OB

Question 1

Neonatal effects of midazolam administration during the third trimester

Answer 1

Floppy baby syndrome: fetal hypotonia, apnea, sedation, trouble suckling

Question 2

What is the concern with using neostigmine and glycopyrrolate in a pregnant woman?

Answer 2

Neostigmine crosses the placenta more than glycopyrrolate does, resulting in profound fetal bradycardia. (Atropine is ok).

Question 3

Mainstay of preeclampsia management

Answer 3

BP control with beta blockers or vasodilators and seizure prophylaxis with Mg sulfate

Question 4

Most common complications of epidural analgesia

Answer 4

Shivering, hypotension, pruritis, inadequate analgesia, nausea/vomiting

Question 5

Definitive treatment of preeclampsia

Answer 5

Delivery

Question 6

When does plasma volume begin to increase during pregnancy? When does it peak? What is the peak increase?

Answer 6

Begins first trimester

Peaks at term at about 50%

Question 7

Expected increase in erythrocyte volume during pregnancy

Why the anemia??

Answer 7

Erythrocyte volume increase: -~25%

Because plasma volume increases more than erythrocyte volume, often see relative anemia

Question 8

Expected increase in intravascular fluid volume

Answer 8

40%

Question 9

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?

Answer 9

• 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.

Question 10

Which coag factors increase during pregnancy? Which decrease? What is the effect on PT and PTT?

Answer 10

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%)

Question 11

Expected platelet change with pregnancy

Answer 11

Decrease by 0-10%

Question 12

Average EBL vaginal delivery

Answer 12

300-500cc

Question 13

Average EBL c section

Answer 13

~1 L

Question 14

Pregnancy effects on SVR, PVR, CVP, PCWP, femoral venous pressure

Answer 14

SVR: decreases
PVR: decreases
CVP: no change
PCWP: no change
Femoral venous pressure: increases

Question 15

Why does BP decrease during pregnancy despite increases in plasma volume and cardiac output?

Answer 15

Decreased SVR

Question 16

Why doesn’t CVP change with pregnancy given the increase in plasma volume?

Answer 16

Increased venous capacitance

Question 17

LE drainage is impaired due to Vena cava compression during pregnancy. What collateral veins dilate to aid in drainage of the lower extremities?

Answer 17

Azygous veins, epidural veins, and vertebral veins

Question 18

Hypotension below 25% of pt baseline for what duration leads to decreased uterine blood flow and progressive fetal acidosis?

Answer 18

10 min

Question 19

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?

Answer 19

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.

Question 20

Arterial hypotension while supine is rare in the parturient despite aortocaval compression. Why? What effect does regional have on this compensatory response?

Answer 20

Compensatory changes in SVR. Regional anesthesia impairs this compensatory response, for this reason supine positioning should be avoided. L uterine displacement is favored.

Question 21

Changes in pregnancy:
PaO2
APaCO2
pH
O2 consumption

Answer 21

Changes in pregnancy:
PaO2: normal or slightly increased
APaCO2: decreased by 10 mmHg
pH: no change or slight alkalosis
O2 consumption