Flexible bronchoscopy is one of the most widely performed procedures for diagnosis of various bronchopulmonary diseases. Most patients tolerate the procedure well although cough is often reported as a distressing symptom. It is likely that the acceptance of bronchoscopy would be significantly improved with control of cough. Use of sedation during bronchoscopy has been reported to improve procedure tolerance. However, awake(no sedation) bronchoscopy is routinely performed at many centres including ours.

Topical lignocaine is administered during bronchoscopy for local anaesthesia. There is limited literature on the efficacy of lower concentrations (1%) versus a higher (2%) during bronchoscopic procedures. This study would help to determine whether 1% lignocaine is as effective as 2% lignocaine for airway anaesthesia during flexible bronchoscopy.

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.

During the procedure, 1.5ml aliquots of the provided lignocaine solution will be delivered through the bronchoscope using spray-as-you go technique. The total number of aliquots used during the procedure will be recorded. The patients would be monitored for any adverse effects throughout the procedure. The bronchoscopist doing the procedure will be provided 2 VAS charts to mark the severity of cough and overall procedure satisfaction.

Post procedure, patients will record the pain experienced while undergoing the procedure on the faces pain rating scale.

Inclusion Criteria:

1. Indication for diagnostic or therapeutic flexible bronchoscopy
2. Age > 18 years
3. Hemodynamic stability (defined as systolic BP >100 mm Hg and, <180 mm Hg).

Exclusion Criteria:

1. Refusal of consent
2. Known documented hypersensitivity to lignocaine
3. Procedure performed under general anaesthesia or sedation
4. Pregnancy
5. Hypoxemia (oxygen saturation [by pulse oximetry] < 92% with Fio2 of ≥ 0.3
6. Bronchoscopy done through endotracheal or tracheostomy tube