The Postoperative Analgesic Effect of Combination With Dexmedetomidine in Fentanyl-based Intravenous Patient Controlled Analgesia Compared With Conventional Thoracic Epidural and Intravenous Patient Controlled Analgesia After Radical Open Gastrectomy

The aim of this study to test hypothesis that addition of dexmedetomidine to fentanyl based intravenous patient controlled analgesia (PCA) improves postoperative pain compared with conventional thoracic epidural and intravenous patient controlled analgesia after radical open gastrectomy.

Inclusion Criteria:

1. ASA class I-II
2. obtaining written informed consent from the parents
3. aged 20-65 years who were undergoing radical open gastrectomy

Exclusion Criteria:

1. abdominal surgery previously
2. patient who refuse the patient controlled analgesia
3. unstable angina or congestive heart failure
4. uncontrolled hypertension (diastolic bp>110mmHg)
5. coagulopathy
6. hepatic failure
7. renal failure
8. bradycardia on EKG (under 50 bpm)
9. Ventricular conduction abnormality
10. drug hyperactivity
11. neurological or psychiatric illnesses
12. mental retardation
13. patients who can't read the consent form due to illiterate or foreigner 14.infection

15. pregnant 16. obesity (BMI > 30kg/m2)