Objective: To observe the effect of preemptive analgesia of electroacupuncture(EA) for patients undergoing thoracic operation. Methods: 54 adult ASA (American Standards for Assessing the State of the Patient of American Anesthesia Association) grade Ⅰ and Ⅱ patients undergoing thoracic operation were randomly divided into three groups. The single blind method was used in the study. Patients in group A (n=18) were given with EA by using Han's Acupoint Nerve Stimulator(HANS) for stimulating Xiayifeng point and Sanyangluo (SJ 8) to Ximen (PC 4; 2/15Hz

2～4 mA and 15～ 20 min) first

then given with inhalational anesthetic (enflurane) and intravenous administration of fentany 2 μg/kg/hr

vecuronium 0.12 mg/kg/0.5 hr and propofol 2 mg/kg

During operation

HANS stimulation was given continuously

and combined with vecuronium 0.12 mg/kg. In group B (n=18)

acupoint surface electrical stimulation (without acupuncture) combined with anesthetics (being same to those of group A) was given. In group C (n=18)

only anesthetics were used. Then

the number of patients needing intramuscular injection of dolantin and the average doses in 3 groups were observed at 0～4 hr

4～8 hr

8～12 hr

12～16 hr

16～20 hr and 20～24 hr after operation. Results: The average dose of the injected dolantin in Group C was significantly higher than those of group A and B(P<0.001). 0～4 hr

4～8 hr

8～12 hr

12～16 hr and 16～20 hr after operation

the number of patients needing intramuscular injection of dolantin in group A

B and C were 2

2 and 9; 1

2 and 7; 1

2 and 6; and 1

3 and 6 respectively. It is clear that the number of patients needing dolantin of group C is evidently more than those of group A and B (P<0.05). Conclusion: Acupuncture stimulation conducted before thoracotomy has a preemptive analgesia effect.