Nefopam will be administered to the patients undergoing laparoscopic gastrectomy under the total intravenous anesthesia (TIVA).
The investigators will evaluate whether the nefopam can decrease the total amount of remifentanil administered during the operation, which will reduce the acute opioid tolerance and following consumption of fentanyl during postoperative period.
Inclusion Criteria:
Exclusion Criteria: