Nephrology and Fluid/Electrolyte Physiology: Neonatology Questions and Controversies (Neonatology: Questions & Controversies)

Front Cover IFC_Expert Consult ad with PIN code Half title page Series page Nephrology and Fluid/Electrolyte Physiology Copyright Page Contributors Series Foreword Preface Table Of Contents A Fetal and Neonatal Fluid and Electrolyte Composition 1 Water Flux and Amniotic Fluid Volume Abstract Keywords Clinical Scenarios Maternal Dehydration Reduced Maternal Plasma Oncotic Pressure Fetal Water Placental Water Flux Fetal Water Compartments Amniotic Fluid Volume and Composition Fetal Water Circulation Urine Production Lung Fluid Production Fetal Swallowing Intramembranous Flow Mechanisms of Water Flow Mechanism of Placental Water Flow Placental Anatomy Controversies in Placental Flow Mechanism of Intramembranous Flow Membrane Anatomy Controversies Regarding Intramembranous Flow Aquaporins Aquaporins in Placentas and Membranes Aquaporin and Intramembranous Water Flow Conclusion References 2 Body Composition in the Fetus and Newborn Abstract Keywords Body Fluid Compartments Body Water in Fetal Growth Aberration Large for Gestational Age Intrauterine Growth Restriction or Small for Gestational Age Body Water and Solids in Intrauterine Growth Restriction or Small for Gestational Age Infants Transitional Changes of Body Water After Birth Clinical Implications of Transitional Body Water Changes in Preterm Very Low Birth Weight Infants References B Perinatal Mineral, Electrolyte, and Acid-Base Homeostasis 3 Potassium Metabolism Abstract Keywords Normal Metabolism General Background Regulation of Internal Potassium Balance Regulation of External Potassium Balance Routes of Potassium Excretion Regulation of Potassium Excretion: Circadian Rhythm, Feedback, and Feedforward Renal Potassium Handling Proximal Tubule Thick Ascending Limb of the Loop of Henle Distal Nephron Influencing Renal Potassium Excretion Developmental Physiology Potassium During Somatic Growth Changes in Internal Potassium Balance Changes in External Potassium Balance Clinical Relevance Hyperkalemia Pseudohyperkalemia Disorders of Internal Potassium Balance Disorder of External Potassium Balance Hypokalemia Disorders of Internal Potassium Balance Disorders of External Potassium Balance Conclusions References 4 Renal Aspects of Sodium Metabolism in the Fetus and Neonate Abstract Keywords Fluid Compartments Placenta and Amniotic Fluid Developmental Changes in Renal Function and Tubular Transport Renal Tubular Sodium Transport Proximal Tubule Sodium Transport Proximal Tubule Water Transport Development of Proximal Tubule Sodium Reabsorption Development of Proximal Tubule Water Permeability Thin Descending and Thin Ascending Loops of Henle Thick Ascending Limb of Henle Distal Convoluted Tubule Collecting Duct Developmental Changes in CCD Sodium Transport Developmental Changes in CCD Water Transport References 5 Perinatal Calcium and Phosphorus Metabolism Abstract Keywords Body Distribution of Calcium and Phosphorous Calcium Phosphorus Regulation of Calcium Homeostasis Placental Transport Parathyroid Hormone Vitamin D Calcitonin Regulation of Phosphorus Homeostasis Placental Transport Parathyroid Hormone Fibroblast Growth Factor 23 Renal Excretion Clinical Disorders Associated With Abnormal Calcium and Phosphorus Homeostasis Neonatal Hypocalcemia Definition Etiology and Pathophysiology Clinical Presentation Diagnosis Therapeutic Approaches Neonatal Hypercalcemia Definition Etiology and Pathophysiology Clinical Presentation Diagnosis Therapeutic Approaches Neonatal Hypophosphatemia Definition Etiology and Pathophysiology Clinical Presentation Therapeutic Approaches Neonatal Hyperphosphatemia Definition Etiology and Pathophysiology Clinical Presentation Therapeutic Approaches References 6 Acid-Base Homeostasis in the Fetus and Newborn Abstract Keywords Introduction Regulation of Acid-Base Homeostasis Respiratory Acidosis Correction of Fetal Respiratory Acidosis Correction of Postnatal Respiratory Acidosis Regulation of Acid-Base Homeostasis Metabolic Acidosis Fetoplacental Elimination of Metabolic Acid Load Postnatal Elimination of Metabolic Acid Load Regulation of Acid-Base Homeostasis Respiratory Alkalosis Correction of Fetal Respiratory Alkalosis Correction of Postnatal Respiratory Alkalosis Regulation of Acid-Base Homeostasis Metabolic Alkalosis Correction of Fetal Metabolic Alkalosis Correction of Postnatal Metabolic Alkalosis Normal Acid-Base Balance and Growth Obstetrical Management and Fetal and Neonatal Acid-Base Balance Summary References C Glomerular Filtration Rate in Neonates 7 Glomerular Filtration Rate in Neonates Abstract Keywords Development of Glomerular Filtration Vasoactive Factors Angiotensin II Prostaglandins Maturational Aspects of the Renin-Angiotensin and Prostaglandins Systems Renin-Angiotensin System Prostaglandins Assessment of Glomerular Filtration Rate Endogenous Markers Creatinine Creatinine as a Marker of Glomerular Filtration Rate in the Neonate Plasma Creatinine Concentration Estimation of Creatinine Clearance by the Length/Plasma Creatinine Ratio U • V/P Urinary Clearance of Creatinine Special Case of Cystatin C: A Nonclassical Glomerular Marker! Cystatin C as a Marker of Glomerular Filtration Rate in the Neonate Serum Cystatin Concentration Exogenous Markers of Glomerular Filtration Rate Inulin Inulin as a Marker of Glomerular Filtration Rate in Neonates Urinary U • V/P Clearance of Inulin Constant Infusion Technique Without Urine Collection Single-Injection (Plasma Disappearance Curve) Technique Iohexol Iothalamate Sodium 99mTc-Diethylenetriamine Pentaacetic Acid and 51Cr-Ethylenediaminetetraacetic Acid Assessment of Renal Function in Neonates: Which Method for Which Purpose? Developmental Investigative Studies Clinical Purposes Conditions and Factors That Impair Glomerular Filtration Rate Perinatal Asphyxia Nonsteroidal Antiinflammatory Agents Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Antagonists Prevention of Oliguric States Caused by Low Glomerular Filtration Rate Furosemide in Oliguric Neonates Dopaminergic Agents (Dopamine, Dopexamine) in Oliguric Neonates Theophylline in Oliguric Neonates References D Normal and Abnormal Renal Development and Abnormalities of Fluid and Electrolyte Homeostasis 8 Renal Development and Molecular Pathogenesis of Renal Dysplasia Abstract Keywords Introduction Nephrogenic Mesenchyme Specification of Nephrogenic Mesenchyme Nephron Induction Nephron Segmentation Podocyte Differentiation Ureteric Bud Development of the Nephric Duct Ureteric Bud Outgrowth Ureteric Bud Branching Morphogenesis and Collecting Duct Elongation Stromal Mesenchyme Origin and Development Stromal Genetics (and Epigenetics) Implicated in Renal Development Vasculature Origin and Development of Renal Endothelial Cells Renal Vascular Mural Cell Development, Genetics, and Epigenetics Human Renal Dysplasia Syndromic Renal Dysplasia References 9 Prenatal Programming of Hypertension and Kidney and Cardiovascular Disease Abstract Keywords Prenatal Programming of Hypertension and Cardiovascular Disease Prenatal Programming of Nephron Endowment: Chronic Kidney Disease and Hypertension Thrifty Phenotype Hypothesis Animal Models of Prenatal Programming Postnatal Modulation of Prenatal Insults Very Premature Infants and Programming References 10 Fluid and Electrolyte Management of High-Risk Infants Abstract Keywords Changes in Body Water in the Fetus and Newborn Fetal Water Balance Newborn Water Balance Insensible Water Loss Fetal Sodium Balance Neonatal Sodium Balance Aldosterone Atrial Natriuretic Peptide Renin-Angiotensin System Principles of Fluid and Electrolyte Therapy Calculations of Fluid Requirement Calculations of Electrolyte Requirements References 11 Renal Modulation Abstract Keywords Components of the Renin-Angiotensin-Aldosterone System Angiotensin Generation Renin-Angiotensin System Outside Juxtaglomerular Cells Effects of Angiotensin Converting Enzyme and Nonangiotensin-Converting Enzymes Other Than the Production of Angiotensin II Cardiovascular System Adipocyte Kidney Blood Vessel Renin-Angiotensin System and Brain Angiotensin II and Its Metabolites Aldosterone Gene Targeting of Angiotensin Synthesis: Lessons From Genetically Manipulated Rodents Gene Targeting of Angiotensin Receptors: Lessons From Genetically Manipulated Rodents Angiotensin Receptors Gene Targeting of Angiotensin Receptors Other Angiotensin Receptors (Pro)Renin Receptor Physiologic Effects of Angiotensin II Via the Ang II Type 1 Receptor Via the Ang II Type 2 Receptor Indirect Effects Regulators of the Intrarenal Renin-Angiotensin System Ontogeny Development of the Renin-Angiotensin System: Structure of the Kidney and Urinary Tract Postnatal Changes in Renin-Angiotensin-Aldosterone System Structure and Function in Humans Studies in Humans Postnatal Changes in Renin-Angiotensin-Aldosterone System Structure and Function in Humans Unconventional Behavior of Renin-Angiotensin System Components Fetal Programming for Hypertension: Failure of Renoprotection? Clinical Aspects References 12 Renal Modulation Abstract Keywords Introduction Arginine Vasopressin Arginine Vasopressin Synthesis and Secretion Development Vasopressin Signal Transduction Development Aquaporins: Water Channels Development Medullary Interstitium Tonicity Atrial Natriuretic Peptide Atrial Natriuretic Peptide Synthesis and Secretion Development Atrial Natriuretic Peptide Signal Transduction Development References 13 Acute Problems of Prematurity Abstract Keywords Introduction Immature Epidermal Barrier Function and the Extremely Low Birth Weight Habitus Transcutaneous (Insensible) Water Loss Water Loss and Pathogenesis of Transcutaneous Dehydration Salt Restriction Prophylaxis Nonoliguric Hyperkalemia in Extremely Low Birth Weight Infants The Epidermal Barrier: Reducing Transcutaneous Evaporation Environmental Humidification Skin Emollients Plastic Shields, Bags, or Blankets Pulmonary Edema Formation Prevention of Iatrogenic Fluid Overload Diuretic Therapy Corticosteroid Therapy Electrolyte Imbalances and Neurodevelopment Hyponatremia Hypernatremia Areas for Further Investigation Between a Rock and a Hard Place: Suggestions for Vigilant Fluid Balance Therapy in Extremely Low Birth Weight Infants References 14 Lung Fluid Balance in Developing Lungs and Its Role in Neonatal Transition Abstract Keywords Fetal Lung Liquid and Its Physiologic Significance How Is the Fetal Lung Fluid Cleared? Sodium Channel Pathology in the Lung What Causes the Neonatal Lung Epithelium to Switch to an Absorptive Mode? Summary References 15 Use of Diuretics in the Newborn Abstract Keywords Introduction Body Fluid Homeostasis Extracellular Fluid Volume Plasma Osmolality Clinical Use of Diuretics Sodium-Retaining States Oliguric States Respiratory Disorders Central Nervous System Disorders Electrolyte Disorders Nephrogenic Diabetes Insipidus Arterial Hypertension Differential Diagnosis of Congenital Tubulopathies Classification of Diuretics According to the Site of Action Filtration Diuretics Osmotic Diuretics Chemistry Mechanisms and Sites of Action Efficacy and Therapeutic Uses Adverse Effects: Interactions Carbonic Anhydrase Inhibitors Chemistry Mechanisms and Sites of Action Pharmacokinetic Properties Efficacy and Therapeutic Uses Specific Indications With Questionable Benefits (See Table 15.5) Posthemorrhagic Ventricular Dilatation. Adverse Effects: Interactions Loop Diuretics: Inhibition of Na+-K+-2Cl− Cotransport Chemistry Mechanisms and Sites of Action Pharmacokinetic Properties Efficacy and Therapeutic Uses Continuous Intravenous Infusion of Loop Diuretics Indications Edematous States. Nephrotic Syndrome. Specific Indications With Questionable Benefits (See Table 15.5) Oliguric States. Respiratory Distress Syndrome. Transient Tachypnea of the Newborn. Preterm Infants With or Developing Chronic Lung Disease. Posthemorrhagic Ventricular Dilatation. Indomethacin-Induced Oliguria. Hypercalcemic States. Severe Hyponatremia. Asthma and Compromised Lung Mechanics. Laboratory Investigation: Assessment of Distal Tubular Acidification. Drug Dosage Adverse Effects: Interactions Hypochloremic Metabolic Alkalosis Hypercalciuria and Nephrocalcinosis Patent Ductus Arteriosus Ototoxicity Necrotizing Enterocolitis Extrarenal Effects of Loop Diuretics Miscellaneous Interactions Distal Convoluted Tubule: Inhibitors of Na+Cl− Cotransport Chemistry Mechanisms and Sites of Action Pharmacokinetic Properties Efficacy and Therapeutic Uses Indications Specific Indications With Questionable Benefits (See Table 15.5) Hypercalciuria Proximal Renal Tubular Acidosis Nephrogenic Diabetes Insipidus Chronic Lung Disease Laboratory Investigation: Diagnosis of Renal Hypokalemic Tubulopathies Drug Dosage Adverse Effects: Interactions Cortical Collecting Duct: K+-Sparing Drugs Chemistry Mechanisms and Sites of Action Pharmacokinetic Properties Efficacy and Therapeutic Uses Specific Indications With Questionable Benefits (See Table 15.5) Drug Dosage Adverse Effects: Interactions Interactions New Developments in Diuretic Therapy Adenosine A1 Receptor Antagonists Natriuretic Peptides Arginine Vasopressin Antagonists References 16 Neonatal Hypertension Abstract Keywords Introduction Normative Values for Neonatal Blood Pressure Factors Affecting Blood Pressure at Birth What Level of BP Should Be Considered Hypertensive? Incidence Differential Diagnosis Clinical Presentation Diagnostic Evaluation Blood Pressure Measurement Diagnostic Approach Treatment Outcome Conclusion References 17 Edema Abstract Keywords The Basics: Body Water Compartments Starling Forces Hydrostatic Forces Osmotic Forces The Osmotic Reflection Coefficient The Filtration Coefficient The Starling Hypothesis The Role of Aquaporins in Regulating Fluid Balance The Importance of Aquaporins in Maintaining Water Homeostasis The Role of Aquaporins in the Kidneys The Role of Aquaporins in the Lungs Factors That Combat the Development of Edema The Lymphatic System Alterations in Starling Forces Factors That Promote the Development of Edema The Porous Nature of the Capillary Wall Loss of the “Edema Safety Factor” Factors That Increase Permeability of the Vascular Endothelium The Role of Hypoalbuminemia Unique Features of Water Homeostasis in the Neonatal Population Changes in Body Water Composition in the Neonate Solute Balance in Healthy Neonates Resistance to the Effect of Arginine Vasopressin in Neonates Increase in Vascular Endothelial Growth Factor Expression Special Circumstances in the Neonatal Population Preterm Neonates Edema After Indomethacin Closure of Patent Ductus Arteriosus Pulmonary Edema in Neonates Respiratory Distress Syndrome and Bronchopulmonary Dysplasia Fluid Retention After Cardiopulmonary Bypass Edema Associated With Extracorporeal Membrane Oxygenation Conclusion References 18 Kidney Injury in the Neonate Abstract Keywords Introduction Definition Biomarkers for Acute Kidney Injury Epidemiology and Incidence of Kidney Injury in Neonates Etiology of Kidney Injury in Newborns Prerenal Injury Acute Ischemic Kidney Injury Nephrotoxic Kidney Injury Vascular Injury Congenital Abnormalities of the Kidney and Genitourinary Tract Medical Management of Acute Kidney Injury in Neonates Preventive Measures Electrolyte Management Therapies to Decrease Injury and Promote Recovery Acute and Chronic Renal Replacement Therapy Peritoneal Dialysis Hemodialysis Hemofiltration Future Directions Prognosis References 19 Hereditary Tubulopathies Abstract Keywords Proximal Tubule Proximal Renal Tubular Acidosis General Characteristics Molecular Pathophysiology Clinical Features Hereditary Aminoacidurias Classic Cystinuria General Characteristics Molecular Pathophysiology Clinical Features Treatment Lysinuric Protein Intolerance General Characteristics Molecular Pathophysiology Treatment Hartnup Disease General Characteristics Molecular Pathophysiology Treatment Hereditary Glycosurias Hereditary Isolated Glycosuria General Characteristics Molecular Pathophysiology Fanconi-Bickel Syndrome Loop of Henle Bartter Syndrome General Characteristics Molecular Pathophysiology Therapy Distal Convoluted Tubule Gitelman Syndrome General Characteristics Molecular Pathophysiology Pseudohypoaldosteronism Type II General Characteristics Molecular Pathophysiology EAST or SESAME Syndrome Collecting Duct Distal Renal Tubular Acidosis General Characteristics Molecular Pathophysiology Autosomal Dominant Distal Renal Tubular Acidosis Autosomal Recessive Distal Renal Tubular Acidosis Clinical Features Treatment Mixed Proximal and Distal Renal Tubular Acidosis (Type 3) Hyperkalemic Renal Tubular Acidosis (Type 4) Pseudohypoaldosteronism Type I General Characteristics and Clinical Features Molecular Pathophysiology Nephrogenic Diabetes Insipidus General Characteristics and Clinical Features Molecular Pathophysiology X-Linked Nephrogenic Diabetes Insipidus Autosomal Recessive and Autosomal Dominant Nephrogenic Diabetes Insipidus Therapy Nephrogenic Syndrome of Inappropriate Diuresis General Characteristics Molecular Pathophysiology Therapy Conclusion Acknowledgment References 20 Inherited Disorders of Calcium, Phosphate, and Magnesium Abstract Keywords Inherited Disorders of Calcium Introduction Regulators of Calcium Homeostasis Hypercalcemia Symptoms of Hypercalcemia PTH-Dependent Hypercalcemia Hypercalcemia Due to Hyperparathyroidism Congenital Hyperparathyroidism/Primary Hyperparathyroidism. Familial Hypocalciuric Hypercalcemia/Neonatal Severe Hyperparathyroidism. Jansen Metaphyseal Chondrodysplasia PTH-Independent Hypercalcemia Severe Infantile Hypophosphatasia Idiopathic Infantile Hypercalcemia (Lightwood Syndrome) Williams-Beuren Syndrome Bartter Syndrome Hypocalcemia Symptoms of Hypocalcemia Hypocalcemia Due to PTH Abnormalities/Hypoparathyroidism Congenital Hypoparathyroidism. Hypoparathyroidism, Deafness, and Renal Anomalies Syndrome. DiGeorge Syndrome. GCMB Mutations. Autoimmune Polyendocrine Syndrome. Mitochondrial Disorders Associated With Hypoparathyrodism. Other Syndromes (e.g., Kenney-Caffey and Blomstrand Disease). Hypocalcemia Due to CaSR Abnormalities or Downstream Signaling Autosomal Dominant (Hypercalciuric) Hypocalcemia. Pseudohypoparathyroidism Hypocalcemia Due to Disturbed Vitamin D Metabolism Inherited Disorders of Magnesium Introduction Regulators of Magnesium Homeostasis Epidermal Growth Factor Insulin Estrogen Other Hormone Interactions Involving Mg2+ Homeostasis Hypermagnesemia Symptoms of Hypermagnesemia Hypomagnesemia Symptoms of Hypomagnesemia Hypercalciuric Hypomagnesemias Familial Hypomagnesemia With Hypercalciuria and Nephrocalcinosis Autosomal Dominant Hypocalcemia Bartter Syndrome Gitelman-Like Hypomagnesemias Gitelman Syndrome (GS) EAST Syndrome (Epilepsy, Ataxia, Sensorineural Deafness, Tubulopathy) Isolated Dominant Hypomagnesemias (IDHs) HNF1B Nephropathy Transient Neonatal Hyperphenylalaninemia and Primapterinuria Other Hypomagnesemias Isolated Recessive Hypomagnesemia Hypomagnesemia With Secondary Hypocalcemia (HSH) Hypomagnesemia With Impaired Brain Development Mitochondrial Hypomagnesemia Inherited Disorders of Phosphate Introduction Regulators of Phosphate Homeostasis Fibroblast Growth Factor 23 Parathyroid Hormone 1,25 Vitamin D Klotho Hypophosphatemia Symptoms of Hypophosphatemia Disorders of Hypophosphatemia Disorders of FGF23 Excess Autosomal Dominant Hypophosphatemic Rickets (ADHR). X-Linked Hypophosphatemic Rickets (XLH). Autosomal Recessive Hypophosphatemic Rickets. Fibrous Dysplasia. Klotho Overexpression Hypophosphatemic Rickets and Hyperparathyroidism. PTH Disorders Hyperparathyroidism and Disorders of 1,25 Vitamin D Homeostasis Proximal Tubulopathies Disorders of Sodium Phosphate Cotransporters Hereditary Hypophosphatemic Rickets With Hypercalciuria. Autosomal Recessive Fanconi’s Syndrome With Hypophosphatemic Rickets. Idiopathic Infantile Hypercalcemia With Hypophosphatemia. Hyperphosphatemia Symptoms of Hyperphosphatemia Disorders of FGF23 Deficiency Hyperphosphatemic Familial Tumoral Calcinosis (HFTC). Loss of Klotho Function PTH Disorders References 21 Congenital Urinary Tract Obstruction—Diagnosis and Management in the Fetus Abstract Keywords Introduction Definitions and Scope of Congenital Urinary Tract Obstruction Antenatal Diagnosis of Congenital Urinary Tract Obstruction Postnatal Outcomes of Antenatally Diagnosed Congenital Urinary Tract Obstruction The Effects of Urinary Tract Obstruction on the Developing Kidney The Effects of Urinary Tract Obstruction on Fetal Kidney Function The Measurement of Fetal Kidney Function The Prediction of Postnatal Outcome In Utero Intervention References Index A B C D E F G H I J K L M N O P R S T U V W X IBC_Clinical Key ad