Working...
This site is intended for US Consumers

Health Journey Support | Spirometry for Healthcare Professionals

Spirometry is a pulmonary function test that measures the volume and flow of air that a patient can inhale and exhale. This video describes the volume-time and flow-volume curves that a spirometer records and introduces specifics of obstructive and restrictive breathing patterns.

Keyword must be at least 2 characters long You must enter a keyword(s) to search

If you are a health care professional affiliated with an employer, institution, or committee, or practicing in a state that restricts what items you may receive from manufacturers, we ask that you not accept or download any restricted items from this site. If you are a health care provider practicing in Vermont, we are required by state law to deny you permission to download any items or review any journal articles made available on this site.

Please enable Javascript
Select language for viewing, sharing, and downloading

Spirometry is a pulmonary function test that measures the volume and flow of air that a patient can inhale and exhale. This video describes the volume-time and flow-volume curves that a spirometer records and introduces specifics of obstructive and restrictive breathing patterns.

Transcript: "Spirometry" is a pulmonary function test measuring the volume and flow of air that a patient can inhale and exhale. A spirometry test is the most common method to detect airway obstruction from diseases, such as COPD. In addition, spirometry can help determine disease severity, monitor disease progression, distinguish between asthma and COPD, and evaluate the patient's response to therapy. Before the test, the caregiver should make sure the patient is seated and comfortable. During the test, patients use a device called a "spirometer. " After full inspiration, the patient blows forcefully through the spirometer. [EXHALING] Exhalation should continue for at least six seconds. The patient repeats the test to produce three consistent blows within 5% of each other. The spirometer records forced exhalation in the form of spirograms. A volume-time spirogram plots the volume in liters of exhaled air over time in seconds. [INHALING] For normal lungs, the plotted exhalation curve rises quickly and smoothly-- plateauing within three to four seconds. Predicted normal values vary based on patient gender, height, age, and ethnicity. Important curve values are Forced Vital Capacity-- or FVC-- which is the maximum amount of forcefully exhaled air in one breath, and Forced Expiratory Volume in 1 second-- or FEV1-- which is the volume of air forcefully exhaled in the first second. The normal FEV1 to FVC ratio is greater than or equal to 0. 7. Curves that may indicate airway obstruction will show a reduced FEV1, a reduced or normal FVC, and an FEV1-FVC ratio less than 0. 7. Curves showing restriction-- seen in pulmonary fibrosis, for example-- will show a reduced or normal FEV1, reduced FVC, and a normal or increased FEV1-FVC ratio. Volume-time curves may also show a mixed obstructive and restrictive pattern. To assess bronchodilator reversibility, patients retake the test after using a bronchodilator, such as albuterol. Prior to reversibility testing, withhold short-acting bronchodilators for 6 hours, long-acting bronchodilators for 12 hours, and sustained release theophylline for 24 hours. COPD patients may show reversibility if they have a greater than or equal to 12% and a 200-milliliter improvement in FEV1 following a bronchodilator. A flow volume spirogram gram plots airflow in liters per second against the volume of inhaled and exhaled air in liters. [INHALING] After inhaling deeply, the patient forcefully exhales, producing a normal expiratory curve that rises quickly to Peak Expiratory Flow-- or PEF-- with a near-straight decline to FVC. Following expiration, the patient may inhale forcefully and deeply to produce a closed-volume loop. Expiratory curves indicating obstruction show a reduced PEF followed by a concave dip to FVC as the patient struggles to expel the rest of the air in their lungs. Severe obstructive curves-- as seen in severe COPD-- show a characteristic steeple pattern with a more reduced PEF and a sudden drop in airflow to FVC. Curves indicating restriction follow a normal pattern, but the reduced lung volume moves FVC to the left. Flow-volume curves may show mixed obstructive and restrictive patterns as well. Training is critical for interpreting spirometry results to achieve a meaningful evaluation of pulmonary function. [BREATHING] more...

You should also consider:

Asthma

Asthma

Asthma is a lung condition in which the airways are narrowed and inflamed. Certain outdoor and indoor substances, foods, infections, and exercise can trigger an asthma attack. This video depicts the symptoms of asthma and common medications used to treat the condition.