scholarly journals Primary site identification in children with obstructive sleep apnea by computational fluid dynamics analysis of the upper airway

2020 ◽  
Vol 16 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Ayaka Yanagisawa-Minami ◽  
Takeshi Sugiyama ◽  
Tomonori Iwasaki ◽  
Youichi Yamasaki
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Primary Site ◽  
Dynamics Analysis ◽  
Obstructive Sleep ◽  
Computational Fluid Dynamics Analysis ◽  
Site Identification

scholarly journals Computational fluid dynamics upper airway effective compliance, critical closing pressure, and obstructive sleep apnea severity in obese adolescent girls

2016 ◽  
Vol 121 (4) ◽  
pp. 925-931 ◽  
Author(s):  
David M. Wootton ◽  
Sanghun Sin ◽  
Haiyan Luo ◽  
Alireza Yazdani ◽  
Joseph M. McDonough ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Obese Adolescent ◽  
Obstructive Sleep ◽  
Critical Closing Pressure ◽  
Effective Compliance ◽  
Closing Pressure

Obstructive sleep apnea syndrome (OSAS) is associated with anatomical abnormalities restricting upper airway size and functional factors decreasing pharyngeal dilator activity in sleep. In this study we hypothesized that OSAS is also associated with altered pharyngeal mechanical compliance during wakefulness. Five OSAS and six control obese girls between 14 and 18 years of age were studied. All underwent polysomnography, critical closing pressure (Pcrit) studies, and dynamic MRI of the upper airway during awake tidal breathing. Effective airway compliance was defined as the slope of cross-sectional area vs. average pressure between maximum inspiration and maximum expiration along the pharyngeal airway. Pharyngeal pressure fields were calculated by using image-based computational fluid dynamics and nasal resistance. Spearman correlations were calculated to test associations between apnea-hypopnea index (AHI), Pcrit, and airway compliance. Effective compliances in the nasopharynx (CNP) and velopharynx (CVP) were lower and negative in OSAS compared with controls: −4.4 vs. 1.9 (mm2/cmH2O, P = 0.012) and −2.1 vs. 3.9 (mm2/cmH2O, P = 0.021), respectively, suggesting a strong phasic pharyngeal dilator activity during inspiration in OSAS compared with controls. For all subjects, CNPand AHI correlated negatively (rS= −0.69, P = 0.02), and passive Pcritcorrelated with CNP(rS= −0.76, P = 0.006) and with AHI (rS= 0.86, P = 0.0006). Pharyngeal mechanics obtained during wakefulness could be used to characterize subjects with OSAS. Moreover, negative effective compliance during wakefulness and its correlation to AHI and Pcritsuggest that phasic dilator activity of the upper pharynx compensates for negative pressure loads in these subjects.

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