Chapter 17: Chapter Newborn Transitioning Flashcards
Hepatic System
Liver takes over placenta: blood coagulation, iron storage, carbohydrate metabolism, conjugation of bilirubin,
Iron: has enough in storage for 6 months
Carb Metabolism: glucose declines, Liver releases glucose 1st 24 hours which is main source of energy the first few hours. No longer have moms glucose stores to rely on.
Bilirubin Conjugation:
Overprodution: blood incompatible, trauma, drugs, polycythemia, delayed cord clamp, breast milk
Decreased: hypothyroidism, breastfeeding
Impaired: biliary obstruction, sepsis, hepatitis, chromosomal abnormalities, drugs.
Jaundice: icterus, yellowing of skin, sclera, and mucous membranes from increased bilirubin. Common in first week of life. can cause encephalopathy, and brain damage. Risks include: blood incompatible, premature, breastfeeding, drugs, gestational diabetes, infrequent feedings, male, trauma in birth, polycythemia, infections TORCH, asian or Native American.
GI System
Development of a mucosal barrier to prevent the penetration of harmful substances. Bacterial colonization occurs within 24 hours.
The physiologic capacity of the stomach is less than capacity during the first 4 days.
Cardiac sphincter and nervous control of the stomach is immature leading to regurgitation and uncordinated peristalsis
108 cal/kg/day from birth to 6 months
Stools: earlier fed, earlier stool, decreased bilirubin
Milk stools Breast:yellow-gold, loose, stringy, sour smell
Formula yellow-green, loose, pasty-formed, odor
Renal System changes
Limited in concentrating urine until 3 months. 6-8 wet diapers a day. Low GFR and limited excretion and concervation capability affect the newborns ability to excrete salt, water, and drugs. Fluid overload is a big risk if having IV.
Immune System
Defense, homeostasis (replace worn out cells), surveillance
Natural: physical barriers, chemical barriers, and resident nonpathological organisms. Ingestion and killing by phagocytosis
Acquired: development of circulating antibodies and immunoglobulins capable of targeting and destroying invaders. Formation of activated lymphocytes that destroy invaders. Aquired immunity is absent until exposed.
IgG most abundant, crosses placenta, protects against bacteria, bacterial toxins, and viral agents
IgA second most, protects the mucous membrane. Found in GI tract, respiratory tract, tears, saliva, colostrum, and breast milk.
IgM found in blood and lymph, first to respond to infection,
How the fetus functions
Respiratory: fluid filled high pressured, shunted from the lungs through the ductus arteriosus to the rest of the body.
Site of gas exchange: the placenta
circulation to the heart: pressures in the right atrium higher than the left, bloodflow goes through the foreman ovale.
Hepatic portal circulation: ductus venosus bypasses, Maternal liver functions as filter.
Thermoregulation: body temperature is maintained by the maternal body temperature.
How the newborn changes compared to the fetus
Respiratory: air-filled, low-pressure system encourages bloodflow through the lungs. Increased oxygen content of the blood in the lungs contributes to the closing of the ductus arteriosus.
Site gas exchange: lungs
circulation through the heart: pressures in the left atrium are greater than the right, causing the foreman ovale to close
Hepatic portal circulation: ductus venosus closes and hepatic portal circulation begins.
Thermoregulation: body temperature is maintained through a flex posture and brown fat
Cardiovascular system adaptations
Changes such as the force of contractions, mild asphyxia, increased intracranial pressure, uterine contractions, cold stress, lead to increased release of catecholamines that is critical for the changes involved in the transition to extrauterine life. Increased level of epinephrine and norepinephrine stimulate increased CO, surfactant release, and promotion of fluid clearance.
Heart rate: right after birth is between 120 and 180. Decreases to one 120 -130. Blood-pressure is highest afterbirth and declines within a week. Tachycardia: volume depletion, cardiorespiratory disease, drug withdrawal, hyperthyroidism. Bradycardia: apnea and hypoxia
Blood volume: depends on the amount transferred from the placenta. it can vary by 25% to 40% depending on the clamping of the umbilical cord. Studies show benefits of delayed cord clamping that can improve cardiopulmonary adaptation, prevent anemia, increased the blood pressure, improve oxygen transport, increased red blood cells. Cord blood is considered the nature’s first stem cell transplant.
Blood component: red blood cell count gradually increases with a lifespan of 80 -100 days. Hemoglobin initially declined. Leukocytosis is a result of the trauma of birth.
Fetal to neonatal circulation
Clamping umbilical cord eliminates the placenta as a reservoir.
Respirations causes a rise in PO2 which
increases pulmonary bloodflow and pressure in the left atrium
which decreases pressure in the right atrium and causes closure of the foreman ovale.
increase O2 after 1st breath increases vascular resistance which
decreases vena cava return, reducing flow to umbilical vein
closure of ductus venosus causes increase in aorta pressure, which closes ductus arteriosus within 10-15 hours after birth
Respiratory system adaptation
Hypercapnia, hypoxia, and acidosis become a stimuli for initiating respirations. Surfactant is a surface tension reducing lipoprotein found in the lungs to prevent alveolar collapse.
A newborn must be able to adjust from fluid filled lungs to gas exchange when in the external environment. If fluid is not removed, transient tachypnea occurs. Causes include cesarean delivery, sedation in newborn, and a too fast delivery.l
Respirations are shallow, irregular, 30 to 60 breath, and short period of apnea. The chest movement should be symmetrical. Periodic breathing with cessation of breathing less than 5-10 sec may be seen and should be monitored. If apneic periods last longer than 15 seconds they must be evaluated.
Body temperature regulation
97.9 to 99.7°
Things that contribute to heat loss:
Thin skin with blood vessels close to the surface.
Lack of shivering ability.
Limited stores of metabolic substrates such as glucose glycogen and fat.
Limited use of voluntary muscle activity or movement.
Large body surface area related to wait.
Lack of subQ fat for insulation
Little ability to conserve heat by changing position.
No ability to change clothing or blankets.
Inability to communicate.
Newborns are also prone to overheat which can increase fluid loss, respiratory rate, and metabolic rate.
Thermoregulation is the balance between heat loss and heat production. The baby needs to be in a neutral thermal environment. This is where the body temperature is maintained without increase in metabloic rate or oxygen use.
The newborn primary method of heat production is through non-shivering thermogenesis in which brown fat is used in a response to cold exposure.
Conduction
Transfer of heat from one object to another when in direct contact.
Convection
The flow of heat from the body to cooler surrounding air or air circulating over the body. Avoid drafts. Transfer in an isolate.
Evaporation
Loss heat when liquid is converted to a vapor. Insensible is from skin and respiration. Sensible from sweating. Evaporating amniotic fluid. You must dry the newborn immediately after birth and bath with warm blankets in place a hat on head. promptly change wet linens and diapers
Radiation
The loss of body heat to cooler, solid surfaces that are in proximity but not in contact. Such as being near a window.
Cold stress
Excessive heat loss that requires a newborn to use compensatory mechanisms to maintain core body temperature. This is extreme in the first 12 hours or in the preterm. It can lead to depleted brown fat stores, Increase oxygen needs, respiratory distress, increased glucose conception and hypoglycemia, metabolic acidosis, jaundice, hypoxia, and decreased surfactant production.
to reduce cold stress: Use warm blankets and hats. Keep infant in warmed Isolette. Dry newborn completely after birth. Encourage skin to skin contact. Promote early breast-feeding. Use heated and humidified oxygen. Use radiant warmers and Isolette. Defer bath until stable. Put temperature probe over liver.
