Objective monitoring of nasal patency and nasal physiology in rhinitis

Abstract

Nasal obstruction can be monitored objectively by measurement of nasal airflow, as evaluated by nasal peak flow, or as airways resistance/conductance as evaluated by rhinomanometry. Peak flow can be measured during inspiration or expiration. Of these measurements, nasal inspiratory peak flow is the best validated technique for home monitoring in clinical trials. The equipment is portable, relatively inexpensive, and simple to use. One disadvantage, however, is that nasal inspiratory peak flow is influenced by lower airway as well as upper airway function. Rhinomanometry is a more sensitive technique that is specific for nasal measurements. The equipment, however, requires an operator, is more expensive, and is not portable. Thus, it is applicable only for clinic visit measures in clinical trials. Measurements require patient cooperation and coordination, and not all can achieve repeatable results. Thus, this objective measure is best suited to laboratory challenge studies involving smaller numbers of selected volunteers. A nonphysiological measure of nasal patency is acoustic rhinometry. This sonic echo technique measures internal nasal luminal volume and the minimum cross-sectional area. The derivation of these measures from the reflected sound waves requires complex mathematical transformation and makes several theoretical assumptions. Despite this, however, such measures correlate well with the nasal physiological measures, and the nasal volume measures have been shown to relate well to results obtained by imaging techniques such as computed tomography scanning or magnetic resonance imaging. Like rhinomanometry, acoustic rhinometry is not suitable for home monitoring and can be applied only to clinic visit measures or for laboratory nasal challenge monitoring. It has advantages in being easy to use, in requiring little patient cooperation, and in providing repeatable results. In addition to nasal obstruction, allergic rhinitis is recognized to be associated with impaired mucociliary clearance and altered nasal responsiveness. Measures exist for the monitoring of these aspects of nasal dysfunction. Although measures of mucociliary clearance are simple to perform, they have a poor record of reproducibility. Their incorporation into clinical trials is thus questionable, although positive outcomes from therapeutic intervention have been reported. Measures of nasal responsiveness are at present largely confined to research studies investigating disease mechanisms in allergic and nonallergic rhinitis. The techniques are insufficiently standardized to be applied to multicenter clinical trials but could be used in limited-center studies to gain insight into the regulatory effects of different therapeutic modalities.

Nasal inflammation in sleep apnoea patients using CPAP and effect of heated humidification

“…Indeed, CONSTANTINIDIS et al [23] demonstrated prolonged mucociliary transport time after 3-10 months of CPAP use along with a desiccation of the epithelial surface and an inflammatory cell infiltration of the mucosa, whereas BOSSI et al [21] failed to discern any change in mucociliary transport time or in nasal resistance after 6 months of CPAP use. However, although measures of mucociliary clearance are simple to perform, they have poor reproducibility and consequently their incorporation into clinical trials is considered questionable [24].…”

Allergic Rhinitis and Its Impact on Sleep

“…In normal subjects occlusion of the nose during the night causes an increase in sleep apnoea and transient arousals (50) suggesting that nasal obstruction irrespective of cause is an important cause of OSAS. In AR there is a general relationship between the presence and degree of nasal obstruction and obstructive sleep apnoea (8,50,51). This has also been confirmed in population studies (17).…”

Impacto de la Inmunoterapia subcutánea con Dermatophagoides farinae y Dermatophagoides pteronyssinus sobre la calidad de vida de pacientes con rinitis y asma alérgica

“…El pico de flujo nasal inspiratorio es una herramienta sencilla, barata y no invasiva que mide de manera objetiva el flujo nasal (22) con valores expresados en litros por minuto (L/minuto) y se define como el máximo flujo de aire logrado durante una inspiración forzada a través de la nariz (23). Se ha propuesto como normal un valor superior a 150 L/minuto (24).…”