OB Module 1: Part 2 - The Newborn Flashcards
The newborn experiences many physiological changes when transitioning to extra uterine life, these changes involve establishment of what things?
- Pulmonary Gas Exchange
- Neonatal Cardiovascular Pattern
- Stable Serum Glucose Level
- Thermoregulation
Assessment and monitoring of neonatal adaptation is needed for early detection of what complications?
Hypoxia
Cold Stress
Hypoglycemia
Infection
Polycythemia
Hyperbilirubinemia
What are some of the Key Newborn Assessments
- VS, especially temperature, but BP is rarely done
- Nutrition
- Elimination
- Transition to extrauterine life
- activity state
- umbilical cord status
7/8/9. (Only if indicated) Glucose monitoring, bilirubin, circumcision assessment
Apgar Score
This score is indicative of the need for resuscitation, NOT the degree of asphyxia in a newborn
Each factor is scored 0, 1, or 2 and a lower number indicates need for resuscitation
When are infants apgar scored?
At 1 and 5 minutes of life, and if needed at 10 minutes
What are the 5 factors apgar scored?
Heart Rate
Respirations
Muscle Tone
Reflex Irritability
Color
Fetal lungs secrete ___ ___ throughout pregnancy
lung fluids
When does lung fluid production diminish in the fetus?
2-4 days before the onset of SPONTANEOUSLY OCCURRING LABOR (may not all be gone if we induce labor)
How much lung fluid remains in the passageway of a full term newborn?
80-100 mL of lung fluid
(This will need to be expelled or absorbed after delivery)
How is part of the lung fluid pushed out of the infant?
During labor and birth, fetal chest is compressed and this squeezes part of the fluid out
This is called VAGINAL SQUEEZE
What 2 ways is the remaining infant lung fluid disposed of?
- Vaginal Squeeze
- Absorption by the lymphatic system
Why can you hear fine crackles over the lungs in the newborn?
Because of the lung fluid remaining there
Transient Tachypnea of the Newborn (TTN)
A repsiratory complication at risk of developing in infants that have difficulty clearing the remaining lung fluid
Why are C Section babies at higher risk for TTN
They did not get the vaginal squeeze to force some fluid out
Why is the chest recoil so important to the initiation of infant resp. stimulation?
It can mechanically stimulate the first breath and respiration (chest recoil occurs during vaginal squeeze)
What are some Chemical Stimuli that initiative infant respiration?
- Increased PCO2 and decreased pH and PO2 from inspiratory gasp
- Changes in aortic and carotid chemoreceptors which trigger the brains respiratory center
- Hormonal - prostaglandin drop
Inspiratory Gasp
first infant breath
triggered by increased PCO2 and decreased pH and PO2
How does a drop in prostaglandins contribute to respiration in the newborn?
It is released by the placenta during pregnancy to suppress respiration, but with the clamping of the cord - the levels drop and there is a rise in inspiratory drive
How does PO2 rise in the newborn?
It starts at 65% in the first minute of life, and then increases 5% every minute for 5 minutes and then is at 90-95% at ten minutes
Skin goes cyanotic to pink remarkably fast
What is the mechanical stimuli that initiates infant respiration?
Natural result of a normal vaginal birth as the “vaginal or thoracic squeeze” is released at the delivery of the chest allowing for lung expansion
What is the thermal stimuli that initiates infant respiration
Significant decrease in environmental temperature after birth stimulates skin nerve endings leading to the newborn responding with rhythmic respiration
Excessive cooling of the infant may lead to…
profound respiratory depression as a result of “cold stress”
Sensory Stimuli: How does Intrauterine life differ from Newborn Experiences at delivery?
Intrauterine: Dark, sound dampened, fluid filled environment, weightless
Newly Born: Light, sounds, gravity effects, abundance of tactile/auditory/visual stimuli
Normal newborn respiratory rate is __ to ___ breaths per minute
30 to 60 BPM
Initial newborn respirations may be what in regard to depth and rhythm?
diaphragmatic, shallow, irregular
VERY ERRATIC - listen for a minute
Respiratory rate of the newborn increases with ___
crying (easy to get respirations then but increases the rate)
In a newborn it is important to do what when counting respirations?
count for a full minute since its so erratic
Is apnea in a newborn abnormal?
Apnea 5-15 seconds is not abnormal (periodic breathing) but pauses longer than 20 seconds are apnea that needs additional assessment
Periodic Breathing
a common breathing pattern in the first few hours of life
It consists of pausing lasting from 5 to 15 seconds (apnea)
S/S of Respiratory Distress in the Newborn Include…
increased/decreased respiratory rate <30->60
flaring of nares
expiratory grunting
see-saw breathing
retractions
color changes
circumoral cyanosis – general cyanosis
decreased muscle tone
problems with temperature regulation
increased water loss
The first sign of respiratory distress in an infant is usually?
Flaring of the nostrils (followed by expiratory grunting)
What is the primary resp. issue for a newborn that can lead to distress?
potential for the alveoli to collapse causing larger areas of the lungs to collapse later
What may a baby do to keep alveoli inflated?
Close the epiglottis while exhaling to try and keep the alveoli inflated
It sounds like humming and is done to keep surface tension
This appears as the second sign of resp. distress, expiratory grunting
Acrocyanosis
a common finding in newborns of cyanosis of the hands and feet
Circumoral Cyanosis
A not uncommon finding of cyanosis around the mouth in newborns due to the fact the tissue is thin and highly vascular in this area
Is cyanosis in the trunk abnormal?
Yes, you need to then monitor O2 Saturation
See Saw Breathing
A later sign of resp. distress where the abdomen and chest effort is alternating in breathing
Why and When does temperature regulation become a problem in resp. distress?
Moist warm air is leaving quickly while cool air is coming in
occurs later down the road
Also since muscle ton is relaxing, the infant cools faster from increased surface area
Cardiovascular adaptation requires the transition from __ to __ circulation (which differ0 with the change from ___ to __ gas exchange
fetal to neonatal
placental to pulmonary
The fetal lungs are essentially ___. Most blood does what in utero?
nonfunctional. Most blood bypasses the lungs and is shunted to other parts of the body
Foramen Ovale
opening between the right and left atriums in the fetus
How does oxygenated blood return in fetal circulation?
Oxygenated blood returns to the fetus from the placenta through the placental vein.
40-60% of Fetal Blood bypasses…
the liver via the DUCTUS VENOSUS and enters the inferior vena cava
As the fetal blood enters the right atrium, what happens next?
50-60% of the blood is shunted across the atrium through the foramen ovale to the left atrium
How does pressure differ in fetal circulation?
There is LOW systemic resistance and HIGH pulmonary resistance
60% of fetal blood from the right ventricle…
is shunted through the ductus arteriosus to the umbilical arteries and toward the placenta
What things change and why do they change from fetal to neonatal circulation?
Openings and Shunts (like the ductus venosus, ductus arteriosus, foramen ovale) close and the pulmonary pressure becomes less than the systemic pressure leading to neonatal blood flow
This occurs due to the pressure changes that occur
What causes the pressure resistance in circulation shift from fetal to neonatal circulation?
Initiation of respirations by the infant and clamping of the cord changes it to low pulm. res. and high systemic res.
The shift of circulatory resistance cause a pressure closure ….
of the foramen ovale in the heart. The ductus arteriosus begins to constrict almost immediately after
How does blood flow in neonatal circulation
right atrium –> right ventricle –> pulmonary arteries –> lungs –> pulmonary veins –> left atrium –> left ventricle –> aorta
The newborn cardio assessment should start with …
a general color assessment (especially oral mucosa and trunk)
Acrocyanosis
occurs in the first 7-10 days
it is not unusual for the hands and feet to remain blue
Circumoral Cyanosis
blue tint to the skin surrounding the lips, but not on the lips
this is normal and is simply the blue color of the veins just below the skin in this area
You may notice this blue tint most of the time
When the arterial blood in this area diminishes for various reasons, you will see the blue tint of the veins underneath
Does not include mucosa
General Cyanosis
blue tint to the skin that covers the face, trunk, and extremities
Associated with poor oxygenation of the tissues and is an ominous sign
Can be respiratory or cardiac in origin
How is newborn heart rate assessed?
Taken apically at the FOURTH INTERCOSTAL SPACE, LEFT
Listened to FOR A FULL MINUTE
What is normal apical heart rate of a newborn?
110-160 BPM at rest
Can be 80-100 when asleep
Can be up to 180 when stressed
___ may increase heart rate and respiratory rate
crying
What heart rates warrant further investigation?
consistently high (above 180) or low (below 100)
Heart Murmurs in Newborns
Not an uncommon finding
Most non pathological and disappear by 6 months
Although newborn murmurs are not uncommon…
ALL MURMURS WARRANT FURTHER INVESTIGATION AND ASSESSMENT
Hearing a murmur in a newborn is the most common means of recognizing cardiac disease
What may make a murmur an abnormal finding in a newborn?
if accompanied by poor feeding, cyanosis, pallor, or apnea
Estimated Blood Volume of a Term Infant
80 mL/kg of body weight (or 92 mL/kg if you delay clamping like you should)
How may blood volume in a newborn vary?
Varies with amount of placental transfusion received by the newborn during expulsion of placenta (the vaginal squeeze forces blood back into the placenta temporarily so do not clamp the cord immediately - wait 30s to a few minutes to allow blood flow back)
Blood volume increases by ___% with delayed cord clamping
50%
Peripheral blood flow in the newborn can be ___, and cause …
sluggish, and cause RBC stasis (increased stasis)
You should not take blood samples from the ___ in a newborn
periphery (since it is slow)
H&H levels are ___ in ___ blood than ___ blood
H&H levels are higher in capillary blood than in venous blood
Blood samples taken from ___ samples are more accurate than those taken from __ samples
venous; capillary
In the new O2 rich environment, what may occur for the babies RBCs?
Breakdown from the extra RBC, leaving bilirubin which causes Jaundice
Bilirubin needs to be bound to a protein that is excreted but there is only so much
If the breakdown is excessive, there can be hyperbilirubinemia and we may need to help treat
(Wanna see jaundice after a few days, not immediately at birth)
How does Newborn blood lab values differ?
- total blood volume 82.3 to 92.6 ml/kg depending on clamp time at three days of life
- H&H are both higher than adults (14-20 dL and 43-64%) - this is to catch more oxygen coming to it
- WBCs are elevated
- Blood glucose is elevated (40-80 or 45-95 mg/dL at 6 hours of life)
these are all at delivery values
What is normal glucose levels in the newborn?
Between 40-80 mg/dL ion the first 6 hours of life and then 45-90 mg/dL after that
What glucose levels are hypoglycemic in the newborn and how can it be treated?
Glc below 40-45 mg/dL
Treated with feeding or a 10% dextrose in sterile water feeding
Persistent hypoglycemia in the newborn can result in …
neurological damage in the newborn
Newborn Hypoglycemia results from what things?
Inadequate availability of glucose (poor feeding)
Abnormal endocrine regulation (infants of diabetic mothers)
Increased utilization of glucose (cold stress, infection)
___ is the primary fuel for the newborn and is stored in the ___ as ____
glucose; liver; glycogen
Hypoglycemia can be __-__ and can result in ___ and ___ ___
life-threatening; seizures; learning disabilities
Which is more common in premature and small for gestational age infants, hypo or hyperglycemia?
Hyperglycemia
S/S of Infant Hypoglycemia
S/S of hypoglycemia are frequently absent despite extremely low blood glucose levels though!
Jitteriness
Hypothermia
Diaphoresis
Hypotonia
Irritability, tremors, muscle twitching, seizures
Abnormal cry
Poor feeding
Lethargy
Resp. distress, tachypnea, apnea
Cyanosis, Tachycardia, cardiac failure, cardiac arrest
What is the most common symptom of hypoglycemia? Second most common?
Most common: Jitteriness (but this is also a withdrawal symptom)
2nd: Hypothermia
Normal Newborn Temperature
> 97.6 F
Rarely elevated
Below 97.6 F is abnormal and can lead to significant distress from cold stress
Temperature instability indicates ___
infection (or even hypoglycemia)
What is the preferred method to take newborn temperature? What are some alternatives?
Preferred: Axillary
Alternative: Axillary, Continuous skin probe, Rectal
Newborn temperature is rarely ___ in regard to infection
elevated
Research indicates ___ and ___ methods are accurate indicators of body temperature
tympanic and (digital) axillary
Heat Stress or Cold Stress is related to ___ issues
metabolic
like hypoglycemia, increased O2 consumption, increased lactic acid production, increased metabolic acidosis and death
Heat loss in the newborn can occur through what 4 mechanisms?
Conduction
Convection
Radiation
Evaporation
Conduction
Loss of heat when the newborn touches something and heat is moved to that object or surface
Occurs if the baby is placed on a cold surface like a weighing scale or cold mattress
Convection
Loss of het to air that is circulating and is cooler/Newborn is exposed to cooler surrounding air
Heat loss increased with air movement
Radiation
Loss of heat from the infant when heat moves to cooler objects in the general area like the walls or window
Transfer of warmth from the baby to cooler objects in the vicinity even if they baby is not actually touching them
Evaporation
Loss of heat from moisture on the skin evaporating away
This is highly significant when the infant first is born and after the first bath!!
___ is the main form of heat loss initially due to the amniotic fluid on the baby’s body
evaporation
What is the first step of neonatal resuscitation?
Very vigorous drying of the baby - the cutaneous stimulation helps and this gets rid of amniotic fluid to prevent further complication with cold stress
In regard to convection, a baby risks getting cold even at a room temperature of ___C(___F) if there is a draft. This changes to __-__F if the infant is naked and ___-___F if the infant is dressed)
30C(86F)
89-92 F Naked
75-80 F Dressed
What exactly is cold stress?
cold stress is a body temperature rectally of less than 97.6F w/ symptoms
What should you do if you get a newborn temp of 97.6 F or lower?
First, repeat under the other arm. If the reading is still low report to the nurse immediately. The infant will either need skin to skin temperature contact with the mother or be placed in a radiant warmer
What kind of infants are at greater risk for cold stress?
smaller and preterm infants
Symptoms of Hypothermia
Body cold to touch
Hypoglycemia (no fuel to make heat)
Restlessness, irritability, tachypnea
Pallor or mottling
Lethargy, decreased activity, hypotonia
central cyanosis, expanding acrocyanosis
Poor feeding, weak suck
Bradycardia
Feeble cry, shallow/irregular respirations, apnea
Non-shivering Thermogenesis
Shivering that occurs when skin receptors perceive a drop in environmental temperature
The newborn will shiver and double the metabolic rate and increase muscle activity
All of this is done to generate heat
What is the primary source of heat in the hypothermic newborn?
BAT - brown adipose tissue (Fat)
BAT
Brown Adipose Tissue (Fat)
Primary source of heat in the hypothermic newborn
Less plentiful and available to Premes rather than Full Term Infants
When does BAT appear in the fetus? How long will it increase after birth?
Appears in fetus at 26-30 weeks, increases until 2 to 5 weeks after birth
How do newborns respond to hypothermia?
They increase their metabolism by breaking down their limited BAT stores
In what areas is BAT located?
around the:
scapula
kidneys
adrenals
head
neck
heart
great vessels
axilla
BAT Metabolism leads to what things? And what do these results lead an infant vulnerable to?
- Increased metabolism –> Hypoglycemia vulnerable
- Increased O2 Metabolism –> Tissue hypoxia vuln.
- FA production –> metabolic acidosis vuln –> increased serum bilirubin
- Increased local temp –> increased axillary temp (may seem stable erroneously)
___ is the best treatment for Hypothermia
PREVENTION
Treatments for Hypothermia
Prevention
Dry infant immediately after birth
Use a hat
Keep room warm
Use skin to skin with mom or a radiant warmer
Delay bathing until over 98F consistently
Rewarm after bath
Dress appropriately and use blankets as needed
Educate parents
Monitor temps and symptoms
return to the radian warmer if temperature is unstable
Why are babies sometimes not bathed until after 24 hours of birth?
To allow needed bacterial colonization
The newborn has enough intestinal and pancreatic enzymes to digest what things?
Simple carbohydrates
Proteins
Fats
What thing can a newborn not digest?
Starch
By birth, what actions of digestion and absorption have the newborn experienced?
Swallowing
Gastric Emptying
Propulsion
Breast milk is __% digestible and is digested in __-__ hours
90%; 2-3 hours