Airway Nerve Block Versus Nebulization by Lignocaine During Diagnostic Flexible Bronchoscopy Under Moderate Sedation.

Inclusion Criteria: * Patients planned for diagnostic fiberoptic procedures such as broncho-alveolar lavage, endobronchial or transbronchial biopsies, or brush cytology. Exclusion Criteria: * Patients less than 21yrs old and patients more than 70 yrs old. * Severe respiratory failure (pH \< 7.35, partial arterial oxygen pressure \<55 mmHg despite supplemental oxygen). * Upper airway surgery or radiation, allergy to lidocaine, Propofol or midazolam, or bleeding disorder. * Hemodynamic instable patient or patient decompensated heart failure. * Epileptic patients, severe neurological or psychiatric disorder. * Patients requiring cryo-biopsy or endobronchial ultrasound because these procedures are performed under deep sedation including fiberoptic intubation.