Osmolality of preterm formulas supplemented with nonprotein energy supplements.
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 < 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.


CONCLUSIONS
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.
Pereira-da-Silva
L
L
Neonatal Intensive Care Unit, Hospital Dona Estefânia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal. l.pereira.silva@netcabo.pt
Dias
M Pitta-Grós
MP
Virella
D
D
Moreira
A C
AC
Serelha
M
M
D000704:Analysis of Variance; D001997:Bronchopulmonary Dysplasia / Q000628:therapy; D004044:Dietary Proteins / Q000032:analysis; D002149:Energy Intake / Q000502:physiology*; D005527:Food, Fortified; D005936:Glucans / Q000008:administration & dosage / Q000737:chemistry; D006801:Humans; D007225:Infant Food / Q000032:analysis; D041943:Infant Formula / Q000737:chemistry*; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D009994:Osmolar Concentration; D014280:Triglycerides / Q000008:administration & dosage / Q000737:chemistry
D004044:Dietary Proteins; D005936:Glucans; D014280:Triglycerides