ObjectiveTo evaluate if intravenous lidocaine can reduce the stress response induced by fiberoptic bronchoscopy in patients under general anesthesia. MethodsSixty patients undergoing fiberoptic bronchoscopy under unconsciousness between November 2013 and July 2014 were randomly divided into two groups: lidocaine group (n=30) and control group (n=30). Patients in the lidocaine group received an intravenous injection of lidocaine for 1 mg/kg during induction and then continuous intravenous infusion of 2% lidocaine with a dose of 3 mg/(kg·h). The same volume of saline was given to patients of the control group in the same way. Laryngeal mask airway was placed after anesthesia induction. Variables of heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse oxygen saturation were observed and recorded at five time points: before induction, immediately after induction, immediately after laryngeal mask airway placement, fiberoptic bronchoscopy across tracheal carina and before leaving examination room. Complications including cough reflex, toxicity reaction of local anesthetics, and injection pain were also observed. ResultsThe examination was successfully completed in all patients. Blood pressure and heart rate increased in all patients when fiberoptic bronchoscopy got across tracheal carina. There were no statistically significant differences in the two groups (P>0.05). Patients in the two groups had no statistic difference in tinnitus and numbness of tongue (P>0.05). Compared with the control group, patients in the lidocaine group had lower incidence of injection pain (P<0.05). ConclusionIntravenous lidocaine cannot suppress stress response induced by fiberoptic bronchoscopy effectively.