bronchoscopy

Reference Ranges
Conditions
Our Records are Incomplete for Conditions

Bronchoscopy


Bronchoscopy is a technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. This allows the practitioner to examine the patient's airways for abnormalities such as foreign bodies, bleeding, tumors, or inflammation. Specimens may be taken from inside the lungs. The construction of bronchoscopes ranges from rigid metal tubes with attached lighting devices to flexible fibreoptic instruments with realtime video equipment.

History

A German, Gustav Killian, performed the first bronchoscopy in 1897. From then until the 1970s, rigid bronchoscopes were used exclusively.

Types

Rigid

A rigid bronchoscope is a straight, metal tube with an inner diameter of up to one centimetre. It is inserted through the mouth, the patient lying in a supine position and the neck hyperextended. The procedure causes significant discomfort and is performed under general anesthesia.

Rigid bronchoscopy is less often used today, but it remains the procedure of choice for removing foreign materials, as the greater diameter of the rigid bronchoscope allows instruments to be more easily inserted through it. Rigid bronchoscopy also becomes useful when bleeding interferes with viewing the examining area, and allows for more interventions, such as cautery to stop the bleeding.

Flexible (fiberoptic)

A flexible bronchoscope is longer and thinner than a rigid bronchoscope. It contains a fiberoptic system that transmits an image from the tip of the instrument to an eyepiece or video camera at the opposite end. Using Bowden cables connected to a lever at the handpiece, the tip of the instrument can be oriented, allowing the practitioner to navigate the instrument into individual lobe or segment bronchi. Most flexible bronchoscopes also include a channel for suctioning or instrumentation, but these are significantly smaller than those in a rigid bronchoscope.

Flexible bronchoscopy causes less discomfort for the patient than rigid bronchoscopy and the procedure can be performed easily and safely under moderate sedation. It is the technique of choice nowadays for most bronchoscopic procedures.

Purposes

Diagnostic

Therapeutic

  • To remove secretions, blood, or foreign objects lodged in the airway
  • Laser resection of tumors or benign tracheal and bronchial strictures
  • Stent insertion to palliate extrinsic compression of the tracheobronchial lumen from either malignant or benign disease processes
  • Bronchoscopy is also employed in percutaneous tracheostomy
  • Surgical procedures on the airways, such as tracheal reconstruction, often require the use of bronchoscopy
  • Intubation of patients with difficult airways is often performed using a flexible bronchoscope

Procedure

Bronchoscopy can be performed in a special room designated for such procedures, operating room, intensive care unit, or other location with resources for the management of airway emergencies. The patient will often be given antianxiety and antisecretory medications (to prevent oral secretions from obstructing the view), generally atropine, and sometimes an analgesic such as morphine. During the procedure, sedatives such as midazolam or propofol may be used. A local anesthetic is often given to anesthetise the mucous membranes of the pharynx, larynx, and trachea. The patient is monitored during the procedure with periodic blood pressure checks, continuous ECG monitoring of the heart, and pulse oximetry.

A flexible bronchoscope is inserted with the patient in a sitting or supine position. Once the bronchoscope is inserted into the upper airway, the vocal cords are inspected. The instrument is advanced to the trachea and further down into the bronchial system and each area is inspected as the bronchoscope passes. If an abnormality is discovered, it may be sampled, using a brush, a needle, or forceps. Specimen of lung tissue (transbronchial biopsy) may be sampled using a real-time x-ray (fluoroscopy). Flexible bronchoscopy can also be performed on intubated patients, such as patients in intensive care. In this case, the instrument is inserted through an adapter connected to the tracheal tube.

Rigid bronchoscopy is performed under general anesthesia. Rigid bronchoscopes are too large to allow parallel placement of other devices in the trachea; therefore the anesthesia apparatus is connected to the bronchoscope and the patient is ventilated through the bronchoscope.

Recovery

Although most patients tolerate bronchoscopy well, a brief period of observation is required after the procedure. Most complications occur early and are readily apparent at the time of the procedure. The patient is assessed for respiratory difficulty (stridor and dyspnea resulting from laryngeal edema, laryngospasm, or bronchospasm). Monitoring continues until the effects of sedative drugs wear off and gag reflex has returned. If the patient has had a transbronchial biopsy, doctors may take a chest x-ray to rule out any air leakage in the lungs (pneumothorax) after the procedure. The patient will be hospitalized if there occurs any bleeding, air leakage (pneumothorax), or respiratory distress.

Complications and Risks

Besides the risks associated with the drug used, there are also specific risks of the procedure. Although a rigid bronchoscope can scratch or tear airways or damage the vocal cords, the risk of bronchoscopy is limited. Complications from fiberoptic bronchoscopy remain extremely low. Common complications include excessive bleeding following biopsy. A lung biopsy also may cause leakage of air, called pneumothorax. Pneumothorax occurs in less than 1% of lung biopsy cases . Laryngospasm is a rare complication but may sometimes require intubation. Patients with tumors or significant bleeding may experience increased difficulty breathing after a bronchoscopic procedure, sometimes due to swelling of the mucous membranes of the airways.

See also

References
GT:0.063