Acupuncture for Pain Control After Ambulatory Knee Arthroscopy

Inclusion Criteria: 1. Patients with an American Society of Anesthesiologists physical status of I to II scheduled for elective ambulatory arthroscopic knee surgery under standardized general anesthesia 2. Surgery time does not exceed 80 minutes 3. Patients without previous opioid and psychotropic medication 4. Patients aged between 19 and 55 years, able to fill in the study questionnaire (Appendix F) 5. Patients who have given written informed consent Exclusion Criteria: 1. Current psychiatric disease 2. Local skin infection at the sites of acupuncture 3. Aged \< 19 or \> 55 years 4. Failure to follow the standardized schema of general anaesthesia 5. Surgery time more than 80 minutes 6. Intraoperative complications (bleeding, required blood transfusion more than 6 units of packed cells, cardiovascular instability, required catecholamines) 7. Patients who consumed opioid medication at least 6 months before surgery 8. Patients who are unable to understand the consent form or to fill in the study questionnaire.