Newborn Adaptation Flashcards
What are some considerations r/t fetal lung fluid?
- Fulid produced in utero
- Fluids move to interstitial space during labor
- Epi and norepi (stress of labor) increase rate of absorption
- Absorption is delayed with a C-section
Describe fetal lung surfactant
- Detergent like lipoprotein
- Detectable by 24-25 weeks
- Reduces surface tension in alveoli so they remain partially open
- sUFFICIENT amount needs to be produced by 34-35 weeks to prevent alviolar collapse (different for mother with DM)
- Secretion increases during and after birth
- Steriods given in preterm labor help
Describe the mechanism that causes respiration in a newborn
INternal- Chemoreceptors are triggered and diaphragm is stimulated
- Externally: Skin sensors, responces to sounds and light all act on respiratory center
- -Cold air stimulates skin receptors
- -Compression during birth causes air to enter lungs
Why do the lungs of neonates sound moist?
-Fetal lung fluid is still moving
-
What are the three fetal cardiac shunts?
- Foramen ovale
- Ductus venosus
- Ductus arteriosus
What happens that stimulates the cardiac shunts to close at birth?
-The infants response to O2 causes a shift in pressure
Describe the flow of fetal blood.
From the placent into the inferior vena cave
- into right A
- through Foramen Ovale into left A
- INto left Ven
- Through aorta
- Some blood goes into Pulm veins but remixes at the ductus arteriosis
- Circulates and exits back to plencent
How does the clamping of the umbilical cord help close cardiac shunts
It decreases the pressure in the Right A and increases systemic resistance
What is the function of the ductus venous?
Shunts 1/3 of blood from UV to inferior cava and away from immature liver
How is the ductus venousus affected at clamping
Occlusion of cord stops flow of blood from placenta through UV to ductus venosus
-allows blood to flow through the liver
What is the function of the foramen Ovale?
Valve allows flow of blood between the RA and LA so that the blood bypasses the lungs and goes directly into the LV and aorta
-R to L shunt
How is the Foramen ovale affected at clamping
- Cord occlusion elevates systemic resistance; blood returns from PV to LA, both increases L heart pressure
- Decreased pulmonary resistance allows free flow of blood into lungs and decreased pressure in RA
- Closes at birth d/t pressure changes
What is the function of the fetal pulmonary blood vessels?
Narrowed vessels increase resistance to blood flow to lungs
How are the fetal pulmonary vessels affect at clamping?
- Elevated blood oxygen and removal of fetal lung fluid
- Decreased pulmonary resistance allows blood to enter freely to be oxygenated
- Transition occurs with first breath
What is the function of the Ductus Arteriosus?
Widely dilated to carry blood from PA to aorta and avoid nonfunctioning lungs
How is the ductus arteriosus affected by clamping?
- Increase of oxygen level in blood
- Blood in PA is directed to lungs for oxygenation
- Functional within minutes after birth, complete constriction 1-6 days
- Permanent 1-4 mos
How do low levels of O2 at birth affect Cardiac shunts?
Low levels of oxygen in the blood (asphyxia at birth, becomes hypoxic, or is preterm) may cause the DA to dilate and the PV to constrict increases resistance to blood flow to the lungs
-This results in the opening of the foramen ovale to allow a right-to-left shunt of blood and flow from the pulmonary artery through the DA and into the aorta
How fast can a newborn lose heat?
0.5 degrees F to 1.7 degrees F per minute if infant is not kept warm at birth
What are some characteristics that lead to heat loss?
- Thin skin close to blood vesses and with very little SQ fat
- 3x more surface area
A healthy, term infant requires a position of ____ what does this help reduce
Flexion
-Reduces heat loss
How do neonates produce heat
- nonshivering Thermogenesis*
- They burn brown fat as fuel the heat is transfered to the blood passing through the fat and is distributed throughout the body
What are the three concequences of reduced neonat body temp?
- Increased metabolic rate
- Brown fat metabolism
- Vasoconstriction
How does hypothermic induced increased metabolism affect the infant?
-increased glucose demand =hypoglycemia
-Increased O2 use
=reduced surfacant and hypoxemia
This leads to respiratory distress and can even cause the return to fetal circulation
How does the burning of brown fat affect the infant?
- Acids are produced
- Metabolic acidosis
- Displaced bilirubin
Causes Jaundice
How does hypothermic induced Vasoconstriction affect the infant?
- Peripheral vascular constriction = Pale, cold, mottled skin
- Pulmondar vessel constriction
Leads to return of fetal circulation and Respiratory distress
What is a neutral thermal environment?
An environment that allows the newborn to have stable temp control
WHat is the neutral environmental temp for a naked healthy full term neoate
-Cothed?
32-33.5 89.6-93.3 -Clothed 24-27 (75.2 to 80.6)
WHat is the HCT for the first month of life?
44-65%
Polycythemia in an infant increases the risk of ____ and ___
Jaundice and Brain injury
How do WBC’s present in infants with an infection?
They may decrease
Signs of an infant infection in blood values are ____ and ___
increase of immature leukocytes and a decrease in platelets
Why are newborns at risk of clotting deficiency?
How is this treated?
- They do not have the Vit K needed from gut flora
- Vit K is given to infants to reduce the risk of a hemmoragic disease
Describe the GI tract of an infant
- 6ml stomach cap.
- Gastric emptying delayed until first sip of milk. then it is doubled
- Gastrocolic reflex is stimulated with full stomach. Increasing parastal. and producing a BM
- Cardiac sphinctor is more relaxed = reflux
Describe an infants digestive enzymes
- Panc. Amalase= deficient for the first 4-6 months (in breatsmilk)
- Amylase: In breast milk, limited production until 3rd month
- Pancriatic Lipase: deficient (in breast milk)
What is the first stool called? what does it look like?
Myconium
- Greenish/black
- Thick
- Passess in first 12-48 hours
Describe the transitional stool
- Greenish-brown
- Breastmilk=Seedy and mustard like
- Formula: Pale yellow to light frown and mor firm
What are the major hepatic functions after birth?
- Glucose matainance
- CONGIGATON OF BILIRUBIN
- Production of clotting factors
- Stores iron
- Metabolized drugs
When does the fetus begin to store glucose? How fast is it used up?
- 3rd tri
- 12 hours
Newborn blood glucose and fall around ___ after birth and stabilized at around ___
60-90 minutes
2-3 hours
Newborn Blood glucose should be ___ on the first day and ___ thereafter
40-60
50-90
What are some factors that increase the risk of hypoglycemia in newborns?
- preterm/late-term
- Post-term=stores used before birth
- LGA and those with DM mothers produce extra insulin
- Stressed infants
- Cold infants
Preterm infants have the reduced ability to conjugate bilirubin. Why
Immature livers
What is the source of bilirubin?
Hemolysis of erythrocytes
Fetal blood has a shorter halflife + there is extra to be broken down at birth
Describe Unconjugated bilirubin
aka indirect bilirubin
- Soluble in fat
- Needs to be water soluble to be excreted
Describe conjugated bilirubin
aka direct bilirubin
- water soluble
- picked up by bile
- excreted in poop
What occurs if there is too much unconjugated bilirubin>
staning of the subcutaneous fat and Brain
jaundice
ONce unconjugated biliribin enters the blood stream, what is its target location?
-Serum albumin binding sites
What is Breastfeeding jaunduce?
An elevated bilirubin of more than 12mg/dl
caused by insuficcent intake
-affects 13% by the first week
What is True Brest milk jaunduce?
(late onset BM jaundice)
- first 3-5 days of life can last 3 weeks to 3 months
- TSB peaks at 5-10mg/dl and falls
- Unknown cause
Describe the NB Urinary system
- Fully developed but not fully functonal kidneys
- Kidney perfusion improves as vascular resistance decreases
- GFR 2x to 3x in first weeks but not fully developed until 1-2
- 50% void in 12 hours
- 92% in 24
- 99 in 48
What is Oligohydraminos and what does it indicate?
Low amniotic fluid
-Indicates renal problems
An infant should be voiding ____or the first few days and _____ or more by the 4th
1-2
6
Describe newborn fluid balance.
-Lower tolorence in fluid changes
-need 60-100 ml/kg in first 3-5 days
150-175ml/kg at day 7
What should the newborn urine output and specific gravity be?
1-2ml/kg/hr for first day and 2-5 after
-1.002 to 1.010
Why are newborns at higher risk for Acid base imbalance?
-Lose bicarb at lower levels than adults
Describe the immune system of the newborn
- No fever or or leukpcytosis with a infection
- Immature immune responses
- Recieves antibodies in last trimester
Describe IgG
- Crosses the plecenta begining in first T
- Passive immunity dissapears at 2-4 months
Describe infant IgM
-Protects against gram neg bacteria
-Produced rapidly after few days after birth
-Cant cross placenta
(too big)
Describe infant IgA
-Does not cross placenta
-Protects GI and Resp
Present in Colostrum and Breast Milk
What are the 3 psychosocial periods of rnewborn reactivity?
First period of reactivity
Period of sleep
Second period of reactivity
Describe the first period of reactivity
- birth to 30 minutes
- Active awake alery
- possible elevated VS
Describe the Period of sleep
Becomes quite and sleeps
-VS return to normal
Describe the second stage of reactivity
lasts 4-6 hours
- Alert and interested in feeding
- Secretions increase (possible gaging or vomiting
