Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- List of abbreviations
- 1 Fetal nutrition
- 2 Determinants of intrauterine growth
- 3 Aspects of fetoplacental nutrition in intrauterine growth restriction and macrosomia
- 4 Postnatal growth in preterm infants
- 5 Thermal regulation and effects on nutrient substrate metabolism
- 6 Development and physiology of the gastrointestinal tract
- 7 Metabolic programming as a consequence of the nutritional environment during fetal and the immediate postnatal periods
- 8 Nutrient regulation in brain development: glucose and alternate fuels
- 9 Water and electrolyte balance in newborn infants
- 10 Amino acid metabolism and protein accretion
- 11 Carbohydrate metabolism and glycogen accretion
- 12 Energy requirements and protein-energy metabolism and balance in preterm and term infants
- 13 The role of essential fatty acids in development
- 14 Vitamins
- 15 Normal bone and mineral physiology and metabolism
- 16 Disorders of mineral, vitamin D and bone homeostasis
- 17 Trace minerals
- 18 Iron
- 19 Conditionally essential nutrients: choline, inositol, taurine, arginine, glutamine and nucleotides
- 20 Intravenous feeding
- 21 Enteral amino acid and protein digestion, absorption, and metabolism
- 22 Enteral carbohydrate assimilation
- 23 Enteral lipid digestion and absorption
- 24 Minimal enteral nutrition
- 25 Milk secretion and composition
- 26 Rationale for breastfeeding
- 27 Fortified human milk for premature infants
- 28 Formulas for preterm and term infants
- 29 Differences between metabolism and feeding of preterm and term infants
- 30 Gastrointestinal reflux
- 31 Hypo- and hyperglycemia and other carbohydrate metabolism disorders
- 32 The infant of the diabetic mother
- 33 Neonatal necrotizing enterocolitis: clinical observations and pathophysiology
- 34 Neonatal short bowel syndrome
- 35 Acute respiratory failure
- 36 Nutrition for premature infants with bronchopulmonary dysplasia
- 37 Nutrition in infants with congenital heart disease
- 38 Nutrition therapies for inborn errors of metabolism
- 39 Nutrition in the neonatal surgical patient
- 40 Nutritional assessment of the neonate
- 41 Methods of measuring body composition
- 42 Methods of measuring energy balance: calorimetry and doubly labelled water
- 43 Methods of measuring nutrient substrate utilization using stable isotopes
- 44 Postnatal nutritional influences on subsequent health
- 45 Growth outcomes of preterm and very low birth weight infants
- 46 Post-hospital nutrition of the preterm infant
- Index
- References
9 - Water and electrolyte balance in newborn infants
Published online by Cambridge University Press: 10 December 2009
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- List of abbreviations
- 1 Fetal nutrition
- 2 Determinants of intrauterine growth
- 3 Aspects of fetoplacental nutrition in intrauterine growth restriction and macrosomia
- 4 Postnatal growth in preterm infants
- 5 Thermal regulation and effects on nutrient substrate metabolism
- 6 Development and physiology of the gastrointestinal tract
- 7 Metabolic programming as a consequence of the nutritional environment during fetal and the immediate postnatal periods
- 8 Nutrient regulation in brain development: glucose and alternate fuels
- 9 Water and electrolyte balance in newborn infants
- 10 Amino acid metabolism and protein accretion
- 11 Carbohydrate metabolism and glycogen accretion
- 12 Energy requirements and protein-energy metabolism and balance in preterm and term infants
- 13 The role of essential fatty acids in development
- 14 Vitamins
- 15 Normal bone and mineral physiology and metabolism
- 16 Disorders of mineral, vitamin D and bone homeostasis
- 17 Trace minerals
- 18 Iron
- 19 Conditionally essential nutrients: choline, inositol, taurine, arginine, glutamine and nucleotides
- 20 Intravenous feeding
- 21 Enteral amino acid and protein digestion, absorption, and metabolism
- 22 Enteral carbohydrate assimilation
- 23 Enteral lipid digestion and absorption
- 24 Minimal enteral nutrition
- 25 Milk secretion and composition
- 26 Rationale for breastfeeding
- 27 Fortified human milk for premature infants
- 28 Formulas for preterm and term infants
- 29 Differences between metabolism and feeding of preterm and term infants
- 30 Gastrointestinal reflux
- 31 Hypo- and hyperglycemia and other carbohydrate metabolism disorders
- 32 The infant of the diabetic mother
- 33 Neonatal necrotizing enterocolitis: clinical observations and pathophysiology
- 34 Neonatal short bowel syndrome
- 35 Acute respiratory failure
- 36 Nutrition for premature infants with bronchopulmonary dysplasia
- 37 Nutrition in infants with congenital heart disease
- 38 Nutrition therapies for inborn errors of metabolism
- 39 Nutrition in the neonatal surgical patient
- 40 Nutritional assessment of the neonate
- 41 Methods of measuring body composition
- 42 Methods of measuring energy balance: calorimetry and doubly labelled water
- 43 Methods of measuring nutrient substrate utilization using stable isotopes
- 44 Postnatal nutritional influences on subsequent health
- 45 Growth outcomes of preterm and very low birth weight infants
- 46 Post-hospital nutrition of the preterm infant
- Index
- References
Summary
Water spaces – life processes
Up to 80% of body weight is water in neonates near term, and even more may be water in premature babies (90%). Cell membranes separate intracellular water (ICW) and extracellular water (ECW) spaces. The ECW is separated further into plasma water and interstitial water across vascular endothelium. The ECW maintains ICW solute concentrations and cell nutrition. The ECW content is regulated physiologically by the heart and the kidneys, and is controlled by several hormone systems.
As shown in Figure 9.1, water coming into the ECW carries mineral solutes, carbohydrates, fats and proteins. Cellular wastes exiting the ECW with water and solutes constitute carbon dioxide (respiratory), urea and fixed acids (renal) and heat dissipation (integument). Also, some water is lost in stool, and a small amount is gained from substrate oxidation. Growth in the newborn also requires water, substrates and solutes for cell proliferation and differentiation. In this chapter, regulation of the cell's ICW, and the interfacing role of the ECW compartment in neonatal water metabolism will be discussed.
Inside the cell membrane – osmotic pressure
Water moves from higher to lower solute concentrations across the cell's membrane. In physiologic solutions, solute concentration is expressed in milliosmoles (mOsm) per kg of water. The movement of water across semipermeable membranes in response to small gradient changes regulates cell volume. Vant Hoff measured physiological osmotic pressure in living cells – determining one milliosmole per liter of water exerts 19.3 mmHg pressure.
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- Information
- Neonatal Nutrition and Metabolism , pp. 104 - 114Publisher: Cambridge University PressPrint publication year: 2006
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