Anesthesia Induction Scheme for Painless Gastrointestinal Endoscopy Patients Based on Nociceptive Stimulation Monitoring

Inclusion Criteria: 1. Aged 18-60 years old; 2. American Society of Anesthesiologists (ASA) Class I-III; 3. Body mass index (BMI): 18-30 kg/m\^2; 4. Individuals scheduled for elective gastroscopy and colonoscopy examinations; 5. Willing to comply with the experimental procedures and voluntarily sign the informed consent form Exclusion Criteria: 1. Pregnant or breastfeeding women; 2. Individuals with allergies to sedatives/anesthetic drugs or other severe anesthetic risks; 3. Patients with chronic preoperative pain or a history of substance abuse; 4. Individuals with severe neurological diseases, such as stroke, hemiplegia, seizures, epilepsy, etc.; 5. Patients with clearly difficult airways, such as those with limited mouth opening, neck or jaw mobility restrictions, rheumatoid arthritis, or temporomandibular joint disorders; 6. Individuals with respiratory diseases, such as bronchitis, asthma, chronic obstructive pulmonary disease, or acute respiratory infections, which may lead to increased airway sensitivity; 7. Patients with chronic pharyngitis, laryngitis, laryngeal edema, or recurrent laryngeal nerve paralysis that may affect normal throat function; 8. Individuals with esophagitis, esophageal strictures, or esophageal motility disorders that may cause difficulty swallowing or reflux; 9. Patients with poorly controlled life-threatening cardiovascular diseases, such as uncontrolled severe hypertension, severe arrhythmias, or unstable angina; 10.10.Patients with liver dysfunction (Child-Pugh grade C or above), acute upper gastrointestinal bleeding with shock, severe anemia, or gastrointestinal obstruction with retained gastric contents.