For all patients meeting the inclusion criteria, the demographic profile including age, sex, weight, smoking history and the type of procedures performed during bronchoscopy shall be recorded. A written informed consent will be obtained from all participants. The patients who undergo flexible bronchoscopy would be randomised in a one is to one ratio either to 1% lignocaine or 2% lignocaine group. Prior to the bronchoscopy blood pressure, pulse rate, respiratory rate and pulse oximetry saturation will be recorded at the baseline Patients in both the groups shall be prepared in a similar fashion except for the concentration of lignocaine used. Two different concentration of lignocaine solution will be labelled as solution 'A' or solution 'B' containing either of 1% or 2% lignocaine solution .Operator will be provided either solution A or B based on the initial randomisation.