Aspects of nutrition, metabolism and growth of the low birth weight infant
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Date
1983Author
Glass, Elizabeth Jean D.
Metadata
Abstract
A dextrose electrolyte solution (5.9mmol/dl sodium) administered
alone or as a component of total parenteral nutrition was
satisfactory for full term infants but produced significant
hypernatraemia in infants of <34 weeks gestation during their
first few days of life. This hypernatraemia was prevented by the
substitution of a solution of lower sodium content (2mmol/dl).
Hyponatraemia was common between the second and fifth postnatal
weeks in enterally fed preterm infants of <1500g birthweight and a
sodium intake of at least 3-4mmol/kg/day was necessary to maintain
plasma sodium above 130mmol/l during this period. Plasma copper,
zinc and albumin levels and alkaline phosphatase activity were
recorded in infants of varying gestational age at birth. Plasma
albumin and copper rose and alkaline phosphatase activity fell
with increasing gestational age at birth, but no differences in
plasma zinc values were noted in infants of between 28 and 41
weeks gestation. Plasma albumin and copper levels increased
postnatally in preterm infants and did not differ from those of
infants of a comparable postconceptual age (gestational age +
postnatal age), in contrast to plasma zinc levels which declined
below such standards. There was a significant correlation
between the radiological features of rickets and plasma alkaline
phosphatase activity which therefore may be used to screen for and
monitor rickets in preterm infants. Routine dietary calcium
supplementation reduced the incidence and severity of rickets in
such infants. Hepatic dysfunction was detected in 14.6% of 122
infants who received total parenteral nutrition and a strong
association was noted between bacterial infection and the
development of hepatic dysfunction. Plasma bile salt
measurements did not prove to be a more sensitive indicator of
hepatic dysfunction than plasma direct bilirubin values. A
comparative study of two feeding regimens was carried out in
preterm infants of <1500g birthweight. Fifty nine infants were
allocated alternately to initial total parenteral nutrition or
nasoduodenal feeding (enteral group). One third of the infants
in the enteral group failed to establish nasoduodenal feeding
during the first postnatal week. The gradual introduction of
nasoduodenal feeding to infants in the parenteral group did not
prevent the recognised deterioration in growth pattern associated
with a rapid switchover from parenteral to enteral nutrition.
The initial use of total parenteral nutrition did not produce any
beneficial effects on growth between birth and the expected date
of delivery and acquired bacterial infection associated with
significant morbidity and mortality was more common in the
parenterally fed infants. Parenteral nutrition should not be
used routinely in very low birthweight infants but reserved for
those in whom enteral feeding is not possible.