physiotherapist, with 6 years’ experience and trained to apply TENS and follow the breast rehabilitation protocol using the R24R technique. During these sessions, participants will be familiarized with the physiotherapy tests indicated and the exercises to be performed during the postoperative period. Anesthetic procedure All the surgeries will be performed under balanced general anesthesia, following a standardized protocol. The anesthetic plan will involve the administration of 5 to 10mg/kg of fentanyl associated with the use of propofol to induce anesthesia. During maintenance of anesthesia, 2 to 3 % sevoflurane will be used in a mixture of oxygen with a content greater than 40%. Sevoflurane level and oxygen concentration will be monitored by a gas analyzer. The neuromuscular blocker will only be used during anesthesia induction. Blood pressure will be controlled by adjusting sevoflurane, and if needed, a vasoactive agent can be administered. Average blood pressure will be monitored and maintained between 50 and 100 mmHg. Surgical technique All the breast augmentation surgeries will be performed by the same plastic surgeon accredited by the Brazilian Society of Plastic Surgery (SBCP), and a multidisciplinary team. The surgeon will be responsible for developing the surgical plan, which includes informing the patient, choice of instrumentation, dissection technique, type of incision and implant size, during the preoperative period. The surgery will follow the specifications of the rapid recovery technique described by Tebbettes (23,24), aimed at maximizing surgical efficiency and reducing surgery time, drug dose and tissue trauma. Postoperative After surgery, all participants will receive an analgesic drug, including 1g of dipyrone every 6 hours and 100mg of ketoprofen every 12 hours, both administered intravenously. These drugs aim to relieve immediate postoperative breast augmentation pain. Rescue analgesia A solution of 100mg of tramadol will be prescribed (every 8 hours during the 24-hour hospital stay) as an additional pain control option, if needed, in addition to previously prescribed analgesics. TENS application One hour after surgery, active TENS group participants will receive a single 20-minute TENS application, applied using a TENS unit with the option of a placebo or active mode, developed specifically for the study (Neurodyn Portable TENS System, Ibramed, Amparo, São Paulo, Brazil). TENS will consist of an asymmetrical biphasic pulsed current, at a frequency of 100Hz and pulse of 100μs. TENS intensity will be adjusted to promote strong, albeit comfortable, paresthesia, as described in previous studies (43–47). TENS will be applied with four self-adhesive electrodes measuring 7cm x 5cm (ValuTrode, Axelgaard, CA), two of which will be placed on breast dermatomes, two centimeters from the spinous processes adjacent to the second and third thoracic vertebra (T2 - T3), and two adjacent to the fourth and fifth thoracic vertebra (T4 - T5) (48) (Fig.1). In the placebo TENS group, the electrodes will be placed at the same sites, with the same application times and duration as the active TENS group, for 20 minutes. Participants will be informed that they may feel or not some sensation during the procedure (46). The device in the placebo TENS group will be turned on in the first 30 seconds and the stimuli will be reduced to 0 in the next 15 seconds (44,47,49). This approach was previously validated and will be used to blind the participants, thereby decreasing expectation bias, without providing analgesia (50,51). The specification of materials, equipment and techniques used, as well as the TENS and analgesic application period, ensures that all participants receive consistent and comparable treatments. Furthermore, adopting a standardized protocol for the anesthetic procedure and surgical technique contributed to reducing possible confounding variables that could interfere in the results. Describing the pre and postoperative procedures is also important to understanding the global approach of the study in assessing the effectiveness of TENS as a complementary therapy to control postoperative breast augmentation pain. Criteria for discontinuing or modifying allocated interventions {11b} Participants will have the right to interrupt treatment at any time and for any reason, without suffering any consequences. No allocation changes will be made, and no individuals will be allowed to transfer between groups during the study. Thus, initial randomization will be maintained, preserving the validity and integrity of the results. If a participant decides to interrupt treatment, the most recent data from the period in which the intervention was performed will be included in the analyses, following the intention-to-treat principle. The reason to withdraw will be registered for result interpretation purposes, since the information is important in understanding the challenges and limitations of the study, as well as assessing intervention acceptance and participant tolerability. Strategies to improve intervention adherence {11c} Researcher 4 will use different strategies to minimize data loss due to low intervention adherence. Preoperative educational sessions will be held to provide detailed information on the proposed treatment and its benefits and resolve any participant doubts. During the postoperative period, the researcher will provide continuous support and encouragement for participants to follow the treatment protocol. In addition, the researcher will facilitate participant access to interventions, thereby guaranteeing that procedures are performed conveniently and comfortably, and be available to answer any questions or concerns throughout the study. Relevant concomitant care permitted or prohibited during the trial {11d} During the study, concomitant care made it possible to include the use of analgesics, such as dipyrone and ketoprofen, administered intravenously to relieve postoperative pain. No concomitant surgeries will be allowed, such as lipoaspiration or abdominoplasty. In addition, participants will not be able to undergo any new intervention during the trial. This restriction aims to guarantee data integrity and prevent external interference that could affect the results. Excluding these concomitant interventions seeks to maintain sample homogeneity and prevent external factors from interfering in the assessment of the effects of TENS on acute postoperative breast augmentation pain intensity. Provisions for post-trial care {30} Participants will receive a single TENS intervention and a document with the care protocol to be considered. They will have access to the researchers’ telephone numbers and the department responsible for the study. Normally, therapy does not pose serious risks to participants. However, in case of harm occurring in the study, the principal researcher will provide comprehensive and immediate assistance free of charge, for the time needed. These measures aim to ensure the safety, well-being and ethical responsibility of the researchers involved. Outcomes {12} The primary outcome will be pain intensity, assessed by the Numerical Pain Scale (NPS) at three different times: before and immediately after TENS treatment and during 90-degree shoulder flexion, The secondary outcomes include pain intensity one hour after TENS treatment, both at rest and during movement; respiratory muscle strength, measured by maximum inspiratory (MIP) and expiratory pressure (MEP), before surgery before TENS treatment, immediately after training and one hour after treatment; satisfaction with the intervention, obtained from the answers "yes" or "no" of participants after TENS treatment; and analgesic use in the first 4 hours after surgery, in order to assess the effectiveness of treatment in reducing the need for analgesics. Pain intensity – Numerical pain scale (NPS) Pain intensity will be assessed before, immediately after and 1 hour after TENS intervention. The Numerical Pain Scale (NPS) is a unidimensional self-reported instrument that measures pain intensity on a scale from 0 to 10. On this scale, zero corresponds to no pain and ten the worst pain imaginable. The NPS is valid and reliable in measuring acute (52–55) and postoperative pain (56). A 1-point decrease in pain intensity after intervention is considered clinically important (57). Respiratory muscle strength RMS) – Analog manometer Participants will be assessed for respiratory muscle strength (maximum inspiratory (MIP) and expiratory pressure (MEP)) before surgery and before, immediately after and 1 hour after TENS intervention. MIP and MEP will be measured using an analog manometer (AM) with an operating range of 300 cmH2O. Participants will be instructed to remain seated with their arms relaxed and knees bent at 90 degrees. Mouthpieces and nose clips will be used to prevent air from escaping during measurements (58). To measure MIP, participants will be instructed to perform maximum expiration up to residual volume (RV) and then maximum inspiration for approximately one second. In order to measure MIP, the rater will block the exhalation orifice of the manometer. To measure MEP, participants will perform maximum inspiration up to total lung capacity (TLC), followed by maximum expiration, also for approximately one second. The rater will also block the exhalation orifice of the manometer to measure MEP. During the procedure, the rater will encourage participants to exert maximum effort. At least three technically suitable maneuvers will be performed, each maintained for at least one second. The highest value that does not exceed the second highest value by 10% will be considered for data analysis. The values measured will be interpreted according to the reference values described by Costa et al. (59) to analyze respiratory muscle strength. Satisfaction with the intervention After TENS intervention, participants will be asked to express their satisfaction with the treatment, using answer options “yes” or “no” (36). In the present study, answers such as “a little”, “more or less” or “I don´t know” will be excluded, in order to obtain a clear response on participant satisfaction. This will result in objective assessment of participant perception of the TENS intervention. Participant timeline {13} Participants will be randomly allocated to two groups (active TENS and placebo TENS) at a 1:1 ratio on the www.randomization.com site. Randomization will be concealed using sequentially numbered envelopes that will be securely guarded. The researcher overseeing TENS application will open the envelopes only at the time of intervention in order to identify the group of each participant. An overview of these procedures is presented in Fig. 2. Sample size {14} Sample size was calculated based on acute postoperative pain intensity, using a clinically important minimum difference of 1 point on the Visual Analog Scale (VAS) (57). The estimated standard deviation was 1.14 (66). Statistical power of 80% was considered with a 5% significance level and possible sample loss of 15%. Based on these parameters, sample size was calculated using Minitab software, version 17 (Minitab, Inc., PA), indicating a total of 52 participants (26 in each group) for the study. This sample size exhibits a suitable statistical capacity to detect possible differences between treatment groups, thereby ensuring the reliability and clinical relevance of the results obtained. Recruitment {15} The plastic surgeon, who will also oversee recruitment, will enroll study patients that opted for breast augmentation. The surgeon will widely disseminate the surgical technique on his social networks, highlighting the advantages of breast augmentation using the R24R protocol in order to attract more patients interested in the surgery. Next, in the postoperative period, patients will be invited to participate in the study. They will be carefully screened to meet the study criteria, receive detailed information, and give written informed consent before inclusion. These strategies will guarantee a suitable number of participants and the scientific relevance of the study. Assignment of interventions: allocation Sequence generation {16a} Participants will be randomized using randomization.com. The site will generate a random sequence that will determine the allocation of each participant in one of the two study groups: active TENS (who will receive TENS) or placebo TENS placebo (who will receive a placebo). Randomization will use the permuted blocks method, with 9 blocks containing 6 participants each, totaling 54 in the study. This ensures that each participant will have the same chance of being selected for either of the groups, thereby reducing any allocation bias. The researcher overseeing randomization will play no other role in the study, guaranteeing impartiality. Concealment mechanism {16b} After the site (http://randomization.com) generates a numerical sequence for random allocation, the study will use the concealment method via sequentially numbered sealed opaque envelopes. These envelopes will contain random participant allocation to the study groups (active TENS and placebo TENS) and be safeguarded in a locker with access restricted to the researcher in charge of randomization. Thus, the researcher will have no prior knowledge of patient allocation, ensuring concealment of the allocation sequence. The researcher accredited to apply TENS will open the envelopes only at the time of intervention to identify participants and the group to which they belong. Implementation {16c} This study will involve five researchers, each with specific independent functions. Researcher R1 will be responsible for participant recruitment and inscription, while R2 will oversee randomization and random allocation using http://randomization.com. Researcher R3 will apply the interventions (TENS and Placebo), and R4 will conduct all assessment including numerical pain scale (NPS), respiratory muscle strength (RMS), skin sensitivity threshold (SST), satisfaction with the intervention (SI) and analgesic use after treatment. Finally, researcher R5 will analyze and record the data obtained throughout the study. This division of responsibilities aims to guarantee impartiality and contribute to the validity and reliability of the results. Assignment of interventions: Blinding Who will be blinded {17a} In the present study, double blinding will be adopted, where both participants and the researcher in charge of assessments will be blind to the randomization and intervention processes. This means that they will have no prior knowledge about which intervention (active TENS or placebo TENS) was attributed to each participant. During assessments, the rater will be instructed to not seek information on the feelings experienced by the participants during TENS application, thereby preserving blinding. In the placebo TENS group, application will be simulated to blind participants, without administering real analgesia. This approach was previously validated and will be used to reduce expectation bias (50,51). The researcher in charge of the treatment will not be blind, due to the nature of the interventions, but suitable measures will be taken to guarantee blind outcome assessment, thereby increasing the reliability of the study results. Procedure for unblinding if needed {17b} Unblinding during the trial will be limited to specific situations, such as medical emergencies. Only one designated researcher will reveal the intervention attributed to the participants who need this information for medical or safety reasons. The researcher overseeing assessments will not be allowed to unblind participants, and only the researcher responsible for the intervention will have knowledge of treatment specifications. Data collection and management Plans for assessment and collection of outcomes {18a} In the study, the data collection methods will include baseline assessments and result collection at different times: before surgery and before, immediately after and one and four hours after TENS treatment, as established by the protocol. In order to guarantee data quality, duplicate measures and assessment training will be used to ensure the accuracy and consistency of the information obtained. The data collection instruments used are known for their reliability and validity. Information on the data collection instruments will be available in the study protocol, describing their reliability and validity, in addition to guidelines for the correct application of assessments. This approach will ensure data collection consistency, allowing a reliable and accurate analysis of the results. Plans to promote participant retention and complete follow-up {18b} In order to retain participants and ensure complete follow-up in the study, after written informed consent is given, specific plans and strategies will be used, including clear communication and guidance from the start, establishing a positive bond, providing incentives and recognition, active in-person follow-up, flexibility and understanding participant needs. These approaches aim to obtain more comprehensive and reliable results, allowing accurate data interpretation. If there are withdrawals, the reasons will be listed, and analysis will be conducted using the intention-to-treat principle, considering the most recent data available. Data management {19} Data management will follow detailed plans for entry, coding, security, and storage. Double entry and range checks will be used to guarantee data quality. Data will be collected weekly, saved in Excel, stored on the Google Drive of the Federal University of São Carlos (UFSCar), and managed by the researcher (R5). Access will be restricted to the researchers and registered participants, with password-protected confidential data. Data will be accurately collected and recorded by the qualified team, and coded to ensure privacy and protection against unauthorized access. Confidentiality {27} Personal information will be collected and stored confidentially on the institutional Google Drive of the Federal University of São Carlos (UFSCar). Only authorized researchers will have access to the data. Participants’ identity will be protected by codes or identification numbers. The data will be shared as a whole, thereby preserving anonymity. Participants will be informed about the confidentiality and will be able to withdraw their consent at any time. Protecting confidentiality is a priority of the research. Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33} Plans for collection, laboratory evaluation and biological specimens for genetic or molecular analysis are not applicable to this study. Statistical methods Statistical methods for primary and secondary outcomes {20a} Statistical analysis will be conducted by a researcher (R5) blinded to randomization and assessment, guaranteeing impartial results. The intention-to-treat approach will be used to analyze the participants in the groups to which they were initially allocated, irrespective of completing or not the study. Histograms will be used to determine data distribution and assess normality. Next, a mixed linear model will be applied to repeated measures, using compound symmetry in the type of repeated covariance, considering the interaction between the factors time (before and after interventions) and group (active TENS vs. placebo TENS). The Bonferroni correction with 95% CI will control type I error. Intergroup comparisons will be presented with mean, standard deviation, difference between means, 95% CI and effect size calculated using Cohen’s d. Effect size interpretation will follow Cohen’s criteria, where values less than 0.2 indicate a small effect, 0.5 moderate, 0.8 superior and 0.8 a large effect. The significance level established for all tests will be 0.05, ensuring the statistical robustness of the conclusions. Statistical analyses will be conducted using IBM® SPSS® Statistics for Windows software, version 20.0, in line with the standard methodology, guaranteeing the accuracy and reliability of the results obtained. Interim analyses {21b} Interim analyses will not be conducted. The protocol explicitly determines that no provisional analysis will be carried out. If any discontinuity occurs during the trial, the intention-to-treat principle will be adopted to deal with the missing data. Methods for additional analyses (e.g., subgroup analyses) {20b} In the present study, subgroups will not be analyzed. Statistical analysis will concentrate only on the overall results of the participants as a whole, without considering differences or subdivisions by specific participant traits. Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c} The intention-to-treat principle will be used to analyze non-adherence to the protocol and missing data. All the participants will be analyzed in the groups to which they were originally allocated, regardless of completing the study or not. In case of discontinuity, the missing data will be analyzed according to this principle in order to make statistical inferences. This will ensure the validity and reliability of the results obtained. Statistical methods, such as data imputation and specific models, will be applied to analyze missing information. Plans to give access to the full protocol, participant level-data and statistical code {31c} There are no plans to give public access to the full protocol, participant-level data, and the statistical code in this research. Oversight and monitoring Composition of the coordinating center and trial steering committee {5d} Not applicable in this study. Composition of the data monitoring committee, its role and reporting structure {21a} The Data Monitoring Committee is an independent impartial entity responsible for organizing the study data. The data will be managed by researcher R5, which will include informed consent information, participants’ clinical traits, pain scales, respiratory muscle strength, skin sensitivity threshold and satisfaction with the intervention. In order to guarantee quality, detailed plans for data entry, coding, security and storage will be implemented. We will use double data entry and range checks to ensure accurate and reliable information. Adverse event reporting and harms {22} The study will follow a rigorous system to notify and manage adverse events and intervention-related harm. All the events will be recorded on notification charts, including detailed information on their occurrence, severity, and relationship with the intervention. The research team will be trained to identify and record these events, and participants will be informed on how to report any discomfort during the study. If any treatment-related harm or complication occurs, appropriate measures will be taken to ensure participant safety. All the information will be documented and reported to the UFSCar Human Research Ethics Committee and the regulatory authorities, following the applicable legal and ethical guidelines. Frequency and plans for auditing trial conduct {23} In the present study, trial conduct will not be audited since it is not applicable to the specific circumstances of the study. Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25} This study protocol was approved by the UFSCar Human Research Ethics Committee and registered on the Brazilian Clinical Trial Registry (ReBEC) - RBR-96h3k97. Any important changes in the protocol, such as eligibility criteria, results, or analyses, were described and submitted to the appropriate centers, the university ethics committee and ReBEC, according to SPIRIT guidelines. The relevant parties will be notified of any changes, including investigators, institutional review boards, research ethics committees, and trial regulators, guaranteeing study transparency and integrity. Dissemination plans {31a} The results of this study will be published in peer-reviewed scientific journals, with access for the academic community and general public. Metadata will be deposited at the UFSCar Institutional Repository (RI-UFSCar) for public access. The results will be disseminated by the public relations department of the university, aimed at reaching a wider public. The results will be shared at zenodo.org, thereby ensuring international access to Ciência Aberta (Open Science). Participants who wish to receive the results will be sent a lay summary. Discussion The present study aimed to investigate the effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative breast augmentation pain in patients submitted to the 24-hour rapid recovery protocol (R24R). Breast augmentation is the most frequently performed plastic surgery worldwide, with 1,601,713 surgeries in 2020, 172,485 of which occurred in Brazil ( 1 ). Controlling postoperative pain is essential for successful patient recovery, but the use of analgesics may cause undesirable side effects and prolong hospital stays ( 2 , 3 ). However, persistent pain is still a concern ( 6 , 23 , 25 ). TENS is a non-pharmacological option to control postoperative pain, with studies demonstrating its effectiveness in different surgical procedures ( 32 , 36 , 37 ). In addition, there are no specific studies on its use in breast augmentation. Thus, the present study aims to bridge this gap in the literature and provide evidence on the effectiveness of TENS as complementary therapy in pain management after breast augmentation. The information resulting from this study can potentially contribute to scientific and technological advancement in the treatment of postoperative pain, promoting better clinical practices and acceptance of TENS as an additional therapeutic approach in breast surgery. This study has some limitations. The randomized clinical trial design may be subject to bias because it precludes blinding the researcher in charge of the intervention, due to the nature of the interventions. In order to minimize possible bias, the researcher will follow a script to standardize the treatments of all the study groups. Another limitation is that the study will be conducted in a single center, which may limit the representativeness of the results for other institutions or patients. As such, generalizing the findings for other clinical configurations should be done with caution. Additionally, patient follow-up duration will be 24 hours after surgery. Although this period makes it possible to assess acute postoperative pain, information on long-term pain will not be obtained. Despite these limitations, the study will provide important information on the use of TENS after breast augmentation surgery applying the R24R protocol, thereby contributing to the advancement of scientific knowledge in this area and paving the way for future research and improving non-pharmacological complementary therapy to control breast surgery pain. Trial status The protocol with registration number RBR-96h3k97, Version 1, was approved on 01/02/2024. Initial recruitment will be on 01/02/2024, and the approximate conclusion of recruitment will be on. 01/10/2024. Abbreviations TENS – Transcutaneous Electrical Nerve Stimulation NPS – Numerical Pain Scale SBCP – Brazilian Society of Plastic Surgery MIP – Maximum Inspiratory Pressure MEP – Maximum Expiratory Pressure SST – Skin Sensitivity Threshold 95% CI – 95% Confidence Interval RMS – Respiratory Muscle Strength RCT – Randomized Clinical Trial VAS – Visual Analog Scale RV – Residual Volume TLC – Total Lung Capacity AM – Analog Manovacuometer Cohen’s d – Cohen´s d coefficient SI – Satisfaction with the intervention UFSCar – Federal University of São Carlos ReBEC – Brazilian Registry of Clinical Trials Declarations Authors’ contributions {31b} The authors contributed to the manuscript as follows: REL is the Principal Investigator, conceived the study, and devised the proposal and protocol. KCS contributed to the study conception, development of the proposal and study conduction. MAAV, AFM and GICN contributed to creating and revising the protocol. All the authors read and approved the final manuscript. Each author made substantial contributions to the conception, data collection or revision of the study. Funding {4} Not applicable. Availability of data and materials {29} The datasets used and/or analyzed will be available from the corresponding author upon reasonable request after the study is complete. Ethics approval and consent to participate {24} The authors declare that they obtained approval from the UFSCar Research Ethics Committee, under protocol number CAAE CAAE 70021023.0.0000.5504. Volunteers interested in participating in the research will be asked to give their informed consent before taking part in the study. Consent for publication {32} Not applicable. Competing interests {28} The authors declare that there are no competing interests. References ISAPS [Internet]. [citado 6 de dezembro de 2022]. Plastic Surgery Statistics | Global Plastic Surgery Statistics. 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Contin Educ Anaesth Crit Care Pain. 1 o de agosto de 2009;9(4):130–5. Liebano RE, Rakel B, Vance CGT, Walsh DM, Sluka KA. An investigation of the development of analgesic tolerance to TENS in humans. PAIN®. 1 o de fevereiro de 2011;152(2):335–42. Sabino GS, Santos CMF, Francischi JN, de Resende MA. Release of Endogenous Opioids Following Transcutaneous Electric Nerve Stimulation in an Experimental Model of Acute Inflammatory Pain. J Pain. 1 o de fevereiro de 2008;9(2):157–63. Sluka KA, Deacon M, Stibal A, Strissel S, Terpstra A. Spinal Blockade of Opioid Receptors Prevents the Analgesia Produced by TENS in Arthritic Rats. J Pharmacol Exp Ther. 1 o de maio de 1999;289(2):840–6. Ao L, Shi J, Bai Y, Zhang S, Gan J. Effects of transcutaneous electrical acupoint stimulation on perioperative immune function and postoperative analgesia in patients undergoing radical mastectomy: A randomized controlled trial. Exp Ther Med. 1 o de março de 2021;21(3):1–1. Fiorelli A, Morgillo F, Milione R, Pace MC, Passavanti MB, Laperuta P, et al. Control of post-thoracotomy pain by transcutaneous electrical nerve stimulation: effect on serum cytokine levels, visual analogue scale, pulmonary function and medication†. Eur J Cardiothorac Surg. 1 o de abril de 2012;41(4):861–8. Erden S, Senol Celik S. The effect of transcutaneous electrical nerve stimulation on post-thoracotomy pain. Contemp Nurse. 2 de novembro de 2015;51(2–3):163–70. Parseliunas A, Paskauskas S, Kubiliute E, Vaitekunas J, Venskutonis D. Transcutaneous Electric Nerve Stimulation Reduces Acute Postoperative Pain and Analgesic Use After Open Inguinal Hernia Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial. J Pain. 1 o de maio de 2021;22(5):533–44. da Silva MP, Liebano RE, Rodrigues VA, Abla LEF, Ferreira LM. Transcutaneous Electrical Nerve Stimulation for Pain Relief After Liposuction: A Randomized Controlled Trial. Aesthetic Plast Surg. 1 o de abril de 2015;39(2):262–9. Erden S, Yurtseven Ş, Demir SG, Arslan S, Arslan UE, Dalcı K. Effects of Transcutaneous Electrical Nerve Stimulation on Mastectomy Pain, Patient Satisfaction, and Patient Outcomes. J Perianesthesia Nurs Off J Am Soc PeriAnesthesia Nurses. 15 de março de 2022;S1089-9472(21)00352-X. Elboim-Gabyzon M, Andrawus Najjar S, Shtarker H. Effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative pain intensity and mobility after hip fracture: A double-blinded, randomized trial. Clin Interv Aging. 2019;14:1841–50. Ilfeld BM, Plunkett A, Vijjeswarapu AM, Hackworth R, Dhanjal S, Turan A, et al. Percutaneous Peripheral Nerve Stimulation (Neuromodulation) for Postoperative Pain: A Randomized, Sham-controlled Pilot Study. Anesthesiology. 1 o de julho de 2021;135(1):95–110. Zhu Y, Feng Y, Peng L. Effect of transcutaneous electrical nerve stimulation for pain control after total knee arthroplasty: A systematic review and meta-analysis. J Rehabil Med. 21 de novembro de 2017;49(9):700–4. Jahangirifard A, Razavi M, Ahmadi ZH, Forozeshfard M. Effect of TENS on Postoperative Pain and Pulmonary Function in Patients Undergoing Coronary Artery Bypass Surgery. Pain Manag Nurs. 1 o de agosto de 2018;19(4):408–14. CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials | The BMJ [Internet]. [citado 30 de junho de 2022]. Available from: https://www.bmj.com/content/340/bmj.c332 Bjordal JM, Johnson MI, Ljunggreen AE. Transcutaneous electrical nerve stimulation (TENS) can reduce postoperative analgesic consumption. A meta-analysis with assessment of optimal treatment parameters for postoperative pain. Eur J Pain. 1 o de abril de 2003;7(2):181–8. Dailey DL, Rakel BA, Vance CGT, Liebano RE, Amrit AS, Bush HM, et al. Transcutaneous electrical nerve stimulation reduces pain, fatigue and hyperalgesia while restoring central inhibition in primary fibromyalgia. Pain. novembro de 2013;154(11):2554–62. DeSantana JM, Sluka KA, Lauretti GR. High and Low Frequency TENS Reduce Postoperative Pain Intensity After Laparoscopic Tubal Ligation: A Randomized Controlled Trial. Clin J Pain. janeiro de 2009;25(1):12–9. Moran F, Leonard T, Hawthorne S, Hughes CM, McCrum-Gardner E, Johnson MI, et al. Hypoalgesia in response to transcutaneous electrical nerve stimulation (TENS) depends on stimulation intensity. J Pain. agosto de 2011;12(8):929–35. Telles JD, Schiavon MAG, Costa AC de S, Rampazo ÉP, Liebano RE. Hypoalgesic Effects of Transcutaneous Electrical Nerve Stimulation Combined With Joint Manipulation: A Randomized Clinical Trial. J Manipulative Physiol Ther. março de 2021;44(3):244–54. Whitman PA, Adigun OO. Anatomy, Skin, Dermatomes. Em: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited on January 3, 2023]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK535401/ Liebano RE, Vance CG, Rakel BA, Lee JE, Cooper NA, Marchand S, et al. Transcutaneous electrical nerve stimulation and conditioned pain modulation influence the perception of pain in humans. Eur J Pain Lond Engl. novembro de 2013;17(10):1539–46. Liebano RE, Rakel B, Vance CGT, Walsh DM, Sluka KA. An investigation of the development of analgesic tolerance to TENS in humans. Pain. fevereiro de 2011;152(2):335–42. Rakel B, Cooper N, Adams HJ, Messer BR, Frey Law LA, Dannen DR, et al. A new transient sham TENS device allows for investigator blinding while delivering a true placebo treatment. J Pain. março de 2010;11(3):230–8. Chibnall JT, Tait RC. Pain assessment in cognitively impaired and unimpaired older adults: a comparison of four scales. Pain. 1 o de maio de 2001;92(1):173–86. Downie WW, Leatham PA, Rhind VM, Wright V, Branco JA, Anderson JA. Studies with pain rating scales. Ann Rheum Dis. 1 o de agosto de 1978;37(4):378–81. Ferreira-Valente MA, Pais-Ribeiro JL, Jensen MP. Validity of four pain intensity rating scales. Pain. outubro de 2011;152(10):2399–404. Paice JA, Cohen FL. Validity of a verbally administered numeric rating scale to measure cancer pain intensity. Cancer Nurs. abril de 1997;20(2):88–93. Seymour RA. The use of pain scales in assessing the efficacy of analgesics in post-operative dental pain. Eur J Clin Pharmacol. 1 o de setembro de 1982;23(5):441–4. Myles PS, Myles DB, Galagher W, Boyd D, Chew C, MacDonald N, et al. Measuring acute postoperative pain using the visual analog scale: the minimal clinically important difference and patient acceptable symptom state. Br J Anaesth. 1 o de março de 2017;118(3):424–9. Galli TT, Chiavegato LD, Santiago NR, Liebano RE. Effects of transcutaneous electrical nerve stimulation on pain, walking function, respiratory muscle strength and vital capacity in kidney donors: a protocol of a randomized controlled trial. BMC Nephrol. 11 de janeiro de 2013;14:7. Costa D, Gonçalves HA, Lima LP de, Ike D, Cancelliero KM, Montebelo MI de L. Novos valores de referência para pressões respiratórias máximas na população brasileira. J Bras Pneumol. junho de 2010;36:306–12. Borges MR, de Oliveira NML, Antonelli IBS, Silva MB, Crema E, Fernandes LFRM. Transcutaneous electrical nerve stimulation is superior than placebo and control for postoperative pain relief. Pain Manag. julho de 2020;10(4):235–46. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Major revision 22 Apr, 2024 Reviewers agreed at journal 20 Mar, 2024 Reviewers invited by journal 20 Mar, 2024 Editor assigned by journal 15 Mar, 2024 First submitted to journal 04 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3946854","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":281738615,"identity":"d357fbc0-2e11-49e9-aa37-d0609b1ce24a","order_by":0,"name":"Kamylla Caroline Santos","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0001-6522-9058","institution":"Universidade Federal de São Carlos: Universidade Federal de Sao Carlos","correspondingAuthor":true,"prefix":"","firstName":"Kamylla","middleName":"Caroline","lastName":"Santos","suffix":""},{"id":281738616,"identity":"9c9fd506-7428-4b1b-9997-e4568e6a1b8d","order_by":1,"name":"Mariana Arias Avila","email":"","orcid":"","institution":"Universidade Federal de São Carlos: Universidade Federal de Sao Carlos","correspondingAuthor":false,"prefix":"","firstName":"Mariana","middleName":"Arias","lastName":"Avila","suffix":""},{"id":281738617,"identity":"f57c7ed7-f291-4392-9307-cc75846967c6","order_by":2,"name":"Gilberto Inacio Cardoso Neto","email":"","orcid":"","institution":"Universidade Federal de Goias - Campus Colemar Natal e Silva: Universidade Federal de Goias","correspondingAuthor":false,"prefix":"","firstName":"Gilberto","middleName":"Inacio Cardoso","lastName":"Neto","suffix":""},{"id":281738618,"identity":"db409338-448e-4eef-a755-9961ff50ad54","order_by":3,"name":"Alexandre Fabricio Martucci","email":"","orcid":"","institution":"Universidade Federal de Jataí: Universidade Federal de Jatai","correspondingAuthor":false,"prefix":"","firstName":"Alexandre","middleName":"Fabricio","lastName":"Martucci","suffix":""},{"id":281738619,"identity":"82bab237-23f5-4f47-953e-b345b32cbf5a","order_by":4,"name":"Richard Eloin Liebano","email":"","orcid":"https://orcid.org/0000-0003-4795-6723","institution":"University of Hartford","correspondingAuthor":false,"prefix":"","firstName":"Richard","middleName":"Eloin","lastName":"Liebano","suffix":""}],"badges":[],"createdAt":"2024-02-10 21:50:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3946854/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3946854/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53255087,"identity":"cf86cf33-e5dd-4ab6-bd65-bc4ca4fbe409","added_by":"auto","created_at":"2024-03-22 13:25:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":644922,"visible":true,"origin":"","legend":"\u003cp\u003eElectrode\u003cstrong\u003e \u003c/strong\u003eposition on breast dermatomes\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSource: \u003c/strong\u003ethe researcher\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3946854/v1/a2e5ff7279e04eed848368ef.png"},{"id":53255088,"identity":"7ef4c68b-a54a-4435-ba41-2a84e78bd983","added_by":"auto","created_at":"2024-03-22 13:25:20","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":63354,"visible":true,"origin":"","legend":"\u003cp\u003eChronogram of enrollments, interventions, and assessments.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3946854/v1/4ac48efe234a5db537b05de8.png"},{"id":53256291,"identity":"84258280-6928-4f73-831a-da83fdc7a6de","added_by":"auto","created_at":"2024-03-22 13:33:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1445601,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3946854/v1/5207750d-3ba6-4424-be3d-0d8aa8a0b939.pdf"}],"financialInterests":"","formattedTitle":"Effects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol.","fulltext":[{"header":"Administrative information","content":"\u003cp\u003e*\u0026nbsp;Note: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the items has been modified to combine similar items.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"630\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eTitle {1}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eEffects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eTrial registration {2a and 2b}.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eThis study will be registered in the Brazilian Clinical Trials Registry (ReBEC).\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eProtocol version {3}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eVersion 1 from 01-02-2024.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eFunding {4}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eThis study will be completely funded by the researchers themselves.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eAuthor details {5a}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eKamylla Caroline Santos\u003csup\u003ea\u003c/sup\u003e, Mariana Arias Avila\u003csup\u003eb\u003c/sup\u003e, Gilberto Inacio Cardoso Neto\u003csup\u003ec\u003c/sup\u003e, Alexandre Fabricio Martucci\u003csup\u003ed\u003c/sup\u003e, Richard Eloin Liebano\u003csup\u003ee,f\u003c/sup\u003e*\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ea\u0026nbsp;\u003c/sup\u003eDepartamento de Fisioterapia, Universidade Federal de S\u0026atilde;o Carlos (UFSCar), Rodovia Washington Luis, km 235, S\u0026atilde;o Carlos, S\u0026atilde;o Paulo, Brasil, CEP 13565-905. E-mail: [email protected]\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003csup\u003eb\u0026nbsp;\u003c/sup\u003eDepartamento de Fisioterapia, Universidade Federal de S\u0026atilde;o Carlos (UFSCar), Rodovia Washington Luis, km 235, S\u0026atilde;o Carlos, S\u0026atilde;o Paulo, Brasil, CEP 13565-905. E-mail: [email protected]\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ec\u0026nbsp;\u003c/sup\u003eDepartamento de Medicina, Universidade Federal de Goi\u0026aacute;s (UFG), Avenida Esperan\u0026ccedil;a, s/n - Ch\u0026aacute;caras de Recreio Samambaia, Goi\u0026acirc;nia, Goi\u0026aacute;s, Brasil, CEP 74690-900. E-mail: [email protected]\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ed\u0026nbsp;\u003c/sup\u003eDepartamento de Medicina, Universidade Federal de Jatai (UFJ), Rodovia BR 364, KM 195. Setor Parque Industrial, n\u0026ordm; 3800, Jata\u0026iacute;, Goi\u0026aacute;s, CEP 75801-615. E-mail: [email protected]\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ee\u0026nbsp;\u003c/sup\u003eDepartamento de Fisioterapia, Universidade Federal de S\u0026atilde;o Carlos (UFSCar), Rodovia Washington Luis, km 235, S\u0026atilde;o Carlos, S\u0026atilde;o Paulo, Brasil, CEP 13565-905.\u0026nbsp;E-mail: [email protected]. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ef\u0026nbsp;\u003c/sup\u003eDepartment of Rehabilitation Sciences, University of Hartford, 200 Bloomfield Avenue, West Hartford, CT 06117. E-mail: [email protected]\u003c/p\u003e\n \u003cp\u003e*Corresponding author: Tel.: +1 860.768.5181. Department of Rehabilitation Sciences, University of Hartford.\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eName and contact information for the trial sponsor {5b}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eThis study has no sponsors\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"23.015873015873016%\" valign=\"top\"\u003e\n \u003cp\u003eRole of sponsor {5c}\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"76.98412698412699%\" valign=\"top\"\u003e\n \u003cp\u003eNot applicable\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Introduction","content":"\u003cp\u003e\u003cstrong\u003eBackground and rationale {6a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBreast augmentation is widely used in plastic surgery, with high prevalence in Brazil and the world (1). Thus, as in other surgeries, it is performed under anesthesia, and pain management generally involves drug treatment (2,3). However, these drugs may cause a series of adverse effects, such as vomiting, nausea, urinary retention and sedation, which could compromise postoperative recovery, prolong hospital stays and hinder physical exercises during hospitalization (4\u0026ndash;8).\u003c/p\u003e\n\u003cp\u003ePostoperative exercise is widely recognized as safe and beneficial, in breast augmentation and other surgeries (6,9\u0026ndash;11). Regular exercise contributes to reducing muscle atrophy, pulmonary complications and length of hospital stay, in addition to improving the functional capacity and quality of life of patients (12\u0026ndash;14). On the other hand, the lack of postoperative exercises is related to complications such as anxiety, depression, increased pain intensity, muscle contractions and adhesive capsulitis (15\u0026ndash;19).\u003c/p\u003e\n\u003cp\u003eSurgical techniques that allow patients to return early to work and physical exercises are preferred by young women submitted to breast augmentation (20\u0026ndash;22). In this respect, a breast augmentation protocol was developed to optimize surgeries, making them more efficient than previous procedures, favoring rapid patient recovery. This protocol proposes to reduce surgical trauma and intra postoperative drug therapy using refined techniques that recover up to 96% of patients in 24 hours, resulting in a return to normal life (23,24).\u003c/p\u003e\n\u003cp\u003eAlthough surgery involving the rapid 24-hour recovery (R24R) protocol is less traumatic than traditional methods, it is important to underscore that it also causes pain and requires suitable relief (6,23,25,26). Postoperative analgesia should be incorporated into the patient recovery process, aimed at comprehensive improvement that goes beyond reducing pain intensity, including decreasing drug use and their possible side effects (2,3). In this respect, implementing non-pharmacological analgesic interventions is recommended as part of the therapeutic plan (6).\u003c/p\u003e\n\u003cp\u003eOne non-pharmacological option widely recognized to control postoperative pain is Transcutaneous Electrical Nerve Stimulation (TENS). This technique involves applying electrical stimuli through surface electrodes that activate nerve fibers and modulate pain perception, stimulating opioid receptor activation in the central and peripheral nervous system (27\u0026ndash;31). TENS is considered a safe, accessible, and easy-to-use option (28,32,33), and can contribute to reducing hospital stays, relieving pain and allowing early mobilization via physical exercises in the immediate postoperative (26,34,35).\u003c/p\u003e\n\u003cp\u003ePrevious studies demonstrated the effectiveness of TENS in reducing pain intensity and analgesic consumption in different surgical procedures, such as lipoaspiration (36), mastectomy (32,37), orthopedic surgeries (38\u0026ndash;40), thoracotomy (33,34), inguinal herniorrhaphy (35) and myocardial revascularization (41). However, to date, no studies have investigated the analgesic effectiveness of TENS in postoperative breast augmentation. Our hypothesis is that TENS, used as a non-pharmacological therapy, can play an important role in reducing pain after breast augmentation performed using the rapid 24-hour recovery protocol (R24R).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjectives {7}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eHypothesis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe study hypothesis is that applying a single TENS session would significantly reduce acute postoperative breast augmentation pain intensity when compared to the placebo group.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePrimary objective\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe primary objective of the study is to assess pain intensity at rest before, immediately after TENS intervention and during 90-degree shoulder flexion.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eSecondary objective\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe secondary objectives include assessing pain intensity at rest and during movement one hour after TENS intervention, respiratory muscle strength, satisfaction with the intervention and analgesia use 4 hours after surgery.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial design {8}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis is a double-blind, placebo-controlled randomized clinical trial (RCT), where participants and raters are blind to the intervention applied. The study will be reported following Consolidated Standards of Trial Reporting (CONSORT) guidelines (42) and was developed based on Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT). Participants will be randomly allocated to two groups: active TENS and placebo TENS, at a 1:1 ratio. Intention-to-treat analysis will be adopted, thereby ensuring the inclusion of all participants of the original groups, regardless of their complete study adherence. Allocation concealment and participant and rater blinding reduce expectation bias and increase internal study validity. This methodology aims at ensuring the quality and reliability of the results obtained in assessing the effects of TENS on acute postoperative breast augmentation pain.\u003c/p\u003e"},{"header":"Methods: Participants, interventions, and outcomes","content":"\u003cp\u003e\u003cstrong\u003eStudy setting {9}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study will be conducted at the UNIMED hospital in Jata\u0026iacute;, Goi\u0026aacute;s state, Brazil. This location was selected because it provides ideal conditions to carry out the research, thereby guaranteeing the required ethical and quality standards. In addition, the infrastructure of the hospital is suitable for breast augmentation surgery and postoperative support, which will make it possible to obtain reliable and relevant results.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eEligibility criteria {10}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe eligibility criteria to participate in the study are established based on the specific characteristics of patients that seek breast augmentation surgery using the R24R technique at the private plastic surgery clinic of researcher 1 (described in item 16c), located in Jata\u0026iacute;, Goi\u0026aacute;s, Brazil. These eligibility criteria are important to ensure participant homogeneity and result validity, in addition to guaranteeing patient safety during the TENS intervention and postoperative period.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003eInclusion criteria:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eIncluded will be women aged between 18 and 65 years, submitted to breast augmentation surgery using the fast 24-hour recovery protocol (R24R) (24). Participants reporting significant pain intensity greater than or equal to 3 points on the Numerical Pain Scale (NPS) in the immediate postoperative will also be included.\u003c/p\u003e\n\u003cp\u003ePatients must be willing to be randomly allocated to one of the two study groups (active TENS or placebo TENS) and understand and accept the possible adverse effects related to the proposed treatments, which will be described on the informed consent form.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003eExclusion criteria:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eExcluded will be those with chronic pain, previous use of electric currents to relieve pain, illicit or psychotropic drug use, chronic opioid use, the presence of a pacemaker, neurological disorders that may interfere in their awareness level and inability to sustain shoulder elevation at 90 degrees.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho will take informed consent? {26a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent will be obtained by researcher 4, responsible for assessments, who will explain the research details to the participants. The informed consent form will be provided for reading and voluntary signing, guaranteeing that the participants are well informed about the procedures and that they may withdraw their consent at any time. Data collection will start after the informed consent form is signed.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdditional consent provisions for collection and use of participant data and biological specimens {26b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere is no participant or biological specimen data collection in this study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eInterventions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExplanation for the choice of comparators {6b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo literature studies were found that compared the analgesic effectiveness of TENS with a TENS placebo in postoperative breast augmentation. In addition, the placebo TENS comparator was selected to guarantee the internal validity and robustness of the results, providing more reliable evidence on the effectiveness of TENS as a complementary pain management therapy after breast augmentation, in addition to minimizing expectation bias and controlling the placebo effect.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIntervention description {11a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePreoperative\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eBefore surgery, participants will be submitted to individual sessions with a qualified physiotherapist, with 6 years\u0026rsquo; experience and trained to apply TENS and follow the breast rehabilitation protocol using the R24R technique. During these sessions, participants will be familiarized with the physiotherapy tests indicated and the exercises to be performed during the postoperative period.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003eAnesthetic procedure \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAll the surgeries will be performed under balanced general anesthesia, following a standardized protocol. The anesthetic plan will involve the administration of 5 to 10mg/kg of fentanyl associated with the use of propofol to induce anesthesia. During maintenance of anesthesia, 2 to 3 % sevoflurane will be used in a mixture of oxygen with a content greater than 40%. Sevoflurane level and oxygen concentration will be monitored by a gas analyzer. The neuromuscular blocker will only be used during anesthesia induction. Blood pressure will be controlled by adjusting sevoflurane, and if needed, a vasoactive agent can be administered. Average blood pressure will be monitored and maintained between 50 and 100 mmHg.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003eSurgical technique \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAll the breast augmentation surgeries will be performed by the same plastic surgeon accredited by the Brazilian Society of Plastic Surgery (SBCP), and a multidisciplinary team. The surgeon will be responsible for developing the surgical plan, which includes informing the patient, choice of instrumentation, dissection technique, type of incision and implant size, during the preoperative period. The surgery will follow the specifications of the rapid recovery technique described by Tebbettes (23,24), aimed at maximizing surgical efficiency and reducing surgery time, drug dose and tissue trauma.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003ePostoperative \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAfter surgery, all participants will receive an analgesic drug, including 1g of dipyrone every 6 hours and 100mg of ketoprofen every 12 hours, both administered intravenously. These drugs aim to relieve immediate postoperative breast augmentation pain.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003eRescue analgesia \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eA solution of 100mg of tramadol will be prescribed (every 8 hours during the 24-hour hospital stay) as an additional pain control option, if needed, in addition to previously prescribed analgesics.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003e TENS application \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eOne hour after surgery, active TENS group participants will receive a single 20-minute TENS application, applied using a TENS unit with the option of a placebo or active mode, developed specifically for the study (Neurodyn Portable TENS System, Ibramed, Amparo, S\u0026atilde;o Paulo, Brazil). TENS will consist of an asymmetrical biphasic pulsed current, at a frequency of 100Hz and pulse of 100\u0026mu;s. TENS intensity will be adjusted to promote strong, albeit comfortable, paresthesia, as described in previous studies (43\u0026ndash;47).\u003c/p\u003e\n\u003cp\u003eTENS will be applied with four self-adhesive electrodes measuring 7cm x 5cm (ValuTrode, Axelgaard, CA), two of which will be placed on breast dermatomes, two centimeters from the spinous processes adjacent to the second and third thoracic vertebra (T2 - T3), and two adjacent to the fourth and fifth thoracic vertebra (T4 - T5) (48) (Fig.1).\u003c/p\u003e\n\n\u003cp\u003eIn the placebo TENS group, the electrodes will be placed at the same sites, with the same application times and duration as the active TENS group, for 20 minutes. Participants will be informed that they may feel or not some sensation during the procedure (46). The device in the placebo TENS group will be turned on in the first 30 seconds and the stimuli will be reduced to 0 in the next 15 seconds (44,47,49). This approach was previously validated and will be used to blind the participants, thereby decreasing expectation bias, without providing analgesia (50,51).\u003c/p\u003e\n\u003cp\u003eThe specification of materials, equipment and techniques used, as well as the TENS and analgesic application period, ensures that all participants receive consistent and comparable treatments. Furthermore, adopting a standardized protocol for the anesthetic procedure and surgical technique contributed to reducing possible confounding variables that could interfere in the results. Describing the pre and postoperative procedures is also important to understanding the global approach of the study in assessing the effectiveness of TENS as a complementary therapy to control postoperative breast augmentation pain.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCriteria for discontinuing or modifying allocated interventions {11b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipants will have the right to interrupt treatment at any time and for any reason, without suffering any consequences. No allocation changes will be made, and no individuals will be allowed to transfer between groups during the study. Thus, initial randomization will be maintained, preserving the validity and integrity of the results. If a participant decides to interrupt treatment, the most recent data from the period in which the intervention was performed will be included in the analyses, following the intention-to-treat principle. The reason to withdraw will be registered for result interpretation purposes, since the information is important in understanding the challenges and limitations of the study, as well as assessing intervention acceptance and participant tolerability.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eStrategies to improve intervention adherence {11c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eResearcher 4 will use different strategies to minimize data loss due to low intervention adherence. Preoperative educational sessions will be held to provide detailed information on the proposed treatment and its benefits and resolve any participant doubts. During the postoperative period, the researcher will provide continuous support and encouragement for participants to follow the treatment protocol. In addition, the researcher will facilitate participant access to interventions, thereby guaranteeing that procedures are performed conveniently and comfortably, and be available to answer any questions or concerns throughout the study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRelevant concomitant care permitted or prohibited during the trial {11d}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDuring the study, concomitant care made it possible to include the use of analgesics, such as dipyrone and ketoprofen, administered intravenously to relieve postoperative pain. No concomitant surgeries will be allowed, such as lipoaspiration or abdominoplasty. In addition, participants will not be able to undergo any new intervention during the trial. This restriction aims to guarantee data integrity and prevent external interference that could affect the results. Excluding these concomitant interventions seeks to maintain sample homogeneity and prevent external factors from interfering in the assessment of the effects of TENS on acute postoperative breast augmentation pain intensity.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProvisions for post-trial care {30}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipants will receive a single TENS intervention and a document with the care protocol to be considered. They will have access to the researchers\u0026rsquo; telephone numbers and the department responsible for the study. Normally, therapy does not pose serious risks to participants. However, in case of harm occurring in the study, the principal researcher will provide comprehensive and immediate assistance free of charge, for the time needed. These measures aim to ensure the safety, well-being and ethical responsibility of the researchers involved.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eOutcomes {12}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary outcome will be pain intensity, assessed by the Numerical Pain Scale (NPS) at three different times: before and immediately after TENS treatment and during 90-degree shoulder flexion, The secondary outcomes include pain intensity one hour after TENS treatment, both at rest and during movement; respiratory muscle strength, measured by maximum inspiratory (MIP) and expiratory pressure (MEP), before surgery before TENS treatment, immediately after training and one hour after treatment; satisfaction with the intervention, obtained from the answers \u0026quot;yes\u0026quot; or \u0026quot;no\u0026quot; of participants after TENS treatment; and analgesic use in the first 4 hours after surgery, in order to assess the effectiveness of treatment in reducing the need for analgesics.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003ePain intensity \u0026ndash; Numerical pain scale (NPS)\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003ePain intensity will be assessed before, immediately after and 1 hour after TENS intervention. The Numerical Pain Scale (NPS) is a unidimensional self-reported instrument that measures pain intensity on a scale from 0 to 10. On this scale, zero corresponds to no pain and ten the worst pain imaginable. The NPS is valid and reliable in measuring acute (52\u0026ndash;55) and postoperative pain (56). A 1-point decrease in pain intensity after intervention is considered clinically important (57).\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003eRespiratory muscle strength RMS) \u0026ndash; Analog manometer \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eParticipants will be assessed for respiratory muscle strength (maximum inspiratory (MIP) and expiratory pressure (MEP)) before surgery and before, immediately after and 1 hour after TENS intervention. MIP and MEP will be measured using an analog manometer (AM) with an operating range of 300 cmH2O. Participants will be instructed to remain seated with their arms relaxed and knees bent at 90 degrees. Mouthpieces and nose clips will be used to prevent air from escaping during measurements (58).\u003c/p\u003e\n\u003cp\u003eTo measure MIP, participants will be instructed to perform maximum expiration up to residual volume (RV) and then maximum inspiration for approximately one second. In order to measure MIP, the rater will block the exhalation orifice of the manometer.\u003c/p\u003e\n\u003cp\u003eTo measure MEP, participants will perform maximum inspiration up to total lung capacity (TLC), followed by maximum expiration, also for approximately one second. The rater will also block the exhalation orifice of the manometer to measure MEP.\u003c/p\u003e\n\u003cp\u003eDuring the procedure, the rater will encourage participants to exert maximum effort. At least three technically suitable maneuvers will be performed, each maintained for at least one second. The highest value that does not exceed the second highest value by 10% will be considered for data analysis. The values measured will be interpreted according to the reference values described by Costa et al. (59) to analyze respiratory muscle strength.\u003c/p\u003e\n\n\u003cp\u003e\u003cem\u003e\u003csup\u003e \u003c/sup\u003eSatisfaction with the intervention \u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAfter TENS intervention, participants will be asked to express their satisfaction with the treatment, using answer options \u0026ldquo;yes\u0026rdquo; or \u0026ldquo;no\u0026rdquo; (36). In the present study, answers such as \u0026ldquo;a little\u0026rdquo;, \u0026ldquo;more or less\u0026rdquo; or \u0026ldquo;I don\u0026acute;t know\u0026rdquo; will be excluded, in order to obtain a clear response on participant satisfaction. This will result in objective assessment of participant perception of the TENS intervention.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eParticipant timeline {13}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipants will be randomly allocated to two groups (active TENS and placebo TENS) at a 1:1 ratio on the www.randomization.com site. Randomization will be concealed using sequentially numbered envelopes that will be securely guarded. The researcher overseeing TENS application will open the envelopes only at the time of intervention in order to identify the group of each participant. An overview of these procedures is presented in Fig. 2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample size {14}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSample size was calculated based on acute postoperative pain intensity, using a clinically important minimum difference of 1 point on the Visual Analog Scale (VAS) (57). The estimated standard deviation was 1.14 (66). Statistical power of 80% was considered with a 5% significance level and possible sample loss of 15%. Based on these parameters, sample size was calculated using Minitab software, version 17 (Minitab, Inc., PA), indicating a total of 52 participants (26 in each group) for the study. This sample size exhibits a suitable statistical capacity to detect possible differences between treatment groups, thereby ensuring the reliability and clinical relevance of the results obtained.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecruitment {15}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe plastic surgeon, who will also oversee recruitment, will enroll study patients that opted for breast augmentation. The surgeon will widely disseminate the surgical technique on his social networks, highlighting the advantages of breast augmentation using the R24R protocol in order to attract more patients interested in the surgery. Next, in the postoperative period, patients will be invited to participate in the study. They will be carefully screened to meet the study criteria, receive detailed information, and give written informed consent before inclusion. These strategies will guarantee a suitable number of participants and the scientific relevance of the study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAssignment of interventions: allocation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSequence generation {16a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipants will be randomized using randomization.com. The site will generate a random sequence that will determine the allocation of each participant in one of the two study groups: active TENS (who will receive TENS) or placebo TENS placebo (who will receive a placebo). Randomization will use the permuted blocks method, with 9 blocks containing 6 participants each, totaling 54 in the study. This ensures that each participant will have the same chance of being selected for either of the groups, thereby reducing any allocation bias. The researcher overseeing randomization will play no other role in the study, guaranteeing impartiality.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConcealment mechanism {16b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAfter the site (http://randomization.com) generates a numerical sequence for random allocation, the study will use the concealment method via sequentially numbered sealed opaque envelopes. These envelopes will contain random participant allocation to the study groups (active TENS and placebo TENS) and be safeguarded in a locker with access restricted to the researcher in charge of randomization. Thus, the researcher will have no prior knowledge of patient allocation, ensuring concealment of the allocation sequence. The researcher accredited to apply TENS will open the envelopes only at the time of intervention to identify participants and the group to which they belong.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eImplementation {16c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study will involve five researchers, each with specific independent functions. Researcher R1 will be responsible for participant recruitment and inscription, while R2 will oversee randomization and random allocation using http://randomization.com. Researcher R3 will apply the interventions (TENS and Placebo), and R4 will conduct all assessment including numerical pain scale (NPS), respiratory muscle strength (RMS), skin sensitivity threshold (SST), satisfaction with the intervention (SI) and analgesic use after treatment. Finally, researcher R5 will analyze and record the data obtained throughout the study. This division of responsibilities aims to guarantee impartiality and contribute to the validity and reliability of the results.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAssignment of interventions: Blinding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWho will be blinded {17a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the present study, double blinding will be adopted, where both participants and the researcher in charge of assessments will be blind to the randomization and intervention processes. This means that they will have no prior knowledge about which intervention (active TENS or placebo TENS) was attributed to each participant. \u003c/p\u003e\n\u003cp\u003eDuring assessments, the rater will be instructed to not seek information on the feelings experienced by the participants during TENS application, thereby preserving blinding. In the placebo TENS group, application will be simulated to blind participants, without administering real analgesia. This approach was previously validated and will be used to reduce expectation bias (50,51). The researcher in charge of the treatment will not be blind, due to the nature of the interventions, but suitable measures will be taken to guarantee blind outcome assessment, thereby increasing the reliability of the study results.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProcedure for unblinding if needed {17b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnblinding during the trial will be limited to specific situations, such as medical emergencies. Only one designated researcher will reveal the intervention attributed to the participants who need this information for medical or safety reasons. The researcher overseeing assessments will not be allowed to unblind participants, and only the researcher responsible for the intervention will have knowledge of treatment specifications.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eData collection and management\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlans for assessment and collection of outcomes {18a}\u003c/strong\u003e\u003c/p\u003e\n\n\u003cp\u003eIn the study, the data collection methods will include baseline assessments and result collection at different times: before surgery and before, immediately after and one and four hours after TENS treatment, as established by the protocol. In order to guarantee data quality, duplicate measures and assessment training will be used to ensure the accuracy and consistency of the information obtained. The data collection instruments used are known for their reliability and validity.\u003c/p\u003e\n\u003cp\u003eInformation on the data collection instruments will be available in the study protocol, describing their reliability and validity, in addition to guidelines for the correct application of assessments. This approach will ensure data collection consistency, allowing a reliable and accurate analysis of the results.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePlans to promote participant retention and complete follow-up {18b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn order to retain participants and ensure complete follow-up in the study, after written informed consent is given, specific plans and strategies will be used, including clear communication and guidance from the start, establishing a positive bond, providing incentives and recognition, active in-person follow-up, flexibility and understanding participant needs. These approaches aim to obtain more comprehensive and reliable results, allowing accurate data interpretation. If there are withdrawals, the reasons will be listed, and analysis will be conducted using the intention-to-treat principle, considering the most recent data available.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eData management {19}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData management will follow detailed plans for entry, coding, security, and storage. Double entry and range checks will be used to guarantee data quality. Data will be collected weekly, saved in Excel, stored on the Google Drive of the Federal University of S\u0026atilde;o Carlos (UFSCar), and managed by the researcher (R5). Access will be restricted to the researchers and registered participants, with password-protected confidential data. Data will be accurately collected and recorded by the qualified team, and coded to ensure privacy and protection against unauthorized access.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConfidentiality {27}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePersonal information will be collected and stored confidentially on the institutional Google Drive of the Federal University of S\u0026atilde;o Carlos (UFSCar). Only authorized researchers will have access to the data. Participants\u0026rsquo; identity will be protected by codes or identification numbers. The data will be shared as a whole, thereby preserving anonymity. Participants will be informed about the confidentiality and will be able to withdraw their consent at any time. Protecting confidentiality is a priority of the research.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePlans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePlans for collection, laboratory evaluation and biological specimens for genetic or molecular analysis are not applicable to this study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eStatistical methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical methods for primary and secondary outcomes {20a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analysis will be conducted by a researcher (R5) blinded to randomization and assessment, guaranteeing impartial results. The intention-to-treat approach will be used to analyze the participants in the groups to which they were initially allocated, irrespective of completing or not the study. Histograms will be used to determine data distribution and assess normality. Next, a mixed linear model will be applied to repeated measures, using compound symmetry in the type of repeated covariance, considering the interaction between the factors time (before and after interventions) and group (active TENS vs. placebo TENS). The Bonferroni correction with 95% CI will control type I error. Intergroup comparisons will be presented with mean, standard deviation, difference between means, 95% CI and effect size calculated using Cohen\u0026rsquo;s d. Effect size interpretation will follow Cohen\u0026rsquo;s criteria, where values less than 0.2 indicate a small effect, 0.5 moderate, 0.8 superior and 0.8 a large effect. The significance level established for all tests will be 0.05, ensuring the statistical robustness of the conclusions. Statistical analyses will be conducted using IBM\u0026reg; SPSS\u0026reg; Statistics for Windows software, version 20.0, in line with the standard methodology, guaranteeing the accuracy and reliability of the results obtained.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eInterim analyses {21b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInterim analyses will not be conducted. The protocol explicitly determines that no provisional analysis will be carried out. If any discontinuity occurs during the trial, the intention-to-treat principle will be adopted to deal with the missing data.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eMethods for additional analyses (e.g., subgroup analyses) {20b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the present study, subgroups will not be analyzed. Statistical analysis will concentrate only on the overall results of the participants as a whole, without considering differences or subdivisions by specific participant traits.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eMethods in analysis to handle protocol non-adherence and any statistical methods\u003c/strong\u003e \u003cstrong\u003eto handle missing data {20c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe intention-to-treat principle will be used to analyze non-adherence to the protocol and missing data. All the participants will be analyzed in the groups to which they were originally allocated, regardless of completing the study or not. In case of discontinuity, the missing data will be analyzed according to this principle in order to make statistical inferences. This will ensure the validity and reliability of the results obtained. Statistical methods, such as data imputation and specific models, will be applied to analyze missing information.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePlans to give access to the full protocol, participant level-data and statistical code {31c}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere are no plans to give public access to the full protocol, participant-level data, and the statistical code in this research.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eOversight and monitoring\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComposition of the coordinating center and trial steering committee {5d}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable in this study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eComposition of the data monitoring committee, its role and reporting structure {21a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Data Monitoring Committee is an independent impartial entity responsible for organizing the study data. The data will be managed by researcher R5, which will include informed consent information, participants\u0026rsquo; clinical traits, pain scales, respiratory muscle strength, skin sensitivity threshold and satisfaction with the intervention. In order to guarantee quality, detailed plans for data entry, coding, security and storage will be implemented. We will use double data entry and range checks to ensure accurate and reliable information.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdverse event reporting and harms {22}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study will follow a rigorous system to notify and manage adverse events and intervention-related harm. All the events will be recorded on notification charts, including detailed information on their occurrence, severity, and relationship with the intervention. The research team will be trained to identify and record these events, and participants will be informed on how to report any discomfort during the study. If any treatment-related harm or complication occurs, appropriate measures will be taken to ensure participant safety. All the information will be documented and reported to the UFSCar Human Research Ethics Committee and the regulatory authorities, following the applicable legal and ethical guidelines.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFrequency and plans for auditing trial conduct {23}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the present study, trial conduct will not be audited since it is not applicable to the specific circumstances of the study.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePlans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study protocol was approved by the UFSCar Human Research Ethics Committee and registered on the Brazilian Clinical Trial Registry (ReBEC) - RBR-96h3k97. Any important changes in the protocol, such as eligibility criteria, results, or analyses, were described and submitted to the appropriate centers, the university ethics committee and ReBEC, according to SPIRIT guidelines. The relevant parties will be notified of any changes, including investigators, institutional review boards, research ethics committees, and trial regulators, guaranteeing study transparency and integrity.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDissemination plans {31a}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe results of this study will be published in peer-reviewed scientific journals, with access for the academic community and general public. Metadata will be deposited at the UFSCar Institutional Repository (RI-UFSCar) for public access. The results will be disseminated by the public relations department of the university, aimed at reaching a wider public. The results will be shared at zenodo.org, thereby ensuring international access to Ci\u0026ecirc;ncia Aberta (Open Science). Participants who wish to receive the results will be sent a lay summary.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe present study aimed to investigate the effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative breast augmentation pain in patients submitted to the 24-hour rapid recovery protocol (R24R). Breast augmentation is the most frequently performed plastic surgery worldwide, with 1,601,713 surgeries in 2020, 172,485 of which occurred in Brazil (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Controlling postoperative pain is essential for successful patient recovery, but the use of analgesics may cause undesirable side effects and prolong hospital stays (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). However, persistent pain is still a concern (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). TENS is a non-pharmacological option to control postoperative pain, with studies demonstrating its effectiveness in different surgical procedures (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e). In addition, there are no specific studies on its use in breast augmentation. Thus, the present study aims to bridge this gap in the literature and provide evidence on the effectiveness of TENS as complementary therapy in pain management after breast augmentation. The information resulting from this study can potentially contribute to scientific and technological advancement in the treatment of postoperative pain, promoting better clinical practices and acceptance of TENS as an additional therapeutic approach in breast surgery.\u003c/p\u003e \u003cp\u003eThis study has some limitations. The randomized clinical trial design may be subject to bias because it precludes blinding the researcher in charge of the intervention, due to the nature of the interventions. In order to minimize possible bias, the researcher will follow a script to standardize the treatments of all the study groups. Another limitation is that the study will be conducted in a single center, which may limit the representativeness of the results for other institutions or patients. As such, generalizing the findings for other clinical configurations should be done with caution. Additionally, patient follow-up duration will be 24 hours after surgery. Although this period makes it possible to assess acute postoperative pain, information on long-term pain will not be obtained. Despite these limitations, the study will provide important information on the use of TENS after breast augmentation surgery applying the R24R protocol, thereby contributing to the advancement of scientific knowledge in this area and paving the way for future research and improving non-pharmacological complementary therapy to control breast surgery pain.\u003c/p\u003e\n\u003ch3\u003eTrial status\u003c/h3\u003e\n\u003cp\u003eThe protocol with registration number RBR-96h3k97, Version 1, was approved on 01/02/2024. Initial recruitment will be on 01/02/2024, and the approximate conclusion of recruitment will be on. 01/10/2024.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTENS \u0026ndash;\u003c/em\u003e\u003c/strong\u003e Transcutaneous Electrical Nerve Stimulation\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eNPS\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u0026ndash; Numerical Pain Scale\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSBCP\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u0026ndash; Brazilian Society of Plastic Surgery\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMIP\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Maximum Inspiratory Pressure\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eMEP\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Maximum Expiratory Pressure\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSST\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u0026ndash; Skin Sensitivity Threshold\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e95% CI\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u0026ndash; 95% Confidence Interval\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eRMS\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Respiratory Muscle Strength\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eRCT\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Randomized Clinical Trial\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eVAS\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Visual Analog Scale\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eRV \u0026ndash;\u003c/em\u003e\u003c/strong\u003e Residual Volume\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTLC\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Total Lung Capacity\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAM\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Analog Manovacuometer\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCohen\u0026rsquo;s d\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Cohen\u0026acute;s d coefficient\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSI\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Satisfaction with the intervention\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eUFSCar\u003c/em\u003e\u003c/strong\u003e \u0026ndash; Federal University of S\u0026atilde;o Carlos\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eReBEC\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u0026ndash; Brazilian Registry of Clinical Trials\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions {31b}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors contributed to the manuscript as follows: REL is the Principal Investigator, conceived the study, and devised the proposal and protocol. KCS contributed to the study conception, development of the proposal and study conduction. MAAV, AFM and GICN contributed to creating and revising the protocol. All the authors read and approved the final manuscript. Each author made substantial contributions to the conception, data collection or revision of the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding {4}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials {29}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed will be available from the corresponding author upon reasonable request after the study is complete.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate {24}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they obtained approval from the UFSCar Research Ethics Committee, under protocol number CAAE CAAE 70021023.0.0000.5504. Volunteers interested in participating in the research will be asked to give their informed consent before taking part in the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication {32}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests {28}\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that there are no competing interests.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eISAPS [Internet]. [citado 6 de dezembro de 2022]. Plastic Surgery Statistics | Global Plastic Surgery Statistics. Available from: https://www.isaps.org/medical-professionals/isaps-global-statistics/\u003c/li\u003e\n\u003cli\u003eBrat GA, Agniel D, Beam A, Yorkgitis B, Bicket M, Homer M, et al. Postsurgical prescriptions for opioid naive patients and association with overdose and misuse: retrospective cohort study. BMJ. 17 de janeiro de 2018;360:j5790. \u003c/li\u003e\n\u003cli\u003eMacintyre PE, Quinlan J, Levy N, Lobo DN. Current Issues in the Use of Opioids for the Management of Postoperative Pain: A Review. JAMA Surg. 1\u003csup\u003eo\u003c/sup\u003e de fevereiro de 2022;157(2):158\u0026ndash;66. \u003c/li\u003e\n\u003cli\u003eBrower RG. Consequences of bed rest. Crit Care Med. outubro de 2009;37(10):S422. \u003c/li\u003e\n\u003cli\u003eHenriksen MG, Jensen MB, Hansen HV, Jespersen TW, Hessov I. Enforced mobilization, early oral feeding, and balanced analgesia improve convalescence after colorectal surgery. Nutr Burbank Los Angel Cty Calif. fevereiro de 2002;18(2):147\u0026ndash;52. \u003c/li\u003e\n\u003cli\u003eJoshi GP, Kehlet H. Postoperative pain management in the era of ERAS: An overview. 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Transcutaneous electrical nerve stimulation. Contin Educ Anaesth Crit Care Pain. 1\u003csup\u003eo\u003c/sup\u003e de agosto de 2009;9(4):130\u0026ndash;5. \u003c/li\u003e\n\u003cli\u003eLiebano RE, Rakel B, Vance CGT, Walsh DM, Sluka KA. An investigation of the development of analgesic tolerance to TENS in humans. PAIN\u0026reg;. 1\u003csup\u003eo\u003c/sup\u003e de fevereiro de 2011;152(2):335\u0026ndash;42. \u003c/li\u003e\n\u003cli\u003eSabino GS, Santos CMF, Francischi JN, de Resende MA. Release of Endogenous Opioids Following Transcutaneous Electric Nerve Stimulation in an Experimental Model of Acute Inflammatory Pain. J Pain. 1\u003csup\u003eo\u003c/sup\u003e de fevereiro de 2008;9(2):157\u0026ndash;63. \u003c/li\u003e\n\u003cli\u003eSluka KA, Deacon M, Stibal A, Strissel S, Terpstra A. Spinal Blockade of Opioid Receptors Prevents the Analgesia Produced by TENS in Arthritic Rats. J Pharmacol Exp Ther. 1\u003csup\u003eo\u003c/sup\u003e de maio de 1999;289(2):840\u0026ndash;6. \u003c/li\u003e\n\u003cli\u003eAo L, Shi J, Bai Y, Zhang S, Gan J. Effects of transcutaneous electrical acupoint stimulation on perioperative immune function and postoperative analgesia in patients undergoing radical mastectomy: A randomized controlled trial. Exp Ther Med. 1\u003csup\u003eo\u003c/sup\u003e de mar\u0026ccedil;o de 2021;21(3):1\u0026ndash;1. \u003c/li\u003e\n\u003cli\u003eFiorelli A, Morgillo F, Milione R, Pace MC, Passavanti MB, Laperuta P, et al. Control of post-thoracotomy pain by transcutaneous electrical nerve stimulation: effect on serum cytokine levels, visual analogue scale, pulmonary function and medication\u0026dagger;. Eur J Cardiothorac Surg. 1\u003csup\u003eo\u003c/sup\u003e de abril de 2012;41(4):861\u0026ndash;8. \u003c/li\u003e\n\u003cli\u003eErden S, Senol Celik S. The effect of transcutaneous electrical nerve stimulation on post-thoracotomy pain. Contemp Nurse. 2 de novembro de 2015;51(2\u0026ndash;3):163\u0026ndash;70. \u003c/li\u003e\n\u003cli\u003eParseliunas A, Paskauskas S, Kubiliute E, Vaitekunas J, Venskutonis D. Transcutaneous Electric Nerve Stimulation Reduces Acute Postoperative Pain and Analgesic Use After Open Inguinal Hernia Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial. J Pain. 1\u003csup\u003eo\u003c/sup\u003e de maio de 2021;22(5):533\u0026ndash;44. \u003c/li\u003e\n\u003cli\u003eda Silva MP, Liebano RE, Rodrigues VA, Abla LEF, Ferreira LM. Transcutaneous Electrical Nerve Stimulation for Pain Relief After Liposuction: A Randomized Controlled Trial. Aesthetic Plast Surg. 1\u003csup\u003eo\u003c/sup\u003e de abril de 2015;39(2):262\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eErden S, Yurtseven Ş, Demir SG, Arslan S, Arslan UE, Dalcı K. Effects of Transcutaneous Electrical Nerve Stimulation on Mastectomy Pain, Patient Satisfaction, and Patient Outcomes. J Perianesthesia Nurs Off J Am Soc PeriAnesthesia Nurses. 15 de mar\u0026ccedil;o de 2022;S1089-9472(21)00352-X. \u003c/li\u003e\n\u003cli\u003eElboim-Gabyzon M, Andrawus Najjar S, Shtarker H. Effects of transcutaneous electrical nerve stimulation (TENS) on acute postoperative pain intensity and mobility after hip fracture: A double-blinded, randomized trial. Clin Interv Aging. 2019;14:1841\u0026ndash;50. \u003c/li\u003e\n\u003cli\u003eIlfeld BM, Plunkett A, Vijjeswarapu AM, Hackworth R, Dhanjal S, Turan A, et al. Percutaneous Peripheral Nerve Stimulation (Neuromodulation) for Postoperative Pain: A Randomized, Sham-controlled Pilot Study. Anesthesiology. 1\u003csup\u003eo\u003c/sup\u003e de julho de 2021;135(1):95\u0026ndash;110. \u003c/li\u003e\n\u003cli\u003eZhu Y, Feng Y, Peng L. Effect of transcutaneous electrical nerve stimulation for pain control after total knee arthroplasty: A systematic review and meta-analysis. J Rehabil Med. 21 de novembro de 2017;49(9):700\u0026ndash;4. \u003c/li\u003e\n\u003cli\u003eJahangirifard A, Razavi M, Ahmadi ZH, Forozeshfard M. Effect of TENS on Postoperative Pain and Pulmonary Function in Patients Undergoing Coronary Artery Bypass Surgery. Pain Manag Nurs. 1\u003csup\u003eo\u003c/sup\u003e de agosto de 2018;19(4):408\u0026ndash;14. \u003c/li\u003e\n\u003cli\u003eCONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials | The BMJ [Internet]. [citado 30 de junho de 2022]. Available from: https://www.bmj.com/content/340/bmj.c332\u003c/li\u003e\n\u003cli\u003eBjordal JM, Johnson MI, Ljunggreen AE. Transcutaneous electrical nerve stimulation (TENS) can reduce postoperative analgesic consumption. A meta-analysis with assessment of optimal treatment parameters for postoperative pain. Eur J Pain. 1\u003csup\u003eo\u003c/sup\u003e de abril de 2003;7(2):181\u0026ndash;8. \u003c/li\u003e\n\u003cli\u003eDailey DL, Rakel BA, Vance CGT, Liebano RE, Amrit AS, Bush HM, et al. Transcutaneous electrical nerve stimulation reduces pain, fatigue and hyperalgesia while restoring central inhibition in primary fibromyalgia. Pain. novembro de 2013;154(11):2554\u0026ndash;62. \u003c/li\u003e\n\u003cli\u003eDeSantana JM, Sluka KA, Lauretti GR. High and Low Frequency TENS Reduce Postoperative Pain Intensity After Laparoscopic Tubal Ligation: A Randomized Controlled Trial. Clin J Pain. janeiro de 2009;25(1):12\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eMoran F, Leonard T, Hawthorne S, Hughes CM, McCrum-Gardner E, Johnson MI, et al. Hypoalgesia in response to transcutaneous electrical nerve stimulation (TENS) depends on stimulation intensity. J Pain. agosto de 2011;12(8):929\u0026ndash;35. \u003c/li\u003e\n\u003cli\u003eTelles JD, Schiavon MAG, Costa AC de S, Rampazo \u0026Eacute;P, Liebano RE. Hypoalgesic Effects of Transcutaneous Electrical Nerve Stimulation Combined With Joint Manipulation: A Randomized Clinical Trial. J Manipulative Physiol Ther. mar\u0026ccedil;o de 2021;44(3):244\u0026ndash;54. \u003c/li\u003e\n\u003cli\u003eWhitman PA, Adigun OO. Anatomy, Skin, Dermatomes. Em: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited on January 3, 2023]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK535401/\u003c/li\u003e\n\u003cli\u003eLiebano RE, Vance CG, Rakel BA, Lee JE, Cooper NA, Marchand S, et al. Transcutaneous electrical nerve stimulation and conditioned pain modulation influence the perception of pain in humans. Eur J Pain Lond Engl. novembro de 2013;17(10):1539\u0026ndash;46. \u003c/li\u003e\n\u003cli\u003eLiebano RE, Rakel B, Vance CGT, Walsh DM, Sluka KA. An investigation of the development of analgesic tolerance to TENS in humans. Pain. fevereiro de 2011;152(2):335\u0026ndash;42. \u003c/li\u003e\n\u003cli\u003eRakel B, Cooper N, Adams HJ, Messer BR, Frey Law LA, Dannen DR, et al. A new transient sham TENS device allows for investigator blinding while delivering a true placebo treatment. J Pain. mar\u0026ccedil;o de 2010;11(3):230\u0026ndash;8. \u003c/li\u003e\n\u003cli\u003eChibnall JT, Tait RC. Pain assessment in cognitively impaired and unimpaired older adults: a comparison of four scales. Pain. 1\u003csup\u003eo\u003c/sup\u003e de maio de 2001;92(1):173\u0026ndash;86. \u003c/li\u003e\n\u003cli\u003eDownie WW, Leatham PA, Rhind VM, Wright V, Branco JA, Anderson JA. Studies with pain rating scales. Ann Rheum Dis. 1\u003csup\u003eo\u003c/sup\u003e de agosto de 1978;37(4):378\u0026ndash;81. \u003c/li\u003e\n\u003cli\u003eFerreira-Valente MA, Pais-Ribeiro JL, Jensen MP. Validity of four pain intensity rating scales. 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Effects of transcutaneous electrical nerve stimulation on pain, walking function, respiratory muscle strength and vital capacity in kidney donors: a protocol of a randomized controlled trial. BMC Nephrol. 11 de janeiro de 2013;14:7. \u003c/li\u003e\n\u003cli\u003eCosta D, Gon\u0026ccedil;alves HA, Lima LP de, Ike D, Cancelliero KM, Montebelo MI de L. Novos valores de refer\u0026ecirc;ncia para press\u0026otilde;es respirat\u0026oacute;rias m\u0026aacute;ximas na popula\u0026ccedil;\u0026atilde;o brasileira. J Bras Pneumol. junho de 2010;36:306\u0026ndash;12. \u003c/li\u003e\n\u003cli\u003eBorges MR, de Oliveira NML, Antonelli IBS, Silva MB, Crema E, Fernandes LFRM. Transcutaneous electrical nerve stimulation is superior than placebo and control for postoperative pain relief. Pain Manag. julho de 2020;10(4):235\u0026ndash;46. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Pain, Postoperative, Acute Pain, Mammaplasty, Breast Implantation, Transcutaneous Electrical Nerve Stimulation, Study protocol","lastPublishedDoi":"10.21203/rs.3.rs-3946854/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3946854/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e● \u003cstrong\u003eBackground\u003c/strong\u003e:\u003cstrong\u003e \u003c/strong\u003eBreast augmentation is a surgical procedure that may result in postoperative pain. The use of analgesics to relieve pain may produce adverse effects and delay recovery. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological approach that can relieve pain by activating nerve fibers. However, the effectiveness of TENS in breast augmentation has yet to be investigated. The aim of this study was to assess the effects of TENS on pain intensity immediately after breast augmentation. The results have the potential to advance scientific and technological knowledge in the treatment of acute postoperative pain, using accessible non-pharmacological interventions that can improve patients’ experiences.\u003c/p\u003e\n\u003cp\u003e● \u003cstrong\u003eMethods: \u003c/strong\u003eA placebo-controlled, double-blind randomized clinical trial will be conducted with 52 participants submitted to breast augmentation following a rapid 24-hour recovery. Participants will be randomly allocated to two groups: active TENS and placebo TENS. Each participant will undergo a TENS treatment session. The primary outcome will be pain intensity assessed at rest and during movement, before and immediately after TENS. Secondary outcomes will include pain intensity one hour after treatment, respiratory muscle strength, satisfaction with the intervention and analgesic use in the first four hours after surgery.\u003c/p\u003e\n\u003cp\u003e● \u003cstrong\u003eDiscussion\u003c/strong\u003e:\u003cstrong\u003e \u003c/strong\u003eThe results of this study will provide important information on the effects of TENS in patients submitted to breast augmentation, contributing to improving ´postoperative pain. It is hoped that the findings of a non-pharmacological approach will contribute to developing more effective and less costly pain management strategies. This may result in a significant improvement in the experience of patients submitted to this surgical procedure.\u003c/p\u003e\n\u003cp\u003e● \u003cstrong\u003eTrial registration\u003c/strong\u003e: This study was prospectively registered in the Brazilian Clinical Trials Registry (ReBEC) on 01/02/2024 under registration number RBR-96h3k97.\u003c/p\u003e","manuscriptTitle":"Effects of transcutaneous electrical nerve stimulation on acute postoperative pain after breast augmentation surgery: placebo-controlled, double-blind randomized clinical trial protocol.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-22 13:25:14","doi":"10.21203/rs.3.rs-3946854/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2024-04-22T06:22:22+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-03-20T11:08:41+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-03-20T09:38:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-03-15T12:22:36+00:00","index":"","fulltext":""},{"type":"submitted","content":"Trials","date":"2024-03-04T12:21:29+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"trials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"trls","sideBox":"Learn more about [Trials](http://trialsjournal.biomedcentral.com/)","snPcode":"13063","submissionUrl":"https://www.editorialmanager.com/trls","title":"Trials","twitterHandle":"MedicalEvidence","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"73cddcca-23ff-4105-ad0e-5083bf5ad560","owner":[],"postedDate":"March 22nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2024-04-22T10:22:42+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-22 13:25:14","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3946854","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3946854","identity":"rs-3946854","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}