Shock therapy? no, just a gentle tingle to ease ERCP sedation risks

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

1\. Inclusion Criteria: 1. Patients aged 18-85 years scheduled for elective diagnostic or therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for pancreaticobiliary indications. 2. American Society of Anesthesiologists (ASA) physical status classification I, II, or III. 3. Body mass index (BMI) between 18 and 30 kg/m². 4. Willing and able to provide written informed consent. 2\. Exclusion Criteria: 1. Known allergy or contraindication to meperidine, diazepam, or any other medication used in the protocol. 2. Chronic use of benzodiazepines or opioids (regular use more than three times per week in the preceding three months). 3. Severe cardiopulmonary, hepatic, or renal dysfunction (e.g., New York Heart Association class III or IV heart failure, uncontrolled chronic obstructive pulmonary disease, estimated glomerular filtration rate \<30 mL/min/1.73m², active liver disease). 4. Anticipated difficult airway (Mallampati score IV, mouth opening \<3 cm, thyromental distance \<6 cm). 5. Untreated or severe obstructive sleep apnea requiring continuous positive airway pressure therapy. 6. Pregnancy or breastfeeding. 7. Psychiatric or cognitive disorders precluding cooperation or valid assessment (e.g., severe anxiety, cognitive impairment). 8. Pre-induction resting heart rate \<50 beats per minute or second-degree or higher atrioventricular block. 9. Conditions predisposing to aspiration (e.g., gastric outlet obstruction, previous esophageal or gastric surgery with delayed emptying). 10. Previous exposure to transcutaneous electrical acupoint stimulation or knowledge of TEAS that could compromise blinding for the sham procedure. 11. Skin lesions, infections, or electronic implants at or near the proposed acupoint locations. 12. Inability to provide informed consent. 3\. Dropout Criteria: 1. Requirement for conversion to general anesthesia due to failed sedation or clinical necessity. 2. Occurrence of a serious adverse event related to the study intervention (e.g., severe allergic reaction, hemodynamic collapse). 3. Life-threatening deterioration during endoscopy (e.g., uncontrolled bleeding, respiratory failure, cardiac arrest). 4. Voluntary withdrawal of consent by participant or legal representative at any time. 5. Occurrence of a major ERCP-related complication (e.g., perforation, major bleeding, severe pancreatitis) requiring surgical or intensive care intervention. 6. Principal investigator-identified safety risks (e.g., sepsis, acute liver failure).