ABSTRACT
Objective To compare the bispectral index score ( BIS) correlationbetween standard frontal sensor position and an alternative zygomatic position under general anesthesia with propofol combined with remifentanil during neurosurgery. Methods Twenty patients undergoing neurosurgery were enrolled. Everyone received total intravenous anesthesia by target-controlled infusion of propofol and remifentanil. Two BISTM Quatro sensors mounted on the frontal and zygomatic regions were connected to BIS VistaTM monitors on each patient during general anesthesia.Data from each position were collected and analyzed at the time of awakening ( t1 ) , intubation ( t2 ) , incision ( t3 ) , the end of surgery ( t4 ) , and extubation ( t5 ) . Results At t1 , zygomatic BIS(88.95±6.42) was significantly lower than frontal BIS (84.85±9.64,P0.05). Scatter plot analysis revealed a significant correlation between BIS of frontal positionand that of zygomatic position( R2=0.892,P=0.000) . Conclusion During the anesthesia maintenance period,the zygomatic position can be availably used as an alternative position for monitoring if the operative field renders the standard frontal position unavailable.