Baylor

If aspiration is present when swallowing milk/formula, the latter is thickened to a consistency that the infant can handle without any further sign of aspiration. Based on such observation, SLPs customarily recommend that the milk/formula be thickened to a consistency similar to that of "nectar", "honey" etc... However, accurate reproduction of the appropriate consistency recommended by SLPs is difficult to replicate because there are different levels of "nectar" or "honey". In addition, VFSS necessitates the use of a contrasting agent, most commonly being 40% barium sulfate, in order to view the swallowing process with the same image quality regardless of the viscosity of the liquid. It is unclear the extent to which barium sulfate intrinsically increase milk/formula even when no thickener is added. It is therefore understandable that attempts at replicating the consistency recommended by SLPs by the bedside is difficult and very subjective. In addition, replicating the recommended thicknesses, at times, can create new problems. Indeed, as thickened milks do not always flow out of the bottles readily, nipple holes are enlarged in order to allow for flow without considering whether the resulting increased flow can be handled safely by the infants.

Depending upon the type of thickeners used, e.g., rice cereal flakes, some will thickened over time. For instance, with rice cereal, over time, flakes agglutinate and plug the bottle nipples making it even more difficult for the infant to suck.