Reproducibility of Acoustic Rhinometry and Rhinomanometry in Normal Subjects

Abstract

The reproducibility of nasal patency measurements was assessed by acoustic rhinometry and active rhinomanometry using previously described Toronto methodologies. Six subjects with normal upper airways were tested with both procedures on six separate occasions within a 2-month period. Topical decongestant was applied to minimize the effects of mucosal variation on the nasal airway. The mean coefficients of variation (mean +/- s.d; %) over time of the measurements were 8.1 +/- 4.1 and 9.7 +/- 5.2 for minimal unilateral cross-sectional area and 4.8 +/- 1.8 and 5.5 +/- 3.5 for nasal volume (0-5 cm) of the right and left sides, respectively. For active rhinomanometry, the mean coefficients of variation (mean +/- s.d.; %) over time of the measurements were 15.9 +/- 7.3, 12.9 +/- 4.6, and 8.5 +/- 2.8 for right, left and combined nasal airflow resistance. The intraclass correlation coefficient was 0.76, 0.70, and 0.96 for right, left, and combined nasal resistance, 0.91 and 0.87 for right and left minimal cross sectional area, and 0.86 and 0.69 for right and left nasal volumes, respectively, also confirming a high level of reproducibility for both methods. In conclusion, performed by an experienced operator under controlled circumstances, the reproducibility of both methods of nasal patency assessment compared favorably with many widely accepted clinical tests.

Áreas seccionais nasais de adultos sadios aferidas por rinometria acústica

“…Normal cross-sectional area values have been reported by many authors [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] , whose findings are summarized on Chart 1. Nonetheless, due to factors such as ethnic, weather, and laboratory-related differences, local reference values must be determined, as stressed by Hilberg and Pedersen 7 and Roithman 26 more recently.…”

“…The papers cited above are quite recent, and two used the same equipment employed in our study. In all others [14][15][16][17][20][21][22] , the average CSA1 values ranged between 0.60cm 2 and 0.78cm 2 . This difference may be attributed to the fact that most studies -specially the ones done longer ago -used olive-type nasal adapters which ae known to introduce nasal cavity deformation, thus leading to overestimated cross-sectional area measurements 14,29 .…”

“…Two methodological issues deserve special attention. Firstly, the group of 30 individuals analyzed in this study were conveniently selected from a population of 54 apparently health individuals based on subjective reports of normal nasal patency sensation and no history of nasal functional and anatomical disorders, as also seen in control groups enrolled by other authors 17,20,21,23 . When comparing the values acquired from our sample to the 0.35cm 2 indicated as normal by Hilberg and Pedersen7, we verified that only one of the 60 cavities analyzed had an area smaller than the value defining adequate nasal patency, strongly indicating that our sample was indeed made up by subjects without nasal obstruction.…”

A reprodutibilidade do espelho de Glatzel modificado na aferição da permeabilidade nasal

“…Acoustic rhinometry is a static test that does not require subjects to actively breathe during testing; it appears to show less test retest measurement variation. 7,[14][15] Rhinomanometry measures transnasal air flow while the subject breathes nasally; it shows more variation between measurements. [15][16][17] Verifying the reproducibility of GM measurements at different times might support improved data interpretation, and therefore its test retest value.…”

“…7,[14][15] Rhinomanometry measures transnasal air flow while the subject breathes nasally; it shows more variation between measurements. [15][16][17] Verifying the reproducibility of GM measurements at different times might support improved data interpretation, and therefore its test retest value. Furthermore, investigating the correlation between subjective perception of nasal patency and mirror measurements may provide a theoretical basis for the clinical use of this tool, which would be desirable.…”