Faculty Collaboration Database

Normative ranges of nasal airflow variables in healthy adults. Int J Comput Assist Radiol Surg 2020 Jan;15(1):87-98

Date

07/04/2019

Pubmed ID

31267334

Pubmed Central ID

PMC6939154

DOI

10.1007/s11548-019-02023-y

Scopus ID

2-s2.0-85069642677 (requires institutional sign-in at Scopus site)   58 Citations

Abstract

PURPOSE: Virtual surgery planning based on computational fluid dynamics (CFD) simulations of nasal airflow has the potential to improve surgical outcomes for patients with nasal airway obstruction (NAO). Virtual surgery planning requires normative ranges of airflow variables, but few studies to date have quantified inter-individual variability of nasal airflow among healthy subjects. This study reports CFD simulations of nasal airflow in 47 healthy adults.

METHODS: Anatomically accurate three-dimensional nasal models were reconstructed from cone beam computed tomography scans and used for steady-state inspiratory airflow simulations with a bilateral flowrate of 250 ml/s. Normal subjective sensation of nasal patency was confirmed using the nasal obstruction symptom evaluation and visual analog scale. Healthy ranges for several CFD variables known to correlate with subjective nasal patency were computed, including unilateral airflow, nasal resistance, airspace minimal cross-sectional area (mCSA), heat flux (HF), and surface area stimulated by mucosal cooling (defined as the area where HF > 50 W/m²). The normative ranges were targeted to contain 95% of the healthy population and computed using a nonparametric method based on order statistics.

RESULTS: A wide range of inter-individual variability in nasal airflow was observed among healthy subjects. Unilateral airflow varied from 60 to 191 ml/s, airflow partitioning ranged from 23.8 to 76.2%, and unilateral mCSA varied from 0.24 to 1.21 cm². These ranges are in good agreement with rhinomanometry and acoustic rhinometry data from the literature. A key innovation of this study are the normative ranges of flow variables associated with mucosal cooling, which recent research suggests is the primary physiological mechanism of nasal airflow sensation. Unilateral HF ranged from 94 to 281 W/m², while the surface area stimulated by cooling ranged from 27.4 to 64.3 cm².

CONCLUSIONS: These normative ranges may serve as targets in future virtual surgery planning for patients with NAO.

Author List

Borojeni AAT, Garcia GJM, Moghaddam MG, Frank-Ito DO, Kimbell JS, Laud PW, Koenig LJ, Rhee JS

Authors

Guilherme Garcia PhD Assistant Professor in the Biomedical Engineering department at Medical College of Wisconsin
Purushottam W. Laud PhD Adjunct Professor in the Data Science Institute department at Medical College of Wisconsin
John S. Rhee MD Chair, Professor in the Otolaryngology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Computer Simulation
Cone-Beam Computed Tomography
Female
Humans
Hydrodynamics
Imaging, Three-Dimensional
Male
Models, Anatomic
Nasal Cavity
Nasal Obstruction
Reference Values