Peak nasal inspiratory flow measurement: an investigation in children.

Theoretically measurement of peak nasal inspiratory flow (PNIF) has promise as a method to objectively evaluate children with nasal airway obstruction. This study establishes normative data for children up to 8 years of age. PNIF increases linearly from a mean value of 30 l/min in early infancy up to a mean value of 80 l/min at age 8 years, apart from a dip at 3 years. There is a reasonably linear incremental rise with increasing height and weight. However, since results depend on both the degree of co-operation of the child and on the subjective impression of the observer as to when a maximal inspiratory effort has been made, there may be drawbacks to its use as a routine clinical method of nasal airway obstruction assessment.