OBJECTIVETo probe into the optimal frequency of electroacupuncture for the access to the best anesthesia.

METHODSSixty cases of optional thyroid surgery were randomly divided into group A, group B and group C, 20 cases in each group. In group A, 2 Hz/100 Hz disperse-dense wave was selected in stimulation. In group B, 2 Hz/15 Hz disperse-dense wave was selected. Group C was the control group without electric stimulation applied. Hegu (LI 4) and Neiguan (PC 6) were stimulated bilaterally. Cervical plexus block was produced after 15 min acupuncture. The concentration changes in plasma cortisone (COR) and beta-endorphin (beta-EP) were compared among 4 time-points, named before anesthesia (T1), before skin incision after induction (T2), thyroid traction in surgery (T3) and the end of surgery (T4).

RESULTSGroup B achieved the highest significant rate of analgesia (50.0%, 10/20) and that in group C was the lowest (10.0%, 2/20). COR content was the highest at T2 in group A and that was the lowest at T3 in group B. At the end of surgery, COR content was up the maximum in 3 groups, but still COR content was the lowest in group B in comparison. The plasma beta-EP content decreased apparently at T3 and T4 in group B as compared with the value before (both P < 0.05).

CONCLUSIONIn electroacupuncture-assisted anesthesia, 2 Hz/15 Hz disperse-dense wave achieves the optimal anesthesia compared with 2 Hz/100 Hz disperse-dense wave, and moreover inhibits stress reaction induced by anesthesia surgery.