Peds deck 4 Flashcards
the chest wall, trachea and the bronci are highly _______________ compared to the adult
compliant
what happens in normal expiration in the child
slightly negative intrathoracic pressure (less than on inspiration) –> maintaning of patency of intrathoracic trachea and bronchi
in normal inspiration in the child, what happens?
increased negative intrathoracic pressure –> dilation and stretching of intrathoracic trachea and bronchi & dynamic collapse of extrathoracic trachea
extrathoracic airway obstruction, what is the result in a child?
- even greater collapse of extrathoracic trachea below obstruction 2. more negative intrathoracic pressure –> greater dilation of intrathoracic trachea and bronchi
extrathoracic airway obstruction is characterized by what lung sounds?
stridor
intrathoracic airway obstruction is characterized by what lung sound
prolonged expiration or wheeze
how do the dynamics of the airway change with intrathoracic airway obstruction
- highly increased intrathoracic pressure –> dynamic collapse of intrathoracic airway
what may cause extrathoracic airway obstruction?
- epiglottitis 2. larngotracheobronchitis 3. extrathoracic foreign body
intrathoracic airway obstruction causes
1.asthma 2. bronchiolitis 3. inhaled foreign body
the ribs of the chest wall are in a more _____________ orientation compared to an adult
horizontal
by what age are the orientation of the ribs comprising the chest wall similar to that of the adult
10
children having a more horizontally oriented chest wall (due to ribs) predisposes them to ?
- respiratory failure 2. lung injury 3. ventilation associated lung injury
inspiration of the infant depends almost exclusively on __________________
the descent of the diaphragm
as work of breathing in the infant increases the _______________ must also increase to maintain tidal volume –> quick fatigue and respiratory distress
diaphragmatic descent
when at rest expirations in infant are _____________
passive
infants have ______________ pulmonary compliance and _____________ static recoid
high; low
_______________ is the principle factor which determines lung compliance
volume
pulmonary lung compliance is ______________ infants
high
static lung compliance
change in volume for any change in pressure
dynamic lung compliance
compliance of lung at any given time during air exchange
clinical implications of infants having high lung compliance and low static recoil
- decreased recoil –> increased possibility of lung collapse with dz 2. excessive lung compliance of the infant = more work to maintain adequate tidal volume 3. during respiratory distress –> diaphragm fatigues –> apnea
infants have a __________ FRC to TLC ratio
low; limits gas excahnge
under general anesthesia the infants FRC may only be __________% of the TLC
10-15 (normally closer to 30-40%)
TLC in the pediatric pt is ____________ than that compared to an adult
less
what static lung volumes are linearly related to the log of height
TLC, VC, FRC, and RV
why is TLC in the infant so much smaller than in the adult?
it is effort dependent which is related to the strength of the inspiratory muscles (estimated by maximum inspiratory pressure at FRC) and the ability to generate negative pressure
_______________ flow is present in the peripheral bronchi and bronchiole
laminar
_____________ flow is present in the upper and lower conducting airways
turbulent
what law determines airway flow/pressures with airway obstruction/edema
poiseuilles
T/F: periodic breathing in neonates is common
TRUE
what defines periodic breathing in infants
apneic spells < 10 seconds without cyanosis or bradycardia
incidence of periodic breathing in: Premies = ___________ neonates = ___________ 1 year of age = ___________
100%; 80%; 30%
define central apnea
apnea > 15 seconds accompanied by cyanosis, bradycardia (<100 bpm) and/or pallor
what is the most common risk factor for central apnea
prematurity
T/F: newborn paO2 is lower than the adult
TRUE
the lower PaO2 in the newborn is compensated for by ________________
presence of fetal hgb
P50 in the neonate
left shift (~19)
during the _______________ week of life, the oxy-hgb dissociation curve of the newborn begins to switch to the left, reflecting the transition of _______________
first; fetal to adult hgb
pH, PaO2, and PaCO2 are all ____________ in the newborn
lower
what type of ABG would you expect the newborn
- metabolic acidosis 2. increased lactate 7.3-7.4/30-35/60-90/<22
why is there metabolic acidosis in the newborn
reduced pH, and increased volume of distribution causes a dilution of bicarb
how do infants increase their alveolar ventilation
by increasing RR (NOT Tv)
metabolism in the infant is _____________
higher
O2 consumption and CO2 production is ______________ in the infant
higher
O2 consumption is _______x that of the adult, which leads to doubling _______________ on a per kg basis
2; alveolar ventilation
what increases the risk of laryngospasm in peds
- upper respiratory infection 2. reactive airway dz 3. passive environmental smoke 4. inadequate anesthetic depth
T/F: laryngospasm is an anesthetic emergency
TRUE
how do you treat a laryngospasm
- jaw thrust 2. positive pressure 3. lidocaine 4. succinylcholine (1 mg/kg)
incidence of bronchospasm in peds
0.40%
what increases the risk of bronchospasm in pediatrics
- upper respiratory infection 2. reactive airway dz 3. inadequate anesthetic depth 4. too deep of endotracheal tube placement 5. CF and BPD
