The determining factors of peak nasal inspiratory flow and perception of nasal airflow in asthmatics

Abstract

Background: The effect of pulmonary pathology on peak nasal inspiratory flow (PNIF) remains largely unknown. We investigated an association between a diagnosis of asthma and of lung function on PNIF when adjusted for possible confounders. Further, we investigated the perception of nasal obstruction in asthmatics compared to healthy controls when adjusted for PNIF.Methodology: Eighty-seven asthmatics and 92 non-asthmatic controls underwent PNIF (categorized into groups of high, medium and low), acoustic rhinometry (AR) and spirometry, and we assessed symptoms of nasal obstruction on visual analogue scales (VAS) in three categories.Results: PNIF was significantly associated with asthma and forced expiratory volume in the first second (FEV1) (% predicted).Other factors associated with PNIF were the degree of nasal obstruction measured both subjectively on a VAS and objectively with AR, age and disease status. Asthma patients were 19 times more likely to be in a higher VAS category compared to non-asthmatic controls independent of PNIF group. Conclusion:Special care has to be taken when interpreting PNIF values in patients with asthma or reduced FEV1 (% predicted).The sensation of nasal obstruction in asthmatics is different from controls despite being in the same PNIF group.

Minimal unilateral peak nasal inspiratory flow correlates with patient reported nasal obstruction

“…PNIF has been shown to be highly reproducible (15) and well suited to identify patients with clinically relevant nasal stenosis (16,17) . It is positively correlated with pulmonary ventilatory capacity measured by peak expiratory flow (PEF) (18) , male sex, height and inversely with age (12) and asthma status (19) . PNIF correlates and compares to the gold standard of nasal airflow measurement, rhinomanometry (20)(21)(22) , and acoustic rhinometry (23) .…”

Measurements of nasal airflow and patency: a critical review with emphasis on the use of peak nasal inspiratory flow in daily practice

“…As in asthma, it has been clearly shown that symptoms and objective measurements do not always correlate well , and the assessment of a patient suffering of nasal obstruction should be based upon both subjective and objective measures. On the one hand, patients with objective nasal obstruction do not always have symptoms , but on the other hand, the correlation between symptoms and objective measurements is far from obvious . It has been suggested that objective measurements do not correlate very well with subjective measurements of nasal obstruction, because the nasal valve region primarily determines nasal resistances, while the sensation of nasal obstruction may be related to congestion in other areas of the upper airway, such as the ethmoid region Nathan et al.…”

Lower airway flow influences peak nasal inspiratory flow in school-aged children

“…This needs to be analysed in future studies with larger samples, but it could be influenced by the fact that CARATkids questionnaire considers nasal symptoms self-reported by the children regarding the last two weeks and not necessarily current symptoms at the time of PNIF measurement. Moreover, in a previous study in adults, patients with asthma significantly rated their nasal obstruction by visual analogue scale more seriously than non-asthmatic controls with comparable PNIF values (29) .…”

“…Apparently, the sensation of nasal obstruction in asthmatics may be different from controls despite being in the same PNIF group (29) . On the opposite direction, children on long-term treatment for chronic rhinitis may underreport the amount of nasal congestion (44) , and it has been reported that children may be more accepting of mouth-breathing than adolescents (43) .…”

“…The impact of lower airway patency on PNIF should be considered (11,12,(28)(29)(30) . A bivariate correlation between baseline PNIF and peak expiratory flow (PEF) has been described in healthy children (26) , but no multivariable analysis including PEF was reported.…”