Spirometry : Interpretation in primary care

Spirometry stands as a cornerstone in the evaluation of pulmonary function, offering critical insights into the respiratory system's performance. This non-invasive test is pivotal in diagnosing, monitoring, and managing various lung conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and other respiratory disorders. By quantifying the amount of air an individual can forcefully exhale following a deep inhalation, spirometry provides a dynamic glimpse into the mechanical function of the lungs.

The procedure is straightforward yet powerful, encompassing three essential phases: a maximal inhalation to fill the lungs to capacity, a forceful and rapid exhalation to expel as much air as possible (the "blast"), and a continued, complete exhalation until no more air can be expelled, ensuring a comprehensive assessment of lung function. The primary metrics derived from this test include the Forced Vital Capacity (FVC), the total volume of air exhaled during the spirometry test; the Forced Expiratory Volume in One Second (FEV1), quantifying the volume of air expelled in the first second of the test; and the FEV1/FVC ratio, a critical determinant in distinguishing between obstructive and restrictive lung diseases.

These results are meticulously plotted on a graph, presenting a visual representation of the individual's lung capacity and...