OB lecture Flashcards
Neonate age
1-28 days
Infant age
28 days- 1 year
Child age group
> 1
Minimum hgb of pedis
10
Some say 15
Fetal lung development
4 weeks- lung buds
16 weeks- branching of bronchial tree into 28 divisions
24w- immature alveoli, surfactant, t2 cells, survivable with artificial ventilation
28 30 weeks- capillary network
36-40 weeks- true alveoli present, 20 million
birth - 3 mo- pao2 rises, shunts close
6 y- 350 mil alveoli
What stimulates first breathe
clamping of umbilical chord
low fetal o2 for continuous breathing
spo2 at 1 hr ph
.95 28
7.36
pressure required for peds to inflate lungs
-70cm h2o
What is the primary event of the respiratory system transition
Initiation of ventilation
How can u maintain frc/ lung inflation up until 6yo during anesthesia
5 peep
How long can peds fight hypoxia
2 minutes
What abolishes hyperneic response to hypoxia
low levels of anesthesia
hypothermia
What abolishes the neonates response to co2
hypoxia
Hypoxia causes ___ in babies
profound brady
Define apnea in infants
respiratory pauses of 20 seconds OR
Pauses with brady or cyanosis
O2 consumption in peds
Increased 6ml/kg
Why and how soon does the ductus arteriosis close?
constricts within minutes from increased PO2, and decreased prostaglandins, physiologic closure 10-15 hr, anatomic closure 2-3 weeks
Hypoxia and acidosis consequences
increased pv
p htn
RAP> LAP
Open a foramen ovale
S&S P htn in the newborn
marked cyanosis
acidosis
tachypnea
shunts FO and DA
PPHTN tx
hyperventilation
Pulmonary vasodilators- pg
Minimal handling
Avoiding stress
Adequate ventilation and oxygenatino
When are all nephrons developed?
34 weeks
Neonate renal characteristics- how much can they concentrate by 1 week, 2, and adult
Cant concentrate urine, so they pee it out
1st week- 70%
2nd- 84%
Adult- 99.5%
Adult vs neonate urine na
5-10
20-25
Lowest hgb hct
35%, 11
blood volume in pre term and term baby
Pre term- 100 ml/kg
Term- 90 ml/kg
stages of heat loss
1- transfer from body core to skin surface (internal gradient)
2- dissipation from surface to environment (external gradient)
Thermal regulation- 3 things
Non shivering thermogenesis major
Voluntary muscle activity
Involuntary muscle activity
What is non shivering thermogensis
neonates warming mechanism
metabolism of brown fat- 5% of tbw
Develops by week 30
Located in the mediastinum, scapula, adrenals, axilla
What is non shivering thermogenesis mediated from
sympathetic nervous system
Cold stress consequences
Increased o2 consumption- hypoxia, acidosis
Increased glucose utilization- lactic acid, hypoglycemia
Decrease surfactant- collapse of alveoli, reopening of fetal shunts
Prevent convection heat loss
High room temp
Prevent radiation HL
French fry lights
Prevent evaporation HL
Cover exposed body cavities, heat, and inspired gases
Prevent conduction heat loss
warm blankets, bair hugger
