Die quantitative Auswertung von Rhinomanometriekurven*

Abstract

With the use of a new evaluation method, the rhinomanometric curve is quantified with only two measurements, both in the laminar and in the turbulent part of the curve. 1) The volume flow measured at a constant delta p of 15 mm of water defines the volume flow increase in the initial, more laminar part of the curve, and is in most cases a sufficient measure of the conductivity of the nose. The rule that governs the addition of parallel resistances is not broken when determining the bilateral breathing resistance. 2) The per cent volume increase (delta V) upon doubling the pressure difference (from 15 to 30 mm of water or, where conductivity is high, from 7.5 to 15 mm of water) quantifies the further increase of the curve and allows to distinguish characteristic from abnormal shapes of the curve. delta V gives an indication of the amount of turbulence in higher flows. The smaller the per cent volume increase the greater the turbulence. An increase by less than 41% indicates total turbulence, and under 25% delta V indicates a one-way stenosis by additional factors that cause narrowing of the lumen. The per cent volume increase (delta V) upon doubling delta p is a simple and easily understandable measurement. It is therefore superior in its simplicity to formula values such as resistance quotient, coefficient of resistance and increase of angle. The use of constant values of delta p (7.5, 15, 30 mm of water) ensures the comparability of the results. This procedure is applicable in both high and low air conductivity of the nose and is therefore suitable for statistical analysis. Furthermore, there is the possibility of an automatic evaluation of the rhinomanometric curve.