Spirometry

Spirometry is one of the best and most commonly used lung function tests. The test is done with a device called a spirometer. The spirometer is an instrument that measures lung capacity which is a reflection of lung function. This instrument displays readings which will be recorded as a part of SHOW data collection.

Spirometry includes but is not limited to the measurement of forced vital capacity (FVC), the forced expiratory  volume in the first second (FEV1), and other forced expiratory flow measurements such  as the FEF25-­75%. In addition, it sometimes includes the measurement of maximum  voluntary ventilation (MVV). A graphic representation (spirogram) of the maneuver  should be a part of the results. Either a volume­time or flow­volume display is acceptable. Other parameters that may be obtained by spirometry include FEFmax (PEF), FEF75%, FEF50%, FEF25%, FIF50%, and FIFmax (PIF).

• to show the presence or absence of lung dysfunctions
• to assess severity of known lung disease
• to assess change of lung function in function of time or in function of therapy
• to assess the potential effect of occupational or environmental exposure
• to assess the potential risk for surgical interventions that can effect lung function
• to assess disability

• Hemoptysis of unknown cause
• Pneumothorax
• Unstable cardiovascular status
• Recent myocardial infarctation
• Recent pulmonary embolism
• Thoracic, abdominal or cerebral aneurism (risk of rupture because the increased intrathoracic pressure during forced expiration)
• Recent ocular surgery (eg. cataract)
• Nausea, vomiting
• Recent thoracic or abdominal surgery
• Eye, ear, oral, brain, or cardiothoracic surgeries in the last 3 months

Although spirometry is a safe procedure, untoward reactions may occur, and the value of the information anticipated from spirometry should be weighed against potential hazards.  The following have been reported anecdotally:

1. Pneumothorax;
2. Increased intracranial pressure;
3. Syncope, dizziness, light­headedness;
4. Chest pain;
5. Paroxysmal coughing;
6. Contraction of nosocomial infections;
7. Oxygen desaturation due to interruption of oxygen therapy;
8. Bronchospasm

1. Spirometry in primary care. http://www.respiratoryguidelines.ca/sites/all/files/CTS_Spirometry_Primary_Care_2013.pdf
2. UMHS Indications for Spirometry in Primary Care Clinics. http://www.med.umich.edu/1info/FHP/practiceguides/asthma/spirometry.pdf
3. . Enright PL, Johnson LR, Connett JE, Voelker H, Buist AS. Spirometry in the lung  health study: 1. Methods and quality control. Am Rev Respir Dis 1991;143(6):  1215­1223.