Newborn Physiologic Adjustments (Respiratory) Flashcards
What is the most critical physiological adaption after birth?
Establishment of effective respirations
During intrauterine life, how does oxygenation occur?
Occurs though transplacental gas exchange.
In utero what is the fetal blood shunted away from?
The lungs.
What happens when the umbilical cord is clamped?
Clamping the umbilical cord causes a rise in BP, which increases circulation and lung perfusion.
The initiation of respirations in the neonate is the result of a combination of:
Chemical, mechanical, thermal, and sensory factors.
What chemical factor initiates respirations based off of contractions?
Decreased levels of O2 and increased CO2 have a cumulative effect that is involved in initiating neonatal breathing by stimulating the respiratory center in the medulla.
What chemical factor initiates respirations based off clamping the cord?
As a result of clamping the cord, there is a drop in level of a prostaglandin that can inhibit respirations.
What mechanical factor promotes respirations based off the birth canal?
Intrathoracic pressure resulting from compression of the chest during vaginal birth can stimulate respirations.
What does negative intrathoracic pressure due to an infants lungs?
Helps draw air into the lungs and may stimulate crying.
How does crying help the stimulation of respirations?
Cry increases the distribution of air in the lungs and promotes expansion of the alveoli.
Helps keep the alveoli open.
What thermal factor promotes respiration?
The profound change in environmental temperature stimulates receptors in the skin, resulting in stimulation of the respiratory center in the medulla.
What sensory factors stimulate respirations?
Include: Handeling infant suctioning the mouth and nose drying the infant lights sounds smells
At term the lungs hold approximately how many mL of fluid per kilogram?
20mL.
Air must be substituted for the fluid that filled the fetal reparatory tract.
Which infants are more likely to develop transient tachypnea of the newborn (TTNB)?
Infants born by cesarean in which labor did not occur before birth.
What exactly causes transient tachypnea of the newborn (TTNB)?
Caused by the lower levels of catecholamines.
What are the alveoli of a term infant’s lung lined with?
Surfactant.
What is lung expansion largely dependent upon?
Depends largely on chest wall contraction and adequate recreation of surfactant.
Why is surfactant important in respirations?
Surfactant lowers surface tension and prevents total alveolar collapse on exhalation.
What is beneficial regarding decreased surface tension during respirations?
Reduces pressure required to keep the alveoli open with inspiration.
Results in increased lung compliance, helping to establish the functional residual capacity of the lungs.
What happens when an infant has absent or decreased surfactant?
More pressure must be generated for inspiration, which can soon tire or exhaust preterm or sick term infants.
What is the normal range of breath per min. in term infants?
30 to 60 breaths/min with periods of breathing that include pauses in respirations lasting less than 20 seconds.
When do the episodes of periodic breathing occur most often?
REM sleep cycle. They decrease in frequency and duration with age.
When should episodes or periodic breathing be a concern?
Apneic periods longer than 20 seconds indicate a pathologic process and should be evaluated.
What airway do newborns prefer to breath from?
Nose
What is the reflex that occurs due to nasal obstruction and when does this reflex present itself?
The reflex response to nasal obstruction is to open the mouth to maintain airway. This response isn not present in most infants until 3 wks after birth.
What can occur due to a nasal obstruction up to 3 weeks after birth?
Cyanosis or asphyxia can occur with nasal blockage.
Why is abdominal breathing a large characteristic in newborns?
Because neonatal respiratory function is largely a matter of diaphragmatic contractions.
What are some major signs of infant respiratory distress?
- Nasal flaring
- Intercostal or subcostal retractions (in-drawing of tissue between the ribs or below the rib cage)
- Grunting with respirations.
What two factors most often represent an upper airway obstruction?
Suprasternal or subclvicula retractions with stridor or gasping.
What two characteristics that replace abdominal respirations are abnormal and should be reported?
- Seesaw
2. Paradoxical respirations (exaggerated rise in abdomen with respirations as the chest falls)
What respiratory rate must be evaluated in a resting infant?
60 breaths/min
How can analgesics or anesthetics that were administered to the mother during labor effect the respirations of infants after birth?
Infant respirations can be slowed, depressed, or absent.
What can apneic episodes be related to?
- Rapid increase in body temp.
- Hypothermia
- Hypoglycemia
- Sepsis
What can tachypnea result from?
Inadequate clearance of lung fluid, or it can be an indication of newborn respiratory distress syndrome (RDS).
What integumentary finding can indicate respiratory distress?
Changes in the infant’s color.
What is acrocyanosis?
The bluish discoloration of hands and feet, is normal finding in the first 24 hours after birth.
What is significant about central cyanosis?
Is an abnormal finding and signifies hypoxemia.
How can a nurse identify central cyanosis?
The lips and mucous membranes are blueish.
What can central cyanosis be the result of?
- Inadequate delivery of O2 to the alveoli
- Poor perfusion of the lungs that inhibits gas exchange
- Cardiac dysfunction
Is central cyanosis an early or late sign?
Late sign of distress, newborns usually have significant hypoxemia when cyanosis appears.
Infants who experience mild TTNB often have signs of respiratory distress during:
The first 1 to 2 hrs after birth as they transition to extrauterine life. Tachypnea rates (up to RR: 100) can be present along with intermittent grunting, nasal flaring, and mild retractions.
What nursing intervention may be necessary for infants experiencing respiratory distress?
Supplemental O2.
What are 4 common respiratory complications affecting neonates?
- RDS
- Meconium aspiration
- Pneumonia
- Persistent pulmonary hypertension of the newborn (PPHN)
