Lung Disease & Respiratory Health Center

How It Is Done continued...

Some people may need bronchoscopy to collect a sputum sample. During bronchoscopy, a thin, lighted tube (bronchoscope) is inserted through your mouth or nose into the airways leading to your lungs. You will be given medicine that numbs your throat and nose so you do not feel discomfort from the bronchoscope. You may also be given a sedative to make you sleepy during the procedure. To collect the sputum sample, a salt solution may be washed into the airway and then suctioned into a container. A small, thin brush may be used to collect a sample.

A sputum sample can also be collected using suction. During this procedure, a soft, flexible tube (called a nasotracheal catheter) is inserted through the nose and down the throat. Suction is applied for up to 15 seconds to collect the sputum sample. This method of collecting a sputum sample is often used for people who are very sick or unconscious.

In rare cases, a sputum sample may need to be collected by inserting a needle through the neck into the windpipe (trachea). This is called a transtracheal aspiration. Before a transtracheal aspiration, a local anesthetic is injected into the site where the needle will be inserted. Oxygen may be used before and after a transtracheal aspiration to help with breathing. This method of collecting a sputum sample may be used for people who are very sick and in the hospital.

Once the sputum sample is collected, it will be placed in a container with substances (growth medium or culture medium) that promote the growth of infecting organisms (bacteria or fungi). Bacteria usually need 2 to 3 days to grow. Fungus often takes a week or longer to grow. The organism that causes tuberculosis may take 6 weeks to grow. Any bacteria or fungi that grow will be identified under a microscope or by chemical tests. Sensitivity testing, to determine the best antibiotic to use against the organism that grows, often takes 1 to 2 additional days.

How It Feels

If you have discomfort when taking a deep breath or when coughing, obtaining a sputum sample may be uncomfortable. If you need to inhale the aerosol mist to produce a sputum sample, you will often feel a deep, uncontrollable urge to cough.

During bronchoscopy or collection of a sputum sample using a catheter, you may feel a strong urge to cough as the bronchoscope or catheter passes into the back of your throat. You may also feel as if you cannot breathe. Try to relax and breathe slowly while the bronchoscope or catheter is in place. If you are given medicine to numb your throat and nose, you may feel as if your tongue and throat are swollen and that you cannot swallow.

In rare cases, a transtracheal aspiration is used to collect a sputum sample. The doctor will inject a local anesthetic to keep you from feeling any pain when the needle is inserted into your trachea. When you are given the local anesthetic, you will feel sharp stinging or burning that lasts a few seconds. When the needle is inserted into the trachea, you will again feel a sharp pain for a few seconds, similar to having your blood drawn. The doctor may ask you to hold your breath during key moments of the procedure.