Nasal histamine challenge: a reproducible model of induced congestion measured by acoustic rhinometry.

We describe the development of a clinical model of nasal congestion using a fixed dose histamine challenge in normals. The objective was to use histamine to induce a similar degree of nasal congestion as a natural common cold (from unpublished data of 250 cold sufferers) and thus establish a rapid screening system for decongestant drug effects. Sixtynine normal subjects were challenged with histamine diphosphate (300 micrograms/nostril) on 2 visits.

Acoustic rhinometry: recommendations for technical specifications and standard operating procedures.

This document is the result of the work and discussion of the Standardization Committee on Acoustic Rhinometry and presents guidelines for quality control and optimal application of acoustic rhinometry at its present stage. It is suggested that: 1. A well-defined standard nose is used for testing and optimising the equipment (data for a standard nose is given in the paper).

Acoustic rhinometry: validation by three-dimensionally reconstructed computer tomographic scans.

The aim of the present study was a validation of acoustic rhinometry (AR) by computed tomography (CT). Six healthy subjects were examined by CT and AR. The CT data were processed in a computer program (AutoCAD), and a virtual three-dimensional model of each nasal cavity was constructed.

Acoustic reflections during rhinometry: spatial resolution and sound loss.

The accuracy of the acoustic reflections method for the evaluation of human nasal airway geometry is determined by the physical limitations of the technique and also by the in vivo deviations from the assumptions of the technique. The present study 1) examines the sound loss caused by nonrigidity of the nasal mucosa and viscous loss caused by complex geometry and its influence on the estimation of the acoustic area-distance function; 2) examines the optimal relation between sampling frequency and low-pass filtering, and 3) evaluates advantages of breathing He-O2 during the measurements on accuracy. Measurements made in eight plastic models, with cavities exactly identical to the "living" nasal cavities, revealed only minor effects of nonrigidity of the nasal mucosa.

Prediction of nasal obstruction based on clinical examination and acoustic rhinometry.

The aim of this study was to find variables which characterize nasal obstruction. Scores from the clinical history, anterior rhinoscopy and objective values from acoustic rhinometry were found of importance. In a randomly-selected adult population of 230 individuals, 14% had the subjective feeling of nasal obstruction.

Effect of corticosteroids on nasal blockage in rhinitis measured by objective methods.

This paper gives an overview of placebo-controlled studies of the effect of corticosteroid treatment on nasal blockage, based on objective measurements of nasal airway patency. A few studies of perennial rhinitis have indicated that pretreatment with an intranasal corticosteroid has a moderate effect on nasal hyperresponsiveness, measured as the histamine-induced increase of nasal blockage. Whereas the effect on allergen-induced early-phase symptoms is variable, the effect on the late-phase blockage is almost complete.

Acoustic rhinometry: influence of paranasal sinuses.

The influence of the maxillary sinuses in acoustic rhinometry (AR) has not been evaluated, and this is the aim of the present study. We examined six subjects with AR and magnetic resonance imaging (MRI) after nasal decongestion to compare the area-distance relationships determined by the two methods. From the MRI data we obtained copies of the nasal cavities with and without maxillary sinuses, which were made in plastic by a stereolithographic method.

Bilateral inferior turbinoplasty in chronic nasal obstruction.

Bilateral inferior turbinoplasty was performed in cases of chronic nasal obstruction, in which conservative treatment had failed. Forty-five patients without significant septal deviation and with chronic nasal obstruction were objectively evaluated by acoustic rhinometry (AR) before and 3-6 months after turbinoplasty, in order to assess the changes of the dimensions of the nasal cavity obtained. Mucosal turbinate hypertrophy (defined objectively by AR) was present in 76% of the cases.

Effect of terfenadine and budesonide on nasal symptoms, olfaction, and nasal airway patency following allergen challenge.

The study investigated the effect of the oral H1-blocker terfenadine on allergen challenge in subjects with nasal allergy in comparison with the topical steroid, budesonide. A randomized, placebo-controlled, double-blind, crossover study with 3 experimental days was performed outside the pollen season. Seventeen nonsmokers with hay fever (symptoms, positive skin prick test, and RAST against timothy) were treated for 14 days before each experimental day, where the response to nasal challenge with four different concentrations of timothy was measured every 15 min for 6 h.

Spontaneous variations in congestion of the nasal mucosa.

Background: Nasal patency shows spontaneous variations but is also influenced by exercise and allergic conditions. These variations have not been described in detail with regard to allergy.

Objectives: The purpose of this study was to examine whether these variations are different in nonallergic subjects and in subjects with nasal allergy to pollen out of the pollen season.

Nasal histamine challenge in nonallergic and allergic subjects evaluated by acoustic rhinometry.

Nasal patency shows spontaneous variations but is influenced by a number of factors like exercise and allergic conditions. Nasal histamine challenge has been used to define nasal hypersensitivity. We have applied acoustic rhinometry as a new objective method to study the spontaneous variations of the nasal mucosa and its response to histamine challenge in 12 nonallergic subjects and 12 subjects with nasal allergy to pollen, but out of the pollen season.

Nasal cavity dimensions in the newborn measured by acoustic reflections.

The acoustic reflections technique was used to measure nasal cavity dimensions in 27 newborns. The results were expressed in terms of curves describing cross-sectional area as a function of the distance into the nose. From these curves, a mean curve with 95% confidence limits, nasal cavity volumes between the nostril and 4.

Posture and nasal patency: evaluation by acoustic rhinometry.

Nasal passage geometry was measured by acoustic rhinometry in 8 healthy medical students (5 males and 3 females, 21-29 years old; mean age 24 years) after 6 min in different postures of head and body. The minimum cross-sectional area (A-min) and volume between the nostril and 7 cm posteriorly were measured on both sides. When changing from sitting to horizontal the total airway dimension (i.

Nasal airway geometry: comparison between acoustic reflections and magnetic resonance scanning.

To evaluate the accuracy of the acoustic reflection (AR) technique for determination of nasal cavity cross-sectional areas, the area-distance function of both sides of the nose was determined in 10 subjects and compared with magnetic resonance imaging (MRI). Interindividual variation for the correlation between MRI and AR was seen, but in general the areas from 1 to 6 cm into the nasal cavity measured by AR were larger than areas measured by MRI, especially where the surface was most convoluted. The total volume for this region was 6.

Nasal reaction to changes in whole body temperature.

The changes in nasal patency following a 1.5 degrees C decrease or increase in whole body temperature were measured in 8 healthy young males, during and after 30 min of immersion in a 15 degrees C cold or a 40 degrees C warm bath, breathing air at the same temperature, in a cross-over experimental design. The nasal reactions were traced by consecutive measurements of changes in nasal cavity volumes by acoustic rhinometry.

Septoplasty and compensatory inferior turbinate hypertrophy: a randomized study evaluated by acoustic rhinometry.

The present study deals with the indication for inferior turbinate surgery in cases of concomitant anterior septal deviation. We define, by acoustic rhinometry, the characteristics of the obstructed nose and define mucosal turbinate hypertrophy. A random sample of 80 patients with nasal obstruction and anteriorly located septal deviation were objectively evaluated by acoustic rhinometry pre- and post-operatively.

Nasal packing after septoplasty.

A prospective study to compare 3 different types of nasal pack after septoplasty with or without a supplementary turbinectomy has been performed with respect to discomfort and complications caused by the packing and the short-term results evaluated 3 months after operation. Fingerstall packings gave less problems than either Merocel or hydrocortisone-terramycine gauze packs with ventilation tubes. They were easier to remove and were associated with less persistent secretion in the post-operative period.

Acoustic rhinometry: values from adults with subjective normal nasal patency.

The nose with normal feeling of nasal patency, and no gross structural changes has been described in 82 individuals by acoustic rhinometry. Curves for one and both sides of the nasal cavity and before and after decongestion have been recorded. We have found that the minimal cross-sectional area (MCA) is located anteriorly in the nasal cavity; in some subjects it is localized at the head of the inferior turbinate and in other subjects more anteriorly at the nasal valve.

Acoustic rhinometry, used as a method to demonstrate changes in the volume of the nasopharynx after adenoidectomy.

Acoustic rhinometry is a method of investigating the geometry of the nasal cavity and the nasopharynx. An acoustic impulse is transferred to the nasal cavity and the reflected signal is analysed expressing the cross-sectional area in the nasal cavity and the nasopharynx as a function of the distance from the nostril. The method provides an accurate and objective measurement of the geometry of the nasal cavity and the nasopharynx in a non-invasive way.

Evaluation of the effect of localized skin cooling on nasal airway volume by acoustic rhinometry.

Ten healthy subjects (four men and six women) were subjected to localized skin cooling by submersion for 5 min of both feet and, in another experiment, one hand and forearm into ice-cold water. Repeated measurements of nasal cavity volumes by a new method, acoustic rhinometry, showed characteristic patterns ranging from marked increases in volumes lasting the entire exposure period to transient monophasic or biphasic responses to no change at all. The pattern in individual subjects was reproducible with the two methods of cooling, and it could be characterized by five types when related to baseline measurements during the preexposure period.

Turbinate hypertrophy. Evaluation of the nasal cavity by acoustic rhinometry.

We used acoustic rhinometry to assess the geometry of the nasal cavity. The cross-sectional area of the nasal cavity as a function of distance from the nostrils was obtained. Seventeen patients with hypertrophy of the inferior turbinate and septal deviations were examined preoperatively and postoperatively; 34 normal subjects served as controls.

Acoustic rhinometry: evaluation of the nasal cavity with septal deviations, before and after septoplasty.

We introduce acoustic rhinometry as a new, objective method to assess the geometry of the nasal cavity. The cross-sectional area of the nasal cavity as a function of distance from the nostrils was obtained. A group of 21 patients with septal deformities was examined with acoustic rhinometry preoperatively and postoperatively.

Acoustic rhinometry: evaluation of nasal cavity geometry by acoustic reflection.

To study the geometry of the nasal cavity we applied an acoustic method (J. Appl. Physiol.