Objective Assessment of Respiratory Tract Function

Nasal obstruction is defined as the subjective perception of discomfort or difficulty in the passage of air through the nostrils. It is a common complaint in many nasal conditions and affects the quality of life and the quality of sleep. Medical history and physical examination are key for diagnosing the specific cause. Objective measures can be used to diagnose and treat nasal obstruction. Mucociliary transport time can be used to study ciliary dysfunction either due to primary ciliary dyskinesia or secondary to inflammation. Peak nasal inspiratory flow, acoustic rhinometry and rhinomanometry have specific characteristics and assess different aspects of nasal obstruction. These methods roughly correlate with each other. They may be alternatively utilized in clinical practice, and to evaluate the results of medical and surgical treatments. Peak nasal inspiratory flow, being inexpensive, fast, portable and simple, may be most accessible for use in everyday practice. Upper and lower airways are linked in physiology and in diseases, a concept referred to as the “unified airways”. An evaluation of the lower respiratory function should be considered when assessing patients with nasal obstruction in chronic inflammatory diseases. In both the upper and lower airways, objective and subjective evaluation gives unique sets of information that are complementary and help optimize the diagnosis and the choice of treatment. Objective methods for the measurement of the respiratory tract are desirable in in the era of evidence based therapies.