The Effect of Transcutaneous Electrical Nerve Stimulation in Patients After Retrograde Intrarenal Surgery

• Transcutaneous Electrical Nerve Stimulation (Device): This intervention is distinguished by the early, standardized, and nonpharmacological application of Transcutaneous Electrical Nerve Stimulation (TENS) within the first 24 hours following Retrograde Intrarenal Surgery (RIRS). Unlike conventional postoperative management that primarily relies on pharmacological analgesics and antiemetics, this approach emphasizes a nurse-administered, bedside, and patient-centered neuromodulation technique that is integrated into routine care without adding invasive procedures. The use of uniform stimulation parameters, predefined electrode placement protocols, and blinded outcome assessment ensures consistency and methodological rigor, allowing the specific effects of TENS on postoperative pain, nausea, vomiting, and quality of recovery to be isolated and compared reliably against standard care.

Primary outcomes

• Primary Outcome Measure (postoperative pain intensity) [0-24 hours postoperatively]: The primary outcome of this study is the intensity of postoperative pain within the first 24 hours following retrograde intrarenal surgery (RIRS). Pain level will be assessed using the validated and reliable Numerical Rating Scale (NRS). Scale Description: Scale name: Numerical Rating Scale (NRS) Minimum value: 0 (no pain) Maximum value: 10 (unbearable pain) Higher score: Indicates a worse clinical outcome Unit of Measure: Scale total score

Secondary outcomes

• Postoperative Nausea and Vomiting (PONV) Intensity Scale [0-24 hours postoperatively]: The frequency and severity of nausea and vomiting occurring within the first 24 hours after surgery will be assessed and recorded using the Postoperative Nausea and Vomiting (PONV) Intensity Scale. Scale Description: Scale name: Postoperative Nausea and Vomiting (PONV) Intensity Scale Minimum value: 0 (no nausea/vomiting) Maximum value: 4 (severe and persistent nausea/vomiting) Higher score: Indicates a worse clinical outcome Unit of Measure: Scale total score
• Quality of recovery [24 hours postoperatively]: The quality of postoperative recovery will be assessed using the Quality of Recovery-15 Questionnaire (QoR-15), which has proven validity and reliability. Scale Description: Scale name: Quality of Recovery-15 (QoR-15) Minimum value: 0 Maximum value: 150 Higher score: Indicates better recovery quality Unit of Measure: Scale total score

Other outcomes

• Analgesic and antiemetic consumption [Post-surgery 0-24 hours]: Total doses of analgesic and antiemetic drugs administered within the first 24 hours post-surgery (in units/day) will be calculated from patient records. The average numbers obtained for both groups will be compared. Unit of Measure: Pharmacological consumption amount/number (units/day)
• Antiemetic Consumption [0-24 hours postoperatively]: Description: Total antiemetic drug consumption within the first 24 hours after surgery will be extracted from medical records. Unit of Measure: Total dose (units/day)
• Time to First Mobilization [Within 24 hours postoperatively]: Description: Time from completion of surgery to first ambulation will be recorded under standardized clinical conditions. Unit of Measure: Minutes
• Patient Satisfaction with Postoperative Care [24 hours postoperatively]: Description: Patient satisfaction with postoperative care will be assessed using a 0-10 Numerical Rating Scale (NRS), where higher scores indicate greater satisfaction. Unit of Measure: Scale total score (0-10)

Sex: All, ages: 18 Years to 70 Years

Inclusion Criteria:

* Participants who have undergone RIRS will be included in our study. Eligibility criteria include being between 18 and 70 years of age,
* Participants having an American Society of Anesthesiologists (ASA) physical status classification of I or II,
* Participants must have sufficient cognitive function and language skills to proceed with the study.

Exclusion Criteria:

* Exclusion criteria include the presence of a painful condition (e.g., inflammatory rheumatic disease, lumbar muscle degeneration, lumbar disc protrusion with back pain, acute or chronic nephritis, and pyelonephritis),
* Major organ system disease,
* Participants with pacemakers,
* Participants using analgesic medications or those with a history of significant drug abuse,
* Those with uncontrolled hypertension, diabetes or malignancies, a history of epilepsy, pregnancy, and breastfeeding,
* Participants in other clinical trials will also be excluded (Mora et al., 2007; Tu et al., 2019).

• Kim, H. Y., Park, J. H., & Yoon, H. J. (2020). The effects of transcutaneous electrical nerve stimulation on postoperative pain and recovery in patients undergoing urological surgery: A randomized controlled trial. Journal of Urology and Renal Diseases, 5(2), 1035-1041. https://doi.org/10.23880/oajurd-16000201