Forty patients undergoing elective resection of esophageal cancer patients who had I ~ II American Society of Anesthesiologist ( ASA ) were randomly divided into total intravenous anesthesia group ( group N , n = 20 ) and total intravenous anesthesia combined with SGB group ( group S , n = 20 , 0.12 mL/kg 1 % lidocaine was used for SGB 10 min before induction ) .