A clinical research about the effect of vagus nerve block in cervical part to prevent Oculocardiac Reflex

Objective To investigate the preventive effect of vagus nerve block in cervical part on Oculocardiac Reflex (OCR). Methods Case control study. 40 patients undergoing prosthesis of right orbital wall bone fracture were randomly divided into two groups: experiment group (group Ⅰ ) and control group ( group Ⅱ ). Both of the group adopted vagus nerve block in cervical part before anesthesia. Group Ⅰaccepted 1% lidocaine and group Ⅱ received 0. 9% Sodium Chloride. The same anesthesia method was applied on both groups. We recorded the index change of mean arterial pressure ( MAP), heart rate (HR)and pulse oxygen saturation (SpO2 ) before (T0) and after vagus nerve block in cervical part 3 min (T1),5 min (T2), 10 min (T3) and 120 min (T4 ); the changes of MAP and HR when we oppressed the eyeball or drag muscular apparatus; the times of using atropine; adverse reactions and the alteration of Acetylcholine (ACh). Numerical data was carried on statistical analysis processing using the SPSS 13.0. Data among groups were compared by t test and numeration data were compared by chi-square criterion. P-value ＜ 0. 05was considered to be statistically significant. Results In group Ⅰ , we found that heart rate significantly increased after block 3 min to 120 min compared with before block (F=15.46, P = 0. 000); The incidence of OCR was lower, and the incidence of adverse effects in PACU such as nausea and vomiting had statistically significant( x2 = 8.28, P = 0. 004); Content of ACh in group Ⅰ changed significantly, it was lower after block than before block (t = 2. 935, P = 0. 003 ). Conclusion Vagus nerve block in cervical part significantly decreased the incidence of OCR and brought into preventive effect. Key words: Ophthalmologic surgical procedures ;  Reflex,oculocardiac ;  Vagus nerve ;  Nerve block ;  Acetylcholine ;