New aerodynamic aspects of nasal patency.

In considering possible aerodynamic indicators of subjective nasal stuffiness, we measured nasal resistance, acceleration change of nasal airflow, and alteration of differential pressure and compared those with the degree of severity of sensation of nasal obstruction in 75 patients. The acceleration change of airflow and alteration of differential pressure are presented as an equation: y = ax2 + bx + c, in which "a" represents the approximate shape of the curve. Nasal resistance, on either inspiration or expiration, and coefficient "a" of acceleration change the rapid phase from inspiration to expiration correlated well with subjective nasal patency, while coefficient "a" of acceleration change the rapid phase from expiration to inspiration and alteration of differential pressure either the rapid phase from inspiration to expiration or from expiration to inspiration did not correlate well with perception of nasal blockage. It seems that measurement of respiratory acceleration of airflow of quiet nasal breathing is a useful indicator of subjective nasal patency.