What does spirometry measure?
A. Spirometry provides an objective measurement of lung function. It will measure: a) Expiratory Vital Capacity (EVC): The maximum volume of gas which can be expired from the lungs during a relaxed expiration from a position of full inspiration. b) Inspiratory Vital Capacity (IVC): The maximum volume of gas which can be inspired into the lungs during a relaxed inspiration from a position of full expiration. The expiratory phase is the one more commonly used to measure obstruction and restriction within the lungs. This can be done in two ways: • 1. Static test – performed without regard to time e.g. Vital Capacity (VC) • 2. Dynamic test – performed at forcible and maximum effort against time. e.g.
