Osmolality of preterm formulas supplemented with nonprotein energy supplements

Abstract

Background: Addition of energy supplements to preterm formulas is an optional strategy to increase the energy intake in infants requiring fluid restriction, in conditions like bronchopulmonary dysplasia. This strategy may lead to an undesirable increase in osmolality of feeds, the maximum recommended safe limit being 400 mOsm/kg. The aim of the study was to measure the changes in osmolality of several commercialized preterm formulas after addition of glucose polymers and medium-chain triglycerides. Methods: Osmolality was measured by the freezing point depression method. Six powdered formulas with concentrations of 14 g/100 ml and 16 g/100 ml, and five ready-to-feed liquid formulas were analyzed. All formulas, were supplemented with 10% (low supplementation) or 20% (high supplementation) of additional calories, respectively, in the form of glucose polymers and medium chain triglycerides, maintaining a 1:1 glucose:lipid calorie ratio. Inter-analysis and intra-analysis coefficients of variation of the measurements were always o 3.9%. Results: The mean osmolality (mOsm/kg) of the non-supplemented formulas varied between 268.5 and 315.3 mOsm/kg, increasing by 3-5% in low supplemented formulas, and by 6-10% in high supplemented formulas. None of the formulas analyzed exceeded 352.8 mOsm/kg. Conclusion: The supplementation of preterm formulas with nonprotein energy supplements with up to 20% additional calories did not exceed the maximum recommended osmolality for neonatal feedings.

Determining the osmolality of over‐concentrated and supplemented infant formulas

“…The effect on osmolality when supplementing infant formulas was found to be additive, suggesting that the final osmolality of a supplemented formula can be estimated when the osmotic effect of the respective additive(s) are known. It was evident that carbohydrate supplements caused the largest increase in osmolality, whereas fat supplements caused a minimal increase, which has also been demonstrated in previous studies (Agarwal et al ., ; Pereira‐da‐Silva et al ., ,b).…”

“…Although manufacturers provide data on the osmolality of different infant formulas at a standard concentration, very little data exist for over‐concentrated or supplemented formulas. However, some studies have demonstrated an increase in osmolality when supplementing specialised infant formulas (Pereira‐da‐Silva et al ., ,b). This creates a dilemma in the dietitian's clinical practice, where the benefits of modifying formulas must be balanced against the unknown increase in osmolality and the potential contribution to NEC or osmotic diarrhoea.…”

Osmolality of elemental and semi‐elemental formulas supplemented with nonprotein energy supplements

“…All formulas were prepared by the same investigator according to a previously reported methodology (Pereira‐da‐Silva et al. , 2008).…”

The Role of Nutrition in the Prevention and Management of Bronchopulmonary Dysplasia: A Literature Review and Clinical Approach

“…In some BPD infants with worse pulmonary function requiring greater fluid restriction, some authors have proposed increasing the energy and macronutrient intake by adding modular supplements of protein, carbohydrate, and fat to enriched formulas [ 123 ]. This formula manipulation has the inherent risks of increasing the osmolality of feedings and compromising the energy/protein ratio [ 124 ].…”