The Effect of Subclinical Dose of Ketamine on Early Postoperative Pain Sensitivity in Patients Undergoing Salpingectomy

Inclusion Criteria: * Age\>18 years old * BMI 18-30 kg/m2; * American Society of Anesthesiologists (ASA) classification I and II * The patient was diagnosed with ectopic pregnancy through ultrasound examination, and it was confirmed that there was no embryo or gestational sac in the uterus; The patient has indications for laparoscopic ectopic pregnancy surgery; * All patients are scheduled to undergo laparoscopic salpingectomy for treatment Normal mental state; * No cognitive impairment; * Normal communication skills, no speech barriers Exclusion Criteria: * Individuals with severe organ dysfunction such as heart, lungs, liver, and kidneys; * Individuals with serious mental illnesses; * Long term use of sedatives and analgesics or long-term alcoholism and smoking; * History of allergy to ketamine and related drugs * There is a serious risk of hypertension or elevated intracranial pressure, as well as contraindications for the use of ketamine in cases of hyperthyroidism Refuse to join the trial; * Patients with a history of other chronic pain diseases.