Chapter 19 Normal Newborn Processes of Adaptation Copyright

Initiation of Respirations: Development of the Lungs Fetal lung fluid Surfactant is produced as lungs mature. Reduces surface tension within alveoli Ø Surfactant usually sufficient by 34 to 36 weeks of gestation Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 2

Initiation of Respirations: Causes of Respirations First breath must force fluid into interstitial spaces Requires negative pressure Initiation of respirations Chemical factors Ø Mechanical factors Ø Thermal factors Ø Sensory factors Ø Continuation of respirations Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 3

Initiation of Respirations Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an

Cardiovascular Adaptation: Ductus Venosus Directs blood away from liver to inferior vena cava during fetal life Blood flow diminishes when umbilical cord vessels are occluded at birth. Fibrosis of ductus venosus occurs by 1 to 2 weeks of life. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 5

Cardiovascular Adaptation: Foramen Ovale Right-to-left shunting of blood Resistance to pulmonary blood flow Blood from left ventricle travels to placental vessels. Pressures reverse as blood flows into dilated pulmonary vessels. Pressure in left ventricle builds, causing foramen ovale to close. Closure of foramen ovale prevents blood flow from right to left. Blood flow through heart and lungs changes to neonatal circulation. Becomes permanently closed within several months Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 6

Cardiovascular Adaptation: Pulmonary Blood Vessels Blood from the superior vena cava and inferior vena cava flow into the right atrium, to the right ventricle, and into the pulmonary artery. Most of the blood passes through the ductus arteriosus, while 10% to 12% of the blood goes to the lungs. After 30 weeks gestation, the amount of blood to the lungs increases. Blood flow to the lungs is limited by constriction. Blood perfusing the lungs returns to the left atrium by the pulmonary veins. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 7

Cardiovascular Adaptation: Ductus Arteriosus Connects the pulmonary artery and the descending aorta during fetal life Dilation is maintained by prostaglandins. The placenta Ø Low oxygen content of the blood Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 8

Cardiovascular Adaptation: Changes at Birth Alterations occur simultaneously within the first few minutes after birth. Pressures between the right and left sides of the heart are reversed. Shunts close, and the pulmonary vessels dilate. The foramen ovale’s flap valve closes. Clamping of the umbilical cord closes the ductus venosus. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 9

Neurologic Adaptation: Thermoregulation Newborn characteristics leading to heat loss Methods of heat loss Evaporation Ø Conduction Ø Convection Ø Radiation Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 10

Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier

Sites of Brown Fat Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders,

Effects of Cold Stress Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders,

Neurologic Adaptation: Thermoregulation (Cont. ) Nonshivering thermogenesis Effects of cold stress Neutral thermal environment Hyperthermia Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 14

Hematologic Adaptation Factors affecting the blood Blood values Erythrocytes and hemoglobin Ø Hematocrit Ø Leukocyte Ø Risk of clotting deficiency Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 15

Gastrointestinal System: Stomach Capacity expands within first few days of life. Peristalsis is rapid. Gastrocolic reflex is stimulated when the stomach fills. Cardiac sphincter is relaxed, leading to regurgitation. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 16

Gastrointestinal System: Intestines Long in proportion to infant's size: more surface area for absorption Infants are more prone to rapid water loss with diarrhea. Bowel sounds are present within the first hour. The digestive tract is sterile until feeding begins. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 17

Gastrointestinal System: Digestive Enzymes Cannot digest complex carbohydrates Saliva production limited until third month of life Ingredients in breast milk more easily digested Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 18

Gastrointestinal System: Stools Meconium is the first stool excreted. Greenish black with a thick, sticky, tarlike consistency Ø First stool is usually passed within 12 hours. Ø Consists of particles from amniotic fluid Ø Transitional stool is the second type. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 19

Gastrointestinal System: Stools (Cont. ) Breastfed infant Stools are seedy and mustard colored. Ø Stools are more frequent than with formula. Ø Stools have a sweet-sour smell. Ø Formula-fed infant Stools are pale yellow to light brown. Ø Stools are firmer in consistency. Ø Stools have the characteristic odor of stools. Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 20

Hepatic System: Conjugation Of Bilirubin Source and effect of bilirubin Hemolysis of erythrocytes Ø Bilirubin is a toxic substance. Ø Liver must convert to a soluble form (conjugated) Ø Unconjugated bilirubin causes jaundice and kernicterus. Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 21

Hepatic System: Conjugation Of Bilirubin (Cont. ) Glucuronyl transferase converts unconjugated bilirubin. Excreted into duodenum Eliminated in the stool Beta-glucuronidase can convert conjugated back to unconjugated bilirubin. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 22

Hepatic System: Conjugation Of Bilirubin (Cont. ) Factors in increased bilirubin Excess production Ø Red blood cell life Ø Liver immaturity Ø Intestinal factors Ø Delayed feeding Ø Trauma can result in increased hemolysis of red blood cells. Ø Fatty acids are released when brown fat is used. Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 23

Hepatic System: Hyperbilirubinemia Physiologic jaundice Caused by transient hyperbilirubinemia Ø Never present during first 24 hours of life Ø Jaundice is visible when bilirubin level is greater than 5 mg/d. L Ø Rate of rise and fall of bilirubin level is important. Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 24

Hepatic System: Hyperbilirubinemia (Cont. ) Nonphysiologic jaundice May occur in the first 24 hours Ø Caused by abnormalities causing excessive destruction of erythrocytes Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 25

Hepatic System: Jaundice Associated with Breastfeeding jaundice Inadequate intake Ø Sleepy infant with poor suck Ø Delay in elimination of meconium Ø Lack of adequate suckling Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 26

Hepatic System: Jaundice Associated with Breastfeeding (Cont. ) True breast milk jaundice Bilirubin levels rise after the first 3 to 5 days. Ø Substances in breast milk may interfere with conjugation of bilirubin. Ø Closely monitor bilirubin levels. Ø Treat with phototherapy; may discontinue breastfeeding. Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 27

Hepatic System Blood coagulation Iron storage Metabolism of drugs Copyright © 2014, 2010, 2006,

Urinary System Kidney development Kidney function Fluid balance Water distribution Insensible water loss Urine dilution and concentration Acid-base and electrolyte balance Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 30

Immune System Less effective at fighting off infection Immunoglobulin G (Ig. G) Ø Immunoglobulin M (Ig. M) Ø Crosses placenta and provides temporary immunity First immunoglobulin produced when exposed to infection Immunoglobulin A (Ig. A) Receive some from colostrum and breast milk Ø Must be produced by the infant Ø Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 31

Psychosocial Adaptation Periods of reactivity First period of reactivity Ø Period of sleep Ø Second period of reactivity Ø Behavioral states Ø Ø Ø Quiet sleep state Active sleep state Drowsy state Quiet alert state Active alert state Crying state Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 32

Question A first-time father is concerned that his 3 -day-old daughter's skin looks "yellow. " In the nurse's explanation of physiologic jaundice, which point should be included? a. Physiologic jaundice occurs during the first 24 hours of life. b. Physiologic jaundice is caused by blood incompatibilities between the mother and infant blood types. c. The bilirubin levels of physiologic jaundice peak at 5 to 7 mg/d. L between the second and fourth days of life. d. This condition is also known as breast milk jaundice. Copyright © 2014, 2010, 2006, 2002, 1998, 1994, by Saunders, an imprint of Elsevier Inc. 33