Effects of decongestion on nasal cavity air conditioning efficiency: a CFD cohort study

• Published in: Scientific reports Vol. 14; no. 1; pp. 8482 - 9
• Main Authors: Xiao, Qiwei, Bates, Alister J., Doorly, Denis J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.04.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/57/2266; 639/166; 639/166/985; 692/308/575; Air Conditioning; Alveoli; Blood flow; Cohort Studies; Computer Simulation; Efficiency; Fluid dynamics; Humanities and Social Sciences; Humans; Hydrodynamics; Hypertrophy; Magnetic resonance imaging; Moisture content; multidisciplinary; Nasal Cavity - diagnostic imaging; Nasal Cavity - physiology; Nasal Obstruction; Nose; Respiration; Science; Science (multidisciplinary); Septum; Turbinates; Water content
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-58758-5

Decongestion reduces blood flow in the nasal turbinates, enlarging the airway lumen. Although the enlarged airspace reduces the trans-nasal inspiratory pressure drop, symptoms of nasal obstruction may relate to nasal cavity air-conditioning. Thus, it is necessary to quantify the efficiency of nasal cavity conditioning of the inhaled air. This study quantifies both overall and regional nasal air-conditioning in a cohort of 10 healthy subjects using computational fluid dynamics simulations before and after nasal decongestion. The 3D virtual geometry model was segmented from magnetic resonance images (MRI). Each subject was under two MRI acquisitions before and after the decongestion condition. The effects of decongestion on nasal cavity air conditioning efficiency were modelled at two inspiratory flowrates: 15 and 30 L min −1 to represent restful and light exercise conditions. Results show inhaled air was both heated and humidified up to 90% of alveolar conditions at the posterior septum. The air-conditioning efficiency of the nasal cavity remained nearly constant between nostril and posterior septum but dropped significantly after posterior septum. In summary, nasal cavity decongestion not only reduces inhaled air added heat by 23% and added moisture content by 19%, but also reduces the air-conditioning efficiency by 35% on average.