Bronchoscopy

0in;mso-line-height-alt:11.3pt">Definition

Bronchoscopy is a procedure in which a cylindrical fiberoptic scope is inserted into the airways. This scope contains a viewing device that allows the visual examination of the lower airways.

0in;mso-line-height-alt:11.3pt">Purpose

During a bronchoscopy, a physician can visually examine the lower airways, including the larynx, trachea, bronchi, and bronchioles. The procedure is used to examine the mucosal surface of the airways for abnormalities that might be associated with a variety of lung diseases. Its use includes the visualization of airway obstructions such as a tumor, or the collection of specimens for the diagnosis of cancer originating in the bronchi of the lungs (bronchogenic cancer). It can also be used to collect specimens for culture to diagnose infectious diseases such as tuberculosis. The type of specimens collected can include sputum (composed of saliva and discharges from the respiratory passages), tissue samples from the bronchi or bronchioles, or cells collected from washing the lining of the bronchi or bronchioles. The instrument used in bronchoscopy, a bronchoscope, is a slender cylindrical instrument containing a light and an eyepiece. There are two types of bronchoscopes, a rigid tube that is sometimes referred to as an open-tube or ventilating bronchoscope, and a more flexible fiberoptic tube. This tube contains four smaller passages—two for light to pass through, one for seeing through and one that can accommodate medical instruments that may be used for biopsy or suctioning, or that medication can be passed through.

Bronchoscopy may be used for the following purposes:

·         to diagnose cancer, tuberculosis, lung infection, or other lung disease

·         to examine an inherited deformity of the lungs

·         to remove a foreign body in the lungs, such as a mucus plug, tumor, or excessive secretions

·         to remove tissue samples, also known as biopsy, to test for cancer cells, help with staging the advancement of the lung cancer, or to treat a tumor with laser therapy

·         to allow examination of a suspected tumor, obstruction, secretion, bleeding, or foreign body in the airways

·         to determine the cause of a persistent cough, wheezing, or a cough that includes blood in the sputum

·         to evaluate the effectiveness of lung cancer treatments

0in;mso-line-height-alt:11.3pt">Precautions

Patients not breathing adequately on their own due to severe respiratory failure may require mechanical ventilation prior to bronchoscopy. It may not be appropriate to perform bronchoscopy on patients with an unstable heart condition. All patients must be constantly monitored while undergoing a bronchoscopy so that any abnormal reactions can be dealt with immediately.

 

0in;mso-line-height-alt:11.3pt">Description

There are two types of bronchoscopes, a rigid tube and a fiberoptic tube. Because of its flexibility, the fiberoptic tube is usually preferred. However, if the purpose of the procedure is to remove a foreign body caught in the wind-pipe or lungs of a child, the more rigid tube must be used because of its larger size. The patient will either lie face-up on his/her back or sit upright in a chair. Medication to decrease secretions, lessen anxiety, and relax the patient are often given prior to the procedure. While breathing through the nose, anesthesia is sprayed into the mouth or nose to numb it. It will take 1-2 minutes for the anesthesia to take effect. Once this happens, the bronchoscope will be put into the patient's mouth or nose and moved down into the throat. While the bronchoscope is moving down the throat, additional anesthesia is put into the bronchoscope to numb the lower parts of the airways. Using the eyepiece, the physician then observes the trachea and bronchi, and the mucosal lining of these passageways, looking for any abnormalities that may be present.

If the purpose of the bronchoscopy is to take tissue samples or biopsy, forceps or a bronchial brush are used to obtain cells. If the purpose is to identify an infectious agent, a bronchoalveolar lavage (BAL) can be used to gather fluid for culture purposes. Also, if any foreign matter is found in the airways, it can be removed.

Another procedure using bronchoscopy is called fluorescence bronchoscopy. This can be used to detect pre-cancerous cells present in the airways. By using a fluorescent light in the bronchoscope, precancerous tissue will appear dark red, while healthy tissue will appear green. This technique can help detect lung cancer at an early stage, so that treatment can be started early.

0in;line-height:11.3pt">Alternative procedures

Depending upon the purpose of the bronchoscopy, alternatives might include a computed tomography scan (CT) or no procedure at all. Bronchoscopy is often performed to investigate an abnormality that shows up on a chest x ray or CT scan. If the purpose is to obtain biopsy specimens, one option is to perform surgery, which carries greater risks. Another option is percutaneous (through the skin) biopsy guided by computed tomography.

 

 

 Preparation

The doctor should be informed of any allergies and all the medications that the patient is currently taking. The doctor may instruct the patient not to take medications like aspirin or anti-inflammatory drugs, which interfere with clotting, for a period of time prior to the procedure. The patient needs to fast for 6 to 12 hours prior to the procedure and refrain from drinking any liquids the day of the procedure. The bronchoscopy takes about 45 to 60 minutes, with results usually available in one day. Prior to the bronchoscopy, several tests may be done, including a chest x ray and blood work. Sometimes a bronchoscopy is done under general anesthesia. Patients usually have an intravenous (IV) line in the arm. Most likely, the procedure will be done under local anesthesia, which is sprayed into the nose or mouth. This is necessary to decrease the gag reflex. A sedative may also be used to help the patient relax. It is important that the patient understands that at no time will the airway be blocked and that oxygen can be supplied through the bronchoscope. A signed consent form is necessary for this procedure.

0in;mso-line-height-alt:11.3pt">Aftercare

After the bronchoscopy, the patient will be monitored for vital signs such as heart rate, blood pressure, and breathing, while resting in bed. Sometimes patients have an abnormal reaction to anesthesia. All saliva should be spit into a basin so that it can be examined for the presence of blood. If a biopsy was taken, the patient should not cough or clear the throat as this might dislodge any blood clot that has formed and cause bleeding. No food or drink should be consumed for about two hours after the procedure or until the anesthesia wears off. Diet is gradually progressed from ice chips and clear liquids to the patient's regular diet. There will also be a temporary sore throat and hoarseness that may last for a few days.

0in;mso-line-height-alt:11.3pt">Risks

Minor side effects arise from the bronchoscope causing abrasion of the lining of the airways. This results in some swelling and inflammation, as well as hoarseness caused from abrading the vocal cords. If this abrasion is more serious, it can lead to respiratory difficulty or bleeding of the airway lining. A more serious risk involved in having a bronchoscopy performed is the occurrence of a pneumothorax, due to puncturing of the lungs, which allows air to escape into the space between the lung and the chest wall. These risks are greater with the use of a rigid bronchoscope than with a fiberoptic bronchoscope. If a rigid tube is used, there is also a risk of chipped teeth.

0in;mso-line-height-alt:11.3pt">Normal results

Normal tracheal appearance consists of smooth muscle with C-shaped rings of cartilage at regular intervals. The trachea and the bronchi are lined with a mucous membrane.

0in;mso-line-height-alt:11.3pt">Abnormal results

Abnormal bronchoscopy findings may involve abnormalities of the bronchial wall such as inflammation, swelling, ulceration, or anatomical abnormalities. The bronchoscopy may also reveal the presence of abnormal substances in the trachea and bronchi. If samples are taken, the results could indicate cancer, disease-causing agents or other lung disease. Other abnormalities include constriction or narrowing (stenosis), compression, dilation of vessels, or abnormal branching of the bronchi. Abnormal substances that might be found in the airways include blood, secretions, or mucus plugs. Any abnormalities are discussed with the patient.

0in;line-height:11.3pt">Resources

0in;line-height:11.3pt">BOOKS

Bone, Roger C., ed. Pulmonary & Critical Care Medicine, 1998 ed. St. Louis, MO: Mosby-Year Book, Inc., 1998.

Fauci, Anthony S. Harrison's Principles of Internal Medicine, 14th Edition. New York: McGraw-Hill, 2000.

0in;line-height:11.3pt">PERIODICALS

"Fluorescence Bronchoscopy Technology Used in Early Detection." Cancer Weekly Plus (Feb 3, 1997): 17.

0in;line-height:11.3pt">ORGANIZATION

American College of Chest Physicians. 3300 Dundee Rd., Northbrook, IL 60062. (800) 343-2227.<www.chestnet.org>.

Cindy L. Jones, Ph.D.

0in;line-height:11.3pt;mso-outline-level:2">KEY TERMS 0in;line-height:11.3pt;mso-outline-level:3">Anesthesia —A drug used to induce loss of sensation. It is used to lessen the pain of surgery and medical procedures. 0in;line-height:11.3pt;mso-outline-level:3">Bronchi —The network of tubular passages that carry air to the lungs and allow air to be expelled from the lungs. 0in;line-height:11.3pt;mso-outline-level:3">Bronchioles —Small airways extending from the bronchi into the lobes of the lungs. 0in;line-height:11.3pt;mso-outline-level:3">Bronchoalveolar lavage —Washing cells from the air sacs at the end of the bronchioles. 0in;line-height:11.3pt;mso-outline-level:3">Trachea —The windpipe.

 ___________________________________________________

0in;line-height:11.3pt">QUESTIONS TO ASK THE DOCTOR

·         Did you see any abnormalities?

·         How soon will you know the results of the biopsy (if one was done)?

·         When can I resume any medications that were stopped?

·         What future care will I need?

·         For what type of problems should I call you?

 

 

Brucellosis

Brucellosis is a disease caused by bacteria in the genus Brucella. The disease infects animals such as swine, cattle, and sheep. Humans can become infected indirectly through contact with infected animals or by drinking Brucella -contaminated milk. In the United States, most domestic animals are vaccinated against the bacteria, but brucellosis remains a risk with imported animal products.

 

0in">Characteristics of Brucella

Brucella are rod-shaped bacteria that lack a diffuse sugary covering (capsule) around their cell membranes. Unlike most bacteria, Brucella cause infection by actually entering host cells. As the bacteria cross the host cell membrane, they are engulfed by host cell vacuoles called phagosomes. The presence of Brucella within host cell phagosomes initiates a characteristic immune response, in which infected cells begin to stick together and form aggregations called granulomas.

0in">Brucella species

Three species of Brucella cause brucellosis in humans: Brucella melitensis, which infects goats; B. abortis, which infects cattle and, if the animal is pregnant, causes the spontaneous abortion of the fetus; and B. suis, which infects pigs. In animals, brucellosis is a self-limiting disease, and usually no treatment is necessary for the resolution of the disease. However, for a period of time from a few days to several weeks, infected animals may continue to excrete brucella into their urine and milk. Under warm, moist conditions, the bacteria may survive for months in soil, milk, and even seawater.

Because the bacteria are so hardy, humans may become infected with Brucella by direct contact with the bacteria. Handling or cleaning up after infected animals may put a person in contact with the bacteria. Brucella are extremely efficient in crossing the human skin barrier through cuts or breaks in the skin.

Symptoms and treatment of brucellosis

The incubation period of Brucella —the time from exposure to the bacteria to the start of symptoms—is typically about three weeks. The primary complaints are weakness and fatigue. An infected person may also experience muscle aches, fever, and chills.

The course of the disease reflects the location of the Brucella bacteria within the human host. Soon after the Brucella are introduced into the bloodstream, the bacteria seek out the nearest lymph nodes and invade the lymph node cells. From the initial lymph node, the Brucella spread out to other organ targets, including the spleen, bone marrow, and liver. Inside these organs, the infected cells form granulomas.

Diagnosing brucellosis involves culturing the blood, liver, or bone marrow for Brucella organisms. A positive culture alone does not signify brucellosis, since persons who have been treated for the disease may continue to harbor Brucella bacteria for several months. Confirmation of brucellosis, therefore, includes being able to grow the bacteria on a suitable food source (generally called a medium), detection of antibodies (proteins produced by the immune system in response to the presence of a foreign proteins

0in;mso-outline-level:3">KEY TERMS Granuloma— An immune response in which cells infected with bacteria clump together. Granuloma formation is typical of tuberculosis and brucellosis. Lymph nodes— Small, bean-shaped structures located along the lymphatic vessels of the body. Lymph nodes function in the immune response to protect the body against foreign cells. Pasteurization— The process in which milk or either dairy products are heated to a high temperature in order to kill disease-causing bacteria.

 

generically termed antigens) to the microorganism in a blood sample, as well as evidence of the characteristic symptoms and a history of possible contact with infected milk or other animal products.

In humans, brucellosis caused by B. abortus is a mild disease that resolves itself without treatment. Brucellosis caused by B. melitensis and B. suis, however, is chronic and severe. Brucellosis is treated with administration of an antibiotic that penetrates host cells to destroy the invasive bacteria.

0in">Prevention

Since the invention of an animal vaccine for brucellosis in the 1970s, the disease has become somewhat rare in the United States. Yet the vaccine cannot prevent all incidence of brucellosis. According to the Centers for Disease Control and Prevention, 100 to 200 cases occur each year in the United States. Most of these were reported in persons who worked in the meat processing industry. Brucellosis remains a risk for those who work in close contact with animals, including veterinarians, farmers, and dairy workers.

Brucellosis also remains a risk when animal products from foreign countries are imported into the United States. Outbreaks of brucellosis have been linked to unpasteurized feta and goat cheeses from the Mediterranean region and Europe. In an outbreak in the 1960s, brucellosis was linked to bongo drums imported from Africa: drums made with infected animal skins can harbor Brucella bacteria, which can be transmitted to humans through cuts and scrapes in the human skin surface.

In the United States, preventive measures include a rigorous vaccination program that involves all animals in the meat processing industry. On an individual level, people can avoid the disease by not eating animal products imported from other countries. If this is not possible or desirable, make sure that imported cheeses have been made with pasteurized milk. If the package does not indicate pasteurization, do not eat the cheese.

As of 2006, there is no vaccine for brucellosis.

0in">Resources

0in">BOOKS

Icon Health Publications. Brucellosis: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. San Diego: Icon Health Publications, 2004.

Lopez-Goni, I. Brucella. Oxford: BIOS Scientific

Publications, 2005.

Prescott, L., J. Harley, and D. Klein. Microbiology 5th ed. New York: McGraw-Hill, 2002.

Kathleen Scogna