Newborn Physiologic Adaptations and Immediate Care

Physiologic Adaptations of the Newborn at Birth

• Major physiologic changes occur as newborns transition to extrauterine life
• Primary challenges are faced by newborns during the transition to extrauterine life
• Newborns progress through three behavioral patterns following birth
• Interventions meet the immediate needs of the term newborn
• Some characteristics contribute to heat loss after birth for newborns
• Common variations can be noted during a newborn's physical assessment
• Discharge planning education is needed for the family with a newborn

Immediate Care After Birth

• An initial assessment is completed in the delivery area
• A patent airway and respirations are maintained
• Apgar scores are assigned
• Vital signs are obtained and monitored.
• Thermoregulation is maintained
• Infant, parents, are given ID bands, along with a security tag
• Assess the umbilical cord for 3 vessels
• Footprints are taken
• Measurements and weight are recorded
• Bonding is promoted
• Documentation is completed

APGAR Score

• Two points are allotted to appearance, pulse, grimace, activity, and respiration at 1 and 5 minutes after birth
• Scores are repeated at 10 minutes if warranted
• A stands for appearance (color)
• P stands for pulse (heart rate)
• G stands for grimace (reflex irritability)
• A stands for activity (muscle tone)
• R stands for respiratory (respiratory effort)

Respiratory System

• Initiation of respirations involves adjusting from a fluid-filled intrauterine environment to a gaseous extrauterine environment
• Surfactant reduces surface tension, preventing alveolar collapse
• Respirations are 30 to 60 breaths per minute
• Newborns respiration is irregular, shallow, and unlabored
• Short periods of apnea of less than 15 seconds may occur
• Chest movements should be symmetrical

Cardiovascular System

• Heart rate is 110-160 beats per minute
• Take apical pulse for one full minute
• Blood pressure is 60-80 mmHg systolic and 40-50 mmHg diastolic
• Delayed umbilical cord clamping increases blood volume and blood pressure

Newborn Temperature Regulation

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

Mechanisms of Heat Exchange

• Conduction is heat transfer when two objects are in direct contact such as a stethoscope
• Convection is the flow of heat from the body surface to cooler surrounding air such as an open window
• Evaporation is heat loss when liquid is converted to vapor
• Radiation is the loss of body heat to cooler, solid surfaces in close proximity such as a cool surface

Transition to Extrauterine Life

• Thermoregulation happens during the first 4-6 hours
• Neutral Thermal Environment (NTE) maintains body temperature without increasing metabolic rate or oxygen consumption
• Brown adipose tissue is brown fat
• Cold stress involves ineffective thermoregulation
• Decreased subcutaneous fat and a large body surface negatively affect thermoregulation
• Decreased brown fat in preterm infants can effect thermoregulation

Thermoregulation and Cold Stress

• Increased oxygen consumption and metabolic demands are associated with hypothermia
• Signs of cold stress include low temperature, weak cry, decreased tone/lethargy, respiratory distress; cool/mottled skin, poor feeding, and hypoglycemia

Renal System

• Newborns have a limited ability to concentrate urine and reduced glomerular filtration rate
• Newborns are susceptible to dehydration and fluid overload
• The ability to excrete drugs is affected
• Many newborns void right after birth, typically within 24 hours
• During the first 2 days, voiding occurs 2-6 times per day, then increases to 6-8 times per day
• Pseudomenstruation due to maternal hormone withdrawal, seen in female neonates
• "Brick dust spots" are urates and normal on diapers

Gastrointestinal System

• The GI system is still immature but has the ability to transport nutrients
• Bowel sounds are audible a short time after birth
• The newborn needs to adapt to bacterial colonization of the gut
• They are dependent on nutrition for Vitamin K production
• Regurgitation of feeding is common due to an immature cardiac sphincter and nervous control of the stomach, leading to regurgitation
• Avoid overfeeding and burp often
• A typical 5-10% weight loss occurs in the first week of life

Characteristics of Newborn Stools

• Meconium occurs within 24 to 48 hours and is greenish black and viscous
• Transitional stools appear around day 3 and are greenish-brown to yellow-brown and less sticky than meconium
• Milk stools appear around day 4
• Breast-fed newborns have yellow and gold stools with a sour milk smell
• Formula-fed newborns have pale yellow to light brown stools with a firmer consistency and unpleasant odor

Hepatic System

• The liver assumes the function of the placenta
• The liver has an important function for iron storage
• With adequate maternal iron intake, newborns should have enough iron stored in the liver to last the first 6 months
• Glucose is an essential fuel for brain metabolism and the main source of energy in the 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

• With hypoglycemia, the transition has issues with glucose regulation
• There is an impaired ability to generate glucose from glycogen stores
• There is a slower postnatal glucose increase
• There is an increased glucose utilization
• Maternal risk factors include diabetes, multiples, and obesity
• Fetal/Neonatal risk factors include hypothermia, birth weight variations, stress, and sepsis

Hypoglycemia Signs

• Signs of hypoglycemia include irritability, tremors/jitteriness, a high-pitched cry, lethargy/floppiness/hypotonia, cyanosis, apnea/tachypnea, hypothermia/temperature instability, and poor feeding

Bilirubin Synthesis

• Imbalance in rate of bilirubin production and elimination occur with total serum bilirubin level >5 mg/dL
• Physiologic jaundice occurs on the 3rd to 4th day of life and is considered benign
• Pathologic jaundice occurs within the first 24 hours of life
• Kernicterus presents when total bilirubin is > 20 mg/dl and is irreversible
• Kernicterus crosses the blood-brain barrier
• It causes permanent impaired neurological function
• Rh isoimmunization an ABO incompatibility can result with Kernicterus
• Nursing assessment involves monitoring skin/sclera, early and frequent feedings, and possible phototherapy
• Check and monitor bilirubin levels

Phototherapy

• Phototherapy reduces bilirubin by converting it to a water-soluble form
• Nursing care involves skin care and eye protection
• Hydration is important with frequent feedings
• Thermoregulation should be monitored
• Educate the parents
• Interpret all bilirubin levels according to the infant's age in hours
• Side effects include 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
• Passive acquired immunity is the transfer of antibodies from mother to fetus
• IgG antibodies cross the placenta and give the neonate protection against infection lasting up to 2 months
• Colostrum is high in IgA
• Active Acquired immunity occurs with immunizations, beginning at 2 months of age

Skeletal System

• Molding occurs with head
• Fontanels are areas that contain that crosses suture line
• Caput succedaneum occurs with the head
• Cephalohematoma contains blood that gets around the sutures but does not cross the suture line
• Hip dysplasia occurs with extremities

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 assess neurologic development and function

Neonatal Assessment points

• Growth - cephalo-caudal / proximo-distal
• Sucking and rooting
• Palmer grasp
• Tonic neck (fencer position)
• Moro
• Stepping
• Babinski

Sensory Behaviors

• Newborns have acute senses of hearing, smell, and taste
• They are able to distinguish mothers breast milk, sweet and sour by 72 hours
• They are touch-sensitive to pain
• Newborns respond to environmental stimuli
• Temperament, habituation
• Consolability and cuddliness
• Irritability and crying

Medications

• Erythromycin ophthalmic ointment 0.5% prevents against STDs such as Chlamydia and Gonorrhea
• Antibiotic ointment is mandatory to prevent opthalmia neonatorum, which is caused by Neisseria gonorrhoeae or Chlamydia trachomatis, and it can cause blindness
• Apply 1-2 cm ribbon of ointment to the lower conjunctival sac of each eye
• Administer Vitamin K 0.5 to 1 mg IM within one hour after birth as phytonadione
• The purpose of Vitamin K is to prevent hemorrhagic disorders
• Vitamin K is not produced by the GI tract of the newborn, it is produced by the colon. - Bacteria form after formula or breast milk
• Hepatitis B protects against hepatitis B
• Parents must sign informed consent
• Dosage is administered at birth, one month, and 6 months
• Do not administer both IM injections into the same site

Newborn Vital Signs

• Temperature is typically 97.7- 99.5 F (36.5-37.5)
• Heart Rate is 120-160 bpm
• Respirations are 30-60 breaths/minute at rest
• Blood Pressure is 50-75 mm Hg systolic, 30-45mmHg diastolic
• Pain assessment can be conducted using the Neonatal Infant Pain Scale (NIPS)

Immediate Care After Birth measurements

• Birth weight: 2500-4000 grams
• Length: 46- 54 cm (19-21 inches)
• Head Circumference: 33-35 cm (13-14 inches)
• Chest Circumference: 30.5-33 cm (12-13 inches)
• Abdominal Circumference
• Neurologic Assessment

Physical Maturity Assessment

• The Ballard tool determines the newborn’s gestational age and looks at physical and neuromuscular maturity
• Some elements of the tool are skin texture, lanugo, plantar creases, breast tissue, eyes and ears and genitals

Care Management

• Laboratory and diagnostic tests are important
• Universal newborn screening is conducted
• PKU is conducted 24-48 hours after feeding
• Newborn hearing screening is conducted
• Screen for Critical congenital heart disease

Circumcision

• Circumcision involves the removal of the foreskin of the penis
• Contraindications include being a preterm neonate, having a genitourinary defect such as hypospadius, or a bleeding disorder
• Compromised neonates with Respiratory distress syndrome cannot get it
• Risks: hemorrhage, infection, pain, adhesions
• Benefits: Reported decrease UTI,STI's-including HIV;penile cancer and cervical cancer in female partner
• The AAP recommends analgesia for the procedure, like a Nerve block, topical, concentrated oral sucrose, pacifier
• Types of circumcisions include Mogen clamp and Plastibell
• A Mogen clamp provides a wound covered with sterile petroleum gauze to prevent bleeding and infection
• Post procedure, assess bleeding every 15 to 30 minutes for first hour then every hour for 4 to 6 hours
• Note first voiding and assess for signs 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

• Newborn care, bathing, cord care, feeding, temperature, positioning
• Swaddling
• Safe infant sleep (SIDS precaution)
• Infant should be rear facing until age 2
• Home safety
• Infection prevention
• Bilirubin and newborn screening
• PKU should be assessed 24-48 hours after protein feeding
• Follow up care with Pediatrician around 1-2 weeks post discharge
• Teach when to call Pediatrician
• Recognize signs of illness