Chapter 9

Chapter 9

Physiologic Adaptation of the Newborn and Nursing Assessment

Copyright © 2012, 2008 by Saunders, an imprint of Elsevier Inc.

1

Adjustment to Extrauterine Life


2

Objectives



Define key terms listed.



Describe four important neonatal adaptations to extrauterine life.





Explain how fluid in the lungs is replaced with air.

Relate how the neonate’s pulmonary circulation is established.



Differentiate among the three fetal circulatory shunts, including their reasons for closure.


3




Quickly breathe and maintain respiration rate



Replace fluid in the lungs with air



Open up the pulmonary circulation and close the fetal shunts



Allow pulmonary blood flow to increase and cardiac output to be redistributed


4


(cont.)



Provide energy to maintain body temperature and support metabolic processes



Dispose of waste products produced by food absorption and metabolic processes



Detoxify substances entering from external environment


5

Respiratory and Circulatory

Function


6

Preparatory Events to Breathing



In utero, lungs are filled with fluid

 Secretions of alveolar cells of lungs with some amniotic fluid



Surfactant produced by mature lungs in fullterm fetus

 Reduces force between moist surfaces of alveoli

 Prevents collapse with expiration

 Promotes lung expansion


7

Onset of Breathing



First breath of healthy term infant occurs within seconds of birth



Stimuli to respiratory center

 Neonate’s brain: sensory, chemical, thermal, mechanical

 External environment: cold, touch, movement, light, sound


8

Chemical Stimulus



Once cord is clamped

 Decreased blood oxygen level

 Increased blood carbon dioxide level

 Decreased pH

 Acidosis results

•

Activates respiratory center in medulla to initiate respirations


9

Changing from Fluid-Filled to Air-Filled Lungs


10

Comparison of Vaginal Delivery and Cesarean Delivery



Vaginal

 Chest is compressed as the fetus is delivered

•

Promotes fluid drainage from lungs

•

Before chest is delivered, almost half of fluid is forced out

 Chest recoils, and infant sucks in 20 to 40 mL of air

•

Creates negative intrapleural pressure



Cesarean

 Chest does not have the compression, recoil, expansion

 Increases risk of respiratory distress

 Some fluid is absorbed by lymphatic vessels

 The rest is removed by the pulmonary capillaries


11

Functional Residual Capacity



Established with first breath



Means there is a small amount of air left in alveoli; allows lungs to stay partially open during expiration



With the second and third breath, not as much pressure is needed, and as newborn continues to breathe, respirations should become easier


12

Respiratory Rate



Normal newborn rate is 30 to 60 breaths/min



Pattern includes 5- to 15-second pauses, called periodic breathing , and is normal



Cessation of breathing for more than 20 seconds is called apnea and is abnormal



Obligate nose breather

 Any nasal obstruction can cause respiratory distress


13

Closing Down the Fetal

Structures (Shunts)



Fetus: blood flow bypasses nonfunctional lungs and liver



Newborn: blood must circulate to lungs for oxygenation and to liver for filtration



Shunts close as a result of

 Shifts in heart pressure

 Increase in blood oxygenation

 Clamping of umbilical cord


14

Major Shunts of Fetal Circulation


15

Foramen Ovale



Fetal

 Opening between right and left atria

 Blood flow and pressure greater in right atrium

 Functions like oneway valve

 Shunts blood away from lungs to aorta

 Cord clamped on delivery



Newborn

 Clamping cord causes blood from placenta to stop

 Pressure on left side of heart becomes greater than on right

 Closes about 1 minute after birth

 Takes about 2 weeks for complete anatomic closure


16

Ductus Arteriosus



Fetal

 Shunts blood from pulmonary artery to aorta

 Bypasses lungs

 Pulmonary arterioles dilate in response to increased oxygen needs of lungs at birth



Newborn

 Constricts and completely closes between 15 and 24 hours after birth

 Anatomic closure takes about

3 to 4 weeks after delivery

 Can reopen (dilate) if newborn has a decrease in blood pressure or oxygen saturation

 Referred to as patent ductus arteriosus (PDA)


17

Patent Ductus Arteriosus



Can lead to right-sided heart failure and pulmonary congestion



If it does reopen, unoxygenated blood will bypass lungs and go through the pulmonary artery into aorta and general circulation



Newborn becomes hypoxic and can die


18

Ductus Venosus



Fetal

 Allows most oxygenated blood to bypass liver and enter inferior vena cava

 Clamping of cord at birth cuts off venous blood flow



Newborn

 Blood redistributed on clamping of cord

 Reduced blood flow through shunt

•

Constricts, closes anatomically about 2 weeks after birth

•

Eventually becomes a ligament

 Forces blood perfusion in the liver

 Mechanism for is closure is unknown


19

Audience Response System

Question 1

Once the umbilical cord is clamped, what type of stimulus is needed to cause the newborn to breathe on its own?

A.

Thermal

B.

Chemical

C.

Mechanical

D.

Sensory


20

Body Adaptation


21

Objectives



Recall the location of brown fat and how it is used in infant heat production.



Explain three reasons why the newborn should not be allowed to chill or experience cold stress.



Explain four ways to prevent heat loss in the newborn.


22

Body System

Adaptations and Functions


23

Thermoregulation



Ability to produce heat and maintain a normal body temperature



Newborn maintains body heat by flexing extremities (if good muscle tone)

 Minimizes exposure of body surface area

 Decreases risk of cold stress


24

Nursing Responsibility







Maintain neutral thermal environment

 Room temperature 25 ° C (77 ° F)

Makes minimal demands on newborn’s energy reserves

Abdominal skin temperature of 36.5

° C

(97.7

° F)



Allows for

 Minimal oxygen consumption

 Conservation of energy


25

Cold Stress



Newborn responds by increasing basal metabolic rate and oxygen consumption

 Depletes glycogen stores

 Results in acidosis


26

Factors Contributing to Heat Loss



Skin is thin



Blood vessels are close to surface



Little subcutaneous fat for insulation



A greater transfer of heat to the external environment compared with adults


27

Heat Loss to Environment









Evaporation – Wet surface exposed to air

Conduction – Loss of heat to a cooler surface by direct skin contact

Convection – Loss of heat from warm body surface to moving cooler air

Radiation – Loss of heat from warm object to cooler one when objects are not in contact with one another


28

Nonshivering Thermogenesis



Newborn cannot use muscle activity

(shivering) to produce heat

 Has difficulty conserving and dissipating heat to maintain optimum temperature

 Relies on nonshivering thermogenesis



Uses brown fat stores



Vasoconstriction in cold environments



Vasodilation in warm environments


29

Newborn Produces Heat



By physiologic mechanisms or thermogenesis



Includes

 Increased basal metabolic rate

 Muscular activity

 Chemical thermogenesis (nonshivering thermogenesis)

•

Primary method of heat production


30

Brown Adipose Tissue (BAT)



Cells contains fat vacuoles



Abundant blood and nerve supply



As it is metabolized, heat produced warms vital areas of body



Can be depleted in newborns who are exposed to prolonged periods of cold stress



Thermogenesis can be impaired



Typically disappears by 3 months of age


31

Brown Fat Locations


32

Nonshivering Thermogenesis



Nonshivering thermogenesis causes vasoconstriction in cold environments and vasodilation in warm environments.


33

Newborn Assessment


34

Objectives



Recognize the normal range of neonatal vital signs.



Differentiate among molding, cephalohematoma and caput succedaneum.



Describe the assessment of the anterior and posterior fontanelles.


35

Nursing Assessment of the Newborn



Includes

 Observation

 Inspection

 Auscultation

 Palpation

 Percussion



Phase 1 begins in the delivery room



Phase 2 begins upon admission to nursery

 1-4 hours of age



Phase 3 is from 4 hours of age until discharge


36

Assessment



Not performed at one time



Series of examinations



Detailed evaluation of all body parts



Includes

 Skin color

 Type of respirations

 Temperature

 Activity

 Feeding behavior


37

General Appearance



Before disturbing infant, evaluate

 Resting posture

 Spontaneous movements

 Flexion and symmetry

•

Term infant able to hold flexion while resting

•

Preterm infant may not be able to maintain flexion


38

Central Nervous System (CNS)



Extension of neck with arched back is opisthotonos, associated with CNS problems



Spontaneous movements potential clues to

CNS problems


39

Newborn’s Cry



Means by which newborns communicate with those around them



Strong and lusty



High-pitched: may indicate neurologic disorder, hypoglycemia, or drug withdrawal


40

Vital Signs



Best if taken while newborn is quiet or resting



Measure at

 15- and 30-minute intervals for first hour after birth, then

 Every 4 to 8 hours thereafter


41

Heart Rate



Apical rate



Listen for 1 full minute



Note

 Rate, rhythm, intensity

 Location of pulse

 Presence of abnormal sounds


42

Variations in Heart Rate



In newborns

 Normal rate is between 110 and 160 beats/min

 Bradycardia is heart rate less than 110 beats/min

 Tachycardia is heart rate greater than 160 beats/min


43

Femoral Pulse



Evaluate two pulses (in groin region)



A weak or slow pulse suggests coarctation of the aorta


44

Respirations



Count for 1 full minute



Observe abdominal movement

 Movement of the chest and abdomen should be synchronized



Rate is 30 to 60 breaths/min



Intermittent cessation of respirations for less than 15 seconds is normal

 Apnea —respirations that cease for more than 20 seconds —must be reported to the health care provider


45

Symptoms of Respiratory

Distress



Nasal flaring



Costal or substernal retractions (sucking in of chest wall with sternum moving inward with inspiration)



Grunting sound on expiration


46

Breath Sounds





Should be clear over most of area; may hear some moisture in lungs during first few hours after birth

Rales —rush of air through fluid



 Resembles rubbing hair together

Rhonchi —coarse sounds

 Resembles snoring


47

Temperature



Drops immediately after birth



Internal organs poorly insulated



Skin relatively thin



Heat-regulating center not yet mature



Rapidly reflects temperature of environment


48

Maintaining Temperature



Newborns cannot shiver



Use brown fat



Skin temperature will drop before core will



Allows for early interventions to prevent core hypothermia


49

Methods for Temperature

Measurement



Stable measurement is

36.5

° C (97.7

° F)



Take every 30 minutes until stable



Each hour for 4 hours



Every 8 hours in normal term newborn


50

Elevated Temperature



Dehydration



Too much clothing



Infection



Environment too hot



Can cause infant to break out in a pinpoint red rash called prickly heat or miliaria


51

Blood Pressure



At birth

 60 to 80 mm Hg systolic

 40 to 50 mm Hg diastolic



If newborn is crying, can increase by 10 to 20 mm Hg



If cardiac anomaly suspected, check blood pressure in all four extremities


52

Assessment of Physical

Characteristics


53

Skin



Provides visible record of health status



Inspect for characteristics related to preterm, term, postterm



Greenish-brown discoloration (meconium stain) of skin, nails, and cord can result if meconium passed before birth



Peeling or excessive cracking of skin associated with postterm


54

Head



If born head-first and vaginally

 Often elongated

 Called molding

 Usually resolves in a few days



Cesarean or breech delivery

 Normally round

 No pressure exerted on head during delivery process


55

Head Circumference



Large surface area compared with body

 Average 33 to 35.5 cm (13 to 14 inches)

 Either equals or exceeds by about 2.5 cm (1 inch) the circumference of the chest



If head is more than 4 cm greater than chest size, serial assessment for increased ICP or hydrocephalus is indicated



Small head, microcephaly, may be caused by rubella or toxoplasmosis exposure in utero


56

Molding



Overlapping of bones of head



Result of head compression during birth process



Usually resolves within 2 or 3 days


57

Caput Succedaneum



Localized swelling of soft tissues of scalp caused by pressure on head during labor



Palpated as soft, fluctuant mass



May cross over suture lines



Absorbed within a few days



No intervention needed


58

Cephalohematoma



Collection of blood between periosteum and bones of skull

 May be unilateral or bilateral

 Does not cross suture line



Emerges first or second day after delivery



May take as long as 3 weeks to be absorbed


59

Fontanelles



“Soft spots”



Covered with sturdy membranes



Openings in skull allow fetal head to mold to fit through birth canal



Should be level with cranial bones in a quiet infant, not elevated or depressed


60

Fontanelle Assessment



Bulging may occur when infant cries, coughs, or vomits



If bulging at rest, may indicate hydrocephalus



Depressed fontanelle may occur with dehydration and is a late sign


61

Large or Delayed Closure of Fontanelles



May indicate

 Congenital hypothyroidism

 Down syndrome

 Congenital rubella or syphilis

 Increased intracranial pressure


62

Anterior Fontanelle



At birth is between 3.6 and 6 cm (1.4 and 2.4 inches)



Usually closed by 18 months of age



Small fontanelle or early closure is called craniosynostosis

 Associated with abnormal brain development

 Caused by chromosomal anomalies, fetal hypoxia, or fetal alcohol syndrome


63

Posterior Fontanelle



Triangle-shaped



Located between occipital and parietal bones



Smaller than anterior



Closes between 2 and 3 months of age



Late closure may indicate hydrocephalus


64

Face



Somewhat recessed



Nose often flat



Cheeks full due to accumulation of fat

 Makes up the “sucking pads”

 Allows for strong sucking reflex in the newborn



Movements should be symmetric


65

Eyes



Assess placement, space between, symmetry, blink reflex



Iris of light-skinned newborns typically slate blue or gray

 Permanent color established around 3 to 6 months of age, or later

 Scleral colors blue-white due to relative thinness



Dark-skinned newborns may have dark eyes at birth


66

Vision



Myopic

 See best at 7 to 10 inches

 Can follow or track objects

 Can focus on an object for about 10 seconds

 Can discriminate between simple and complex patterns

 Prefer simple patterns

 High-contrast colors, such as black and white


67

Nose



Usually flat due to passing through birth canal



Obstruction can cause various degrees of respiratory distress, since newborns are obligate nose breathers

 Flaring nostrils is one sign of distress



Sneezing common

 Helps clear nasal passages


68

Mouth



Assess

 Palate for closure

 Presence of teeth

•

If present, usually removed to prevent aspiration

 Excessive salivation

•

May indicate tracheoesophageal fistula or atresia

 Tongue

•

Large, protruding may indicate Down syndrome


69

Sucking



Reflex present at birth

 Sucking stimulated when lips touched

 Depends on state of wakefulness and hunger

 Weak reflex may result from

•

Respiratory depression

•

CNS damage

•

Drug exposure

•

Prematurity


70

Rooting




 Elicited by stroking mouth or cheek

 Normal newborn should turn head toward stimulated side (positive rooting reflex)


71

Extrusion






Tongue pushes outward after it has been touched



Present until 4 months of age



May be mistaken as a refusal to eat or spitting out


72

Ears



Placement

 Low-set may indicate chromosomal or kidney problem



Formation



Amount of cartilage

 Term newborn —firm



Hearing test



Hearing established after first sneeze


73

Nurse’s Role in Hearing Tests


74

Neck



Short, creased with folds

 Cannot support full weight of head

 Lags when pulled from a supine to sitting position



Palpate for masses or injury to large muscles



Assess

 Clavicles for symmetry and smoothness

 Range of motion and neck muscle function with head movement


75

Chest



Normally round, symmetric, slightly smaller than head



Protrusion of lower part of sternum, called xiphoid cartilage , common



Measure at nipple line

 30.5 to 33 cm (12 to 13 inches)

 Approximately 2.5 cm (1 inch) less than head size



Assess breath sounds


76

Nipples



Distance between is about 8 cm (3 inches)

 Wide distance may indicate congenital defect



Breast engorgement common in both sexes due to maternal hormones



Nipples may secrete milklike substance called “witch’s milk” for a few weeks


77

Abdomen



Slightly protuberant and symmetric



Moves with chest during respiration



No masses should be palpable


78

Umbilicus



Umbilical stump assessed for two arteries, one vein

 Single artery associated with congenital anomalies



Stump falls off around 7 to 9 days after delivery



Assess for signs of bleeding, discharge, or infection



May appear as if it is a hernia



Will slowly disappear or invaginate



Primary site of infection is the umbilical stump


79

Bladder



Document when first void occurs

 Urine should not have an odor

 Typically dark amber due to uric acid crystals

•

May cause pink stain on diaper

 With fluid increases, urine lightens in color



Monitor number of wet diapers per day


80

Female Genitalia



Should be clearly differentiated





Labia majora cover labia minora in term infant

Hymenal tags —small tags of tissue protruding from vaginal opening —disappear in a few weeks



May have milky white, mucoid discharge due to withdrawal of maternal hormones

 Can be pink; called pseudomenstruation



Smegma often seen on labia minora


81

Male Genitalia





Urethral meatus should be on the tip of penis

 If on undersurface —hypospadias

 If on upper surface —epispadias

Foreskin adhered to glans penis —phimosis



Testes usually descended in term newborn

 Palpated bilaterally in scrotum

 If not palpated, observe for inguinal hernia



Rugae present on scrotum of term newborn

 Preterm lacks rugae


82

Anus



Assess if open and if anal sphincter has good muscle tone



Open anus allows for passage of meconium stool



If no stool is passed within first 24 hours after birth, newborn must be assessed for bowel obstruction


83

Stools



GI tract begins to function at birth



 Stools change color over a few days

Breastfed —may have more than three a day



 Should not be watery

Bottle-fed —may have less than three a day


84

Normal Newborn Stool Cycle


85

Back



Should be straight and flat



Lumbar and sacral curves do not develop until baby begins to sit up



Assess for dimples, masses, hair tufts, spinal curvatures


86

Spinal Reflex



If one side of back is stroked or stimulated, the spine should curve in the direction of the stimulus


87

Ortolani Maneuver



Hips are examined for dislocation



Assess gluteal and popliteal folds

 Should be symmetric

 If asymmetric and limited abduction, requires further evaluation


88

Ortolani Maneuver (cont.)


89

Extremities



Assess for extra or missing digits, deformities, palmar creases, and diminished femoral pulses

 Extra digits: polydactyly

 Webbing of digits: syndactyly

 Hands should have three creases



Assess location of feet

 If not in normal position, may be clubfoot


90

Erb-Duchenne Paralysis



Also called Erb’s palsy



Arm lies limply at side or newborn unable to elevate arm



Orthopedic care needs to implemented immediately


91

Unilateral Moro’s Reflex



May indicate fractured clavicle


92

Femoral Pulses



Palpate at same time



Diminished or unequal may indicate heart defect


93


Question 2

A white- to pink-tinged mucoid discharge from the vagina is noted during the nursing assessment of a female newborn. The nurse knows this is not an unusual finding as it is likely due to:

A.

Withdrawal of maternal hormones.

B.

Blood not completely removed during the bath.

C.

Rust-colored uric acid crystals in the diaper.

D.

Residual amniotic fluid.


94

Neurological and Behavioral

Assessment


95

Objectives



Review key physical and behavioral assessments of the newborn.



Discuss normal newborn reflexes.



State the purpose of newborn screening test.


96

Neurologic Assessment



Noticeable jerky or jittery movements



Excessive electrical discharge from neurons or metabolic disorder such as

 Hypoglycemia, hypocalcemia, hypoxia

 Neurologic damage

 Drug withdrawal



Repetitive blinking or pedaling movements of lower extremities may represent seizure activity


97

Estimation of Gestational Age



Ballard scoring system

 12 scores are totaled and maturity rating is expressed in weeks of gestation

 Performed within first few hours of birth and repeated again at 24 hours



Preterm born at less than 38 weeks



Term is 38 to 42 weeks



Postterm is born after 42 weeks


98

Fetal Size



Small for gestational age (SGA): weight less than 10th percentile



Large for gestational age (LGA): weight greater than 90th percentile



Weight alone does not determine prematurity or maturity level of newborn


99

Behavioral Assessment



Phases of reactivity newborn passes through during first 6 to 8 hours after birth


100

First Period of Reactivity



At birth —quiet alertness



Followed by phase of active alertness

 Demonstrates strong sucking reflex; may appear hungry

 Facilitates bonding and attachment

 Eye-to-eye contact



After 30 minutes to 1 hour becomes drowsy and falls asleep; lasts about 2 to 4 hours


101

Second Period of Reactivity



May last 4 to 6 hours



Awake, alert, and may cry



Shows activities such as rooting, sucking, swallowing



May respond to eye-to-eye contact



Bonding promoted



Feeding initiated if not done in first period


102

Understanding Newborn Cues

Newborn Desires

Interaction

Focuses on face of parent

Ceases random body movement

Reaches out

Newborn Desires to End

Interaction

Turns head away

Fussy

Yawns

Squirms

Newborn Is Hungry

Places hand at mouth

Sucking, rooting are evident

Flexes arm and clenches fist over body

Newborn Is Not Hungry

Arches back

Falls asleep

Relaxes arms at sides

Turns head away from nipple


103

Behavioral States



Sleep states

 Quiet sleep

 Active sleep



Transitional state

 Drowsiness



Awake state

 Quiet alert

 Active alert

 Crying


104

Screening



Procedure used to detect abnormal condition before symptoms appear



Not diagnostic



Enables early interventions



Most are state-funded



Screening for PKU mandatory in all states


105

Screening (cont.)



Screening may include

 Endocrine conditions

 Organic acid metabolism

 Fatty acid metabolism

 Amino acid metabolism

 Hearing

 Cystic fibrosis


106


Question 3

What does it mean when a newborn turns its eyes away, is fussy, yawns, and squirms?

A.

The newborn wants some form of interaction with others.

B.

The newborn is hungry.

C.

The newborn wants to be left alone.

D.

The newborn no longer is hungry.


107

Review Key Points


108