Types of diet/fluids offered as oral trials
There was a lack of consistency in the types and quantities of oral trials offered and no standard approach was identified to guide decision-making around oral trials offered. Interestingly, one individual who was on full meals but NBM for fluids was documented as ‘oral trials’, showing inconsistency in terminology and delivery of this approach. Some recommendations gave more precise recommendations such as, ‘5 sips’ whilst others left more breadth in recommendations, for example ‘10-15 teaspoons’. There is a general lack of uniformity in treatment strategies in the SLT community, which is evident both in treatment approaches and intensity of treatment 6,25.
The range of quantity and type of oral trials recommendations may reflect clinical judgements regarding how to provide adequate challenge or ‘load’ to the swallow system. Different viscosities and volumes of boluses have been found to provide specific sensory input, which consequently affects the nature of swallow physiology by altering the load, intensity or volume of exercise 26. This is the mechanism behind the McNeill Dysphagia Therapy Program (MDTP) which focuses on the use of swallowing as an exercise and involves offering food or fluid boluses of varying viscosity and volume in a hierarchical fashion to improve strength and skill of swallowing27. Decision-making is often informed by ‘practice-based rules’ which are established through experience28 and, although there is no evidence-base to guide decision making within oral trials, there may be a range of unwritten rules established. Further research is indicated to explore this.