Modeling Flow in a Compromised Pediatric Airway Breathing Air and Heliox
Modeling Flow in a Compromised Pediatric Airway Breathing Air and Heliox
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DOI：
10.1097/mlg.0b013e3181856051
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发表时间：
2008-12-01
期刊：
影响因子：
2.6
通讯作者：
Willging, J. Paul
中科院分区：
文献类型：
--
作者：
Mihaescu, Mihai;Gutmark, Ephraim;Willging, J. Paul
目的/假设：本研究的目的是在一个精确的儿童声门下气道狭窄模型中进行血流的计算机模拟。我们认为狭窄气道的气流特性与呼吸困难的感觉密切相关。方法：通过声门下狭窄的婴儿呼吸道的计算机断层扫描图像，用于构建气道的三维几何形状。通过计算流体动力学（CFD）建模来捕捉气道吸气和呼气过程中的流动模式，我们获得了有关流速、气道壁面静态压力、狭窄处压降和壁面剪切应力的信息。这些模拟是在空气和螺旋下进行的。结果：与空气不同，螺旋在狭窄处维持层流。螺旋流条件下狭窄处的压降比气流条件下的压降要低。当使用heliox时，这导致气道阻力减少约40%，并且可能导致呼吸所需的努力水平降低。结论：CFD模拟提供了一种定量评估气道异常患者气道流动动力学的方法。CFD模型显示了声门下狭窄儿童气道内的流动特征和量化的流动参数。与空气和螺旋条件的模拟反映了已知的螺旋条件与空气相比的临床益处。我们预计，计算机模拟模型最终将使我们更好地理解由特定的医疗和手术干预引起的呼吸困难患者的血流变化。
Objectives/Hypothesis: The aim of this study was to perform computer simulations of flow within an accurate model of a pediatric airway with subglottic stenosis. It is believed that the airflow characteristics in a stenotic airway are strongly related to the sensation of dyspnea.Methodology: Computed tomography images through the respiratory tract of an infant with subglottic stenosis, were used to construct the three-dimensional geometry of the airway. By using computational fluid dynamics (CFD) modeling to capture airway flow patterns during inspiration and expiration, we obtained information pertaining to flow velocity, static airway wall pressure, pressure drop across the stenosis, and wall shear stress. These simulations were performed with both air and heliox.Results: Unlike air, heliox maintained laminar flow through the stenosis. The calculated pressure drop over stenosis was lower for the heliox flow, in contrast to the airflow case. This lead to an approximately 40% decrease in airway resistance when using heliox, and presumably causes a decrease in the level of effort required for breathing.Conclusions: CFD simulations offer a quantitative method of evaluating airway flow dynamics in patients with airway abnormalities. CFD modeling illustrated the flow features and quantified flow parameters within a pediatric airway with subglottic stenosis. Simulations with air and heliox conditions mirrored the known clinical benefits of heliox as compared with air. We anticipate that computer simulation models will ultimately allow a better understanding of changes in flow caused by specific medical and surgical interventions in patients with conditions associated with dyspnea.