Newborn Physiologic Adaptations

Physiologic Adaptations of the Newborn at Birth

• The major physiologic changes that occur as the newborn transitions to extrauterine life should be examined
• The primary challenges faced by the newborn during the transition to extrauterine life is needed
• Learning the three behavioral patterns newborns progress through following birth, is key

Learning Outcomes

• Interventions that meet the immediate needs of the term newborn is needed
• Characteristics that contribute to heat loss for newborns should be known
• It is important to distinguish common variations that can be noted during a newborn’s physical assessment
• The discharge planning education needed for the family with a newborn should be discussed

Immediate Care After Birth

• Begins with an initial assessment completed in the delivery area
• A patent airway and respirations must be maintained
• Apgar scores must be assigned
• Vital signs are obtained and monitored
• Thermoregulation is also maintained
• Infant, parents, and security tags are ID Banded
• A 3 vessel umbilical cord is assessed
• Footprints are taken
• Measurements and weight are recorded
• Bonding is promoted
• Documentation is completed

Apgar Score

• Allotted in areas at 1 and 5 minutes after birth and repeated at 10 minutes if warranted
• Appearance relates to color
• Pulse relates to heart rate
• Grimace relates to reflex irritability
• Activity relates to muscle tone
• Respiration relates to respiratory effort

Respiratory System

• Initiation of respirations involves adjusting from a fluid-filled intrauterine environment to a gaseous extrauterine environment
• Surfactant lowers surface tension reducing lipoprotein to prevent alveolar collapse
• Respirations are 30 to 60 breaths per minute; irregular, shallow, and unlabored
• It is normal if the baby has short periods of apnea (less than 15 seconds)
• Symmetrical chest movements are expected

Cardiovascular System

• Heart Rate should be 110-160 beats per minute
• the Apical pulse needs to be for one full minute
• BP should be 60-80 mmHg systolic and 40-50 mmHg diastolic
• Delayed umbilical cord clamping affects blood volume
• There is an increase in blood volume and blood pressure because of clamping

Newborn Temperature Regulation

• Thermoregulation maintains the balance between heat loss and production.
• Newborns are predisposed to heat loss
• Thin skin and blood vessels are close to the surface
• Newborns have a large body surface area relative to body weight
• There is a lack of subcutaneous fat so they have little ability to conserve heat by changing posture
• There is a lack of shivering, and limited stores of glucose, glycogen, and fat

Mechanisms of Heat Exchange

• Conduction transfers heat when two objects are in direct contact (stethoscope)
• Convection is the flow of heat from the body surface to cooler surrounding air or to air circulating over a body surface (open window)
• Evaporation is the loss of heat when liquid is converted to vapor (covered with amniotic fluid)
• Radiation is the loss of body heat to cooler, solid surfaces in close proximity, but not in direct contact (place by a cool surface)

Transition to Extrauterine Life: Thermoregulation

• The first 4-6 hours of birth

• A Neutral thermal environment (NTE) is needed

• Body temperature is maintained without an increase in metabolic rate or oxygen consumption

• Brown adipose tissue is brown fat

• Cold Stress is found through ineffective thermoregulation

• Factors that negatively affect thermoregulation

• Decreased subcutaneous fat along with a large body surface

• Decreased brown fat in preterm infants

• Increased oxygen consumption and metabolic demands occur with hypothermia

Signs of Cold Stress

• Low temperature
• Weak cry
• Decreased tone and lethargy
• Respiratory distress
• Cool, mottled skin
• Poor feeding
• Hypoglycemia

Thermoregulation and Distribution of Brown Fat

• Thermal neutral environment is important for successful transition, especially in SGA and preterm newborns

Effects of Cold Stress

• Cold causes an increase in O2 consumption and respiratory rate
• O2 uptake by lungs and Pulmonary vasoconstriction is possible
• O2 decreases in tissues
• Peripheral vasoconstriction increases
• Anaerobic glycolysis increases
• PO2 and pH levels decrease
• Metabolic acidosis then can occur

Renal System

• There is a limited ability to concentrate urine and reduced glomerular filtration rate
• Patient may be susceptible to dehydration and fluid overload
• This state affects the ability to excrete drugs
• Many newborns void right after birth
• Typically they void within 24 hours of birth
• For the first 2 days of life, voids are 2-6 times per day
• Then they increase to 6 to 8 times /day
• Pseudomenstruation results in withdrawal of maternal hormones seen in female neonates
• "Brick dust spots" are Urates which are normal and may be seen on the diaper

Gastrointestinal System

• The GI system is still immature but has the ability to transport nutrients
• Bowel sounds are audible a short time after birth
• A newborn needs to adapt to bacterial colonization of the gut
• Dependent on nutrition is required for production of Vitamin K
• Regurgitation of feeding is common due to immature cardiac sphincter and nervous control of the stomach which leads to regurgitation
• A newborn should not be overfed and needs to be burped often
• Newborns will experience weight gain
• There is typically 5-10% weight loss in the first week of life

Characteristics of Newborn Stools

• Within 24 to 48 hours after birth, Meconium will occur
• They are Greenish black and viscous
• Transitional stools will occur on day 3
• They will be Greenish brown to yellow brown
• These stools are Thin and less sticky than meconium
• Milk stools will appear by day 4
• Breast-fed newborns stool should be Yellow/gold, mustard/cottage cheese looking with a sour milk smell
• Formula-fed newborns stools should be pale yellow to light brown
• It can be expected that there is a firmer consistency and unpleasant odor with formula fed stool

Hepatic System

• The liver assumes function of placenta
• It is important for iron storage
• If maternal iron intake is adequate, a newborn should have enough iron stored in the liver to last 6 months
• Carbohydrate metabolism occurs
• Glucose is essential fuel for brain metabolism-main source of energy for first few hours after birth
• The liver releases glucose from glycogen stores for the first 24 hours
• Initiate early feedings to help stabilize glucose levels

Hypoglycemia

• Issues during transition with glucose regulation
• Impaired ability to generate glucose from glycogen stores
• Slower postnatal glucose increase
• Increased glucose utilization

Risk Factors for Hypoglycemia

• Maternal
• Diabetic, multiples, obesity
• Fetal/Neonatal
• Hypothermia
• Birth weight variations
• Stress
• Sepsis

Hypoglycemia Signs

• Irritability
• Tremors/jitteriness
• High-pitched cry
• Lethargy/floppiness/hypotonia
• Cyanosis
• Apnea/Tachypnea
• Hypothermia/temperature instability
• Poor feeding

Bilirubin Synthesis

• Imbalance in rate of bilirubin production and elimination, total serum bilirubin level >5 mg/dL or 0.3 mg-1 mg/dL
• The two types of jaundice include:
• Physiologic jaundice (3rd to 4th day of life), considered benign
• Pathologic jaundice (within first 24 hours of life)

Kernicterus

• Total Bilirubin > 20 mg/dl
• Irreversible
• Crosses blood-brain barrier
• Causes permanent impaired neurological function
• Can be a result of Rh isoimmunization; ABO incompatibility

Nursing Assessment For Synthesis Issues

• Monitor skin, sclera, Early and frequent feedings, possible phototherapy
• Check and monitor bilirubin levels

Phototherapy

• Reduces bilirubin by converting it to a water soluble form
• Nursing care includes skin care and eye protection, hydration with frequent feedings, and thermoregulation
• Education on bilirubin levels according to the infant's age in hours is key.
• Side effects - increased insensible water loss, decreased maternal-newborn interaction, and lack of visual sensory input

Immune System

• The newborn immune system is immature and does not readily respond to infections
• Hypothermia may be a sign of infection in the first days of life
• A temp less than <36.5-37.5℃/97.7-99.5°F
• Passive acquired immunity is a transfer of antibodies from the mother to fetus
• IgG antibodies cross the placenta and give the neonate protection against infection which lasts up to 2 months
• Colostrum is high in IgA
• Active Acquired immunity happens through immunizations, begin at 2 months of age

Mongolian Spot

• Bluish-purple pigmentation

Skeletal System / Head

• Molding of the head happens due to delivery
• Fontanels move the head through birth canal
• Head also has a Caput succedaneum
• As well as Cephalohematoma

Skeletal System / Extremities: Hip Dysplasia

• Screen due family history, if the baby is female, had a breech presentation at birth
• Positive Barlow and Ortolani test is a sign

Neuromuscular System

• The nervous system is immature and develops during the first year
• Development follows cephalocaudal (head to toe) and proximal-distal (center to outside) patterns
• Reflexes are how neurologic development and function is assessed

Neonatal Assessment Continued

• Growth is observed via a cephalo-caudal / proximo-distal exam

Reflexes

• Sucking and rooting
• Palmer grasp
• Tonic neck (fencer position)
• Moro
• Stepping
• Babinski

Sensory Behaviors

• There are acute senses of hearing, smell, and taste that are well-developed
• A newborn is Able to distinguish a mother's breast milk, sweet, and sour smells by 72 hours
• Touch-sensitive from the start
• There is a Response to environmental stimuli
• This involves an evaluation of Temperament, habituation, Consolability and cuddliness, as well as Irritability and crying

Newborn Matching

• Erythema Toxicum - Pink rash
• Stork Bite - Red marks on the back of the neck, forehead
• Rooting Reflex - Baby turns head when their cheek is stroked
• Moro Reflex - Extends and abducts arms in a “C” shape
• Mongolian Spots - Bluish-purple pigmentation
• Molding - Shaping of head moving through birth canal
• Kernicterus - Long-term effects of bilirubin toxicity
• Babinski Reflex - Toes fan upward and out
• Milia - White papules on face
• Jaundice - Yellowing of skin
• Vernix - Protective thick, white covering

Medications

• Erythromycin ophthalmic ointment 0.5% prevents STDs: chlamydia and Gonorrhea
• This Mandatory antibiotic ointment prevents ophthalmia neonatorum caused by Neisseria gonorrhoeae or Chlamydia trachomatis can causes blindness
• To apply 1-2 cm ribbon of ointment should be put into the lower conjunctival sac of each eye

Vitamin K (Phytonadione)

• Give 0.5 to 1 mg via the IM route within one hour after birth
• Prevents hemorrhagic disorders
• Not produced by the GI tract of a newborn until day 7
• Produced by the colon and bacteria, which form after formula or breast milk

Hepatitis B

• Protects against hepatitis Band is given via IM route
• Parents must sign Informed consent
• Dosage at birth, one month, and 6 months
• Do not administer both IM injections into the same site

Newborn Vital Signs

• Temperature norm is 97.7- 99.5 F (36.5-37.5)
• Heart Rate average is 120-160 bpm
• Respirations should be 30-60 breaths/minute at rest
• Blood Pressure average is 50-75 mm Hg systolic, and 30-45mmHg diastolic
• Always complete Pain assessment with the Neonatal Infant Pain Scale (NIPS)

Immediate Care After Birth

• Birth weight average is 2500-4000 grams
• Length should measure from 46- 54 cm or 19-21 inches
• Head Circumference average is 33-35 cm or 13-14 inches
• Chest Circumference average is 30.5-33 cm or 12-13 inches
• Also complete an abdominal Circumference measurement and a full Neurologic Assessment

Physical Maturity Assessment: Ballard

• Determines the newborn’s gestational age
• Looks at physical and neuromuscular maturity
• Assessment evaluates Skin texture, Lanugo, Plantar creases, Breast tissue, Eyes and ears, and Genitals

Care Management

• Laboratory and diagnostic tests are completed
• Universal newborn screening is done
• PKU testing is done 24 -48 hours after feeding
• Newborn hearing screening is completed
• Then critical congenital heart disease screening

Circumcision

• This is the Removal of foreskin of the penis
• Important Contraindications: Preterm neonates, Genitourinary defects (hypospadius), Bleeding disorders (like a baby that is not getting vitamin K) and a Compromised neonate from a Respiratory distress syndrome
• Risks: hemorrhage, infection, pain, adhesions
• Benefits: Reported decrease UTI,STI’s-including HIV along with a lowered risk of penile cancer and cervical cancer in a female partner

Circumcision Procedures

• Procedure: The AAP recommends analgesia
• Nerves are blocked when topical and concentrated oral sucrose along with pacifiers are given
• There are different Types of circumcisions:
• Mogen clamp- wound is covered with sterile petroleum gauze to prevent bleeding and infection
• Plastibell- falls off 5-7 days, plastibell, no petroleum gauze is used

Post Procedure

• Assess bleeding every 15 to 30 minutes for first hour, then every hour for 4 to 6 hours
• Note first voiding, assess for signs of infection
• May prescribe acetaminophen 10-15 mg/kg every 4 to 6 hours for 24 hours post procedure
• Caution the maximum dose is 30-45 mg/kg/day

Discharge Planning

• It should involve Newborn care, Bathing, Cord care, feeding, temperature, and positioning
• Review Swaddling
• Talk about SIDS awareness
• Sleeping and Activity safety
• Infant car seat placement and safety
• Educate the parent, Rear facing, back seat in middle until age 2
• Home safety tips should be review
• Review the parents ability to prevent infection and practice proper hygiene
• The Bilirubin screen procedure *** should be clear

Newborn Screen

• The PKU should be done 24 to 48 hours after protein feeding***
• Hearing tests
• Testing for congenital cardiac disorder if any
• Follow up care with Pediatrician after testing
• Have a follow up appointment in 1-2 weeks post discharge
• Educate the client on When to call the Pediatrician and how to Recognize signs of illness

Summary

• Identify the assessments performed during the immediate newborn period and after
• Describe interventions that meet the immediate needs of the term newborn
• Define the key laboratory and newborn screening tests conducted in the newborn period
• Distinguish common variations that can be noted during a newborn’s physical assessment
• Explore the discharge needs for the neonate
• Examine the major physiologic changes that occur as the newborn transitions to extrauterine life
• Identify the primary challenges faced by the newborn during the transition to extrauterine life
• Outline the three behavioral patterns that newborns progress through following birth