Clinical study on effect of electro-acupuncture combined with different anesthetics on auditory-evoked potential index.
OBJECTIVE
To observe the effect of electro-acupuncture (EA) on auto regressive with exogenous input model (ARX-model) auditory evoked index (AAI) in patients anesthetized with different anesthetics.


METHODS
Forty-eight adult patients undergoing scheduled surgical operation were enrolled and divided into two groups (24 in each group) according to the anesthetics applied, Group A was anesthetized with propofol sedation and Group B with Isoflurane-epidural anesthesia. Group A was subdivided into three groups of low, middle and high concentration of target effect-site of 1.0 microg/ml, 1.5 microg/ml and 2.0 microg/ml through target controlled infusion (TCI) and Group B into 3 subgroups of minimum alveolar effective concentration of isoflurane (0.4 MAC, 0.6 MAC and 0.8 MAC for B1, B2 and B3 subgroups) respectively, with 8 patients in every subgroup. EA on acupoints of Hegu (LI4) and Neiguan (P6) was applied on all the patients during anesthesia, and the change of AAI at various time points was recorded.


RESULTS
In the three subgroups of Group A, levels of AAI were significantly elevated in the first few minutes after EA, and significantly lowered 20 min after EA in subgroup A2. While in the subgroups of Group B, except the elevating in Group B1 1-2 min after EA, levels of AAI remained unchanged at other time points.


CONCLUSIONS
Pain response could be reflected by AAI during EA. EA could enhance the sedative effect of propofol in middle concentration, but its effect on isoflurane epidural anesthesia is insignificant.
Department of Anesthesia, Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032. samlily@citiz.net
Li
L
Lu
Sheng-jin
SJ
Ge
Zhang-gang
ZG
Xue
D015669:Acupuncture Points; D000328:Adult; D000768:Anesthesia, General; D000777:Anesthetics / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D016292:Procedural Sedation; D015671:Electroacupuncture; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D005260:Female; D006801:Humans; D007530:Isoflurane / Q000494:pharmacology*; D007813:Laparotomy; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010147:Pain Measurement; D015742:Propofol / Q000494:pharmacology*
D000777:Anesthetics; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D007530:Isoflurane; D015742:Propofol