Peds pt 2 Flashcards
What increases the risk of neonatal intracerebral hemorrhage
htn, immature cerebral autoregulation, fragile cerebral vasculature
Normal ICP
2-4 mmhg
Cushing response in peds
absent cushing response
Where does the spinal cord end in peds
L3 and is normal by age 8
Consider sinus brady____ until proven otherwise
hypoxia
CO is derived form ___ and ____
HR and volume
Explain peds being HR dependent
-Peds don’t have the startlings law; the ability to increase force of contraction to maintain CO.
-The under developed myocardium/ immature contractile elements = decreased contractility
- Poorly compliant ventricles; can’t increase contractility to overcome elevated afterload.
- with increased SVR in an underdeveloped heart it cant compensate for the increased pumping needs/ increased workload
- maximum contracltity in neonates because of increased beta stimulation and thyroid hormone
- have a higher resting tesion but develop less stress during transition
What is the primary determinant of SBP
HR
In the setting of hypovolemia + bradycardia what is the medication of choice
epi because it augments contractility
Which vasopressor should be avoided in peds
Phenylephrine because the HR needs to be able to adjust to the increased SVR
How does the ventricle eventually become more compliant
SVR increases with age -> LV pumps against higher SVR -> develops stronger contractile elevments= better adjust contractlity
Normal CO
200 ml/kg/min
Normal SVR in peds
Low
Explain where the PFO is
R to left atrium. R-> left shunt.
How does the PFO close
when blood returns to the heart from the pulmonary veins increases the pressure in the LA and above that of the RA -> closure.
When is PFO usually closed
closes between 3 months - 1 year. 10-30% of ppl have a PFO.
Risk of PFO
Venous air embolism.
PDA location
Between the pulm artery and the aorta.
When does the PDA close
10-15 hrs of life and anatomical closure takes place in 4-6 weeks.
Premature Ductus arteriosus closure causes
NSAIDs, preterm bitht, inc PAP, dec PBF.
During stress / hypoxia what changes does the heart make
hypoxemia, hypercarbia, and acidosis the heart reverts back to utilizing the vessels; R->L shunting, arterial hypoxia- > further increases PVR -> worsening shunting and persistent pulm htn.
Parasymathatic nervous system -> hypotension
Baroreceptors in neonates
baroreceptor reflex is poorly developed in neonates = reflex fails to increase the HR in the setting of hypovolemia.
Stroke volume in neonates
static/ doesn’t move
peds and the BBB
immature, allows the passage of drugs that would otherwise not be able to enter the brain -> higher sensitivity to sedative- hypnotics.