Bispectral index evaluation of the sedative effect of acupuncture in healthy volunteers.

OBJECTIVE

To evaluate the sedative effect of acupuncture in healthy volunteers by means of the BIS monitor. Secondary end-points were the evaluation of subjective sedative sensation induced by acupuncture and possible lasting of the sedative effect post needles removal.

METHODS

We performed a cross-over, single-blinded study on 10 healthy volunteers to evaluate objective and subjective sedative effect of acupuncture compared to sham acupuncture. We recorded heart rate, pulse-oxymetry, BIS at baseline, during a 20-min. stimulation period, and for the following 20 minutes after needles removal. Besides, we asked volunteers to score their subjective state by VAS at baseline, after the stimulation period (20th minute) and 20 minutes after needles removal.

RESULTS

BIS values were not significantly different between true and sham acupuncture. A suggestive but not statistically significant difference was evident in VAS score, with true- better than sham acupuncture. There was no difference in the incidence of sleep during the experimental phases, nor in the incidence of insomnia or somnolence in the following 24 hours. HR and SpO2 remained always in a normal range.

CONCLUSIONS

The sedative effect of true acupuncture was not different from that of sham acupuncture in healthy volunteers. We suggest that acupuncture could have a mild sedative action that can be demonstrated only treating anxious patients and not calm volunteers. In our opinion, the low potency of this technique can be an advantage allowing acupuncture safe application in a wide range of settings.