Neonatal Period Flashcards
- Weeks 25-30, Type II alveolar cells begin production
- Mature amount at 35-37 weeks gestation
- Phospholipid
Surfactant
- Decrease surface tension of pulmonary fluids
- Prevents alveolar collapse at end of expiration
- Facilitates gas exchange
- Lower inflation pressures needed to open airway
- Improves lung compliance
- Decreases labor of breathing
Functions of Surfactant
Marker of fetal lung maturity; test of fetal amniotic fluid to assess for fetal lung immaturity; surfactant
lecithin–sphingomyelin ratio ( L/S ratio): 2:1 or >
A phosphatidic acid that is a constituent in human amniotic fluid and is used as an indicator of fetal lung maturity when present in the last trimester of gestation (36 weeks)
Phosphatidyl glycerol
- Secreted by lungs, amniotic cavity, trachea
- Air must replace lung fluid
- 1/3 removed at birth; 2/3 pulmonary circulation and lymphatic system
- Total time to clear = 6-24 hours after vaginal delivery
- Inadequate clearance = TTN
Lung fluid
- Term
- Delivery route - cesarean birth
- Low dose oxygen thereapy
- Rapid improvement (3 days)
TTN - Transient Tachypnea of Newborn
- Mild asphyxia in normal birth - high carbon dioxide and low oxygen
- Others: thermal, tactile stimulation (flicking the soles of the feet; rubbing the back gently), lights, noise, cord occlusion
Breathing stimuli at birth
Respiratory rate in neonates
30-60
- Diaphragmatic, shallow, irregular depth and rhythm
- Abdominal, synchronous with chest movement
- Short periods of apnea
- Deep sleep - regular breathing
- REM sleep - periodic breathing
- Crying/ motor activity - grossly irregular
Characteristics of respirations in neonates
Until age 3 weeks, obstruction → respiratory distress (sleep on the back)
Reflex takes over
Relation to SIDS (Sudden infant death syndrome)
Oral mucus secretions, cough/gag
Obligatory Nose Breathers
Assessment tool to determine the degree of respiratory distress (0,1 or 2) ; > 7 - severe respiratory distress Features observed: 1. Chest movement 2. Intercostal retraction 3. Xiphoid retraction 4. Nares dilation 5. Expiratory grunt
Silverman-Anderson Index - RDS : respiratory distress syndrome (resulting from lung immaturity and lack of alveolar surfactant )
Purposes:
Decrease blood flow to fetal lungs
Direct blood to the placenta
Increase blood flow to head & heart
Fetal Circulation
Fetal pulmonary BP > adult pulmonary BP
Diverts blood flow away from non-functioning fetal lungs
Decrease Blood Flow to Fetal Lungs
Fetal systemic BP lower than adult
Flow leads to the placenta readily
Direct Blood to the Placenta
- Umbilical vein - oxygenated blood from the placenta to the fetus
- Umbilical artery - waste
- Wharton’s jelly - keep vein and artery from tangling ; keep them separated
Umbilical Cord
Ductus venosus
Ductus arteriosus
Foramen ovale
Increase Blood Flow to Head and Heart
Shunts arterial blood into inferior vena cava
Functional closure - few hours after birth
Anatomic closure - turns into ligament
Ductus venosus
Shunts arterial and some venous blood from pulmonary artery to aorta; allows blood to go around lungs
Functional closure
Anatomic closure
Ductus arteriosus
Leads to abnormal blood flow between the aorta and pulmonary artery, two major blood vessels that carry blood from the heart.
Patent Ductus Arteriosus (PDA)
Connects right and left atria ( allows more than half the blood entering the right atrium to cross immediately to the left atrium, passing the pulmonary circulation)
Usually obliterated within hours after birth
Pressure highest right atrium
Foramen ovale
Umbilical cord clamped - neonate draws first breath - Systemic vascular resistance increases- Blood flow through ductus arteriosus decreases - Most of right ventricular output flows through lungs, boosting pulmonary venous return to the left atrium - Left atrial pressure rises in response to the increased blood volume to the lung - This, combined with increased systemic resistance causes functional closure of foramen ovale
Changes to Neonatal Circulation
Neonatal Heart Rate
Check apical for full minute
Also evaluate peripheral pulses (brachial, femoral)
120-150 awake
Range: 70-90 asleep, 180 crying
Blood Pressure
Sensitive to changes in blood volume that occur with transition to neonatal circulation
Most accurate: measure in quiet newborn
At term, 60-80/40-50 mm Hg. (75/42 avg.)
Turbulent blood flow, transient
Abnormal valve, ASD (atrial septal defect) or VSD (ventrical) , too high a blood flow across normal valves
Check all 4 extremity BPs if heard, record MAP, pulse ox.
Heart Murmurs
- blotchy and mottled skin in the extremities; feels “chilly”
- first few hours after delivery
- response to exposure to cold - normal and intermittent
Acrocyanosis
Blue around philtrum & lips
Tongue & mucous membranes pink
Type of acrocyanosis
Resolves spontaneously
Perioral (Circumoral) Cyanosis
10-15% total body weight
Low O2 tension of maternal blood stimulates fetal RBCs (↑ HCT)
About 300 ml.
Mode of delivery effects TBV
Vaginal vs. C/S
- clamping of the umbilical cord : early ( before 30-40 sec) vs late (after 3 min additional 150 ml of blood)
Total Blood Volume
- clamping of the umbilical cord : early ( before 30-40 sec) vs late (after 3 min additional 150 ml of blood)
↓ anemia →↓ transfusions
Stem cells
↓ disorders R/T prematurity
Delayed Cord Clamping benefits
R/T normal destruction of fetal RBCs
Bilirubin transported to liver for conjugation
Immature livers
50%+ develop
Physiologic Jaundice
Hemolysis of erythrocytes (normal after birth) - bilirubin - liver - water soluble pigment - GI system via bile - feces + urine
Bilirubin
Predisposition: Asians, Greeks, Native Americans
Less likely: African-Americans
Differentiate from pathologic jaundic
- if not treated - kernicterus - brain damage - death
Physiologic Jaundice
Yellowish skin , mucous membranes, and sclera within the first 3 days of life ; asses by pressing gently with a fingertip on the bridge of the nose , sternum, or forehead - if present the blanched area will appear yellow before the cap refill
Visual Inspection for Jaundice
Involves exposing the newborn to ultraviolet light , which converts unconjugated bilirubin into products that can be excreted through feces and urine
Phototherapy ( Light changes the angle of bonds within bilirubin molecule, making it easier to excrete it
(unconjugated) in the bile)
is a way to find out how much bilirubin is in the blood; The test sends a quick flash of light through the skin; The measurement is usually taken by gently pressing the meter against the sternum or forehead ; no blood test.
Transcutaneous Bilirubin Measurement
Place the automated lancing device on the appropriate area on the side of the heel
Heelstick
First 24 hours of life Rises 5 mg/dL every 24 hours Premature neonates LBW neonates Rh or ABO incompatibility G6PD deficiency: x-linked recessive High H/H 17-20 g/dL, 52-63% normal
Pathologic Jaundice
Bilirubin neurotoxic at high levels
Crosses blood-brain barrier, causes irreversible CNS damage
Kernicterus
Watch temperature
Watch hydration status
Protect eyes and genitals
Positioning
Nursing Care of Neonate “Under the Lights”
removes the newborn’s blood and replaces it with nonhemolyzed RBC from a donor ; monitor cardiovascular status continuously ; second line therapy after phototherapy
Exchange Transfusion - Treatment for Severe Hyperbilirubinemia
After first week of life → 6 weeks
1 - 2% of newborns
Unclear cause
Calories, wt. loss, components of breast milk
Avoid by frequent nursing, supplementing
If 14-16 mg/dL, stop breastfeeding for 24-48 hours
Rapid drop in bilirubin
Breastmilk Jaundice
Normal finding, due to birth trauma
10,000-30,000 ccm
Neutrophils predominate in first week of life, then overall WBC count falls and lymphocyctes
primary form
Leukocytosis (elevated WBC)
Low at birth (7, 9, 10, prothrombin)
Synthesized by intestinal bacteria
Untreated, transitory deficiency in clotting, days 2-5
Vitamin K-Dependent Clotting Factors
Aquamephyton 1 mg. IM
Vitamin K ; Treats blood clotting problems.
Give Vitamin K into …
Vastus Lateralis of Thigh
Same range of adults at birth, but may have mild transient aggregation defect ( 150000-400000 )
Phototherapy makes this worse
Platelets/Bleeding Problems
Score 8-10: good condition
Score 4-7: fair condition, call peds
Score 0-3: poor condition; need immediate resuscitation
Apgar Score Meaning ( done at 1 and 5 min of age; can be extended prn )
Appearance (skin color) Pulse (heart rate) Grimace (reflex irritability) Activity (muscle tone) Respirations (crying & breathing)
Apgar Score Mnemonic
At birth, enters cooler environment
Temperature varies with environmental temperature
Limited subcutaneous fat
Large surface area in relation to body weight
Blood vessels closer to skin
Thermoregulation in Newborns
- Conduction - objects in direct contact with each other (cold surface )
- Convection - flow of heat from the body surface to cooler surrounding surface ( e: cool breeze)
- Evaporation - when a liquid is converted to a vapor (e: amniotic fluid that covers body)
- Radiation - to cooler, solid surfaces in close proximity but not in direct contact with the newborn (e: away from walls, windows, air conditioners )
Means of Heat Loss
Taking Axillary Temperature
36.5-37.5 C
Transition to Extrauterine Life: Initial VS Checks
Every 15 minutes x 4 (=1 hour)
Every 30 minutes x 2 (=1 hour)
Every 60 minutes x 2 (=2 hours)
- Double-wrapping (36.4 C )
- Kangaroo care ( 36.4 C )
- Radiant heat warmer ( 36 C - for 1 hour)
Warming a Neonate
Primary mechanism of heat production
Increase metabolic rate
Chemical reaction in brown fat ( good blood supply )
Non-shivering Thermogenesis
metabolic rate, non-shivering thermogenesis
Leads to O2 and energy use
Causes physiologic stress
Leads to metabolic acidosis
Result → hypoxia, hypoglycemia, acidosis
Cold Stressed Neonates
Thermal balance O2 consumption and metabolism are at minimal level Internal body temperature maintained Needs high environmental temperature Flexed, term vs. extended, preterm NBs
Thermal Neutral Zone (TNZ)
Liver is large, 40% abdominal cavity
Palpate 2-3 cm. below right costal margin
Aids in Fe storage
Aids in carbohydrate metabolism
Hepatic Adaptation
Fe stores determined by total body Hgb. content & length of gestation
If maternal diet was adequate, Fe stores last until age 5 months
Need Fe for RBC production
Fe Storage
Glycogen in fetal liver, starting at 9-10 weeks’ gestation
Major energy source for fetus
Major energy source for neonate until begins feeding
Glucose level influenced by liver output and uptake, body temp., insulin, muscular activity
Carbohydrate Metabolism
Diabetic mother SGA or LGA status Premature Postmature Fetal distress in labor/low Apgars Maternal corticosteroid use (asthmatic moms)
Neonates at Risk: Hypoglycemia
Signs of Hypoglycemia
- Lethargy
- Jitteriness
- Poor feeding
- Pallor
- Vomiting
- Apnea
- Respiratory distress
- Cyanosis
- Loss of swallowing reflex
- Seizure activity
- High-pitched cry
Glucose-checking is part of differential diagnosis if sepsis, CNS disease, metabolic disorders, drug withdrawal, temperature instability, hypocalcemia, polycythemia, heart disease occur or are suspected.
Hypoglycemia
Vary from one institution to another
Most check 1 heelstick on all newborns, then more prn
At-risk newborns: check hourly x4, then 4 before-meal checks
Glucose Protocols
Normal glucose
40 – 80 mg/dL
Critical glucose value
< (25) 30 mg/dL
Early feeding
Check blood glucose, feed, re-check 30-60 minutes after feeding
Prevent Hypoglycemia
If feeding doesn’t resolve issue or blood glucose is
Dextrose 5 – 10% IV @ 6-8 mg/kg/minute (NICU)
Causes kernicterus at lower bilirubin levels (10 mg/dL or less), due to baby switching to fat metabolism instead of carbohydrate metabolism
Untreated hypoglycemia can cause permanent, irreversible CNS damage or death
Prevent Hypoglycemia!!!!!
NBs swallow, digest, metabolize, absorb proteins & simple carbohydrates
Fat digestion poor
GI tract proportionately longer
Immature motility & sphincter control
Gastrointestinal Adaptation
Feeding behavior rehearsed in utero: rooting
Reflexes: gag, suck & swallow
Salivary glands immature
Sucking pads
Gastrointestinal Adaptation
Stomach capacity 50 -60 ml.
Problems with vomiting, regurgitation
Calorie requirements vary; however, most books state 108 cal/kg/day
Regular formula 20 cal/oz.
Initial weight loss of 5 -10% within first 5 – 10 days
Gastrointestinal Adaptation
Lose water to respirations, from skin, stool, urine
Radiant warmers & phototherapy
Need to 150 ml/kg/day
Hydration Requirements
Formed in utero: amniotic fluid, intestinal secretions, mucosal cells
Thick, tarry, green-black
Usually passed within first 48 hours
Stool: Meconium
~ meconium plug - 24 hr (tickle anus with thermometer; measure abdomen); 48 hr ( pediatrics put finger in anus )
Part meconium, part feces
Have these for a couple days, then entirely fecal
Bright green or yellow
“Seedy” appearance of milk curds
Stool: Transitional
Pale yellow or pasty green color
More liquid, more frequent
Not watery
Stool: Breastfed Newborn
Pale color
Firmer than stool of breastfed newborn
Stool: Formula-fed NB
Perform gastric lavage in all babies born with meconium stained amniotic fluid after stabilisation
stomach pumping or gastric irrigation, is the process of cleaning out the contents of the stomach.
Relatively immature
Susceptible to dehydration, acidosis, electrolyte imbalance if vomiting or diarrhea occur
Limited ability to reabsorb sodium and hydrogen
Low GFR until 34 weeks’ gestation
Renal System
Birth: 70% body is water, 40% extracellular
Most void by 24 hours
First void: dark red & cloudy, no odor, low specific gravity
As intake , output & urine clears
6 – 10 voids/day expected
Fluid Balance
Many immunologic mechanisms not fully-developed in NB; therefore, resistance to disease
is limited
Phagocyctes (destroy)
Serum immunoglobulins (antibodies)
Immune System Changes
- IgG ( cross the placenta) Infections that generated maternal antibody response IgM Bloodborne infections IgE Hypersensitivity (allergy) reactions
Serum Immunoglobulins
NB produce little or no IgA
IgA provides local mucosal immunity to respiratory and GI viruses and bacteria
Predominant immunoglobulin in colostrum (pre-milk)
Breastfeeding gives some passive immunity
Serum Immunoglobulin: IgA
Immature
Traditional measures for detecting inflammation not valuable (fever, leukocytosis)
Response to Inflammation
Immature
All neurons present, but takes 4 years to fully myelinate them
Brain ¼ adult size
Uncoordinated, labile temperature regulation, poor control over musculature
Development rapid in neonatal period
Neurologic System
Indicators of development
Assist in safety and survival
Primitive reflexes (Moro, palmar & plantar grasp) give way to righting reflexes (righting of
head & neck) and protective reactions: blinking, sneezing, gagging, caughing
Feeding reflexes
Newborn Reflexes
Newborn Reflexes
- Sucking reflex - touch lips
- Moro reflex - startled baby
- Stepping reflex - walking
- Tonic neck reflex -
- Rooting reflex - stroking cheek
- Babinski reflex - toes fan out (disappears at 1 year)
- Palmar&plantar grasp reflexes -
Range of focus Poor acuity Contrast sensitivity Peripheral vision Can defend against unpleasant visual stimuli
Vision
Innate preference for human face
2 months: follow object smoothly
~2 months: differentiate colors (red/green)
Visual Response
T. Berry Brazelton
Optimal responses
Orientation
Habituation
Hearing threshold 40-50 dB > adults Can’t hear quiet sounds Limited range of frequencies •Hear low frequencies better •Soothing Can discriminate between voices Brazelton: orientation/habituation
Hearing
Scent-memory: Amniotic fluid Breast odors •Breast pad experiments •Painful stimuli experiments •Well-developed Prefer sweet odors (breastmilk & vanilla)
Smell
5 primary tastes: sweet, salt, bitter, sour, umami (glutamate)
Can’t taste salt until ~4 months
Sweet: the sweeter the better
Breastmilk: glutamate
Bitter & sour: negative reactions
Research, July 2011: newborn taste influenced by mother’s diet
Taste
Most advanced sense at birth
Important cognitive, emotional development, immune function
Best able to feel using mouth
Can recognize temperature differences, but can’t regular own body temperature
Move more/sleep less if cold
Touch
Predictable
Generally within first 24 hours of life
Physiologic & behavioral adjustments
Influenced by difficulty of L & D, intrapartal medications taken by mother
Periods of Reactivity in NB
First Period of Reactivity: 30 Minutes
15 minutes: quiet alert •Eyes open, bright •Focus on faces, attend to voices, especially mom’s 15 minutes: active alert •Bursts of movements •May be crying •Strong sucking reflex •Act hungry
- Deep sleep
- Light sleep
- Drowsiness or semidozing
- Quiet alert
- Active alert
- Intense crying
Brazelton: Behavior in Newborns, 6 Levels of Arousal
Diurnal pattern desirable
Nighttime sleep periods > daytime by 4-6 weeks
•Longest stretch 3-5 hours
Sleeps 13 hours/day (5.4 day/7.8 night)
2-6 night wakings
Diurnal influences: feeding, nurturing, fussing, weight
Sleep – Wake Cycles
Orientation/habituation Consolability: change from crying state Self-quieting: sucking, motor activity Cuddliness: response to being held Motor Organization: help NB control & coordinate movements; rhythmic & spontaneous, CNS organization
Behavioral Responses to Environment & Caregivers
