Gallegos Crispulo, Turcanu Mihaela, Assegehegn Getachew, Brito-de la Fuente Edmundo
Product and Process Engineering Center, Fresenius Kabi Deutschland GmbH, Daimlerstrasse 22, 61352, Bad Homburg, Germany.
Dysphagia. 2023 Apr;38(2):558-585. doi: 10.1007/s00455-021-10337-w. Epub 2021 Jul 3.
There is an increasing proof of the relevance of rheology on the design of fluids for the diagnosis and management of dysphagia. In this sense, different authors have reported clinical evidence that support the conclusion that an increase in bolus viscosity reduces the risks of airway penetration during swallowing. However, this clinical evidence has not been associated yet to the definition of objective viscosity levels that may help to predict a safe swallowing process. In addition, more recent reports highlight the potential contribution of bolus extensional viscosity, as elongational flows also develops during the swallowing process. Based on this background, the aim of this review paper is to introduce the lecturer (experts in Dysphagia) into the relevance of Rheology for the diagnosis and management of oropharyngeal dysphagia (OD). In this sense, this paper starts with the definition of some basic concepts on Rheology, complemented by a more extended vision on the concepts of shear viscosity and elongational viscosity. This is followed by a short overview of shear and elongational rheometrical techniques relevant for the characterization of dysphagia-oriented fluids, and, finally, an in-depth analysis of the current knowledge concerning the role of shear and elongational viscosities in the diagnosis and management of OD (shear and elongational behaviors of different categories of dysphagia-oriented products and contrast fluids for dysphagia assessment, as well as the relevance of saliva influence on bolus rheological behavior during the swallowing process).
流变学在吞咽困难诊断和管理用流体设计中的相关性证据日益增多。从这个意义上讲，不同作者报告了临床证据，支持团块粘度增加可降低吞咽期间气道穿透风险这一结论。然而，这一临床证据尚未与有助于预测安全吞咽过程的客观粘度水平定义相关联。此外，最近的报告强调了团块拉伸粘度的潜在作用，因为吞咽过程中也会出现拉伸流动。基于此背景，本综述论文的目的是向授课者（吞咽困难专家）介绍流变学在口咽吞咽困难（OD）诊断和管理中的相关性。从这个意义上讲，本文首先定义流变学的一些基本概念，并辅以对剪切粘度和拉伸粘度概念的更广泛视角。接下来简要概述与吞咽困难导向流体表征相关的剪切和拉伸流变测量技术，最后深入分析当前关于剪切粘度和拉伸粘度在OD诊断和管理中的作用的知识（不同类别的吞咽困难导向产品和吞咽困难评估用造影剂的剪切和拉伸行为，以及吞咽过程中唾液对团块流变行为影响的相关性）。
