Week 1 Maternal and Fetal Phy 3 of 4 Flashcards
When talking about circulation in the fetus, most of the oxygenated blood reaching the heart is because of what two veins?
umbilical vein and inferior vena cava.
Most of the oxygenated blood reaching the heart via the umbilical vein and inferior vena cava is diverted through the ? and pumped out the ? to the ?
diverted through the FORAMEN OVALE and pumped out the AORTA to the HEAD.
What four “products” are transferred from fetal circulation to mother circulation?
- CO2
- H2O
- Hormones
- Urea, waste products
“CHHU” like shoo :D
What seven “items” are transferred from mother circulation to fetal circulation?
- O2
- H2O, Electrolytes
- Nutrients
- Hormones
- IgG
- Drugs (alcohol)
- Pathogens (TORCHES*)
When talking about the placental membrane and specifically fetal trophoblast, what layer is outer and what layer is inner?
syncytiotrophoblast is outer
cytotrophoblast (Langhans’ cells) is inner
What are the three layers of the Placental membrane?
- Fetal trophoblast
a. Cytotrophoblast (inner layer); make cells
b. Syncytiotrophoblast (outer invading layer; secrete HCG) - Fetal connective tissue
- Endothelium of the fetal capillaries
What does a home pregnancy test detect?
HCG in urine
In relation to fetal circulation, deoxygenated blood is returned via what vein?
superior vena cava
In relation to fetal circulation, the deoxygenated blood that is returned via the superior vena cava is mostly pumped through which two arteries?
Pulmonary artery and ductus arteriosus
In relation to fetal circulation, the deoxygenated blood when it is pumped through the pulmonary artery and ductus arteriosus where does it then go?
to the feet and the umbilical arteries.
In relation to to fetal circulation, if you are thinking of deoxygenated blood- then what is the final or ultimate destination of this deoxygenated blood?
The feet and the umbilical arteries
Where is most of the oxygenated blood pumped out of ultimately when talking about fetal circulation?
pumped out the aorta (to the head.)
Am I talking about oxygenated or deoxygenated blood in fetal circulation below:
blood returned via the superior vena cava?
deoxygenated
Am I talking about oxygenated or deoxygenated blood in fetal circulation below:
reaching the heart via the umbilical vein and inferior vena cava?
oxygenated
Am I talking about oxygenated or deoxygenated blood in fetal circulation below:
diverted through the foramen ovale?
oxygenated
Am I talking about oxygenated or deoxygenated blood in fetal circulation below:
Pumped out the aorta to the head?
oxygenated
Am I talking about oxygenated or deoxygenated blood in fetal circulation below:
mostly pumped through pulmonary artery and ductus arteriousus?
deoxygenated
Am I talking about oxygenated or deoxygenated blood in fetal circulation below:
to the feet and the umbilical arteries?
deoxygenated
Fetal Circulation:
- Oxygenated blood from placenta enters through what vein?
umbilical vein
Fetal Circulation:
- Most of the blood bypasses fetal liver via ?
ductus venosus
Fetal Circulation:
2.(cont) once blood bypasses the fetal liver via the ductus venosus it mixes with deoxygenated blood in the ?
inferior vena cava
Fetal Circulation:
- WHAT shunts blood from the right atrium (increased pressure) directly into the left atrium (decreased pressure)?
Foramen ovale
Fetal Circulation:
- Blood is shunted away from what fetal structure?
fetal lungs (increased resistance)
Fetal Circulation:
- WHAT connects pulmonary artery directly to aorta?
Ductus arteriosus
Fetal Circulation:
- Deoxygenated blood returns to the placenta via the ?
umbilical arteries
Tell me the pathway of blood through fetal circulation (simple answers, this to this to this to this)
Umbilical vein to ductus venosus to inferior vena cava to right atrium to left atrium (through foramen ovale) to left ventricle to aorta to body
In relation to pathway of blood through fetal circulation, Some blood does not pass to left atrium (through foramen ovale), but enters the right ventricle and pumped into the pulmonary artery. If this occurs where does it go next?
From pulmonary artery blood passes to the aorta through ductus arteriosus bypassing lungs that are rock solid (infinite pulmonary resistance) during fetal life.
(how Mo worded it)
during fetal life why are the lungs hard as a rock?
due to atelactasis and hypoxic vasoconstriction
What does the umbilical arteries (2) do?
return deoxygenated blood from fetal internal iliac arteries to placenta
What does the umbilical vein do?
supplies oxygenated blood from placenta to fetus, drain into IVC via ductus venosus or liver.
What structure is responsible for returning deoxygenated blood from fetal internal iliac arteries to placenta?
The umbilical arteries
How many umbilical arteries and veins is their?
2 umbilical arteries and 1 umbilical vein.
What structure is responsible for supplying oxygenated blood from placenta to fetus?
Umbilical vein
Is the umbilical vein or arteries more saturated with 02?
The umbilical vein is 80% saturated with 02.
Umbilical arteries have LOW 02 saturation.
In relation to fetal circulation what are the three important shunts?
ductus venosus
foramen ovale
ductus arteriosus
Blood entering the fetus through umbilical vein is conducted via the ? into IVC to bypass the liver.
ductus venosus
Most oxygenated blood reaching the heart via the IVC is diverted through ? and pumped out the aorta to head and body.
foramen ovale
Deoxygenated blood from the SVC is expelled into the pulmonary artery and ? to the lower body of the fetus .
ductus arteriosus
explain to me the ductus arteriosus shunt?
Deoxygenated blood from the SVC is expelled into the pulmonary artery and ductus arteriosus to the lower body of the fetus.
explain to me the foramen ovale shunt?
shunts blood from the R atrium into the L atrium
explain to me the dectus venosus shunt?
blood is shunted through the dectus venosus to bypass the liver and go to the IVC.
Tell me what happens at birth when the infant takes a deep breath?
decreased resistance in pulmonary vasculature causes increased left atrial pressure vs. right atrial pressure; formen ovale closes (now called fossa ovalis); increase in O2 leads to decrease in prostaglandins, causing closure of ductus atreriosus.
Do prostaglandins help close or keep open the PDA?
prostaglandins help keep PDA open.
Indomethacin does it help close or keep open the PDA?
Indomethacin helps close PDA.
What is the PACO2 of Fetal blood?
PaCO2 = 48 mmHg
What is the PaO2 of Fetal blood?
and what increment increase if the mother is on 100% 02?
30 mmHg (+10 increase if mother is on 100% O2)
How long does it take the ductus arteriosus to close?
2-3 weeks
How long does it take the foramen ovale to close?
months
In relation to fetal circulation, hypoxia or acidosis in the first few days will ultimately lead to what? (tell me the process for this as well)
pulmonary hypertension
Hypoxia or acidosis in first few days leads to PDA or PFO –> left to right –> pulmonary hypertension
(How MO worded it above)
What is the most serious risk factor associated with surgery during pregnancy .
Uterine asphyxia
Do pregnant ladies have increased gastric emptying time or delayed? How do you treat?
Delayed gastric emptying time.
prophylaxis with antacids.
What can uterine displacement cause in a pregnant lady? (thus you do not want to place them in supine position)
supine hypotension
Do pregnant women have increased or decreased FRC?
decreased FRC, more prone to hypoxia
Do lipid soluble substances diffuse more or less rapidly through the placenta?
more rapidly
During C/S what will you do to prevent Thromboembolism?
prevent DVT with pneumatic compression stockings. (board question)
Most frequent complication of spinal and epidural on pregnant women?
HYPOTENSION
How would you treat hypotension in a pregnant lady who was given a spinal or epidural?
(3 answers)
- perform left uterine displacement
- IV hydration
- Ephedrine
What Beta 2 agonist is given to stop premature contractions?
Albuterol ( what mo mentioned in lecture)
Ritodrine
Side effects for the mom and for the baby due to Ritodrine?
Mom: hypokalemia, hyperglycemia, tachycardia
Fetus: : hypokalemia, hyperglycemia, tachycardia (+/-)
Why would you avoid atropine with ritodrine?
can cause tachycardia leading to pulmonary edema.
Mag sulfate increases the sensitivity to both depolorizing and non depolorizing muscle relaxants, thus will you increase or decrease the dose of muscle relaxant?
decrease the dose of muscle relaxant.
What can lidocaine cause in high doses to the pregnant patient.
in high doses can cause uterine vasoconstriction and increased tone.
What PH of the fetus will cause MORE ion trapping of LA?
the lower the fetal PH the more ion trapping.
All LA that we use in an IV or injected form (not topical) are what PH?
Higher PH, they are bases
What is the issue if the mom has alkalosis and the baby has acidosis?
because LA are bases the mothers alkalosis promotes un-ionized drug (LA) and thus can cross the placenta very easily, but once it crosses the placenta the babies acidosis promotes ion trapping.
Base + acid = ?
base + acid = ionized (can not cross, trapped in fetus)
Base + base = ?
un-ionized (can cross)
Pregnant patients are always considered full stomach True or False?
True, they are high risk for aspiration
What two drugs can you give a full stomach mom?
H2 blockers and metoclopramide
What are two morbidities associated with Mother/Child?
Hemorrhage
Preeclampsia
When trying to give pain management to a pregnant patient, are opioids or regionals preferred and why?
Regional preferred bc opioids cross placental barrier.
Mother/child issues with lumbar epidural?
what will you give to treat?
hypotension, give ephedrine and IV fluids.
Problems with GA and a pregnant patient?
Rapid desaturation, laryngeal spasm/edema, aspiration.
Since you do not want to use GA for pregnant patient if you can help it, what type of anesthesia would you prefer to use for C/S?
spinal epidural anesthesia/ analgesia
Level of the block for a C/S?
T4
What is an adverse effect of regional for Mother/Child? How would you treat this?
hypotension
give phenylephrine with fluid.
