Reference values for acoustic rhinometry in decongested school children and adults: the most sensitive measurement for change in nasal patency.

Only a limited reference material for acoustic rhinometry (AR) exists for school children most often calculated as the minimum cross-sectional area (MCA) in the non-decongested nose. We want to establish a set of reference values for MCA and nasal volumes for both adults and children and include values also for the decongested nose and determine the most sensitive measurement for change in nasal patency. Data from two studies were used; one comprising of 53 (20M, 33F) school children, age 9-11 years, and one comprising 146 (127M, 19F) healthy workers in the wood industry. Measurements by acoustic rhinometry were done before and after decongestion with two puffs of oxymethazoline nasal spray (1 mg/ml). We found the decongested nasal volume (2-5 cm) to be 3.71 cm3 (3.58-3.84) in school children and 5.44 cm3 (5.21-5.67) in adults. We found the volume from 2-5 cm into the nasal cavity to be the most sensitive measure of change in nasal patency by decongestion, and MCA to be the least sensitive in both adults and children. A larger study population of children, covering a broader range of age, is needed to stratify for gender and height. Our data in adults are in accordance with previous findings. We have provided a reference material for acoustic rhinometry in school children and adults. Future evaluation of change in nasal patency should contain information about nasal volume from 2-5 cm into the nasal cavity and not just MCA in adults and school children.