Invasive Pulmonary Testing: Bronchoscopy

The RT must have the capability to anticipate each step in bronchoscopy, including good assessment skills to detect changes in the patient’s condition during the procedure.

RTs often assist pulmonary physicians in invasive procedures. Assisting in bronchoscopy is one of the more frequently undertaken roles for RTs in this capacity. They need knowledge of the procedure, understanding of disease processes, insight into patient assessment, familiarity with the medications and equipment used, and the ability to anticipate the physician’s next step.

Reasons for Bronchoscopy
Bronchoscopic procedures fall into two categories: diagnostic and therapeutic. Diagnostic bronchoscopy is used to evaluate the patient who has unknown lesions, hemoptysis, unexplained cough, wheezing, or stridor; has suspicious or positive cytology studies from sputum samples; has suspected airway abnormalities (such as stenosis, tracheomalacia, or bronchomalacia) or an abnormal chest radiograph; has unexplained laryngeal-nerve paralysis or diaphragmatic paralysis of recent onset; has lung cancer that needs to be staged prior to surgery; needs to have tissue or fluid samples taken from the lungs; has experienced chemical or thermal burns or thoracic trauma; or needs to have endotracheal-tube placement verified.

Therapeutic bronchoscopy procedures are performed to remove retained secretions or plugs of mucus; remove foreign bodies; perform difficult intubations; excise small tumors or polyps in the tracheobronchial tree; dilate a stenotic airway or reinflate areas of atelectasis; stop hemoptysis; employ brachytherapy, cryotherapy, laser therapy, or photodynamic therapy; or place stents in the airway.^1,2

Bronchoscopes are either rigid or flexible. Rigid bronchoscopes are stainless-steel tubes that are inserted under general anesthesia through the mouth of the patient and into the right or left main stem bronchus. Rigid bronchoscopes allow direct visualization, and the physician can take photographic or video images. A rigid bronchoscope is 40 cm long and has a diameter ranging from 9 mm to 13.5 mm.³ Flexible bronchoscopes are inserted through the mouth or nose and, due to the flexibility of their tips, can be advanced farther into the lung (down to the lobar bronchi and some segmental branches). The flexible bronchoscopes used for adults are generally 3.4 mm to 6.2 mm in external diameter and have a suction channel from 1.2 mm to 3.2 mm.⁴ Pediatric bronchoscopes are 3.5 mm to 4 mm in diameter and slightly shorter than the adult bronchoscopes (about 450 mm to 550 mm in working length). An ultrathin bronchoscope ranges from 2.2 mm to 2.8 mm in diameter.⁵ Procedural sedation, rather than general anesthesia, is generally provided when a flexible device is used. Flexible fiber-optic bronchoscopes transmit the image to the eyepiece (or, with newer systems, use a miniature video system to show the image on a video screen). Patients undergoing fiber-optic bronchoscopy are given analgesia and sedation to make them comfortable, reduce pain, and reduce coughing, while allowing them to maintain spontaneous breathing. Rigid bronchoscopy is done in the operating room, while flexible bronchoscopy is most often done in a special procedure room; some fiber-optic bronchoscopy procedures are done at the patient’s bedside. A light source connects to either type of bronchoscope to provide a clear view of the distal airways.

William C. Pruitt, CPFT, RRT

Accessory Instruments, Lasers, and Agents
Accessory instruments can be passed through the bronchoscope. Most are designed to obtain tissue for pathology; some are used to deliver solutions to aid in diagnosis or to treat lung diseases. Miniature forceps, brushes, and needles are used to obtain tissue from the bronchial wall or the area just beyond the bronchial wall. In brachytherapy, special catheters are used to deliver radioactive seeds to a localized area of the bronchial tree to kill cancer cells. In cryotherapy, the catheters deliver a supercooled agent like liquid nitrogen to freeze and kill cells in an area of cancer. The bronchoscope can be used as a channel for laser light energy to open stenotic areas or kill malignant cells. Photodynamic therapy is one specific method in which a laser is used to kill cancer cells. A photosensitizing agent that concentrates itself preferentially in malignant tissue is injected 2 to 3 days before the procedure. The suspected areas of malignancy are then exposed to laser light energy and the sensitizing agent causes the production of singlet oxygen, which damages the cancer cells.⁶ Photodynamic therapy can be delivered through a rigid or flexible bronchoscope.

Bronchoscopes have also been used to deliver cyanoacrylate glues that seal areas causing hemoptysis.⁷ Miniaturized ultrasound probes have been used to examine the pulmonary tree and parenchyma. Endobronchial ultrasound has been used to stage bronchogenic carcinoma, to evaluate tumor infiltration in adjacent structures, and to differentiate between benign and malignant lesions.⁸ Angioplasty balloon catheters have been used with bronchoscopes to apply pressure on the bronchial wall and stop bleeding, or to open stenotic areas in the airway.^1,5

Bronchoalveolar lavage uses a bolus of sterile saline to wash out a fluid sample from the distal airways and alveoli. The procedure involves inserting the tip of the fiber-optic bronchoscope until it wedges in an airway, injecting a bolus of 20 mL to 50 mL of saline, and then applying suction to retrieve the fluid. Another diagnostic tool is fluorescence bronchoscopy, which uses the same photosensitizing agents used in photodynamic therapy. When exposed to ultraviolet light, the abnormal tissue appears a different color than normal tissue. A similar technique involving fluorescence bronchoscopy uses a helium-cadmium laser and special filters to visualize abnormal tissues.⁶ Bronchoscopy is also used to place stents in the airway. Stents help stabilize airway collapse that is the result of bronchomalacia, and are used to reinforce an area after stenosis has been corrected by balloon or laser treatment.⁹

The RT’s Role
RTs are often involved throughout fiber-optic bronchoscopy. The RT will set up and check the equipment; administer the preprocedure medications; assess the patient prior to, during, and after the procedure; and handle the documentation/ charge information. Besides monitoring the patient during the procedure, the RT assists in injecting medications and fluids, activates the forceps and manipulates the brush to take tissue samples, and prepares the tissue and fluid samples for the necessary laboratory tests.

After the procedure, the RT may be responsible for cleaning the bronchoscope and testing it for leaks to ensure sterility, as well as setting up the room (or the portable cart) for the next bronchoscopy. Inventory and maintenance of supplies are other jobs that may belong to the RT. When a bronchoscope is damaged, the RT often prepares it for shipping, contacts the manufacturer or repair agent regarding the repair, and receives the repaired scope when it arrives. As new procedures are introduced, the RT must learn each procedure and acquire the skills and knowledge needed to become competent in assisting the physician, in addition to ensuring that the proper supplies are present.

William C. Pruitt, CPFT, RRT, is an instructor, cardiorespiratory care, University of South Alabama, Mobile.

References:
1. Raoof S, Mehrishi S, Prakash U. Flexible bronchoscopy update: the role of bronchoscopy in modern medical intensive care unit. Clin Chest Med. 2001;22:241-261.
2. Chang D, Elstun L, Jones A. The Multiskilled Respiratory Therapist. Philadelphia: FA Davis; 2000:176-191.
3. Ayers M, Beamis J. Flexible bronchoscopy update: rigid bronchoscopy in the twenty-first century. Clin Chest Med. 2001;22:355-364.
4. Liebler J, Markin C. Fiberoptic bronchoscopy for diagnosis and treatment. Crit Care Clin. 2000;16:83-100.
5. Wood R. Flexible bronchoscopy update: the emerging role of flexible bronchoscopy in pediatrics. Clin Chest Med. 2001;22:311-317.
6. Sheski F, Mathur P. Endoscopic treatment of early-stage lung cancer. Cancer Control. 2000;7:35-44.
7. Bhattacharyya P, Dutta A, Samanta A, Chowdhury S. New procedure: bronchoscopic endobronchial sealing: a new mode of managing hemoptysis. Chest. 2002;121:2066-2069.
8. Turner J. Endobronchial ultrasound and peripheral pulmonary lesions: localization and histopathologic correlates using a miniature probe and the flexible bronchoscope. Chest. 2002;122:1874-1875.
9. Chajed P, Malouf M, Tamm M, Spratt P, Glanvill A. Interventional bronchoscopy for the management of airway complications following lung transplantation. Chest. 2001;120:1894-1899.