Thickened Liquids for Dysphagia Management: a Current Review of the Measurement of Liquid Flow

Curr Phys Med Rehabil Rep. 2018 Dec;6(4):220-226. doi: 10.1007/s40141-018-0197-6. Epub 2018 Aug 25.


Purpose of review: The use of thickened liquids has become one of the most common management strategies for individuals with dysphagia. The purpose of this paper is to review methods that can be used to measure the flow characteristics of liquids used in dysphagia management. We describe the measurement of apparent viscosity, measures of extensional flow, slump tests (specifically the line-spread test and Bostwick consistometry), gravity flow tests, and subjective methods.

Recent findings: We discuss the relationship between different approaches to measuring flow, the 2002 American National Dysphagia Diet and the 2017 International Dysphagia Diet Standardisation Initiative (IDDSI) framework. A comparison of test results across four methods is provided.

Summary: A consistent approach is needed for the measurement of flow for thickened liquids used in dysphagia management. This review highlights differences that can be expected across different flow testing methodologies. Adherence to a common method and measurement definitions will promote patient safety and facilitate future research regarding the effectiveness of texture modification as an intervention for dysphagia.

Keywords: Deglutition; Deglutition disorders; Dysphagia; Texture modification; Thickened liquids; Viscosity.