Instrumental texture assessment of IDDSI texture levels for dysphagia management. Part 1: Thickened fluids

Abstract

Thickened fluids are commonly used in the medical management of individuals who suffer from swallowing difficulty (known as dysphagia). International Dysphagia Diet Standardization Initiative (IDDSI) developed a standardized terminology and description for texture-modified foods and thickened fluids to allow dysphagia patients to receive the correct consistency of food/drink. Syringe flow test and fork drip test are suggested by IDDSI to identify the drink category (IDDSI Levels 1-4). These practical methods are widely welcomed by carers and patients because of their simplicity. However, these methods are not most feasible for industrial applications, where objective measurements are required for industry for the purpose of quality control of such products. Therefore, our aim in this work was to develop quantitative and objective measurements that best describe IDDSI level category for use as an objective framework. Two measuring techniques, syringe flow test and fork drip test, recommended by IDDSI were evaluated in two different sets of experiment. Participants were recruited to categorize fluid samples of known texture parameters using syringe flow test and fork drip test techniques. The apparent stress measured from Ball-Back Extrusion (BBE) technique for each of the fluid category (IDDSI Levels 1-4) was calculated. Bands of apparent stress for each of the fluid category were developed from two measuring techniques, syringe flow test and fork drip test. An inconsistency was observed between these two measuring techniques for IDDSI Level 3 fluid due to different dominating factors in the two tests. However, we proposed to combine the results from the two experiments to develop a quantitative range for each IDDSI Level as objective complements to the IDDSI Framework. Thickened fluid manufacturers are encouraged to follow the proposed guidelines presented once they are clinically validated and use them fine-tune their products, thus enhancing the safety of individuals with dysphagia.

Keywords: IDDSI; dysphagia; food texture; fork drip test; swallowing; syringe flow test; thickened fluids.