Introduction The acoustic rhinometry (RA) is a nasal complementary exam that allows to measure the cross-sectional areas of the nose in function of the distance. Nowadays is used world-wide and its indications are well established. However, the normal values, indispensable for the valuation of its results in its indications, are not universal and depending on the population where has been obtained and also the selection criteria. Each centre should know its own normal values. Besides, the papers comparing the results obtained with both acoustic rhinometry and rhinomanometry (RNM) have demonstrated a different level of correlation, from no correlation to high.
Objectives 1. To establish the rhinometryc normal values in baseline situation in adults, men and women 2. Quantification of the increasing of these normal values in vasoconstriction 3. Study the differences between the normal values in men a women 4. Comparison study between acoustic rhinometry and rinomanometry 4.1 Sensibility and specificity of the anterior rinoscopy, anterior active rhinomanometry and acoustic rhinometry respect the feeling of nasal obstruction and respect the detection of nasal abnormalities 4.2 Concordance among nasal symptoms, nasal exploration and RA/RNM 4.3Creation of a extrapolation model between measurements Results and conclusions 1. Normal values in men I-notch: 0,77 cm2 (IC95%=0,60-0,94) located at 0,18 cm (IC95%=0,04-0,32) from the narine C-notch: 0,56 cm2 (IC95%=0,44-0,68) located at 1,87 cm (IC95%=1,69-2,05) from the narine Volume from the narine to the MCA: 1,75 cm3 (IC95%= 1,38- 2,12) Volume from the narine to the fifth centimetre: 5,17 cm3 (IC95%= 4,12-6,22) Volume from the narine to the seventh centimetre: 8,35 cm3(IC95%=6,51- 10,19) 2. Normal values in women I-notch: 0,55 cm2 (IC95%=0,42-0,68) located from the narine 0,26 cm (IC95%=0,12-0,40) C-notch: 0,47 cm2 (IC95%=0,38-0,56) located at 1,83 cm (IC95%=1,67-2,00) from the narine Volume from the narine to the MCA: 1,29 cm3 (IC95%= 1,06- 1,52) Volume from the narine to the fifth centimetre: 4,35 cm3 (IC95%= 3,53-5,17) Volume from the narine to the seventh centimetre: 7,42 cm3(IC95%=5,99- 8,85) 3. Vasoconstriction effect the vasoconstriction produces an increment of the whole nasal dimensions. The average of increment of the first five centimetres is of 30%. The nasal area that suffers the biggest increment is the cross sectional area at the fourth centimetre, with an average increasing of 55% in men and 39% in women.
4. Height effect The rhinometryc measurements suffer a direct and proportional increment to the height of the person. The nasal dimensions of the tall people is bigger than those of the small people 5. Sensibility and specificity of the anterior active rhinomanometry and acoustic rhinometry respect the feeling of nasal obstruction In our sample, from the point of view of absence or presence of the symptom of nasal obstruction, AR offered more sensibility and lesser specificity than RNM (87,5% Vs 72,5% and 31% Vs 69% respectively). Both had the same absolute value of 71%. From the point of view of the intensity of the symptom and the level of the alteration of the objective prove, both RA and RNM showed similar concordance. Despite of the fact than RNM is more functional, it did not have better correlation. In conclusion it can be said that both are acceptable techniques for the monitorization of the feeling of nasal obstruction. Besides. there are external factors to the techniques that produce that this correlation can not be always complete 6. Sensibility and specificity of the anterior active rhinomanometry and acoustic rhinometry respect the detection of structural nasal obstructions In our sample, from the point of view of absence or presence of the structural nasal obstruction, AR offered more sensibility and lesser specificity than RNM ((93% Vs 75 %; 59% Vs 75% respectively). Both had the same absolute value of 71%. However AR obtained better absolute value than RNM (86% Vs 71%). From the point of view of the intensity of the structural obstruction and the level of the alteration of the objective prove, both RA shoed slightly better correlation.. These results lead to the fact that both techniques are equal in the quantifications of the structural nasal obstruction.
7. Correlation between rhinometric measurements and rhinomanometrics measurements Rhinometric measurements and rhinomanometrics measurements had a statistically significant correlation. The correlation, quantitatively more significant, was established between the volume of the first seven centimetres of the nasal cavity and the airflow at 75 pa of pressure (r2 = 0,29; F= 43,4; p = 0,001).
8. Extrapolation measurements model.
It is feasible to design a extrapolation measurements based on a regression model that follows the next formula: Airflow 75 Pa (cc/s)= 37,6 + 27,9 x volume 3 (cc) However the confidence interval between correlations is too large for that this model has a clinical value 9. Acoustic rhinometry and computed rhynomanometry comparison The different method employed by AR and RNM produces that its measurements and results are not directly comparable. None substitute to the other. Their have a complementary relationship.