Newborn Physiologic Adjustments (Respiratory) Flashcards
(43 cards)
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
