ITE OB 1 Flashcards
______ is a tocolytic that can cause hyperglycemia, tachycardia and hypokalemia
terbutaline
B2 > B1 receptors
- B agonism in liver: glycogenolysis
- B agonism in pancreas: glucagon secretion and suppress insulin release
______ is a contraindicated tocolytic agent in pts w/ myasthenia gravis
Magnesium (competitive antagonist of calcium)
Pudendal block aka “saddle blocks” targets ___ nerve, which originates at ___ level
Pudendal nerve
S2 - S4
- Not useful for first stage of labor
Active stage of labor starts when ______. And ends with _____.
Contractions are regular intervals of 2-3 min
Full cervical dilation (10cm)
Stage two of labor starts with _______.
Full cervical dilation
First stage of labor includes innervation from _____ nerve roots. Pain travels via sympathetic fibers going through the _____ nerve plexus
T10 - L1
inferior hypogastric plexus
The second stage of labor includes innervation from the ____ nerve roots.
T12 - L1, and S2-S4
__________ is the formation of scar tissue in the uterine cavity
asherman syndrome
Two autoantibodies associated with antiphospholipid syndrome are:
- Lupus anticoagulant
2. anticardiolipin antibody
Is it safe to administer neuraxial anesthesia to pts with antiphospholipid syndrome?
Yes, Lupus anticoagulant has no true ac activity
- does not suggest bleeding tendency
Which is elevated in antiphospholipid syndrome, Pt or aPTT?
elevated aPTT
- does not suggest bleeding tendency
________ is a uterotonic agent that is contraindicated in pts with coronary artery spasm and systemic vasoconstriction that increases systemic hypertension
methylergonovine (methergine)
High dose of the uterotonic, _______, stimulates antidiuresis and natriuresis, which can lead to hyponatremia
oxytocin
The cervix is covered by dermatomes _____, and the vaginal/perineal are covered by _____
T10-L1
S2-S4
Why are paracervical blocks not typically tolerated in pregnant pts?
associated with high freq of fetal bradycardia -> decreased fetal oxygenation and fetal acidosis
The 45% increase in maternal blood volume is mediated by ___________
sodium retention via the renin angiotensin system
Treatment choice of polyhydramnios is ______
indomethacin
Sensory block of ____ dermatomes is the goal of neuraxial anesthesia for cesarean delivery.
T4-S4
In an awake pt with no hemorrhage, _____ is the best first line choice for uterine relaxation
nitroglycerin
In an awake pt with hemorrhage, _____ is the best first line choice for uterine relaxation
GA
- Epidural, spinal, vasodil drugs would create vasodilation and promote bleeding
_______ is the pressure transduced in the RA of the heart, and does NOT change with pregnancy
Central venous pressure
The tocolytic, terbutaline MOA ______, and can result in fetal hyperinsulinemia.
B-agonist
- raises moms BG -> cross placenta to fetus (insulin does not), and in response to hyperglycemia -> fetal pancreas secretes more insulin
_________ can be initially treated with B-adrenergic agonists (terbutaline, ritodrine), CCB, COX-inhibitors (NSAIDS), Mg sulfate
Preterm labor
_______ is the drug of choice for pruritus induced by neuraxial opioids
Nalbuphine in 3mg small doses
*intrathecal opioids does not cause histamine release
DIC is associated with elevated (PT/PTT) and if it is seen, it is very likely that a pt has a significant in consumption of clotting factors.
PT
Heparin and LMWH are effective only when adequate lvls of ______ are present
antithrombin III
Glycocopyrrolate is poorly transferred across the placenta b/c it is a ______, which is highly ______ and does not easily cross lipid membranes
quaternary amine
highly hydrophilic
Glycocopyrrolate is poorly transferred across the placenta b/c it is a ______, which is highly ______ and does not easily cross lipid membranes
quaternary amine
highly hydrophilic
*Atropine and scopolamine easily cross
______ is an antidopaminergic medication that enhances motility, accelerated gastric emptying, and increased resting lower esophageal sphincter tone in both nonpregnant and pregnant women
Metoclopramide (reglan)
In pregnant women, gastric secretions are more (acidic/basic)
acidic
In pregnant women, (lower/upper) esophageal sphincter tone is decreased
lower
In pregnant women, overall gastrointestinal time is prolonged (true/false)
true
Ondansetron is a ________, blocking serotonin, both peripherally on the vagal nerve terminals and centrally in the chemoreceptor trigger zone
5-HT3 receptor antagonist
Ranitidine is a ________ of the gastric parietal cells, resulting in decreased gastric acid secretion, decrased gastric volume, and decreased H ion [ ]
competitive inhibitor of histamine at H2-receptors
______ is the only commonly used inhalational anesthetic that does NOT cause uterine relaxation
nitrous oxide (blue)
Colors of tanks Helium Air Oxygen Nitric oxide Nitrogen Carbon Dioxide
Helium - brown Air - yellow Oxygen - green Nitric oxide - blue Nitrogen - black Carbon Dioxide - gray
Cornual pregnancy (rare implantation of fetus in horn/fundus of uterus), predisposes a pt to _____
having a baby in breech position
Factors associated with breech presentation include:
Anything weird with uterus (causing distention) or baby or fluids
- Uterine anomalies
- Cornual-fundal placental
- multiparity
- multiple gestations
- hydramnios and oligohydramnios
- macrosomia
- pelvic tumors
- anencephaly
- hydrocephalus
- preterm gestation
Risk of DVT increases during pregnancy mainly bc of increase circulating lvls of ______
fibrinogen (factor I)
- Almost doubles!
*remember fibrinogen is activated by thrombin to fibrin
Coagulation factors __ and ___ decrease during pregnancy
XI and XIII
Protein S and C degrades/inactivates factors __ and ___, promoting (anticoagulation/thrombosis)
Va and VIIa
anticoagulation
If oxytocin is ineffective in IOL d/t prolonged use, what medication is indicated?
IM Carboprost (hemabate) - a PG
Then Misoprostol (PG) or IM methylergometrine (eergot alkaloid)
1 side effect of carboprost (hemabate)?
brOnchOspasm
1 side effect of IM methylergometrine?
HYpERtension
- esp if given IV
metHYlERgometrine
at high doses, magnesium sulfate can cause _____
complete heart block
std treatment for preeclampsia includes
- bedrest
- antihypertensives (labetalol, hydral)
- mg sulfate gtt
Magnesium sulfate is used in preeclampsia why?
- antiseizure medication to prevent eclampsia
2. antihypertensive - vasodilating
First sx of magnesium toxicity
loss of DTR and generalized weakness
Serum Cr [ ] > __ mg/dL or a BUN > __ mg/dL suggests renal insufficiency in pregnant women
Cr > 0.8 mg/dL
BUN > 13
- production of creatinine is same during preg, but GFR is increased, so Cr should be reduced.
- normal in nonpregnant pts
Placenta accreta, where placenta adheres to implantation site. Treatment is ____
cesarean hysterectomy
Fetal heart rate variability is mediated by (sympathetic/parasympathetic) tone.
Parasympathetic
The primary cause of fetal bradycardia is increased parasympathetic activity via the ____ nerve, in the setting of fetal ____
vagus nerve
hypoxia
GA during pregnancy has the advantages of relaxing uterine smooth muscle -> _________
decreased intrauterine pressure
(True/False) elective C/S are associated with significantly more complications than vaginal delivery
True
*uterine rupture risk goes down though with elective c/s
Spinal block after failed epidural is a risk factor for _____
a high spinal
- you usually bolus the epidural, but volume in the epidural space can displace your spinal meds higher
- Brennan
Bupivacaine is highly protein bound and high pKa of 8.1, which results in (high/low) placental transfer
low
high pKa = more [ionized] drug, which does not easily cross the placenta
Two important determinants of local anesthetic placental transfer
- degree of ionization at physiological pH
- more ionized, less placental transfer - amt of protein binding
- more protein bound, less placental transfer
These drug characteristics _______ maternal to placental transfer
- Ionized
- High protein binding
- Low free drug fraction
- Charged
decrease
These drug characteristics _______ maternal to placental transfer
- Unionized
- Low protein binding
- High free drug fraction
- Uncharged
Increase
“______” refers to fetal drug accumulation d/t pH differences btwn maternal and fetal blood, particular in cases of fetal acidosis
Ion trapping
Since fetal blood pH is less than maternal blood pH, most of the drug will exist in (ionized/nonionized) forms in fetal circulation, and does not readily transfer back across the placenta to the maternal circulation
ionized
Amniotic fluid embolism leads to intense pulmonary vasospasm, and typically involves ______ shock and ______ coagulopathy. WHich can lead to fetal bradycardia and distress.
cardiogenic (RHF), consumptive
Terbutaline (beta 2) and nitroglycerin are used as ___ to help with preterm labor
tocolytics through uterine muscle relaxation
_____ is the most sensitive presenting sx of uterine rupture. Anesthetic management is ____
Fetal distress (bradycardia)
- Emergent ETGA
_____ has been shown to reduce neonatal morbidity and mortality when given to mothers in preterm labor (20-37 weeks)
corticosteroids
- betamethasone or dexamethasone
Hypercalcemia inhibits ___ resulting in sodium and water depletion. Initial treatment is _____
ADH
Normal saline
______ is the hormonally active metabolite of vitamin D
Calcitriol
- can worsen hypercalcemia
Hyperparathyroidism most often manifested by _____, which can lead to preop skeletal muscle weakness and unpredictable response to NMBs
hypercalcemia
