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Nephrology and Fluid/Electrolyte Physiology: Neonatology Questions and Controversies E-Book

Nephrology and Fluid/Electrolyte Physiology: Neonatology Questions and Controversies E-Book

William Oh | Jean-Pierre Guignard | Stephen Baumgart

(2012)

Additional Information

Book Details

Abstract

Nephrology and Fluid/Electrolyte Physiology, a volume in Dr. Polin’s Neonatology: Questions and Controversies Series, offers expert authority on the toughest neonatal nephrology and fluid/electrolyte challenges you face in your practice. This medical reference book will help you provide better evidence-based care and improve patient outcomes with research on the latest advances.

  • Reconsider how you handle difficult practice issues with coverage that addresses these topics head on and offers opinions from the leading experts in the field, supported by evidence whenever possible.
  • Find information quickly and easily with a consistent chapter organization.
  • Get the most authoritative advice available from world-class neonatologists who have the inside track on new trends and developments in neonatal care.
  • Stay current in practice with coverage on lung fluid balance in developing lungs and its role in neonatal transition; acute problems of prematurity: balancing fluid volume and electrolyte replacement in very-low-birth-weight and extremely-low-birth-weight neonates; and much more.

Table of Contents

Section Title Page Action Price
Front Cover cover
Pin page fm2
Half-title page i
Series page ii
Nephrology and Fluid/Electrolyte Physiology: Neonatology Questions and Controversies iii
Copyright Page iv
Contributors v
Series Foreword ix
Foreword x
Preface xi
Table Of Contents xiii
Front Matter xv
A Placenta and Fetal Water Flux 1
1 Water Flux and Amniotic Fluid Volume: 3
Clinical Scenarios 3
Maternal Dehydration 3
Reduced Maternal Plasma Oncotic Pressure 3
Fetal Water 4
Placental Water Flux 4
Fetal Water Compartments 4
Amniotic Fluid Volume and Composition 5
Fetal Water Circulation 5
Urine Production 5
Lung Fluid Production 6
Fetal Swallowing 6
Intramembranous Flow 7
Mechanisms of Water Flow 7
Mechanism of Placental Water Flow 8
Placental Anatomy 8
Controversies in Placental Flow 9
Mechanism of Intramembranous Flow 11
Membrane Anatomy 11
Controversies Regarding Intramembranous Flow 11
Aquaporins 12
Aquaporins in Placentas and Membranes 13
Aquaporin and Intramembranous Water Flow 13
Conclusion 14
References 15
2 Body Water Changes in the Fetus and Newborn: 19
Body Fluid Compartments 19
Body Water in Fetal Growth Aberration 20
Large for Gestational Age 20
Intrauterine Growth Restriction or Small for Gestational Age 21
Body Water and Solids in Intrauterine Growth Restriction or Small for Gestational Age Infants 21
Transitional Changes of Body Water after Birth 23
Clinical implications of Transitional Body Water Changes in Preterm Very Low Birth Weight Infants 24
References 26
B Electrolyte Balance during Normal Fetal and Neonatal Development 29
3 Renal Aspects of Sodium Metabolism in the Fetus and Neonate 31
Body Water Compartments 31
Cell Volume Regulation 32
Fetal Sodium Metabolism 33
Amniotic Fluid Dynamics 33
Mechanisms of Placental Sodium Transfer 34
Fetal Homeostatic Reactions 35
Body Water Compartments and Initial Weight Loss 36
Physical Water Compartments 37
The Principle of Physical Water Compartments 38
Determination of Motionally Distinct Water Fractions 38
Physical Water Compartments during the Early Postnatal Period 38
Role of Hyaluronan in the Perinatal Lung and Brain Water Metabolism 39
Role of Hyaluronan in Neonatal Renal Concentration 39
Sodium Homeostasis 39
Renal Sodium Excretion under Basal Conditions 39
Molecular Basis of Proximal Tubular Sodium Reabsorption 42
Molecular Basis of Distal Tubular Sodium Reabsorption 43
Other Factors Influencing Renal Sodium Handling 44
Renal Sodium Excretion in Response to Salt Loading 45
Intestinal Sodium Transport 47
Disturbances in Plasma Sodium Concentrations 48
Early-Onset Hyponatremia 48
Late-Onset Hyponatremia 48
Early Hypernatremia 51
Clinical Consequences of Inadequate Sodium Intake 51
Clinical Consequences of Excessive Sodium Intake 52
Sodium Homeostasis and Acid–Base Balance 53
References 53
4 Potassium Metabolism 61
Normal Metabolism 61
Regulation of Internal K Balance 61
Regulation of External K Balance 63
Renal Potassium Excretion 63
Intestinal Potassium Excretion 66
Sweat Gland Potassium Excretion 67
Plasma [K+] 67
Feedback and Feedforward Control of Plasma [K+] 67
Developmental Physiology 68
Fetus 68
Neonate 69
Internal Potassium Metabolism 69
Renal Potassium Metabolism 69
Intestinal K Metabolism 70
Feedback and Feedforward Control of Plasma [K+] 70
Clinical Relevance 70
Hyperkalemia 70
Spurious Hyperkalemia 70
Nonoliguric Hyperkalemia 70
Renal Failure 71
Hypokalemia 71
Loop and Thiazide Diuretics 71
Alkalosis 72
References 72
5 Renal Urate Metabolism in the Fetus and Newborn 75
Uric Acid in Human Disease 75
Uric Acid in Diseases of Fetuses and Newborns 77
Generation of Uric Acid 77
Glomerular Filtration Rate 78
Proximal Tubular Urate Transport 79
Developmental Implications and Conclusions 80
References 81
6 Perinatal Calcium and Phosphorus Metabolism 85
Body Distribution 85
Calcium 85
Phosphorus 86
Regulation of Serum Calcium and Phosphorous Concentrations 87
Calcium 87
Parathyroid Hormone 87
Placental Transport 88
Serum Calcium and Calcium Homeostasis after Birth 88
Vitamin D 88
Calcitonin 89
Phosphorus 89
Placental Transport 89
Fibroblast Growth Factor 23 90
Renal Excretion 91
Parathyroid Hormone 91
Serum Phosphorous and Phosphorous Homeostasis after Birth 91
Clinical Disorders Associated with Abnormal Calcium and Phosphorus Homeostasis 92
Neonatal Hypocalcemia 92
Definition 92
Etiology and Pathophysiology 92
Clinical Presentation 93
Diagnosis 93
Therapeutic Approaches 93
Neonatal Hypercalcemia 94
Definition 94
Etiology and Pathophysiology 94
Clinical Presentation 95
Diagnosis 96
Therapeutic Approaches 96
Neonatal Hypophosphatemia 97
Definition 97
Etiology and Pathophysiology 97
Clinical Presentation 98
Therapeutic Approaches 99
Neonatal Hyperphosphatemia 99
Definition 99
Etiology and Pathophysiology 99
Clinical Presentation 100
Therapeutic Approaches 100
References 100
7 Acid–Base Homeostasis in the Fetus and Newborn 105
Regulation of Acid–Base Homeostasis 105
Respiratory Acidosis 105
Correction of Fetal Respiratory Acidosis 105
Correction of Postnatal Respiratory Acidosis 106
Metabolic Acidosis 106
Fetoplacental Elimination of Metabolic Acid Load 106
Postnatal Elimination of Metabolic Acid Load 107
Respiratory Alkalosis 109
Correction of Fetal Respiratory Alkalosis 109
Correction of Postnatal Respiratory Alkalosis 109
Metabolic Alkalosis 109
Correction of Fetal Metabolic Alkalosis 109
Correction of Postnatal Metabolic Alkalosis 109
Normal Acid–Base Balance and Growth 110
Obstetric Management and Fetal and Neonatal Acid–Base Balance 111
Summary 112
References 112
C The Kidney: Normal Development and Hormonal Control 115
8 Glomerular Filtration Rate in Neonates 117
Development of Glomerular Filtration 117
Vasoactive Factors 118
Angiotensin II 118
Prostaglandins 119
Maturational Aspects of the Renin–Angiotensin and Prostaglandins Systems 119
The Renin–Angiotensin System 119
The Prostaglandins 120
Assessment of Glomerular Filtration Rate 120
Glomerular Markers 120
Inulin 121
Inulin as a Marker of Glomerular Filtration Rate in Neonates 121
Creatinine 121
Creatinine as a Marker of GFR in the Neonate 122
Iohexol 122
Iothalamate Sodium 122
99mTc-DTPA and 51Cr-EDTA 123
Techniques Used to Assess Glomerular Filtration Rate in Neonates 123
The Plasma Concentration 123
Urinary Clearance 124
Inulin 124
Creatinine 124
The Constant Infusion Technique without Urine Collection 125
The Single-Injection (Plasma Disappearance Curve) Technique 126
Estimation of Creatinine Clearance from Its Plasma Concentration without Urine Collection 126
The Special Case of Cystatin C: A Nonclassical Glomerular Marker! 127
Cystatin C as a Marker of Glomerular Filtration Rate in Neonates 127
Assessment of Renal Function in Neonates: Which Method for Which Purpose? 128
Developmental Investigative Studies 128
Clinical Purposes 129
Conditions and Factors That Impair Glomerular Filtration Rate 129
Perinatal Asphyxia 129
Nonsteroidal Antiinflammatory Agents 129
Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Antagonists 130
Prevention of Oliguric States Caused by Low Glomerular Filtration Rate 131
Furosemide in Oliguric Neonates 131
Dopaminergic Agents (Dopamine, Dopexamine) in Oliguric Neonates 131
Theophylline 131
References 132
D Special Problems 137
9 The Developing Kidney and the Fetal Origins of Adult Cardiovascular Disease 139
Developmental Origins of Health and Disease 139
Birth Weight and Developmental Origins of Adult Cardiovascular and Renal Diseases 140
Postnatal Growth and Developmental Origins of Adult Cardiovascular and Renal Diseases 141
Biologic Mechanism of Developmental Programming of Adult Disease 143
Developing Kidney and Long-Term Consequences 143
Nephrogenesis and Environment 144
Long-Term Vascular and Renal Disease: Role of Nephron Number 145
Developing Kidney, Postnatal Factors, and Long-Term Vascular and Renal Diseases 146
Molecular Mechanisms Involved in the Developmental Origins of Cardiovascular Disease 147
Fetal Environment and Altered Kidney Gene Expression 147
Imprinted Genes and Programming 148
Genomic Imprinting and Nutrient Supply to the Fetus 148
Conclusion 149
References 150
10 Renal Modulation: 155
Components of the Renin–Angiotensin– Aldosterone System 155
Angiotensin Generation 155
Renin–Angiotensin System Outside Juxtaglomerular Cells 155
Effects of Angiotensin-Converting Enzyme and Non–Angiotensin-Converting Enzyme Other Than the Production of Angiotensin II 157
Cardiovascular System 157
Adipocytes 157
Renal 157
Mesenteric Bed 157
Angiotensin II and Its Metabolites 158
Aldosterone 158
Gene Targeting of Angiotensin Synthesis: Lessons from Genetically Manipulated Rodents 158
Angiotensin Receptors 159
Gene Targeting of Angiotensin Receptors 160
Other Angiotensin II Receptors 160
Renin Receptors 160
Physiologic Effects of Angiotensin II 161
Via the Angiotensin1 Receptor 161
Via the Angiotensin2 Receptor 161
Concepts and Controversies in Our Current Understanding of the Renal Effects of the Renin–Angiotensin–Aldosterone System in Maintaining Fluid and Electrolyte Homeostasis and Blood Pressure 162
Ontogeny 162
Development of the Renin–Angiotensin–Aldosterone System: Structure of the Kidney and Urinary Tract 162
Studies in Humans 162
Postnatal Changes in Renin–Angiotensin–Aldosterone System Structure and Function in Humans 163
Sodium Homeostasis in the Neonatal Period 163
Development of Tubuloglomerular Feedback 164
Development of Glomerulotubular Balance 164
Current Concepts and Controversies 165
What is the Physiologic Basis and Purpose, If Any, of the “Third Mechanism?” 166
Mediators and Modulators of Tubuloglomerular Feedback 166
Adenosine 167
Adenosine Triphosphate 167
Nitric Oxide 167
Reactive Oxygen Species 168
Sodium Transporters 168
Sodium Potassium 2 Chloride Co-transporters 168
Na+, K+-ATPase 168
Calcium Wave 169
New Directions 169
Unconventional Behavior of Renin–Angiotensin System Components 169
Molecular Mechanisms Underlying Salt Sensing by the Macula Densa 169
Fetal Programming for Hypertension: Failure of Renoprotection? 169
Clinical Aspects 170
References 170
11 Renal Modulation: 179
Arginine Vasopressin 180
Normal Arginine Vasopressin Physiology 180
Arginine Vasopressin Synthesis 180
Sensor Mechanisms for Arginine Vasopressin Secretion 180
Arginine Vasopressin Receptors and Signal Transduction 181
Renal Arginine Vasopressin Action and Aquaporin 2 Water Channels 182
Modulation of Arginine Vasopressin Action 182
Developmental Differences Between Fetuses and Newborn Infants 182
Role of Arginine Vasopressin in the Placenta 182
Arginine Vasopressin in Fetal Life 183
Arginine Vasopressin in Newborns 184
Role of Arginine Vasopressin in Pathologic Conditions of Neonates 185
Diabetes Insipidus 185
Syndrome of Inappropriate Secretion of Antidiuretic Hormone 185
Arginine Vasopressin Secretion in Neonatal Pathologic Conditions 185
Atrial Natriuretic Peptide 186
Normal Physiology of Atrial Natriuretic Peptide and Related Natriuretic Peptides 186
Introduction to Natriuretic Peptides 186
Synthesis of Natriuretic Peptides 186
Sensor Mechanisms for Atrial Natriuretic Peptide Secretion 186
Natriuretic Peptide Receptors and Signal Transduction 186
Biologic Action of Natriuretic Peptides 187
Modulation of Atrial Natriuretic Peptide Action 188
Developmental Differences Between Fetuses and Newborn Infants 188
Role of Atrial Natriuretic Peptide in the Placenta 188
Atrial Natriuretic Peptide in Fetal Life 189
Atrial Natriuretic Peptide in Newborns 190
Role of Atrial Natriuretic Peptide in Pathologic Conditions of Newborns 190
Fetal Distress 190
Postnatal Diseases 191
Congestive Heart Failure and Congenital Heart Diseases 191
References 192
12 Acute Problems of Prematurity: 199
Immature Epidermal Barrier Function and the Extremely Low Birth Weight Habitus 200
Transcutaneous (Insensible) Water Loss 201
Water Loss and Pathogenesis of Transcutaneous Dehydration 202
Salt Restriction Prophylaxis 203
Nonoliguric Hyperkalemia in Extremely Low Birth Weight Babies 205
The Epidermal Barrier: Reducing Transcutaneous Evaporation 208
Environmental Humidification 208
Skin Emollients 209
Plastic Shields, Bags, and Blankets 210
Pulmonary Edema Formation 210
Prevention of Iatrogenic Fluid Overload 211
Diuretic Therapy 213
Corticosteroid Therapy 213
Electrolyte Imbalances and Neurodevelopment 214
Hyponatremia 214
Hypernatremia 215
Areas for Further Investigation 215
Between a Rock and a Hard Place: Suggestions for Vigilant Fluid Balance Therapy in Extremely Low Birth Weight Babies 216
A Parting Shot at Aggressive Patent Ductus Arteriosus Management 217
Conclusion 218
References 218
13 Lung Fluid Balance in Developing Lungs and Its Role in Neonatal Transition 221
Fetal Lung Liquid and Its Physiologic Significance 221
How Is the Fetal Lung Fluid Cleared? 224
Sodium Channel Pathology in the Lung 225
What Causes the Neonatal Lung Epithelium to Switch to an Absorptive Mode? 227
Summary 229
References 229
14 Use of Diuretics in the Newborn 233
Body Fluid Homeostasis 233
Extracellular Fluid Volume 233
Plasma Osmolality 233
Clinical Use of Diuretics 234
Sodium-Retaining States 234
Oliguric States 234
Respiratory Disorders 234
Central Nervous System Disorders 234
Electrolyte Disorders 234
Nephrogenic Diabetes Insipidus 234
Arterial Hypertension 235
Differential Diagnosis of Congenital Tubulopathies 235
Classification of Diuretics According to the Site of Action 235
Filtration Diuretics 236
Osmotic Diuretics 239
Index 361
A 361
B 362
C 363
D 364
E 365
F 366
G 366
H 367
I 369
J 369
K 369
L 369
M 370
N 370
O 371
P 371
R 373
S 373
T 375
U 376
V 376
W 376
X 377