OB Flashcards
Neonatal effects of midazolam administration during the third trimester
Floppy baby syndrome: fetal hypotonia, apnea, sedation, trouble suckling
What is the concern with using neostigmine and glycopyrrolate in a pregnant woman?
Neostigmine crosses the placenta more than glycopyrrolate does, resulting in profound fetal bradycardia. (Atropine is ok).
Mainstay of preeclampsia management
BP control with beta blockers or vasodilators and seizure prophylaxis with Mg sulfate
Most common complications of epidural analgesia
Shivering, hypotension, pruritis, inadequate analgesia, nausea/vomiting
Definitive treatment of preeclampsia
Delivery
When does plasma volume begin to increase during pregnancy? When does it peak? What is the peak increase?
Begins first trimester
Peaks at term at about 50%
Expected increase in erythrocyte volume during pregnancy
Why the anemia??
Erythrocyte volume increase: -~25%
Because plasma volume increases more than erythrocyte volume, often see relative anemia
Expected increase in intravascular fluid volume
40%
Estimated increase in cardiac output:
- at end of first trimester
- by third trimester
- during labor
- immediately after delivery
By what mechanism does cardiac output increase? When does it start to decrease back toward baseline? When does it decrease back to pre-labor values? When does it decrease back to pre-pregnancy values?
- at end of first trimester: 35%
- by third trimester: 50%
- during labor: 60-75%
- immediately after delivery: 75-80%
Increased cardiac output is d/t increased HR and stroke volume
CO begins to decrease within hours of delivery. Back to pre-labor values within 48hrs post-partum. Back to pre-pregnancy values within 2 weeks.
Which coag factors increase during pregnancy? Which decrease? What is the effect on PT and PTT?
Increase in concentration of factors 1, 7, 8, 9, 10, and 12
Decrease in concentration of factors 11 and 13 and a tighten in 3
Overall result is hypercoagulable state with decreased PT (by ~20%) and decreased PTT (by ~20%)
Expected platelet change with pregnancy
Decrease by 0-10%
Average EBL vaginal delivery
300-500cc
Average EBL c section
~1 L
Pregnancy effects on SVR, PVR, CVP, PCWP, femoral venous pressure
SVR: decreases PVR: decreases CVP: no change PCWP: no change Femoral venous pressure: increases
Why does BP decrease during pregnancy despite increases in plasma volume and cardiac output?
Decreased SVR
Why doesn’t CVP change with pregnancy given the increase in plasma volume?
Increased venous capacitance
LE drainage is impaired due to Vena cava compression during pregnancy. What collateral veins dilate to aid in drainage of the lower extremities?
Azygous veins, epidural veins, and vertebral veins
Hypotension below 25% of pt baseline for what duration leads to decreased uterine blood flow and progressive fetal acidosis?
10 min
Aortocaval compression—What is it? What are the effects on CO, preload and BP? What are the symptoms? What are the effects on the fetus?
Compression of the aorta and vena cava by the gravid uterus when the partitions is in the supine position.
CO: decreased
Preload: decreased
BP: decreased
Sx: diaphoresis, N/V, mental status changes
Can lead to fetal acidosis d/t decreased uterine and placental blood flow.
Arterial hypotension while supine is rare in the parturient despite aortocaval compression. Why? What effect does regional have on this compensatory response?
Compensatory changes in SVR. Regional anesthesia impairs this compensatory response, for this reason supine positioning should be avoided. L uterine displacement is favored.
Changes in pregnancy: PaO2 APaCO2 pH O2 consumption
Changes in pregnancy: PaO2: normal or slightly increased APaCO2: decreased by 10 mmHg pH: no change or slight alkalosis O2 consumption
