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why should long periods without oral intake be avoided in children with polycythemia?
there is an increase in blood viscosity, and dehydration increases the blood viscosity and increases risk for increased vascular resistance, thromboses.

IV hydration is required if PO is withheld
what increases more PVR/SVR with increasing hematocrit d/t dehydration with polycythemia?
PVR increaes and will decrease pulmonary blood flow, making cyanosis worse
occurence of coagulopathies with cyanotic CHD?
coagulopathies are common
what Hct impairs microvascular perfusion?
>65%
definition of dependent shunts?
size and direction of shunting through abnormal cardiac communications depends on relationship of PVR and SVR

these types of shunts are variable
why are dependent shunts variable?
because they are based on relationship of PVR and SVR, which determine the size and direction of shunting
what are 4 examples of dependent shunt?
1. PDA
2. ASD/VSD
3. aortopulmonary windows
4. systemic-to-pulmonary shunt, ie blalock-taussig shunt
definition of obligatory shunt?
shunts that are relatively independent of SVR and PVR

resistance is fixed, and blood flow occurs between structures having pressure differences
3 examples of obligatory shunts
1. shunting between LV and RA (atrioventricular canal defect)
2. shunts between systemic arteries and veins in peripheral arteriovenous fistulas
3. shunts that occur with atresia disorders
what type of shunt occurs with tricuspid or mitral atresia?
shunting between atria d/t no atria outlet on side of atresia
example of a dependent and obligatory shunt occuring simulatenously?
PDA with aortic atresia

systemic blood flow occurs as a result of blood from pulmonic artery to aorta (PDA) and increase systemic blood flow d/t aortic atresia
with L->R dependent shunt what occurs with high SVR and low PVR?
there is an increase in shunt from L->R
with R -> L dependent shunt what occurs with low SVR and high PVR?
there is an increase in shunt from R -> L
what happends with bidirectional shunts when there is a change in vascular resistance?
there is an increase in shunt away from side with elevated vascular resistance
what type of shunt is more problematic, L to R OR R to L? y?
Right to left is more problematic because unoxygenated blood is reentering circulation
when is L to R shunt problematic? what defects
when there is a substantial "steal" of systemic blood flow by pulmonary circulation

i.e. AV canal, truncus arteriosus, and HLHS
why are coagulopathies more frequent in children with CHD?
because there is impaired hepatic synthesis d/t impaired perfusion

Vitamin K dependent factors are not synthesized (II,VII, IX, X)
where should pulse oximeters be placed in children with PDA?
one on right arm (preductal) and one on left leg (postductal)
do pulse oximeters over/underestimate arterial oxygen saturation?
overestimate
where should pulse oximeter and NIBP cuff be placed on child with coarciation of aorta?
Pulse oximeter on right hand, to best estimate

NIBP- 2 placed on upper right limb and lower limb, to monitor difference in BP d/t obstruction of flow
what is the best measurement of PaCO2 in child with cyanotic-shunting cardiac lesion?
ABG, d/t V/Q mismatch altering ETCO2 measurement
what should be monitored if neonate is receiving significant PRBC?
monitor ionized calcium d/t inability of liver to metabolize citrate.

neonate with CHD tolerates ionized hypocalcemia poorly d/t decrease in myocardial contractility
how do the esophagus, tympanic, and rectal sites differ in body temp measurement?
1. esophagus most closely matches brain temp
2. tympanic and rectal overestimate the brain temps
what artery is cannulated easily in infants? small infants?
regular infants- radial artery
small infants- femoral arteries or axillary arteries
what type of chromosomal disorder is associated with radial anomalies? consideration?
Trisomy 21 have radial anamolies, therefore cannulation may be challenging
what artery is avoided for arterial cannulation?
the brachial artery
what can be assumed when monitoring CVP in children with unrestrictive VSD/ASD, or single atria or ventricle?
that CVP is equal to LVEDP
why are the femoral veins the preferred site for venous pressure monitoring in children undergoing surgery for HLHS?
because they are goinging to have the Fontan procedure, and thrombosis of the SVC is devastating
are PACs used in pediatric cardiac surgery? y?
no, because they are difficult to place and may not provide meaningful CO. Central line can provide enough info on filling pressures
does a right to left shunt cause an increase/decrease in time of inhalation induction? which type of agent is effected more
decrease in inhalation induction d/t decrease in pulmonary blood flow

insoluble are effected more than soluble
what is the benefit of using sevoflurane before cross clamping during CPB?
that there is a degree of ischemic preconditioning to the heart, brain and kidneys

4% for 10 minutes
does IV induction increase/decrease with right to left shunt?
Induction time happens faster due to increase recirculation of blood that bypasses lungs
do potent inhalation anesthetics reduce SVR/PVR the most?
they reduce SVR more than PVR
What is a strategy with ventilation that decreases PVR?
100% FiO2 and hyperventilation to a pH of 7.6 or greater
what increases PVR?
PEEP
acidosis
hypothermia
use of 30% or less O2
Do vasoconstrictors increase PVR/SVR the most?
increase SVR more than PVR
what will happen to a R/L shunt and L/R shunt if Phenylephrine is given?
There is a decrease in R/L shunt

There is an increase in L/R shunt
what MAC of Sevo is required to cause bradycardia?
> 1.5 MAC
should Nitrous oxide be used for anesthesia in children with CHD?
No, because it increases risk of enlarging intravascular air emboli. It has potential to increase PVR
what effect does ketamine have on a denervated heart?
negative inotropic effect
what IV anesthetic should be avoided in pt with severe cardiomyopathy?
Ketamine
what happens if propofol is given slowly at induction?
smaller dose is required, although induction time increases

slower infusion results in more stable HD
what anesthetic technique is effective in preterm infant having ligation of PDA?
high-dose fentanyl technique
what type of shunt is an ASD, VSD, PDA, AVSD, AP window?
simple left to right shunt
what pulmonary condition occurs due to L/R shunt?
pulmonary HTN doe to increase blood flow into lungs
when should child with ASD repair be extubated?
in OR or early in ICU
how common is post op pulmonary HTN in ASD repair?
rare
what is the most common congenital defect in children?
VSD
what is the difference between a restrictive and unrestrictive VSD?
If flow through VSD is small it is restrictive

If flow through VSD is large it is unrestrictive
when does pulm HTN occur with VSD?
if L/R shunt was significant preoperatively

if surgery is undertaken late
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