lung and airway disorders
Pulmonary Function Testing (PFT)
Lung flow rate measurements
The assessment of a lung disorder often involves testing How much air the lungs can hold (lung volume) How much and how quickly air can be exhaled (airflow) Airflow measurements are made with a spirometer, which consists of a mouthpiece and tubing connected to a recording device. The person’s lips should be held tightly around the mouthpiece, and nose clips should be worn to ensure that all the air inhaled or exhaled goes through the mouth. A person inhales deeply, then exhales forcefully as quickly as possible through the tubing while measurements are taken. The volume of air inhaled and exhaled and the length of time each breath takes are recorded and analyzed. This measurement is repeated several times to be sure the results are consistent. Often, the tests are repeated after a person takes a medication that opens the airways of the lungs (bronchodilator). In disorders such as Asthma and A spirometer consists of a mouthpiece, tubing, and a recording device. To use a spirometer, a person inhales deeply, then exhales vigorously and as quickly as possible through the tubing. The recording device measures the volume of air inhaled or exhaled and the length of time each breath takes. Spirometry is used to test lung function. The person breathes normally, then quickly inhales deeply through a mouthpiece with attached tubing. She next exhales quickly until she has emptied her lungs as much as possible. These breaths are measured by the spirometer (at the right), which has a black plastic attachment that rises and falls with each complete breath. Many spirometers are electronic and do not have a piston or bellow that moves as a person breathes. Video from Lahey Clinic Media Center. Spirometry uses a computer (that is, a spirometer) to measure lung function. Normal breathing is recorded on a video monitor as small circles. Next, a deep inhalation is recorded as a larger dotted semicircle on the bottom, and a full exhalation is recorded as a dotted descending curve on top. Video from Lahey Clinic Media Center. A simpler device for measuring how quickly air can be exhaled is the small, hand-held peak flow meter. After inhaling deeply, a person blows into this device as hard as possible. 