Spirometry Tests Health Article

Precautions

The patient should inform the physician of any medications he or she is taking, or of any medical conditions that are present; these factors may affect the validity of the test. The patient's smoking habits and history should be thoroughly documented. The patient must be able to understand and respond to instructions for the breathing maneuvers. Therefore, the test may not be appropriate for very young, unresponsive, or physically impaired persons.

Spirometry is contraindicated in patients whose condition will be aggravated by forced breathing, including:

• hemoptysis (spitting up blood from the lungs or bronchial tubes)
• pneumothorax (free air or gas in the pleural cavity)
• recent heart attack
• unstable angina
• aneurysm (cranial, thoracic, or abdominal)
• thrombotic condition (such as clotting within a blood vessel)
• recent thoracic or abdominal surgery
• nausea or vomiting

The test should be terminated if the patient shows signs of significant head, chest, or abdominal pain while the procedure is in progress.

Spirometry is dependent upon the patient's full compliance with breathing instructions, especially his or her willingness to extend a maximal effort at forced breathing. Therefore, the patient's emotional state must be considered.

Preparation

The patient's age, gender, and race are recorded, and height and weight are measured before the procedure begins. The patient should not have eaten heavily within three hours of the test. He or she should be instructed to wear loose-fitting clothing over the chest and abdominal area. The respiratory therapist or other testing personnel should explain and demonstrate the breathing maneuvers to the patient. The patient should practice breathing into the mouthpiece until he or she is able to duplicate the maneuvers successfully on two consecutive attempts.

Aftercare

In most cases, special care is not required following spirometry. Occasionally, a patient may become lightheaded or dizzy. Such patients should be asked to rest or lie down, and should not be discharged until after the symptoms subside. In rare cases, the patient may experience pneumothorax, intracranial hypertension, chest pain, or uncontrolled coughing. In such cases, additional care directed by a physician may be required.

Normal results

The results of spirometry tests are compared to predicted values based on the patient's age, gender, and height. For example, a young adult in good health is expected to have the following FEV values:

• FEV-0.5—50-60% of FVC
• FEV-1—75-85% of FVC
• FEV-2—95% of FVC
• FEV-3—97% of FVC

In general, a normal result is 80–100% of the predicted value. Abnormal values are:

• mild lung dysfunction—60–79%
• moderate lung dysfunction—40–59%
• severe lung dysfunction—below 40%

BOOKS

Braunwald, Eugene et al., editors. Harrison's Principles of Internal Medicine. Philadelphia: McGraw-Hill, 2001.

PERIODICALS

Blonshine, S. and J.B. Fink. "Spirometry: Asthma and COPD Guidelines Creating Opportunities for RTs." AARC Times (January 2000): 43-7.

ORGANIZATIONS

National Lung Health Education Program (NLHEP). 1850 High Street, Denver, CO 80218. <http://www.nlhep.org>.

OTHER

Gary, T., et al. "Office Spirometry for Lung Health Assessment in Adults: A Consensus Statement for the National Lung Health Education Program." (March 2000): 1146-61.

National Institutes of Health. [cited April 4, 2003] <http://www.nlm.nih.gov/medlineplus/encyclopedia.html>.

"Spirometry—AARC Clinical Practice Guide." American Association for Respiratory Care. 1130 Ables Lane, Dallas, TX 75229. [cited April 4, 2003] <http://www.muhealth.org/~shrp/rtwww/rcweb/aarc/spirocpg.html>.

Robert Harr Paul Johnson Mark A. Best

QUESTIONS TO ASK THE DOCTOR

• What preparation is needed before the test?
• What results are expected?
• When will the results be available?
• What are the risks of the test in this particular case?