Bronchoscopy is anendoscopictechnique of visualizing the inside of theairways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through atracheostomy. This allows the practitioner to examine the patient's airways for abnormalities such as foreign bodies, bleeding,tumors, orinflammation. Specimens may be taken from inside thelungs. The construction of bronchoscopes ranges from rigid metal tubes with attached lighting devices to flexible optical fiber instruments with realtime video equipment.
The GermanlaryngologistGustav Killian is attributed with performing the first bronchoscopy in 1897.[1] Killian used a rigid bronchoscope to remove a pork bone. The procedure was done in an awake patient using topicalcocaine as alocal anesthetic.[2] From this time until the 1970s, rigid bronchoscopes were used exclusively.
Chevalier Jackson refined the rigid bronchoscope in the 1920s, using this rigid tube to visually inspect thetrachea andmainstem bronchi.[3] The British laryngologistVictor Negus, who worked with Jackson, improved the design of his endoscopes, including what came to be called the "Negus bronchoscope".
Shigeto Ikeda invented the flexible bronchoscope in 1966.[4] The flexible scope initially employedfiberoptic bundles requiring an external light source for illumination. These scopes had outside diameters of approximately 5 mm to 6 mm, with an ability to flex 180 degrees and to extend 120 degrees, allowing entry into lobar and segmental bronchi. Fiberoptic scopes have been superseded by bronchoscopes with acharge-coupled device (CCD)video chip located at their distal end.[5]
The rigid bronchoscope is a hollow metal tube used for inspecting the lower airway.[6] It can be for either diagnostic or therapeutic reasons. Modern use is almost exclusively for therapeutic indications. Rigid bronchoscopy is used for retrieving foreign objects.[7] Rigid bronchoscopy is useful for recovering inhaled foreign bodies because it allows for protection of the airway and controlling the foreign body during recovery.[8]
Massivehemoptysis, defined as loss of over 600 mL of blood in 24 hours, is a medical emergency and should be addressed with initiation of intravenous fluids and examination with rigid bronchoscopy. The larger lumen of the rigid bronchoscope (versus the narrow lumen of the flexible bronchoscope) allows for therapeutic approaches such aselectrocautery to help control the bleeding.
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 aneyepiece or video camera at the opposite end. UsingBowden cables connected to a lever at the hand piece, the tip of the instrument can be oriented, allowing the practitioner to navigate the instrument into individuallobar orsegmental bronchi. Most flexible bronchoscopes also include a channel forsuctioning 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.
Tracheal intubation of patients with difficult airways is often performed using a flexible bronchoscope
Interventional bronchoscopy in chronic obstructive airway inflammatory diseases includingasthma andCOPD has greatly evolved and show promising results for the clinical management of patients.[10]
Video of a bronchoscopy of the right bronchial tree
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.[11]
A flexible bronchoscope is inserted with the patient in a sitting orsupine position. Once the bronchoscope is inserted into the upper airway, thevocal 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.[11]
If an abnormality is discovered, it may besampled using a brush, a needle, or forceps. Specimen of lung tissue (transbronchialbiopsy) may be sampled using a real-timeX-ray (fluoroscopy) or anelectromagnetic tracking system.[12] 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.
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 anddyspnea resulting fromlaryngeal edema,laryngospasm, orbronchospasm). Monitoring continues until the effects of sedative drugs wear off andgag 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 may need to be hospitalized if any bleeding, pneumothorax, orrespiratory distress occurs.
Bronchoscopy has an important role to play in the management of critically ill patients in theIntensive care unit. Fibreoptic bronchoscopy can be applied via anendotracheal tube ortracheotomy in mechanically ventilated patients, or via the native airway in those not requiring ventilation.[13] Indications for bronchoscopy in critically ill patients can be broadly divided into diagnostic and therapeutic categories.[14]
Figure showing complications of bronchoscopy, from[21]
Besides the risks associated with the drugs used, there are also specific risks of the procedure. Although a rigid bronchoscope can scratch or tearairways or damage the vocal cords, the risk of bronchoscopy is limited in otherwise well patients. Complications are more frequent in critically ill patients in intensive care.[22] The risk of complications from fiberoptic bronchoscopy are minimized with good training, careful technique and an ongoing dialogue with the anesthesiologist or sedationist.[9] 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 tracheal 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. Other complications includearrhythmias,bronchospasm,hypoxia,hypercapnia and raisedintracranial pressure.
^Kollofrath O. Entfernung Eines Knochenstucks Aus Dem Rechten Bronchus Auf Naturlichem Wege Und Unter Anwendung Der Directen Laryngoskopie. Munch Med Wochenschr 1897;38:1038-1039.
^Ikeda S, Tobayashi K, Sunakura M, Hatakeyama T, Ono R (August 1969). "[Diagnosis using a fiberscope--the respiratory organs]".Naika (in Japanese).24 (2):284–91.PMID5352887.
^Rosbe KW, Burke K (2012)."Chapter 39. Foreign Bodies". In Lalwani A (ed.).CURRENT Diagnosis & Treatment in Otolaryngology—Head & Neck Surgery (3rd ed.). New York, NY: The McGraw-Hill Companies. RetrievedJuly 16, 2012.