Measurement of maximal pressures and the sniff manoeuvre in children.

Maximal static inspiratory and expiratory pressures are simple, noninvasive tests that evaluate global inspiratory and expiratory muscle strength. But these tests may be difficult or impossible to perform in young children. The sniff is a natural maneuver which many children find easier to perform than maximal pressures. The measurement of the nasal inspiratory pressure represents a valuable inspiratory muscle test which allows the extension of inspiratory muscle testing to a younger and larger paediatric population.