Peds Week 1 Flashcards
Neonate is defined as:
0-30 days old
Infants are defined as:
1 month- 1 year
Children are defined as:
older than 1 year
A fetus is considered “viable” outside the mother at how many weeks?
24 weeks gestation
Alveolar formation begins at ___-___ weeks gestation.
32-36 weeks
Surfactant production begins at ___ weeks gestation.
27 weeks.
Surfactant is produced by____?
Type II pneumocytes.
The absence contributes to RDS in premies.
For a preterm delivery, the mother is given betamethasone or dexamethasone 48 hours prior to delivery. Why?
- Accelerates lung maturation in the premie
- Stimulates surfactant production
- Decreases mortality after 30 weeks gestation
The first breath of an infant needs a pressure of 40-80 cm H2O. why?
(normal is ~20 cm H2O)
-To overcome surface tension forces
-To introduce air into fluid filled lungs
(adequate surfactant is needed to achieve this)
The lecithin/sphingomeylin (L/S) ratio in amniotic fluid correlates with what?
Lung maturity
Surfactant synthesis is increased by:
- Glucocorticoids
- thyroxine
- Heroin
- cAMP
Surfactant is inactivated by:
- Alveolar-capillary leak
- Pulmonary edema
- Hemhrrhage (hemoglobin)
- Alveolar cell injury
- Meconium
Synthetic surfactant is used to treat:
- Premies with surfactant deficiency
- Pulmonary HTN
- Congenital diaphragmatic hernia (one lung collapsed)
- Meconium aspiration syndrome
- ARDS (Adults and Children)
Lung development continues until a child is about ___ years old.
10 years old
- The number and size of alveoli increases until age 8
- Developmet of alveoli from saccules is completed by age 18 months
Neonatal lung compliance and chest wall compliance are high. Why?
- cartilaginous ribs
- limited thoracic muscle mass
- more prone to atelectasis
Diaphragm is most important muscle of breathing in infants
Infants are obligate nose breathers until:
5 months
The larynx is located:
Cephalad C3-C4
Adults=C5-C6
____ is the narrowest part of the airway in children.
Cricoid Cartilage
Adults = vocal cords
Compared to adults, the pediatric epiglottis is:
Long and U shaped and often stiffer than the adult epiglottis and more difficult to displace.
T/F In neonates, hypoxia depresses ventilation via suppression of medullary centers.
True.
Macroglossia
Large Tongue
Trisomy 21 (Down’s) and many more
Airway Retrognathia (micrognathia)
Small jaw/mouth; retrognathia =posterior mandible or “overbite”
Bohr effect:
Explains how hydrogen ions and carbon dioxide affect the affinity of oxygen in Hemoglobin. If pH was lower than it normally was (normal physiological pH is 7.4), then the hemoglobin does not bind oxygen as well.
Apnea in infants =
pause in ventilation lasting > 20 seconds that is accompanied by bradycardia and cyanosis.
Periodic breathing =
Apneic spells <10 seconds, no bradycardia or cyanosis.
Periodic breathing is a NORMAL phenonmenon.
100% of premies
80% of term neonates
30% of infants age 10-12 months.
-Can be abolished by adding 3% CO2 to inspired gas.
Central Apnea =
No initiation of breath. Most common in premature.
Obstructive Apnea =
breaths initiated, but no passage of gas due to obstruction in airway