Flexible bronchoscopy is a procedure in which a bronchoscope is advanced into the lungs. If the procedure is performed to evaluate a lung mass, a biopsy will almost certainly be taken. Thus, the patient should have normal coag results prior to the procedure. The nurse can verify this by reviewing recent lab results. Additional preparations for bronchoscopy include removing dentures, removing glasses, confirming the patient is NPO status, and placing the patient in a supine position. Methacholine nebulizer is sometimes used to provoke airway constriction prior to spirometry in the diagnosis of asthma. This agent has no role in bronchoscopy.