Testing and Development of Slightly Thick Infant Formula Recipes for Dysphagia Management: An Australian Perspective

Viscosity study of maternal and formula milks according to the assessment proposed by the International Dysphagia Diet Standardisation Initiative Model: a comparison with Rheological Assessment

PURPOSE

The present study aimed to investigate the behavior and the viscosity classification of liquids recommended for infants, up to six months, in Brazil, and their formulations used in Videofluoroscopy Swallowing Studies.

METHODS

Breast milk from different gestational and breastfeeding time, two regular infant formulas, and one anti-reflux formula were evaluated in five different formulations: pure, mixed with liquid barium sulfate, in two proportions (20 and 33%), thickened with a specific thickener for neonates and thickened and mixed with 20% liquid barium sulfate, using the International Dysphagia Diet Standardisation Initiative model. The results were compared with data obtained from a previous rheological study.

RESULTS

The breast milk samples and the infant formulas, in pure presentation, exhibited similar behavior except for the anti-reflux formula. The thickened samples with the addition of barium and the pure liquid barium sulfate exhibited the highest viscosity among the formulations. The increase in viscosity with the addition of barium occurred for all samples and for the thickened formulations, but not in linear behavior. The results showed minor differences of IDDSI classification compared to the findings obtained in the rheological study.

CONCLUSION

The present study revealed the variability of liquid viscosity across different formulations, supporting the idea of the importance of this knowledge in videofluoroscopic assessment. It has also highlighted the risk associated with using a subjective method in preparing the stimuli offered, allowing for greater reliability in diagnosing swallowing dynamics in neonates and infants. This approach may help prevent inaccurate diagnoses and harmful interventions.

The viscosity-enhancing effect of carob bean gum and sodium carboxymethylcellulose when added to infant formula

Despite limited supporting evidence, the practice of thickening breast milk or infant formula with commercially available thickening agents is prevalent. This study explored the viscosity-enhancing impact of carob bean gum (CBG) and sodium carboxymethylcellulose (NaCMC) when added to infant formula at various concentrations and for different thickening durations. The findings indicate that thickening leads to an exponential increase in milk viscosity, from 25% of the recommended dosage onward. This suggests that minor adjustments in dosage can significantly impact formula thickness, underscoring the importance of accurately dosing and preparing infant milk. The considerable variability in viscosity also emphasizes the need for thoughtful selection of teat size, considering the energy expenditure of the sucking infant. When using 50% of the recommended CBG dose or 25% of NaCMC, the resulting viscosity matches that of a commercially available casein-based formula containing CBG for anti-regurgitation. In the case of CBG, a viscosity plateau is only reached after 30 min. Therefore, educating parents on the correct handling and preparation steps for CBG-thickened infant milk is crucial, including a 30-min waiting period to achieve the intended thickening effect.

The Effectiveness of Slightly Thick Liquids for Improving Swallowing in Bottle-Fed Children With Aerodigestive Concerns

Purpose

Strategies for facilitating safe and functional bottle feeding in children with dysphagia include selecting nipples that reduce flow rate, pacing, altered positioning, and thickening liquid consistencies. We aimed to determine the impact of slightly thick liquids on swallowing through retrospective review of a convenience sample of clinical videofluoroscopic swallowing studies (VFSS) from 60 bottle-fed children (21 boys and 39 girls, mean age of 9.9 months) referred due to suspected aspiration.

Method

Eligible VFSS exams were those in which the child swallowed both thin and slightly thick barium (40% w/v Varibar barium) using the same nipple. VFSS sequences (i.e., uninterrupted portions of the VFSS recording) were randomly assigned in duplicate for rating by trained raters; discrepancies were resolved by consensus. Parameters measured included number of swallows/sequence, sucks/swallow, swallow and sequence duration, number and timing of penetration or aspiration events, laryngeal vestibule closure integrity, and pharyngeal residue. Chi-square tests, linear mixed-model analyses of variance, and Wilcoxon signed-ranks tests identified consistency effects.

Results

There were no aspiration events in these recordings. Slightly thick liquids resulted in significantly fewer penetration events (p < .05), increased sucks/swallow, fewer swallows/sequence, and longer swallow and sequence durations. The number of children with ≥ 1 sequence showing pyriform sinus residue was significantly higher with slightly thick liquids.

Conclusions

Slightly thick liquids can be effective in reducing penetration in bottle-fed children with dysphagia. However, slightly thick liquids may also lead to a safety-efficiency trade-off, with increased risk of pyriform sinus residue. Thickening for children with dysphagia should be considered only when other approaches are not effective. Overthickening should be avoided to limit negative impact on swallowing efficiency.