newborn adaptations

neonatal period

first 28 days of life. first 24 hours most precarious. most transitions occur during first 6-10 hrs of life. physiologic and behavioral changes.

nursing in neonatal period

be aware of changes and deviations from the norm

normal newborn temperature

97.7-99.5, axillary.

normal heart rate

110-160 bpm; regular rhythm

normal respirations

30-60 bpm. respirations irregular, shallow, unlabored. symmetrical chest movements.

umbilical vein

carries O2 blood from placenta to fetus

ductus venosus

allows most of umbilical vein blood to bypass liver to get to heart sooner; closes within a few days after birth.

foramen ovale

allows most blood entering RA to cross directly into LA bypassing pulmonary circulation, closes within 1-2 hours after birth

ductus arteriosus

connects pulmonary artery to aorta (bypasses pulmonary circuit), usually closes within 15 hrs after birth.

at birth

switch from placenta to pulmonary gas exchange.

force of contractions labor/birth, mild asphyxia, increased ICP d/t cord compression and UC, and cold stress leads to

increase release of catecholamines.

epinephrine and norepinephrine stimulate

increased CO, cardiac contractility, surfactant release. promotes pulmonary fluid clearance.

transformation of fetal circulation to adult is triggered by

increased pulmonary pressure. cutting off blood flow from umbilical cord.

ductus arteriosus, ductus venosus, umbilical vessels

no longer needed, become non-functional ligaments

changes in HR when baby is born

increases, then decreases slightly

1st and 2nd heart sounds

clear and well defined. count for full minute.

newborn BP

higher immediately after birth then reaches plateau within a week. sensitive to blood volume.

can transient functional heart murmurs be heard?

yes

HR and BP change with behavior state...

crying, movement, awakeness

tachycardia

volume depletion. cardio/resp disease. drug withdrawal. hyperthyroidism.

volume depletion d/t

cord clamp early, placental insufficiently, dehydration

bradycardia

oxygen issue. apnea and hypoxia.

blood volume depends on...

amount of blood transferred from placenta at birth

blood volume effected by

timing of cord clamping. gestational age. hemorrhage during delivery.

early cord clamping time

30-40 seconds

late cord clamping time

after 3 min

studies for delayed clamping benefit

improves cardiopulmonary adaptation. prevents anemia. increases BP and RBC flow. improves O2 transport. may have volume overload and polycythemia.

RBC in newborn

large in size so carry more O2, shorter life span than adult RBCs, gradual increase in number as size decreases

Hgb

initially decreases (d/t decrease neonatal red cell mass - physiologic anemia of infancy)

WBC

increases (leukocytosis) result of birth trauma

platelets

same as adults

values affected by...

site of of sample (capillary blood has higher H/H levels), placental transfusion (delayed cord clamping), and gest age (increased age has higher RBC and Hgb)

fetal life in relation to respiratory

fluid filled lungs

extrauterine respiratory

fluid must be removed and replaced with air

vaginal birth in relation to respiratory adaptations

thorax is squeezed, helps rid fluid from lungs

pulmonary capillaries and lymphatic system

rid rest of fluid

fluid may be removed too slowly or inadequately...

decreased thoracic squeezing during birth (c-section). diminished respiratory effort (newborn sedation).

results of fluid being removed too slowly or inadequatelty

transient tachypnea

results of chest wall being floppy, high cartilage content, poorly developed musculature

ineffective accessory muscles, therefore abdominal/diaphragmatic breathers

surfactant lining alveoli enhances

aeration

events precipitating respiratory function in the newborn

initiation of respiratory movement, expansion of the lungs. establishment of functional residual capacity, increases pulmonary blood flow.

initial breath

reflex

initial breath d/t

pressure changes, noise and light (sensory stimulation), chilling (room temp, thermal brain sensors), compression of chest during delivery. high CO2 and low O2 in newborns blood.

pressure forces air into alveoli and fetal lung fluid into...

interstitial spaces

chest compression during birth causes...

recoil once and draws air into lungs. 1/3 of fluid is squeezed out of lungs. remaining fluid flows into interstitial tissue by osmosis into capillaries (approx 80% of the fluid is absorbed in 2 hrs and the rest in 12-24 hrs)

great effort is required to...

expand the lungs for 1st breath and fill collapsed alveolie

2nd breath takes...

less effort and 3rd even less b/c by this time most of the small airways are open

surfactant

a lipoprotein of the lungs keeps alveoli (keeps them from sticking together)

pulmonary blood vessels respond to pressure changes by

dilating and this increases blood flow to the lungs and decreases right sided heart pressure

after respirations are established

shallow and irregular, average rate. short periods of apnea, rate changes with activity.

periodic breathing

apnea for 5-10 sec, no color change, no change in HR. may be seen in first few days, need to monitor closely for further changes.

characteristics of normal respirations

consider how old the infant is. count for 1 min. lung fields are from just above middle 3rd of clavicle to 6th rib at midclavicular line and 8th rib at midaxillary line. auscultate back and lower lobes to 11th rib at vertebrae line. obligatory nose breathers.

obligatory nose breathers

reflex develop at 3 months to open mouth

abnormal respirations

labored breathing (moaning, nasal flaring, chest retractions). tachypnea (rapid, above 60). unsymmetrical chest movements. apnea lasting more than 15 sec. cyanosis and HR changes.

thermoregulation

process of maintaining balance between heat production and heat loss.

stable body temp

one of the most important to transition and severe.

true or false - newborns vulnerable to BOTH under and over heating

true

newborn characteristics that predispose to heat loss

thin skin with blood vessels close to the surface. lack of shivering ability to produce heat involuntarily. limited stores of metabolic substrates. limited use of voluntary muscle activity. large body surface area. lack of subq fat. little ability to conserve heat by changing posture. no ability to adjust own clothing or blankets to achieve warmth. inability to communicate that they are too cold or too warm. amniotic fluid on newborn cools and evaporates. temp decreases up to 5 degrees within minutes.

four mechanisms of heat loss

conduction, convection, evaporation, radiation

conduction

transfer of heat from one surface to another (direct contact). newborns and scale, blankets, hands, circ board.

nurses prevent heat loss through conduction...

warm blankets and hands, paper on scale, t-shirt, hat and booties left on when circ. performed

convection

flow of heat from body surface to cooler surrounding air (or air circulating over body surface). cool breeze, fans, a/c, pushing crib down the hallway.

nursing management for convection

transport in warmed isolette, clothing/blankets

evaporation

loss of heat when liquid is converted to vapor

insensible evaporation

from skin and respiration (unaware). amniotic fluid evaporates off infant after birth. newborn bath.

sensible evaporation

sweating (observed)

nursing management of evaporation

dry immediately after birth (and bath) with warm blankets and hat. prompt changing of wet linens (includes diapers)

radiation

loss of body heat to cooler, solid surfaces near infant but not in direct contact. isolette next to a cold window, a/c, outside wall.

nursing management of radiation

keep cribs away from cold windows. use radiant warmer when transporting, performing procedures, admission assessment

prone to overheating d/t

large body surface area, limited insulation, limited sweating ability. immature CNS (difficult to balance temp due to complex neg. feedback system)

nursing management of overheating

check isolette or radiant warmer temp, check infant temp, monitor cribs near sunny windows

newborn attempts to conserve heat and increase heat production

increased metabolic rate, muscular activity through movement, peripheral vasoconstriction. assuming fetal position to hold heat.

neutral thermal environment

body temp is maintained w/o an increased in metabolic rate or O2 use. thermal balance.

newborns have trouble maintaining temp =

need increased environmental temp

if environmental temp decreases...

newborn consumes more O2 in response. RR rate increases. metabolic rate increases.

newborn heat production primary method

non-shivering thermogenesis

brown fat

oxidized in response to cold exposure, mostly found in newborns. seen over sternum, scapular and kidneys.

what is brown fat capable of ?

intense metabolic activity

when does brown fat first appear?

26-30 wks gestation and lasts up to 2-5 wks pp

brown fat is a primary source of what?

heat conservation, chemical reaction in brown fat in shoulders and chest breaks down triglycerides into glycerol and fatty acids to produce heat

newborn heat loss through any of the four mechanisms leads to...

cold stress

cold stress

excessive heat loss, requires newborn to use compensatory mechanisms to maintain body temp (nonshivering, thermogenesis, tachypnea)

since babies cannot shiver, cold stress will what?

increase O2 needs and acidosis. may increase voluntary muscle activity.

s/s of cold stress

less active, lethargic, hypotonic, weaker.

are all infants at risk for cold stress first 12 hours?

yes

what population is at an increased risk of cold stress?

preemies

preemies s/s of cold stress

increased metabolic rate, need for O2, RR. anaerobic metabolism. metabolic acidosis, fatigue, CV collapse.

if heat is not reserved...

depletes brown fat stores. hypoglycemia. respiratory distress. jaundice. hypoxia. metabolic acidosis. decreased surfactant production.

nursing measures to prevent cold/stress/minimize

prewarm blankets, hats. transporter/isolette warmed. dry baby immediately after birth. skin to skin contact (kangaroo care). early breast feeding. heated/humidified O2. radiant warmers. environment should be 32-34 C. don't bathe until stable! skin temp probe not accurate if on bone or brown fat.

iron stores

released and stored by liver until new RBC's needed. newborn stores 4-6 months.

carbs-glucose metabolism

initially decreased after cord cut. main source of energy first few hours. released from liver glycogen stores. stabilized by feedings. dextrostick at birth and PRN per protocols.

liver conjugates bilirubin from breakdown of...

RBC's

after conjugation is excreted in...

bile

normal hemolysis of erythrocytes

heme in Hgb is converted to bilirubin

bilirubin (unconjugated)

indirect bilirubin. fat soluble (binds to albumin, can't be excreted by kidneys)

conjugated bilirubin

direct bilirubin. water soluble, can enter GI system via bile, excreted in feces (small amt, excreted by kidneys)

do newborns produce more bilirubin than adults?

yes

immature liver pathways

can't conjugate quick enough. increased unconjugated amount in blood, deposits in skin/sclera, mucous membranes (jaundice, icterus). extreme levels of bilirubin is toxic (kernicterus = liver brain damage)

lab test - total bilirubin

combined direct and indirect levels

risk factors for jaundice

fetal maternal blood group incompatibility. prematurity. breast feeding. drugs (diazepam, oxytocin, sulfisoxazole/erythromycin, chloramphenicol), maternal gestational diabetes. trauma (results in cephalhematoma, increases hemolysis). bruising. male. polycythemia. previous sibling with hyperbilirubinemia. TORCH infections. asian/native american.