OBJECTIVETo observe the impacts of different frequencies of electroacupuncture (EA) on post-operative cognitive function and the change in serum S-100beta protein under the compound anesthesia of acupuncture and drugs.

METHODSOne hundred and twenty-four patients of abdominal operation at selective time were randomized into a routine drug anesthesia group (group A, 24 cases), a meridian point 2 Hz group (group B, 26 cases), a me ridian point 2 Hz/100 Hz group (group C, 25 cases), a meridian point 100 Hz group (group D, 24 cases) and a transcutaneous acupoint electric stimulation 2 Hz/100 Hz group (group E, 25 cases). In group A, the endotrachea-lgeneral anesthesia was applied. In the rest groups, the acupuncture anesthesia was induced for 30 min before the endotracheal general anesthesia, at Baihui (GV 20), Yintang (GV 29) and Neiguan (PC 6), with G6805-2 electric acupuncture apparatus used. In group B, the continuous wave and 2Hz in frequency were selected. In group C, the disperse-dense wave and 2 Hz/100 Hz in frequency were selected. In group D, the continuous wave and 100 Hz in frequency were selected. In group E, the disperse-dense wave and 2 Hz/100 Hz in frequency were selected, and the electrode pads were stick on the acupoints and connected with the electric stimulation till the end of operation. Mini-mental state examination (MMSE) was adopted to evaluate and record the changes in cognitive function 1 day before operation and on the 3rd day after operation. The conditions of post-operative cognitive dysfunction (POCD) in the patients and the changes in serum S-100beta protein were monitored before and at the end of operation.

RESULTSThe incidence rate of POCD on the 3rd day after operation was 41.7% (10/24) in group A. The incidence rates of POCD were 26.9% (7/26), 16.0% (4/25), 33.3% (8/24) and 16.0% (4/25) in group B, C, D and E separately. Compared with group A, the incidence rate of PCOD in group B, C, D and E were reduced (all P<0.05), the incidence rate in group C and E were lower than that in groups B and D (all P<0.05). At the end of operation, the level of serumS-100beta protein was (0.186 +/- 0.027) microg/L in group A, the levels were (0.165 +/- 0. 028) microg/L, (0.166 +/- 0.027) microg/L, (0.163 +/- 0.025) microg/L and (0.164 +/- 0.025) microg/L in group B, C, D and E separately. The levels of serum S-100beta protein in group B, C, D and E were lower than that in group A separately (all P<0.05).

CONCLUSIONThe general anesthesia assisted with EA at different frequencies reduces the incidence of cognitive dysfunctionand, decreases the level of serum S-100beta protein after intestinal cancer resection. The effects of the meridian point electric stimulation at 2 Hz/100 Hz and the transcutaneous electric stimulation at 2 Hz/100 Hz are the best. Hence, these two approaches of anesthesia deserve to be recommended practically.