Deviated nasal septum hinders intranasal sprays: a computer simulation study.
BACKGROUND
This study investigates how deviated nasal septum affects the quantity and distribution of spray particles, and examines the effects of inspiratory airflow and head position on particle transport.


METHODS
Deposition of spray particles was analysed using a three-dimensional computational fluid dynamics model created from a computed tomography scan of a human nose with leftward septal deviation and a right inferior turbinate hypertrophy. Five simulations were conducted using FluentTM software, with particle sizes ranging from 20-110 &#956;m, a spray speed of 3 m/s, plume angle of 68(deg), and with steady state inspiratory airflow either present (15.7 L/min) or absent at varying head positions.


RESULTS
With inspiratory airflow present, posterior deposition on the obstructed side was approximately four times less than the contralateral side, regardless of head position, and was statistically significant. When airflow was absent, predicted deposition beyond the nasal valve on the left and right sides were between 16% and 69% lower and positively influenced by a dependent head position.


CONCLUSIONS
Simulations predicted that septal deviation significantly diminished drug delivery on the obstructed side. Furthermore, increased particle penetration was associated with presence of nasal airflow. Head position is an important factor in particle deposition patterns when inspiratory airflow is absent.
Department of Otorhinolaryngology, University of North Carolina, Chapel Hill, NC, USA. dennis_frank@med.unc.edu
D O
DO
Frank
J S
JS
Kimbell
D
D
Cannon
S S
SS
Pawar
J S
JS
Rhee
D000281:Administration, Intranasal; D000328:Adult; D003198:Computer Simulation; D005260:Female; D006801:Humans; D057446:Hydrodynamics; D021621:Imaging, Three-Dimensional; D001239:Inhalation / Q000502:physiology*; D008954:Models, Biological; D015508:Nasal Obstruction / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D009300:Nasal Septum / Q000002:abnormalities*; D059085:Nasal Sprays; D011187:Posture / Q000502:physiology
D059085:Nasal Sprays