Chapter 9 Physiologic Adaptation of the Newborn and Nursing Assessment Copyright © 2012, 2008 by Saunders, an imprint of Elsevier Inc. 1

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


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.


Adjustment to Extrauterine Life

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


Adjustment to Extrauterine Life (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


Respiratory and Circulatory Function


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 full-

term fetus Reduces force between moist surfaces of alveoli Prevents collapse with expiration Promotes lung expansion


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


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


Changing from Fluid-Filled to Air-Filled Lungs


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


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


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


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


Major Shunts of Fetal Circulation


Foramen Ovale Fetal

Opening between right and left atria

Blood flow and pressure greater in right atrium

Functions like one-way 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


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)


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


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


Audience Response SystemQuestion 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


Body Adaptation


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.


Body System Adaptations and Functions


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


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


Cold Stress

Newborn responds by increasing basal metabolic rate and oxygen consumption Depletes glycogen stores Results in acidosis


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


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


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


Newborn Produces Heat

By physiologic mechanisms or thermogenesis Includes

Increased basal metabolic rate Muscular activity Chemical thermogenesis (nonshivering

thermogenesis)• Primary method of heat production


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


Brown Fat Locations


Nonshivering Thermogenesis

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


Newborn Assessment


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.


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


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


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


Central Nervous System (CNS)

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

Spontaneous movements potential clues to CNS problems


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


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


Heart Rate

Apical rate Listen for 1 full

minute Note

Rate, rhythm, intensity

Location of pulse Presence of

abnormal sounds


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


Femoral Pulse

Evaluate two pulses (in groin region) A weak or slow pulse suggests coarctation of

the aorta


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


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


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


Temperature

Drops immediately after birth Internal organs poorly insulated Skin relatively thin Heat-regulating center not yet mature Rapidly reflects temperature of environment


Maintaining Temperature

Newborns cannot shiver Use brown fat Skin temperature will drop before core will Allows for early interventions to prevent core

hypothermia


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


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


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


Assessment of Physical Characteristics


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


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


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


Molding

Overlapping of bones of head Result of head compression during birth

process Usually resolves within 2 or 3 days


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


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


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


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


Large or Delayed Closureof Fontanelles

May indicate Congenital hypothyroidism Down syndrome Congenital rubella or syphilis Increased intracranial pressure


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


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


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


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


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


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


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


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


Rooting

Reflex present at birth Elicited by stroking mouth or cheek Normal newborn should turn head toward

stimulated side (positive rooting reflex)


Extrusion

Reflex present at birth 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


Ears Placement

Low-set may indicate chromosomal or kidney problem

Formation Amount of cartilage

Term newborn—firm Hearing test Hearing established after first

sneeze


Nurse’s Role in Hearing Tests


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


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


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


Abdomen

Slightly protuberant and symmetric Moves with chest during respiration No masses should be palpable


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


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


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


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


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


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


Normal Newborn Stool Cycle


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


Spinal Reflex

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


Ortolani Maneuver

Hips are examined for dislocation Assess gluteal and popliteal folds

Should be symmetric If asymmetric and limited abduction, requires

further evaluation


Ortolani Maneuver (cont.)


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


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


Unilateral Moro’s Reflex

May indicate fractured clavicle


Femoral Pulses

Palpate at same time Diminished or unequal may indicate heart

defect


Audience Response SystemQuestion 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.


Neurological and Behavioral Assessment


Objectives

Review key physical and behavioral assessments of the newborn.

Discuss normal newborn reflexes. State the purpose of newborn screening test.


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


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


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


Behavioral Assessment

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


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


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


Understanding Newborn Cues

Newborn Desires Interaction

Newborn Desires to End Interaction

Focuses on face of parent

Ceases random body movement

Reaches out

Turns head away

Fussy

Yawns

Squirms

Newborn Is Hungry Newborn Is Not Hungry

Places hand at mouth

Sucking, rooting are evident

Flexes arm and clenches fist over body

Arches back

Falls asleep

Relaxes arms at sides

Turns head away from nipple


Behavioral States

Sleep states Quiet sleep Active sleep

Transitional state Drowsiness

Awake state Quiet alert Active alert Crying


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


Screening (cont.)

Screening may include Endocrine conditions Organic acid metabolism Fatty acid metabolism Amino acid metabolism Hearing Cystic fibrosis


Audience Response System 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.


Review Key Points


Documents

Chapter 9 Physiologic Adaptation of the Newborn and Nursing Assessment Copyright © 2012, 2008 by Saunders, an imprint of Elsevier Inc. 1