8.1a Newborn Transition and Adaptation Flashcards
First Period of Reactivity
- Baby is awake and alert
- Once cord gets clamped/cut the baby uses its own heart and transfers to adult circulation.
- HR 160-180
- Not unusual for baby to have irregular respirations, crackles, retractions
- Tachycardia/Tachypnea (Up to 80 breaths a minute)
- Breastfeeding is essential as soon as possible (skin to skin immediately)
- Resuscitation should be done on mom’s chest
- Best and most important time for breastfeeding
Period of Decreased Responsiveness
- After first 30 minutes baby will be sleepy for a few hours (60-100 minutes)
- Rapid and shallow respirations are common
- Acrocyanosis (Normal for the first 12-24 hours)
Second Period of Reactivity
- Occurs 2-8 hours after birth (Hyperalert and responsive phase)
- Lasts 10 minutes to several hours
- Good to keep baby on skin to skin contact at all times (breastfeed)
- Increased mucus secretions that may need to be suctioned
- Often pass meconium
- Tachycardia/Tachypnea (Transient)
Fetal Lung Development
- 20-24 weeks of gestation (alveolar ducts appear)
- 24-28 weeks gestation (primitive alveoli, supports gas exchange, surfactant present)
- 28-32 weeks of gestation (Active surfactant production)
- 35 weeks of gestation (peak surfactant production)
Surfactant
- Composed of phospholipids which line and lower surface tension of alveoli
- Stabilizes alveoli by allowing air to remain in alveoli during expiration
L/S - 2:1 Ratio - Indicates lung maturity
Lecithin - Peak production at 35 weeks of gestation (Most abundant phospholipid in surfactant)
Sphingomyelin - Levels remain constant throughout gestation
- Synthetic surfactant can be used if lungs are not mature
Respiratory Adaptations
Initiation of Breathing
- Chemical (Babies have asphyxia from vaginal birth due to squeeze and contractions. When cord is clamped, chemical factors trigger effort of respiration.)
- Mechanical (The contractions that occur push the fluid out of the babies lungs which allows baby to breathe)
- Thermal (Cooler environment stimulates baby to take a deep breath)
- Sensory (Once babies are born and exposed to loud noise, bright lights, skin stimulation, it stimulates baby to take their first breath)
Characteristics of First Breaths
- Periodic Breathing - Pauses lasting 5-15 seconds followed by regular rate (no color or HR change. This is normal)
- Obligatory nose breathers (low oxygen would be put by their nose if needed)
- 30-60 breaths a minute is normal
(Always count for 1 full minute because of periodic breathing)
Respiratory Distress
- Increased respiratory rate
- Grunting, Nasal Flaring, Intercostal or Subcostal Retractions
Color Change - Acrocyanosis (Lasting longer than first 24 hours ABNORMAL)
- Central cyanosis (Best place to look is mucus membranes - Hypoxemia)
- Circumoral Cyanosis (Blue around the mouth. Cardiac Disease is Worried)
Interventions for Respiratory Adaptation
- Clear the airway (mouth first, nose second) - With suction
- Stimulate the newborn to cry by drying the baby
- Administer oxygen if necessary
Integumentary Adaptations
- At birth skin is covered with Vernix Caseosa (yellow stuff on baby)
- Term infant may be red (erythematous) which fades at birth
- Skin may be blotchy or mottled and extremities may be slightly blue (acrocyanosis)
- Fine lanugo hair may be noted (the younger the baby the more lanugo)
Fetal Shunts
- Ductus Venosus - Bypasses the liver
- Foramen Ovale - Between the atria
- Ductus Arteriosus - Between pulmonary artery and aorta
These 3 shunts, send blood away from organs that don’t need it (these make up fetal circulation)
- Minimizes blood that goes to lungs and liver
Cardiovascular Adaptations
Once cord is clamped and baby takes their first breath..
- Pulmonary vascular resistance decreases (so blood starts flowing to the lungs)
- Increased systemic pressure causes closure of ductus venosus
- Increased pulmonary blood flow from left side increases pressure in left atrium and closes foramen ovale
- The ductus arteriosus closes as pulmonary circulation increases
- Sometimes the foramen ovale and ductus arteriosus can stay patent in the first 24-72 hour which cause murmurs. Babies must be watched closely.
Cardiovascular Adaptations
HR
- Apical pulse should be 100-160
- During sleep it may be less than 100
Murmurs
- 90% are transient related to incomplete closure of fetal shunts
Blood Pressure (This is not routine unless their are risks)
- Vary in the first 24 hours
- Full term 60-90/40-60
Hematologic Adpatations
- Fetal circulation is less efficient at oxygen exchange due to bypass of lungs so greater RBC’s are required in utero
- Average RBC, Hgb, Hct are higher than adults
- RBC’s also die at a faster rate
Hematologic Adaptation
- 80% of newborns blood at birth contains fetal hemoglobin. (These cells have a shorter life resulting in dramatic RBC decrease resulting in minor brief anemia) - take some extra iron
- Leukocytosis (elevated WBC count) is normal and not a sign of infection
Coagulation Concerns
- Clotting factors 2,7,9,10 are activated by Vitamin K
- Injection of Aquamephyton (Vitamin K) given at birth due to absence of flora in the intestines
- Bacteria in the gut is required to produce vitamin K. Babies have a sterile gut when they are born so they do not have vitamin K. This is why we need to supplement vitamin K at birth.
- Babies won’t have vitamin K until they start eating. Bottle feeding, normal flora takes a while to develop. Breast feeding is better.
Factors Affecting Thermal Stability
- Babies have low subcutaneous fat
- Babies have a large body surface area compared to their weight
- Blood vessels are closer to the skin so it cools more quickly
- Babies cannot shiver (flexion state)
- Babies have limited brown fat
- Rate of heat loss is 4x faster than adults
Types of Heat Loss
Convection - Air is blowing over baby causing heat loss
Conduction - Baby loses heat from being in touch with cold surface
Radiation - Baby are next to a cold surface which radiates cold air
Evaporation - Baby cools very quickly when they are wet
Thermogenesis
- How do babies generate heat (thermogenesis)
- BMR increases to create heat (uses oxygen and glucose)
- Brown fat is used as primary heat source because babies cannot shiver (brown fat is limited)
- If baby uses up all their brown fat, they will use glucose to stay warm. It is essential to keep a baby warm to keep their blood glucose stable. Low blood glucose (baby will get cold)
Response to heat
- Warmth will cause baby to be relaxed and not tight flexion
- If a baby is extended (arms wide out) and flushed skin, it means they are too warm
- Babies have limited sweat glands so they are easily overheated
- Sweat production matured at 4 weeks
What Happens When Baby is Cold
- They have increased o2 consumption which causes increased respiratory rate
- Increased respiratory rate causes both pulmonary and peripheral vasoconstriction
- Pulmonary vasoconstriction causes less oxygen uptake my lungs, which causes less oxygen to tissues, which leads to baby requiring use of anaerobic glycolysis (conversion of glucose)
- Peripheral vasoconstriction causes less o2 to tissue as well which also leads to glycolysis
- Glycolysis leads to less oxygen and less pH in the blood
- Less pH and oxygen causes acidosis in the baby
- Glucose and coldness of baby go hand in hand
Renal Adaptations
- Almost all babies void in the first 30 hours
- At least 1 void is expected in the first 24 hours
- If a baby hasn’t voided in 48 hours, interventions may be needed. We wait 48 hours because sometimes babies urinate at birth but goes unnoticed because of other fluids
- Babies have a low GFR so they cannot concentrate their urine until 3 months of age. This is why we must watch a babies fluid load.
- Uric acid crystals are common (looks like brick dust spots). You need to explain this to parents
GI Adaptations
- Babies can swallow, digest, metabolize, absorb simple carbs, and protein
- Coordination of breathing, sucking and swallowing reflexes are something we need to watch for
- Babies have very small stomachs (size on next slide)
- 15-30 mL per meal per day increased feedings
- Immature cardiac sphincter leads to intermittent “spitting”
- Babies may lose up to 5-10% birth weight in the first week
- Colostrum (immature milk) gives babies all the nutrients they need, but it does not have volume. Mature milk does not come in until day 3-4.
Baby Stomach Size
Day 1 - 5-7 mL (Size of a cherry)
Day 3 - 22-27 mL (Size of a radish)
Day 7 - 45-60 mL (Size of a large egg)
1 Month - 80-150 mL (Size of an apricot)
GI Adaptations
Stool Characteristics
- Meconium stool first 8-24 hours
- Transitional Stool (yellow/light green) day 2-3
- Breastfeed babies - Looser, watery, thin, pale, yellow (breastmilk is a natural laxative)
- Bottle fed babies - Brown and pasty