OB Flashcards
What does magnesium do to blood vessels and catecholamines? why do people even use mag in preggo?
It vasodilates them, and inhibits catecholamine release. It’s used because it is a tocolytic
Less than 0.8 of magnesium?
Arrhythmia, and disorientation if also with hypocalcemia
Magnesium of 1.4-2.1
Normal
Magnesium of 2.1-4.2
Typically asymptomatic
Magnesium of 4.2-5.8
Lethargy, drowsiness, flushing, nausea and vomiting, diminished DTRs
Magnesium of 5.8-10
Somnolence, complete loss of DTRs (10), hypotension and EKG changes
Magnesium of 10-20
Respiratory arrest, AV conduction block, QRS widening, bradycardia
Magnesium of >25
Cardiac arrest
When is excessive magnesium eliminated? How?
Eliminated within 4-8 hours by the kidneys, and can be done via fluid loading followed by diuresis
How exactly does magnesium work?
Acts at NMDA receptor-so an option for pain, acts at nicotine AcH receptor-prolonging non depolarize gets NM blockade, and L type calcium channels causing antagonism
Why are methylergovine and Carboprost contraindicated in HTN and asthma (respectively)?
Methykergovine-ergot derivative that could cause HTN
Carboprost-prostaglandin like effects that can cause bronchospasm
SEs of mwthykergovine and carbaorost
Methyl-cardiogenic pulmonary edema, bradycardia, coronary vasospasm, HTN
Carboprost-nausea, diarrhea, bronchiapasm
How does oxytocin work?
Activated uterine myosin
Placenta accreta, increta, and percreta
Placenta implants with absent decidua-accreta
Increta-invades myometrium
Percreta-invades surrounding structures
Risk factors for accreta-worse one being:
AMA, multiparty, previous myomectomy, Asherman’s syndrome, but number one is precious c section with placenta overlying the scar
Definition of PET:
Elevated BP (even postpartum), with some kind of end organ dysfunction
Can PET happen without fetal development? What Can NOT cross the placenta?
Yes
What are the two most important parts of placental transfer? What does this mean?
Degree of ionization at physiological pH and amount of protein binding. Protein bound drugs have a more difficult time crossing the placenta. And Bupi has a pKa of 8.1, making it ionized at the physiologic pH of 7.4
What’s the difference in the difficult airway algorithm between regular adults and pregnant adults?
If the baby is in Fetal distress, you have to do stuff differently and if that means you have to mask ventilate during the section, then so be it.
Describe late decelerations. What does it mean, and what can cause the meaning?
Deceleration in heart rate at or after the peak of uterine contraction. Associated with uteroplacental insufficiency which is indicative of fetal hypoxia. Maternal hypotension is a cause of fetal hypoxia
What are variable decelerations? What causes them?
They are when the heart rate abruptly decreases-NOT associated with uterine contractions, and they are due to core compression.
Why are early decelerations?
Gradual deceleration in heart rate that is associated with the beginning of uterine contractions. Fetal head compression
Explain the anemia of preggo. Which coach factors decrease and which ones increase? When are pregnant women considered anemic?
Anemia is because RBC mass increases to increase oxygen carrying capacity, but plasma VOLUME increases disproportionately. Pregnant women are anemic when Hgb falls below 11. Factors 8,9, and 10 and fibrinogen are increased while protein S is decreased=hypercoagulable state.
If patient is getting subcutaneous heparin and then wants an epidural, then how long do they have to wait for an epidural? What about if she was getting 7500 to 10000? More than 10000 per dose or 20000 per day?
6 hours for subcutaneous
12 hours fir high dose
24 hours for therapeutic