Spirometry

Spirometry is a common pulmonary function test that measures how well a person is breathing by assessing the amount and speed of air that can be inhaled and exhaled.

What is Spirometry Used For?

Spirometry is used to diagnose and monitor various lung conditions, such as:

• Asthma
• Chronic obstructive pulmonary disease (COPD)
• Cystic fibrosis
• Pneumonia
• Pulmonary fibrosis

How is Spirometry Performed?

Spirometry is typically performed in a doctor's office or pulmonary function laboratory. The test involves:

1. The patient sits comfortably and wears a nose clip to prevent air from escaping through the nose.
2. The patient takes a deep breath and then exhales as quickly and completely as possible into a mouthpiece connected to a spirometer.
3. The spirometer measures the amount and speed of air exhaled, and the results are recorded on a graph called a spirogram.

Types of Spirometry Tests

There are several types of spirometry tests, including:

• Forced Vital Capacity (FVC): measures the total amount of air that can be exhaled after a maximum inhalation.
• Forced Expiratory Volume in One Second (FEV1): measures the amount of air that can be exhaled in one second.
• Peak Expiratory Flow (PEF): measures the fastest rate at which a person can exhale air.

Interpretation of Spirometry Results

The results of spirometry are compared to normal values based on the patient's age, sex, height, and weight. Abnormal results may indicate:

• Obstructive lung disease: characterized by a decrease in FEV1/FVC ratio.
• Restrictive lung disease: characterized by a decrease in FVC and a normal or increased FEV1/FVC ratio.

Risks and Contraindications

Spirometry is generally a safe and non-invasive test, but it may be contraindicated in certain situations, such as:

• Recent eye or abdominal surgery
• Recent myocardial infarction or stroke
• Pregnancy (in some cases)

Preparation for Spirometry

To prepare for spirometry, patients should:

• Avoid smoking and heavy meals for at least 4-6 hours before the test.
• Avoid wearing tight clothing that may restrict breathing.
• Bring a list of medications and medical history to the appointment.