Computational fluid dynamics upper airway effective compliance, critical closing pressure, and obstructive sleep apnea severity in obese adolescent girls.
Computational fluid dynamics upper airway effective compliance, critical closing pressure, and obstructive sleep apnea severity in obese adolescent girls.
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计算流体动力学肥胖少女的上呼吸道有效顺应性、临界闭合压和阻塞性睡眠呼吸暂停严重程度。
DOI：
10.1152/japplphysiol.00190.2016
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Arens,Raanan
中科院分区：
文献类型：
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作者：
Wootton,DavidM;Sin,Sanghun;Luo,Haiyan;Yazdani,Alireza;McDonough,JosephM;Wagshul,MarkE;Isasi,CarmenR;Arens,Raanan
阻塞性睡眠呼吸暂停综合征（OSAS）与限制上呼吸道大小的解剖学异常和减少睡眠中咽扩张活动的功能因素有关。在这项研究中，我们假设阻塞性睡眠呼吸暂停综合征也与清醒时咽部机械顺应性的改变有关。研究了5名14至18岁的OSAS和6名对照肥胖女孩。所有患者均接受多导睡眠图、临界关闭压（Pcrit）研究和清醒潮式呼吸时上气道的动态MRI检查。有效气道顺应性定义为横截面积与沿咽部气道沿着最大吸气和最大呼气之间的平均压力的斜率。利用基于图像的计算流体力学和鼻阻力计算咽部压力场。计算斯皮尔曼相关性以检验呼吸暂停低通气指数（AHI）、Pcrit和气道顺应性之间的关系。与对照组相比，OSAS患者鼻咽部（CNP）和咽喉部（CVP）的有效顺应性较低且为阴性：分别为-4.4 vs. 1.9（mm 2/cmH 2 O，P= 0.012）和-2.1 vs. 3.9（mm 2/cmH 2 O，P= 0.021），表明与对照组相比，OSAS患者吸气时有较强的相位性咽扩张活动。对于所有受试者，CNP和AHI呈负相关（rS=-0.69，P = 0.02），被动Pcrit与CNP（rS=-0.76，P = 0.006）和AHI（rS= 0.86，P = 0.0006）相关。在清醒状态下获得的咽力学可用于表征OSAS受试者。此外，在清醒期间的负有效的顺应性及其与AHI和Pcrit的相关性表明，在这些受试者中，上咽的阶段性扩张活动补偿了负压负荷。
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.