Well NB Flashcards
How long does it take for the foramen ovale to close?
Functional closure happens within hours after birth. 6 months-1 year for permanent closure
How long does it take for the ductus arteriosus to close?
12-24 hours for functional
2-3 weeks for permanent
Why are preterm infants susceptible to heat loss?
Skin thin
Muscle tone decreased so don’t flex to conserve heat
Blood vessels near surface
Little SQ fat
More surface area
What is acrocyanosis?
Blueish hands and feet from heat loss
What is non shivering thermogenesis?
NST-Metabolism of brown fat to produce heat
NB’s primary method of heat production
What is role of brown fat in NB and where are locations?
Brown fat (also called brown adipose tissue or BAT)
Heat generators for NB’s
—Preemies don’t have enough—
Located in: Axillae, sternum, between shoulder blades, back of neck
When will you see a temp drop in NB using NST (non shivering thermogenesis)?
After the fact…by the time see change in rectal temp the brown fat stores have been depleted.
What are the metabolic effects of cold stress in NB?
Metabolism rises, glucose stores burn»>hypoglycemia
What are the effects when NB metabolizes brown fat?
Increases acid release»>metabolic acidosis
Acid release also releases bilirubin»>jaundice
What are effects of cold stress on respiratory system of NB?
Increases demand for O2 and decreases production of surfactant»>hypoxia and respiratory distress syndrome
What is thermoneutral zone for full term naked baby?
89-92 degrees
What is thermoneutral zone for full term dressed baby?
75-80 degrees
Normal range of RBCs in NB.
4.8——-7.1million/microliter
Normal range of hemoglobin in NB.
15——24g/dL
Normal range of hematocrit in NB.
44%——-70%
Normal range of WBCs in NB.
9.1——–30 thousand/mm
Normal range of glucose in NB at 24 hours.
40-60
Normal range of glucose in NB at >24hours
50-90
What is polycythemia?
–Elevated RBC, HGB, HCT–
Increases risk of jaundice
What is considered hypoglycemia in NB?
Less than 45
What is kernicterus?
Brain damage from elevated bilirubin levels (usually from chronically elevated bili)
What is bilirubin?
byproduct of hemolysis (breakdown of RBCs)
Why are bilirubin levels high in NBs?
Many reasons:
They make twice as much for 3-6 weeks.
More RBCs with shorter life spans. (dying RBCs mean lots of bili going into blood)
Liver is immature and can’t process fast enough.
Fewer albumin to bind bili.
Intestinal flora isn’t established yet.
(remember they got to poop it out)
If feeding/pooping is slow bili stays in system.
When jaundice starts to become noticeable what are the usual bili levels?
5-6