Spirometry is used to measure forced expiratory flow rates and volumes. It is the most commonly used pulmonary function test and is useful in the evaluation of patients with respiratory symptoms (eg, dyspnea, cough, wheeze) or risk factors for respiratory disease (eg, smoking, occupational exposures, family history).
In the office setting, spirometry is typically used to detect, confirm, and monitor obstructive airway diseases (eg, asthma, COPD) [1-4]. In this setting, the clinician must be knowledgeable about issues related to equipment, performance of the forced expiratory maneuver, and interpretation of the data to obtain reliable and clinically useful information [5-7]. International guidelines for performance of office spirometry have been published .
The performance of spirometry in the office setting will be reviewed here. More general issues related to pulmonary function tests, the interpretation of flow volume loops, and the technique of bronchoprovocation testing are discussed separately. (See "Overview of pulmonary function testing in adults" and "Flow-volume loops" and "Bronchoprovocation testing".)
The majority of spirometers manufactured since 1990 are accurate, although some flow-sensing office spirometers can produce falsely high results [9-11]. The National Lung Health Education Program (NLHEP) has published guidelines for office spirometers and has a list of features (eg, graphic output) that should be available .
To avoid cross-contamination between patients when using permanent flow sensors, it is preferable to employ single use disposable flow sensors that practically eliminate the risk of inhalational cross contamination. Disposable one-way mouthpieces may also be used; otherwise, patients should be instructed not to inhale from the spirometer prior to forced exhalation maneuvers. Volume sensing spirometers maintain accuracy over many years, but are more difficult to clean and are rarely used for office spirometry.