rhinomanometry

Rhinomanometry is a clinical test that assesses nasal airway resistance by measuring the relationship between pressure and airflow during nasal breathing. It provides a quantitative estimate of how open or obstructed the nasal passages are, which can help in evaluating chronic obstruction, rhinitis, polyps, deviated septum, and the effects of treatments or surgeries.

Most commonly, active anterior rhinomanometry is used. The patient breathes normally through the nose while pressure and flow are measured across the nasal cavity with a transducer and a flow meter, often via a facemask or nasal adapters. The basic calculation expresses nasal resistance as R = ΔP / V̇, where ΔP is the pressure difference across the nasal cavity and V̇ is the airflow. Measurements are typically reported for unilateral sides and for the combined (total) nasal resistance, usually at a standardized reference pressure, commonly 100 pascals, to allow comparisons.

Rhinomanometry is frequently complemented by other assessments such as acoustic rhinometry, which maps the cross-sectional area and volume of the nasal passages, to provide a more complete picture of nasal patency. It is used in both clinical practice and research to quantify obstruction, monitor treatment responses (medical therapy or surgical intervention), and aid in preoperative and postoperative evaluations. Results can be influenced by factors such as the nasal cycle, mucosal edema, patient effort, and equipment calibration, and normative values vary with age, sex, and technique.

In summary, rhinomanometry offers a standardized, objective measure of nasal airway resistance, aiding diagnosis, treatment planning, and outcome assessment in disorders of nasal obstruction.