Abstract: Abstract Objective To evaluate whether the way of intubation by intubated laryngeal mask airway (ILMA) and stylet optical system (SOS) could take advantage of intubation by macintosh laryngeal scope (MAC) in reducing cardiovascular response.Methods Sixty undergoing orbital plastic surgery patients, ASA gradeⅠor Ⅱ, airway evalutated normal, were randomly divided into three groups: Macintosh group (MAC, n=20), intubated laryngeal mask airway group (ILMA, n=20) and stylet optical system group (SOS, n=20), and all the patients of three groups received intubation by MAC, ILMA, SOS respectively after induction intravenously. Record the patients’ IBP, HR and BIS at time point 5minutes after arriving (baseline value, TBL), immediately before intubation (TBI), immediately after intubation (TAI), 1-5min after intubation (T1-T5); The blood samples of left radial artery were taken for determination of serum NE concerntration at the moment before intubation (baseline value, TBL), 1 min after intubation (T1), 3 min after intubation (T3). Results Inter-group comparison: SBP, DBP and HR of group SOS at time point T1 were lower than that of group MAC (P<0.05) and group ILMA, but no significant difference was found between group ILMA and group MAC. There is also no significant difference of plasma NE at time point TBI (P>0.05), but at time point T1 AND T3 Plasma NE concentration of group SOS is the lowest among the three groups.. Conclusion Endotracheal intubation could cause cardiovascular response compared to intubation by Macintosh laryngeal scope, intubation by ILMA could not decrease the level of cardiovascular, but SOS could decrease the cardiovascular response. Key words Tracheal intubation Macintosh laryngeal scope Intubating laryngeal mask airway Stylet optical system Cardiovascular response

Key words: Tracheal intubation, Macintosh laryngeal scope, Intubating laryngeal mask airway, Stylet optical system, Cardiovascular response