NUR 113 Exam 4

Newborn Care, Prematurity, Thermoregulation, SIDS

What is thermoregulation?

Maintaining balance between heat loss and heat production in order to maintain the body’s core internal temperature

What is the average core temperature?

97.9-99.7 °F (36.6-37.6 °C)

How is body temperature maintained in a newborn?

• Flexed posture

• Brown fat

Characteristics that put a newborn at risk for heat loss.

• Thin skin

• Lack of shivering ability

• Limited stores of metabolic substances (glucose, glycogen, fat)

• Large body surface area relative to body weight

• Lack of subcutaneous fat; little ability to conserve heat by changing posture

• Lack of ability to communicate

Conduction

Transfer of heat from one object to another when the two objects are in direct contact with each other

How can you prevent conduction?

• Skin-to-skin contact with the mother

• Using a warmed blanket to cover any cold surface touching a newborn directly

Convection

Flow of heat from the body surface to cooler surrounding air or to air circulating over a body surface

How can you prevent convection?

• Keep the newborn out of direct cool drafts

• Using clothing and wraps in isolettes is an effective means of reducing exposed surface area and providing external insulation

Evaporation

Loss of heat when a liquid is converted to vapor

How to prevent evaporation.

• Drying newborns immediately after birth with warmed blankets and placing a cap on head, drying after bath

• Promptly changing wet linens, clothes, or diapers

Radiation

Loss of body heat to cooler, solid surfaces in proximity but not in direct contact with newborn (Ex. windows and walls)

How to prevent radiation.

• Keep cribs and isolettes away from:

  • Outside walls

  • Cold windows

  • Air conditioners

• Use radiant warmers for transporting newborns and when performing procedures

Thermogenesis

Brown fat (adipose tissue) is oxidized in response to cold exposure

When thermogenesis is activated what happens in the body? (happens in a non-neutral thermal environment)

• Metabolic rate increases

• RR increases

• Brown fat is activated, blood is warmed, and baby warms up

What is brown fat?

• Tissue able to convert chemical energy directly into heat (activated by the sympathetic nervous system)

• Vital for thermogenesis

• Cardiac output increases, increasing blood flow through the fat tissue

• Blood becomes warmed because of the increased metabolic activity of the fat

What is a neutral thermal environment?

• Environment in which body temperature is maintained without an increase in metabolic rate or oxygen use​

• Internal body temperature is maintained because of thermal balance​

• Promotes growth and stability, conserves energy for basic bodily functions, and minimizes heat (energy) and water loss

What is a key indicator of a need for more oxygen?

Tachypnea (happens in a non-neutral thermal environment)

Do you need a higher or lower environmental temperature (room temperature) to maintain an environment that decreases oxygen consumption?

Higher

Cold Stress

Excessive heat loss that requires a newborn to use compensatory mechanisms to maintain core body temperature.

When are newborns at the highest risk for cold stress?

First 12 hours

Consequences of cold stress.

• Become less active, lethargic, hypotonic

• Depleted brown fat stores

• Respiratory distress

• Depletion of glycogen leading to hypoglycemia

• Decreased surfactant production

How to minimize the effects of cold stress.

• Prewarming blankets and hats to reduce heat loss through conduction

• Drying the newborn completely after birth to prevent heat loss from evaporation

• Encouraging skin-to-skin contact with the mother

• Promoting early breastfeeding

• Using heated and humidified oxygen

• waiting for the baby to be stable before bathing

What is SIDS?

Sudden death of an infant younger than one year of age, which remains unexplained after a thorough case investigation

What is SUID?

Sudden and unexpected death of a baby less than 1 year old in which the cause was not obvious before investigation

Incidence of SIDS peaks in infants between the ages of…

2-4 months

Risk factors for SIDS

• Low birth weight, prematurity, or undiagnosed underlying respiratory illness

• Maternal substance abuse; secondhand smoke exposure

• Inadequate prenatal care

• Prone sleeping position

• Co-sleeping

• Blankets, loose bedding, and stuffed animals in sleeping space

• Soft sleep surface

Ways to prevent SIDS

• Infants sleep in the supine position

• Firm sleep surface and avoid soft bedding, excess covers, pillows, and stuffed animals in the crib

• Infant sleeps in a separate bed from the parents, for the first 12 months

• Pacifier use during naps and at bedtime

• Avoid maternal prenatal alcohol and illicit drug exposure and second-hand smoke exposure for infant

Safe Sleep ABCDs

• Alone: Always sleep alone

• Back: Sleep on their backs

• Crib: Fitted sheets and firm mattress

• Danger: Always aware never impaired

What does surfactant do?

• Prevents alveolar collapse at the end of expiration

• Helps maintain lung volume

• Provides stability for gas exchange

Apneic periods lasting more than 15 seconds with _____ and _____ require further evaluation.

• Cyanosis

• Heart rate changes

What happens once the placenta is clamped?

Increases pulmonary blood flow →  Increases pressure in the left atrium → Decreases pressure in the right atrium of the heart → causes closure of the foramen ovale

What does the increase in oxygen levels after the first breath cause?

Increase in systemic vascular resistance → Reduces blood flow in the umbilical vein → Closure of the ductus venosus → Increase in pressure in the aorta → Closure of the ductus arteriosus

What is the respiratory system like in a fetus?

Fluid-filled, high-pressure system causes blood to shut from the lungs through the ductus arteriosus to the rest of the body

Where is the site of gas exchange on a fetus?

Placenta

Circulation through the heart of a fetus.

Pressure in the right atrium are greater than in the left, encouraging blood flow through the foreman ovale

Hepatic portal circulation in a fetus

• Ductus venosus bypasses

• Maternal liver performs filtering functions

What is the respiratory system like in a newborn?

• Air-filled, low-pressure system encourages blood flow through the lungs for gas exchange

• Increased oxygen content of blood in the lungs contributes to the closing of the ductus arteriosus (becomes a ligament)

Circulation through the heart in an infant.

Pressure in the left atrium is greater than in the right, causing the foreman ovale to close

Hepatic portal circulation in a newborn.

• Ductus venosus closes (becomes a ligament)

• Hepatic portal circulation begins

What is an essential fuel for the brain and is the main source of energy for the first several hours after birth?

Glucose

Risk factors that put neonates at risk for glucose abnormalities.

• Mothers who have diabetes ​

• Preterm newborns​

• Inadequate caloric intake​

• Sepsis​

• Hypothermia​

• Glycogen storage disorders​

• Large for gestational age (LGA)

Signs of hypoglycemia in a newborn

• Jitteriness ​

• Lethargy ​

• Cyanosis​

• Apnea ​

• Seizures​

• High-pitched or weak cry

A blood sugar less than _____ is considered hypoglycemic in a newborn.

30

How to prevent hypoglycemia in newborns?

Early, frequent feedings

What does APGAR stand for?

• Appearance (color)

• Pulse (heart rate)

• Grimace (reflex irritability)

• Activity (muscle tone)

• Respiratory (respiratory effort)

When is APGAR scoring done?

• 1 and 5 minutes after birth (scored as 0, 1, 2)

• Repeated at 10 minutes if 5 minutes is less than 7

How many points are each of these on the APGAR scale?

• Flexion of arms and legs

• Pulse is below 100 bpm

• Some extremity flexion or cry

• Body pink, extremities blue

• Slow and irregular respirations

1 point

How many points are each of these on the APGAR scale?

• Active movement

• Pulse over 100 bpm

• Pulls away, sneezes, or coughs

• Body and extremities pink

• Robust cry

2 points

What is the normal length of a newborn?

45-55 cm

What is the normal weight of a newborn?

2500-4000 g

What is the normal head circumference of a newborn?

33-37 cm

What is the normal chest circumference of a newborn?

30-33 cm

Normal heart rate range for a newborn.

• 110-160 BPM

• Can go to 180 while crying

Normal respiration range for newborns

30-60 breaths/min at rest (will increase when crying)

Normal blood pressure for newborn

• 50-75 mmHg systolic

• 30-45 mmHg diastolic

Preterm/Premature

Prior to 37 weeks’ gestation

Term

38 to 42 weeks’ gestation

Post-term/Post-dates

After week 42 of gestation

Post-mature

After week 42 of gestation with signs of placental aging

Skin texture of a premature infant.

Sticky/Transparent

Is lanugo present of absent on a premature infant?

Absent

Plantar creases on a premature infant.

Mostly absent

Breast tissue on a premature infant

Imperceptible

Eyes and ears on a premature infant.

• Eyes open or fused

• Ear cartilage soft and pliable

Genitals on a premature infant.

• Testicles undescended scrotum smooth

• Clitoris prominent

Skin texture in a full term baby.

Smooth to mild peeling and cracking

Lanugo, plantar creases, and breast tissue are all _____ in a full-term baby.

Present

Eyes and ears on a full term baby.

• Eyes open

• Ear present moderate stiffness

Genitals on a full term and post term baby.

• Testicles descended scrotum rugae

• Clitoris mostly covered

Skin texture in a post-term baby.

Cracking to leathery

Lanugo on a post term baby.

Balding to absent

Plantar creases on a post-term baby.

Entire foot

Breast tissue on a post term baby.

Full budding

Eyes and ears on a post term baby.

• Eyes open

• Ear cartilage stiff

What are the 6 things assessed in a neuromuscular maturity assessment?

• Posture

• Square window

• Arm recoil

• Popliteal angle

• Scarf sign

• Heal to ear

Physical Maturity Score + Neuromuscular Maturity Score=?

Maturity Rating

Small for gestational age (SGA)

Weight less than the 10th percentile on standard growth charts (usually >5.5 lb)

Complications of small gestational age.

• Perinatal asphyxia

• Meconium aspiration

• Hypoglycemia

• Polycythemia (to many RBCs)

• Hypothermia

Appropriate for gestational age (AGA)

Weight between 10th and 90th percentiles

Large for gestational age (LGA)

Weight more than the 90th percentile on standard growth charts (usually >9 lb)

Most common problem for large for gestational age (LGA) babies.

• Hypoglycemia

• Birth injuries

• Lung problems

Why and when is vitamin K given to newborns?

• Prevents neonatal hemorrhagic complications

• Phytonadione (Vitamin K1) within 1 hour of delivery

• Necessary for production of adequate clotting factors during the first week of birth until newborn can manufacture it​

• Prevents vitamin K deficiency bleeding (VKDB) of the newborn

• Given IM

Why is erythromycin ointment (eye prophylaxis) given to newborns?

• Prevents bacterial eye infections that can occur during birth (mainly gonorrhea and chlamydia)

• Untreated or non–use of ointment can lead to blindness

When is the Hep B vaccine given to newborns?

Within 12 hours of birth

Strabismus is normal for the first _____ of life.

3-6 months

Microcephaly

• Caused by failure of brain development; reduced production of neurons leading to a reduction of brain volume

• Can be genetically derived or may be associated with infections (cytomegalovirus, rubella, toxoplasmosis), syndromes such as trisomy 13, 18, or 21 and in utero exposure to alcohol or other drugs 

• NOT common

Complications associated with microcephaly.

• Seizures

• Developmental delay

• Hearing loss

• Problems with:

  • Vision

  • Movement

  • Balance

  • Feeding

Macrocephaly

• A head with a circumference more than 90% of normal, typically related to hydrocephalus

• Benign

• Often familial (with autosomal dominant inheritance)

Molding

• Elongated shaping of the fetal head to accommodate passage through the birth canal

• Resolves on its own a week after birth

Caput Succedaneum

• localized edema on the scalp that occurs from pressure of the birth process​

• Common after prolonged labor​

• Soft tissue swelling that crosses suture lines. Pitting edema overlying petechiae and ecchymosis are noted​

• Swelling will gradually dissipate in about 3 days without any treatment

Cephalhematoma

• localized collection of blood of the skull which is always confined by one cranial bone​

• Pressure on the head and disruption of the vessels during birth. It occurs after prolonged labor ​

• Swelling does not cross suture lines ​

• Usually appears on the second or third day after birth and disappears within weeks or months.

Normal posture for a newborn

• Hips abducted and partially flexed; knees flexed

• Arms abducted, flexed at elbow

What do you stimulate to check babinski reflex

Sole of baby’s foot

What should happen when your checking for a babies babinski reflex?

• Toes fans out

• Foot twist in

When does the babinski reflex appear?

Birth

First period of the reactivity phases

• 30 minutes up to 2 hours

• Optimal time for interaction

What happens during the decreased responsiveness phase of the reactivity phases

• Sleep

• No interest in sucking/feeding

• Difficult to awaken

• Mom and baby rest together

Second period of reactivity phases

• Last 2-8 hours

• Shows interest in environmental stimuli

• Peristalsis- may pass stool/void

• Teaching about feeding, diaper changing can be reinforced

Vernix Caseosa

White, creamy naturally occurring biofilm that protects the fetus's skin for the first 2 or 3 days after birth

Stork Bite (Salmon Patches)

• Superficial vascular areas found on the nape of the neck, on the eyelids, and between the eyes and lip

• Caused by a concentration of immature blood vessels

• Most visible when the newborn is crying

• Disappear within the first year