Objective To observe the effect of electroacupuncture(EA) combined with cervical plexus block(CPB) on the stress response of patients undergoing thyroid surgery.Methods Forty thyroidectomy patients were randomly divided into sham EA plus CPB group(sham group) and EA+CPB group(20 cases in each group).For patients of the sham group

deep cervical plexus block(25% ropivacaine hydrochloride + 1% lidocaine hydrochloride) was performed first

followed by inserting acupuncture needles into bilateral Hegu(LI 4) and Neiguan(PC 6)separately without needle manipulation and then connecting the output wires of the EA therapeutic instrument to the handles of the acupuncture needles but without electric current output.For patients of the EA+CPB group

deep cervical plexus block was performed first followed by EA stimulation [10 Hz

(6±2) mA] of the bilateral LI 4 and PC 6 for 20 min.Systolic blood pressure(SBP)

heart rate(HR) and breathing frequency were detected using a multipurpose monitor.Plasma adrenocorticotropic hormone(ACTH) and cortisol(Cor) contents were determined using chemiluminescence method

plasma epinephrine(E) level was detected by enzyme-linked immunosorbent assay

glucose(Glu) assayed by oxidase method

and plasma C-reactive protein(CRP) level detected using immumofluorescence technique.Results(1) During surgery

the patients' SBP and HR of both sham and EA groups were increased significantly compared with their basic values(P<0.05)

but the levels of the increased SBP and HR of the EA group were obviously lower than those of the sham group(P<0.05).(2) The levels of plasma ACTH during surgery and at the immediate time after surgery

Cor level at the immediate time after surgery

plasma E and Glu contents during surgery

at the immediate time and on day 1 after surgery

and plasma CRP at the immediate time

and on day 1 and 3 after surgery in the sham group were upregulated considerably(P<0.05)

while the levels of plasma ACTH

Cor

E

Glu and CRP in the above-mentioned time-points of the EA group were all remarkably lower than those of the sham group(P<0.05).Conclusion EA combined with cervical plexus block significantly reduces peri-operative cardiovascular stress responses and inhibits abnormal increases of plasma stress hormones and inflammatory reaction in patients undergoing thyroid surgery.