Mod IV: Pediatric Airway Flashcards
Pediatric Airway
There are some unique traits to the pediatric airway if compared to adult airway. What could make DL challenging and Mask ventilation difficult in peds?
Large tongue
(Peds have a disproportionally large tongue)
Pediatric Airway
Why is Mask ventilation difficult with peds?
The disproportionally large tongue tends to want to Obstruct the airway
You also may or may not obstruct the airway accidently by applying excessive submandibular pressure, and not really focusing on keeping your hands or your fingers on the mandible
Pediatric Airway
Where is the glottic opening located in peds?
More cephalad & anterior appearing
Pediatric Airway
What is the vertebral level of the glottic opening in Premature Infant/Neonate
C3
Pediatric Airway
What is the vertebral level of the glottic opening in Full Term Infants?
C4
Pediatric Airway
Where is the Narrowest portion of the peds airway?
Cricoid ring
This is different from the adult airway
Pediatric Airway
Why would 1mm edema in peds have greater effect than adult?
Trachea shorter/smaller diameter
Pediatric Airway
Where is the narrowest portion in the adult airway?
Glottic opening
Pediatric Airway
1mm edema in peds has greater effect than adult because the peds trachea is shorter/smaller in diameter compared to the adult trachea. Which physical law is responsible for this?
Poiseuille’s law
Which states the “resistance to air flow is directly proportional to the radius to the 4th degree”
Pediatric Airway
How does pediatric larynx differ from adult’s larynx in shape?
Peds Larynx is funnel shaped vs. Adult latynx is cylindrical
Relative Effects of Airway Edema
In a normal infant how much space do you have across the trachea?
~ 4mm
Relative Effects of Airway Edema
In a normal adult, how much space do you have across the trachea?
~ 8mm
Relative Effects of Airway Edema
In an adult
1mm of edema increases the resistance by ___ times
and decreases the cross sectional area by ___ %
3 times
44 %
Relative Effects of Airway Edema
In pediatrics
1mm of edema increases the resistance by ___ times
and decreases the cross sectinal area by ___ %
16 times
75%
This is why tracheal edema in peds is significant as far as the obstruction of air flow
Pediatric Airway
In the peds airway, why is the Epiglottis Difficult to fix with DL?
Weird shape!!!
Narrow, long, U (omega)-shaped, floppier & protruding
Pediatric Airway
In the peds airway, which blade aids in lifting the Epiglottis out of the way during DL?
Straight blade
You can acually catch the epiglottis and move it, instead of passively lifting it with a Mac blade
Pediatric Airway
Why is nasal/blind “intubation” difficult in peds?
Vocal cords are in a diagonal position,
not perpendicular
Pediatric vs. Adult Airway
See picture
Note:
Large tongue
Shape of the larynx
Glottic opening (more anterior in peds)
Pediatric Airway
Why are pediatric pts “Obligate nose breathers”?
Weak pharyngeal muscles
As a result they can easily obstruct because of secretions or choanal atresia (if born with that)
Pediatric Airway
What is choanal atresia?
Congenital disorder where the back of the nasal passage (choana) is blocked, usually by abnormal bony or soft tissue (membranous) due to failed recanalization of the nasal fossae during fetal development
Pediatric Airway
Why should you always have LMA/OA/ET readily available with peds?
Complete airway obstruction is possible and must be anticicpated
Place LMA/OA/ET to reestablish airway patency
Pediatric Airway
Why is positioning the patient for intubation, including putting them in the sniffing position sometimes difficult?
Peds have Large heads
It’s best to apply something under the infant shoulders to bring their chest up, so you can really bring them into that true sniffing position for intubation
ORAL BREATHING
What percentage of infants with a PCA of 31-32 weeks are capable of oral breathing if the nasal passages are obstructed?
Only about 10%
ORAL BREATHING
What percentage of infants with a PCA of 35-36 weeks are capable of oral breathing if the nasal passages are obstructed?
About 30%
ORAL BREATHING
What percentage of infants with a PCA of full term infants (PCA of 40 weeks) are capable of oral breathing if the nasal passages are obstructed?
About 40% (less than half)
ORAL BREATHING
By what age do almost all infants are capable of oral breathing if the nasal passages are obstructed?
By about 5-months of age
Pulmonary Function
Why can’t peds maintain negative intrathoracic pressure?
They have a Compliant chest and a Pliable rib cage
Pulmonary Function
What’s a negative outcome of peds attempting to maintain negative intrathoracic pressure
It diminishes attempts to increase ventilation
Pulmonary Function
Why are peds at high risk for premature alveolar collapse?
High closing volumes which fall within lower range of normal VT
Leads to premature alveolar collapse
Pulmonary Function
From a diaphragmatic standpoint, why are peds at risk for quicker respiratory failure?
Diaphragm deficient in
Type I, slow-twitch, fatigue resistant muscle fibers
This results in earlier fatigue of muscles fibers involved in supporting breathing
These muscle fibers are necessary for performing repetitive work a/w respiration
These muscle fibers are essential for sustained increase respiratory effort
As a result, peds fatigue earlier than adults
This places them at risk for quicker respiratory failure
Muscle Composition
At what age do “Type I slow-twitching, high oxidative muscle fibers” become as predominant in peds as in adults?
At aorund 2 yrs of age
Pulmonary Function
Regarding Lung Development, when do Earliest alveolar/capillary network appear?
24-26 weeks gestation
Pulmonary Function
Which protein is responsible for preventing alveolar collapse during expiration? How?
Surfactant
It lowers alveoli surface tension, improving pulmonary compliance and allowing the lungs to inflate more easily
This helps eliminate some of the work-of-breathing
It also prevents the alveoli from collapsing at the end of expiration
The reduction in alveoli surface tension is required for the maintenance of alveoli surface area on which respiration is dependent
Pulmonary Function
At what gestational age does Surfactant first appear?
At 20 weeks gestation
Pulmonary Function
At what gestational age does Surfactant production accelerate?
At 30-34 weeks gestation
Pulmonary Function
At what age is full maturation of the lungs completed?
At 8 y/o
Pulmonary Function
Why do peds have increased RR (35-40/min) & alveolar ventilation?
They have a higher metabolic demand
Tissues need more O2 b/c peds are constantly growing until they reach their adult state
Pulmonary Function
Why would peds desaturate quicker than adults?
Lower FRC compared to adults
25-30 ml/kg in infants vs 40 ml/kg in adults
Higher minute ventilation to FRC ratio
5:1 in infants vs. 1.5:1 in adults
Pulmonary Function
Why are peds subject to more rapid inhalational induction?
Higher minute ventilation to FRC ratio
5:1 in infants vs. 1.5:1 in adults
Pulmonary Function
T/F: VT & deadspace are equivalent to adults
True
Pulmonary Function
What’s the average VT?
5-7 mL/kg/min
Pulmonary Function
What’s the average Deadspace?
2-2.5 mL/kg/min
Pulmonary Function
Apnea characterized by “cessation of breathing >15 secs”, Quite common in premature infants (<55 weeks PCA), Rare in full term neonates is also known as:
Central apnea
Pulmonary Function
Why is Central apnea Quite common in premature infants (<55 weeks PCA)
Immature CNS
Pulmonary Function
Why is it important to know if a pt was a premature infant with underdevelopped lungs or if they are less than 55 weeks PCA?
B/c if they are less than 55 weeks PCA, and even if it is a typical outpatient procedure, they will usually spend the night for obeservation, just so we can monitor their breathing
Pulmonary Function
The type of apnea characterized by breathing with 10-15 sec periods of apnea
Periodic apnea
Occurs in 80% of full term infants & 95% of preterm infants
Pulmonary Function
Periodic apnea occurs in what percentage of full term infants?
80%
Pulmonary Function
Periodic apnea occurs in what percentage of preterm infants?
95%
Pulmonary Function
What’s a benefit of Hypoxia during apneic episodes?
Hypoxia initially stimulates ↑ in ventilation
Pulmonary Function
Outline of neonate Mean Pulmonary Function values as compared to an adult
See table
Pulmonary Function
Treatment of larygospasm in peds
Sux + Atropine
PPV via bag mask
You do not necessarily need to intubate
