Nasal congestion and airway obstruction: the validity of available objective and subjective measures.

Rhinomanometry and acoustic rhinometry provide the best methods for objective assessment of nasal obstruction. Advanced equipment for these methods is now available, and most devices are reliable provided that care is taken to calibrate the device properly and, for rhinomanometers, the user is completely familiar with the mathematical algorithm for resistance used by the accompanying software. Suggestions for improvement in standardization of rhinomanometry are given. Rhinomanometry and rhinometry are both capable of objectively measuring nasal obstruction, but they are complementary methods that assess different nasal attributes, the former being a test of nasal function, and the latter a representation of nasal geometry. Objective methods are strongly recommended for use in the evaluation of pharmacologic agents that are expected to improve nasal airflow. When further studies needed to validate their use for long-term comparisons are done, these methods should find an increasing place in clinical practice.