the newborn

With the transition to extra uterine life the newborn undergoes many physiological changes.

These changes involve the establishment of:

Pulmonary gas exchange

A neonatal cardio vascular pattern

A stable serum glucose level

Thermoregulation

Assessment and monitoring of neonatal adaptation is essential for early detection of complications such as:

  Hypoxia

  Cold stress

  Hypoglycemia

  Infection

  Polycythemia

  Hyperbilirubinemia

newborn assessments include:

Vital signs, especially temperature (BPs are rarely done)
Nutrition
Elimination
Transition to extrauterine life
Activity state
Umbilical cord
If indicated: 
  Glucose monitoring 
  Bilirubin
  Circumcision assessment

apgar score

indicative of the need for resuscitation, not the degree of asphyxia.

Infants are scored at one and five minutes of life and if needed at ten minutes.

1st step in neonatal resuscitation

vigorously dry baby starting at head

apgar scoring categories

1. HR

2. respirations

3. muscle tone

4. reflex irritability

5. color

normal oxygen satruation at birth baby

60% rises rapidly

fetal lungs…

secrete lung fluid throughout pregnancy.

Production of lung fluid diminishes 2 to 4 days before?

the onset of spontaneously occurring labor

how much remains in passageway of a full term newborn

80 to 100 mL

During labor and birth, fetal chest is compressed and this squeezes part of the fluid out.

any baby born c section is more likely to have?

retained lung fluid during delivery

has to be expelled or absorbed into lymphatic system

what can the fluid ofren be heard in the lungs at delivery as?

fine crackles

Infants who have difficulty clearing the fluid are at risk to develop a respiratory complication called…

transient tachypnea of the newborn (TTN).

initiation of respiration in the newborn chart

chemical stimuli of first breath

First breath is inspiratory gasp - triggered by increased PCO2 and decrease in pH and PO2

Changes trigger aortic and carotid chemoreceptors - trigger brain's respiratory center

hormonal chemical stimuli

Prostaglandins are released by the placenta throughout pregnancy and suppress respiration.

With the clamping of the cord prostaglandin levels drop and there is an increase in respiratory drive.

mechanical stimuli lung expansion

—Natural result of a normal vaginal birth as the “vaginal or thoracic squeeze” is released at the delivery of the chest allowing for lung expansion.

The significant decrease in environmental temperature after birth:

Stimulates skin nerve endings

Newborn responds with rhythmic respiration

Warning- Excessive cooling of the infant may led to profound depression as the result of “cold stress”.

Intrauterine life sensory stimuli

Dark

Sound dampened

Fluid-filled environment

Weightless

Newborn experiences at delivery sensory stimuli:

Light

Sounds

Effects of gravity

Abundance of tactile, auditory, and visual stimuli of birth

The normal newborn respiratory rate is

30-60 breaths/min

—It is important to count respirations with a stethoscope in the newborn for a full minute!

Initial respirations may be mainly

diaphragmatic, shallow and irregular in depth and rhythm.

respiratory rate may…

increase with crying

normal breathing in first few hours of life

perioidc breathing

pasuses lasting from 5-15 seconds

—Pauses of longer than 20 seconds are apnea and always need additional assessment.

Signs of respiratory distress in the newborn include:

increased/decreased respiratory rate <30->60

flaring of nares

expiratory grunting

see-saw breathing (abdomen-chest)

retractions

color changes

circumoral cyanosis (blue around lips: normal finding) – general cyanosis no good (look at abdomen)

decreased muscle tone

problems with temperature regulation

increased water loss

cardiovascular adaptation requires

the transition from fetal to neonatal circulation with the change from placental to pulmonary gas exchange.

fetal lungs

are essentially nonfunctional.

Most blood bypasses the lungs and is shunted to other parts of the body.

in fetal circulation Oxygenated blood returns to the fetus from the placenta through the?

placental vein.

Much of the blood (40-60%) bypasses the liver via the ductus venosus and enters the inferior vena cava.

as the blood enters the right atrium in fetal circulation, what happens?

50-60% is shunted across the atrium through the foramen ovale to the left atrium.

in fetal circulation, systemic resistance and pulmonary resistance…

There is low systemic resistance and high pulmonary resistance.

60% of the blood from the right ventricle is shunted through the ductus arteriosus to the umbilical arteries and toward the placenta

transitional circulation

neonatal circulation

The initiation of respirations by the infant and the clamping of the cord at birth shifts the resistance in the circulation to be low pulmonary resistance and higher systemic resistance.

what do the neonatal circulation changes cause?

a pressure closure of the foramen ovale in the heart.

The ductus arteriosus begins to constrict almost immediately.

in neonatal circulation, blood now flows:

From the right atrium to the right ventricle To the pulmonary arteries

To the lungs

Back to the heart through the pulmonary veins

Into the left atrium

Through the aorta to the body.

cardiovascular assessment should start with a:

general color assessment

Acrocyanosis occurs in the?

—first 7-10 days it is not unusual for the hands and feet to remain blue

circumoral cyanosis

a blue tint to the skin surrounding the lips, but not on the lips.

This is normal and is simply the blue color of the veins just below the skin in this area.

You may notice this blue tint most of the time.

When the arterial blood in this area diminishes for various reasons, you will see the blue tint of the veins underneath.

general cyanosis

—blue tint to the skin that covers the face trunk and extremities.

It is associated with poor oxygenation of the tissues and is an ominous sign.

It can be respiratory or cardiac in origin.

newborn cardiac assessment

Heart rate is taken apically at the 4^th intercostal space, left.

The rate is assessed for a full minute.

HR newborn

Normal- 110-160 at rest.

May drop to 80-100 when asleep.

May accelerate up to 180 BPM when stressed.

Crying may increase rate.

Consistently high >180 or low <100 warrants further investigation.

heart murmur and newborns

it is not uncommon to hear a heart murmur in the newborn. Most are non-pathological and disappear by 6 months.

However, all murmurs warrant further investigation and assessment. Hearing a murmur in the newborn is the most common means of recognizing cardiac disease.

If accompanied by poor feeding, cyanosis, pallor or apnea these are abnormal findings .

blood volume newborn

80 mL/kg of body weight

Varies with amount of placental transfusion received by the newborn during expulsion of placenta

Blood volume increases by 50% with delayed cord clamping

try to delay clamping of cord for…

at least 30 seconds to a few mins

site of blood sample

Peripheral blood flow can be sluggish and create RBC stasis - increases RBC stasis

Hemoglobin and hematocrit levels higher in capillary blood than in venous blood

blood vessels taken from accuracy

Blood vessels taken from venous samples are more accurate than capillary samples

newborn total BV values

•82.3 ml/kg at three days life with early cord clamping (before 30 second of life)

•92.6 ml/kg at three days life with early cord clamping (after 30 second of life)

hgb newborn values

—14-20 g/dl

hct newborn values

—43-64%

wbcs newborn values

—10,000-30,000 mm³

BG newborn values

•40-80/mg/dl for the first 6 hours of life

•45-95/mg/dl for the first 6 hours of life

—There are two types of feeding for the healthy newborn:

-Breastfeeding

-Bottle feeding commercial formula or pumped breastmilk

—Although there are additional health benefits to breastfeeding, the decision of how an infant is it to be fed is made by the parents and should be respected.

—There are different types of commercial formulas and an infant’s formula order is on par with a medication order. Only the ordered formula should be used.

Bottle fed infants should be fed…

—every 3-4 hour unless ordered more frequently.

frequency breast feeding

Breast milk is  digested more easily and quickly than formula.

The frequency for breastfeeding is every 1 ½ to 3 hours or 8-12 times a day

Normal glucose levels in the newborn are between

40 and 80 mg/dl in the first six hours of life and 45 and 90 mg/dl after that.

BG levels below 40-45 are treated with…

either a concentrated glucose gel, a feeding or 10% dextrose in sterile water feeding.

Persistent hypoglycemia can result in neurological damage in the newborn.

hypoglycemia results from

inadequate availability of glucose (poor feeding), abnormal endocrine regulation (infants of diabetic mothers) or increased utilization of glucose (cold stress, infection)

glucose is the …

primary fuel for the newborn and is stored in the liver as glycogen.

hypo vs hyperglycemia newborns

Hypoglycemia can be life-threatening and can result in seizures and learning disabilities.

Hyperglycemia is more common in premature and small for gestational age infants.

signs and symptoms of hypoglycemia are frequently…

—absent despite extremely low blood glucose levels!

—

signs and symptoms hypoglycemia

Jitteriness (this is the most common symptom)

Hypothermia (another common symptom)

Diaphoresis

Hypotonia

Irritability, tremors, muscle twitching, seizures

Abnormal cry

Poor feeding

Lethargy

Respiratory distress, tachypnea, apnea

Cyanosis, tachycardia, cardiac failure, cardiac arrest

below what temp is hypothermia…

97.6

The newborn temperature rarely elevated.    Below 97.6 is abnormal and can lead to significant distress from cold stress

normal temp

>97.6F

Temperature instability indicates

infection

temp methods

Research indicates tympanic and digital axillary methods are accurate indicators of body temperature

Can be assessed by axillary skin method, continuous skin probe, rectal route - axillary temperature is preferred method

thermoregulation newborn

Inappropriate management of heat stress and cold stress in neonates is associated with metabolic complications such as hypoglycemia, increased oxygen consumption, increased lactic acid production, increased metabolic acidosis and death.

Heat loss in the newborn can occur through four mechanisms:

1. conduction

2. convection

3. radiation

4. evaporation

thermoreg diagram

whats main form of heat loss initally for newborns?

Evaporation

due to of amniotic fluid evaporating from the baby's body.

convection occurs in newborns when…

a newborn is exposed to cooler surrounding air.

Heat loss increases with air movement, and a baby risks getting cold even at a room temperature of 30°C (86°F) if there is a draught.

(89° - 92° if the infant is naked and 75°- 80° if the infant is dressed)

conduction occurs in newborns if…

the baby is placed on a cold surface (weighing scale or cold mattress)

radiation occurs in newborns when…

there is transfer of warmth from the baby to cooler objects in the vicinity (a cold wall or a window) even if the baby is not actually touching them.

cold stress…

a body temperature rectally of less than 97.6F with symptoms.

If you get a temperature of 97.6 or lower,

repeat the temperature under the other arm.

If you still have a low reading report it to the nurse immediately.

The infant needs to either be put in skin to skin temperature with the mother or be placed in a radiant warmer!

smaller and preterm infants thermoregulation

greater risk of hypothermia

symptoms of hypothermia include:

Body cold to touch    

Hypoglycemia

Restlessness, irritability, tachypnea

Pallor or mottling

Lethargy, decreased activity, hypotonia

Central cyanosis, acrocyanosis

Poor feeding, weak suck

Bradycardia    

Feeble cry, shallow/irregular respirations, apnea

Nonshivering thermogenesis

Occurs when skin receptors perceive a drop in environmental temperature

if newborn shivers:

, metabolic rate doubles

increases muscle activity

what is primary source of heat in hypothermic newborn?

BAT

Appears in fetus at 26 to 30 weeks

Increases until 2 to 5 weeks after birth

newborns respond to hypothermia by….

increasing their metabolism.

This is done by breaking down their limited brown adipose tissue (BAT or “brown fat”) stores.

where is BAT located?

around the scapula, kidneys, adrenals, head, neck, heart, great vessels and axilla.

bat metabolism chart

treatment of hypothermia

Prevention is best treatment!

Dry infant immediately at birth

Use hat

Keep room warm

Use skin to skin with mom or radiant warmer

Delay bathing until >98

Rewarm after bath

Dress appropriately and use blankets as needed

Educate parents

Monitor temps and symptoms

Return to the radiant warmer if temperature is unstable

newborn digestion

Newborn has enough intestinal and pancreatic enzymes to digest simple carbohydrates, proteins, and fats - newborn cannot digest starch

By birth, newborn has experienced swallowing, gastric emptying, and propulsion

breast milk is digested in… vs cows milk formula

Breast milk, which is 90% digestable, is digested in 2-3 hours

Cows milk formula is digested in 3-4 hours.

meconium is formed…

in utero

Newborn passes meconium within 48 hours - frequency of bowel movement varies

voiding newborns

93% void by 24 hours after birth and 100% void by 48 hours after birth - initial bladder volume is 6 to 44 mL of urine

If newborn does not void within 48 hours…

nurse should assess adequacy of fluid intake, bladder distention, restlessness, and symptoms of pain

newborn immune system

Immune system isn't fully activated until after birth - newborn has poor hypothalamic response to pyrogens

Fever not reliable indicator of infection - in newborn period, hypothermia is more reliable indicator of infections

passive immunity from mother

Lasts 4 weeks

Passive acquired immunity occurs during third trimester

Preterm infant may be more susceptible to infection

newborns own immunity

Breastfed newborn may have additional passive immunity from mother

Newborns start to produce secretory IgA in the intestinal mucosa at four weeks

newborn pain assessment categories

1. face

2. legs

3. activity

4. cry

5. consolability

face pain

0 No particular expression or smile

1 Occasional grimace or frown, withdrawn, disinterested

2 Frequent to constant frown, clenched jaw, quivering chin

legs pain

0 Normal position or relaxed

1 Uneasy, restless, tense

2 Kicking or legs drawn up

activity pain

0 Lying quietly, normal position, moves easily

1 Squirming, shifting back/forth, tense

2 Arched, rigid, or jerking

cry pain

0 No cry, awake or asleep

1 Moans or whimpers, occasional complaint

2 Crying steadily, screams or sobs, frequent complaints

consolability pain

0 Content, relaxed

1 Reassured by occasional touching, hugging, or "talking to," distractible

2 Difficult to console or comfort

sleep states

Quiet sleep

Active sleep (REM)

awake states

Drowsy

Quiet alert

Active alert

Crying

when is the best state to assess a newborn?

quiet alert

first period of reactivity

Period lasts about 30 minutes

Newborn is awake and active

Appears hungry and has a strong reflex

Natural opportunity to start breastfeeding

Vital signs are elevated