Exam #3 Cardiac Flashcards
When we are in the uterus, we do not need our lungs. So they are collapsed down, but they still make surfactant.
since we do not use lungs as a fetus, we get oxygenated blood via the placenta.
From the placenta… oxygenated blood flows through the umbilical vein to the fetus.
Once it enters the fetus….it goes to the liver where we have something that is called the DUCTUS VENOSUS.
What does the ductus venosus do?
It shunts the oxygenated blood straight into the inferior vena cava.
Once the blood has been shunted from the ductus venosus into the inferior vena cava…..Where does it go next?
Into the right atrium.
In a fetus, the problem is that we do not need it to go to the lungs….because of the pressure…we have a trap door that opens called the Foramen ovale.
What does the foramen ovale do?
It is literally a hole between the atriums with a little flap. So blood goes from the right atrium into the left atrium and bypasses the lungs.
And because the pressure is stronger coming from the mother…it keeps it open.
After the blood enters the right atrium and travels through the foramen ovale into the left atrium….where does it go next.
It goes through the mitral valve into the left ventricle and out through the aorta.
Most of it goes from the aorta to the brain.
This is where most of it is shunted
Even though fetal circulation bi-passes the lungs….there is still a little bit of leakage through the tricuspid valve into the right ventricle…into the lungs.
Even though the fetus does not use the lungs….they still need a little bit of blood in order to make surfactant.
Most of the blood needed is given to the brain due to its rapid growth.
This is done though a shunt called the ductus arteriosis.
What does the ductus arteriosus do?
The ductus arteriosus takes most of mommas blood that did
NOT
Go through the foramen ovale and shunts it over to the pulmonary vein…to the left atrium….and left ventricle and out to the brain.
When the fetus is done getting the oxygenated blood from momma, how is the blood returned to the fetus to be reoxygenated?
Through the umbilical arteries.
Name the 2 shunting systems that deliver oxygenated blood to the fetus….
Ductus Venosus
Ductus Arteriosus
Which one shunts blood into the pulmonary veins?
Ductus Venosus
Ductus Arteriosus
Ductus Arteriosus
Which one shunts blood into the inferior vena cava?
Ductus Venosus
Ductus Arteriosus
Ductus Venosus
Which one carries oxygenated blood to the fetus?
Umbilical artery
Umbilical vein
Umbilical vein
Which one carries unoxygenated blood away from the the fetus?
Umbilical artery
Umbilical vein
Umbilical artery
Name the 5 fetal circulation structures.
Umbilical vein, umbilical arteries Foramen ovale Ductus arteriosus Ductus venosus
Fetal Circulation through the heart….
Placenta umbilical vein liver, ductus venosus inferior vena cava right atrium foramen ovale left atrium mitral valve left ventricle aorta brain back through umbilical artery return to the placenta
leak through tricuspid right ventricle ductus arterosus pulmonary vein left atrium mitral valve left ventricle aorta brain back through umbilical artery return to the placenta
When you are born you come out of the vagina…..you take your first breath of life….it is about 40-60 sonometers of pressure that expands the lungs.
When you expand the lungs for the first time….you have changed the whole system.
Meanwhile, when the cord is cut, the pressure of the whole system changes.
The body now has a higher pressure in the lungs, and the placenta is gone.
So the foramen ovale closes.
Why does the foramen ovale close shortly after birth?
because we have more pressure from the lungs expanding for the first time.
Now the blood travels through the heart like it is supposed to.
Change Happens in about 1 min.
A fetus is used to getting ___% oxygen from the mother
18
Once the cord is cut and the baby is breathing on their own…What percent of oxygen are they now getting?
21%
So when we look at congenital heart problems, we are looking at something that has gone wrong with the setup of ____ ______.
Fetal Circulation
Most babies will do just fine with a congenital heart condition as long as the fetus is in the uterus getting all of their oxygen from the placenta.
True or false
True
When you put them in their own world, that is when any defects in their heart start showing up.
Congenital defects are classified by what?
Increased blood flow to the lungs and decreased blood flow to the lungs.
After the baby is born, and the cord is cut….
What stimulates the ductus arteriosus to close?
The ductus arteriosus will close slowly ( it constricts) in reaction to the fact that the baby is breathing 21% oxygen.
Also closes in response to a decrease in prostaglandins.
So if we have a good healthy baby (that has not been recusitated), the ductus arteriosus closes and we may hear a _____ in the first 1 - 2 hours of life.
Murmur
Because it closes slowly
If we have a sick baby, especially a preterm baby…..they will not be getting enough oxygen…This means that their _____ _____ will stay open/patent.
ductus arteriosus
It stays open because they baby is not getting enough oxygen and this is what stimulates it to close (along with dropping prostaglandin levels)
If a newborn baby that was fine originally gets sick later on 4-5 hours later….will their ductus arteriosus open again?
yes
because the body thinks that it is without oxygen and back in the uterus
What are the Pediatric Indicators of Cardiac Dysfunction. (6 of them)
Poor feeding
Tachypnea, tachycardia
Failure to thrive, poor weight gain
Activity intolerance
Developmental delays esp. gross motor
Positive family history of cardiac disease
What are we looking for on a cardiac assessment of a child?
History – prenatal and postnatal
Feeding, respiratory
infections, activity
Color Auscultation Pulses Blood pressure – 4 extremity Capillary refill Abdomen
What are the 3 signs that you have an unhealthy baby?
poor feeding
tachycardia
tachypnea
When you see these signs in a baby you have to start going down the list of problems.
Do they have a GI bug?
Do they have any S/s of illness at all?
If a baby has tachycardia but no other signs of illness….what do you do next?
Check temp…
Check o2….make sure oxygenating.
The big signs to look for that something may be wrong…that the baby may have a problem is
poor feeding and poor growth..
You will also see a big delay in gross motor…
Because the baby will use up all of their calories trying to keep their heart beating and they are unable to grow.
and because they are usually short of breath, and working real hard for oxygen anyway because they have poor cardiac output….you will find that they do not have enough effort to be able to develop.
So in cardiac babies….you will see a delay mostly in gross motor….
So they will have good interaction….they will be smiling…they will be normal for personal social….they will be normal for language as long as there are no other defects.
They will also be normal for fine motor because it does not require a whole lot of effort.
What is considered gross motor in a baby…
learning to sit up
learning to pull up
learning to crawl and walk
all of this requires calories and oxygen, along with the ability to not get tired.
This is why gross motor is delayed in cardiac babies
You must always assess the history of a cardiac baby. What are some important things to consider when asking about the history.
Prenatal and Postnatal history
Risk factors for CHD:
2 big ones: Down’s Syndrome and Fetal Alcohol Syndrome. 50% have CHD
Maternal Diabetes
Rubella
When assessing the heart….what do you do first?
YOU LOOK AT THE BABY FIRST
Is he tired
Is he squatting if older child
What is his color
Then listen to the heart
When listening to the heart what are some things to consider?
With a premie, you can set the stethoscope anywhere
For older or bigger babies…. Listen to Aortic, Pulmonic, Tricuspid, and Mitral..
Mitral is where apical pulse is heard.
If a patient has a patent ductus…..you have to listen on the back. This is where it is heard the most.
After you auscultate you palpate pulses.
If on auscultation of the heart you hear a murmur….what are you going to do next?
You immediately go into an assessment
assess the pulses, BP on 4 extremities, chest x ray capillary refill palpate abdomen (enlarged liver/spleen)
(Feel carotid pulses, femoral, radial, and pedal pulses)
The reason is because of coarctation of the aorta that decreases the amount of blood going to the lower part of the body. So BP is greater in the upper part of the body. This is a BIG CLUE FOR COARCTATION OF THE AORTA
Suppose you are assessing pulses on a kid and they have great radial pulses but you cannot feel the femoral or pedal pulses…..What are you going to do next?
get 4 extremity BP
Capillary refill to assess cardiac output
palpate abdomen
Just to let you know about murmurs……
Just because a child has a murmur it does
NOT
Mean they have a congenital heart defect/disease.
If a child has anemia, we will hear a flow murmur until the anemia is corrected
Sometimes a child with a fever can have a murmur and it will go away if the fever goes away. This is called an innocent murmur.
Heart can make flow noises if it is stressed out.
If you hear a murmur…..you put down exactly what you hear….
Do not chart a murmur just because the person in front of you charted a murmur…
Maybe they didn’t hear one…
or maybe it is gone.
After a murmur was heard…We have done:
x-ray / bloodwork
4- extremity BP
Cap refill
Pulses ect…
What do we do now?
Get Echo to try and locate the defect.
Then send to cardiac cath for 2 reasons.
#1 - Diagnosis #2 - Nonsurgical repairs of smaller defects.
Cardiac Catherization potential complications
arrhythmias, ***hemorrhage, vascular damage, vasospasm, thrombus, embolus, infection, catheter perforation
What interventions do you do BEFORE a cardiac cath?
Mark distal pulses before procedure (femoral, pedal)
get baseline vitals
What interventions do you do AFTER a cardiac cath?
Insertion site dressing checked q 15 min. first 2 hr.
Monitor HR and vitals
Monitoring for bleeding
