OB

Question 1

Why is nausea common after a spinal?

Tx?

Answer 1

Results from hypotension from sympathectomy

Tx: pressors (phenylephrine, ephedrine)
L-lateral tilt of table

Question 2

CNS changes during pregnancy?

Answer 2

• MAC requirements decrease (up to 40%)
• Epidural veins distended from fetus - more risk of intravascular injection
• Operative awareness high during C-sections

Question 3

Respiratory changes during pregnancy?

Answer 3

• Increased MV, Tv, RR
• Decreased PaCO2
• Increase 2,3-DPG –> shifts O2 dissociation curve to R
• Decreased FRC + Increased O2 consumption = rapid desaturation
• Airway edema + friable tissue

Question 4

CV changes during pregnancy?

Answer 4

• Increased plasma volume and RBC mass = dilutional anemia
• CO increased (HR and SV increased)
• Rapid increase in CO after delivery from auto-transfusion from placenta (if lifted above height of patient)

Question 5

GI changes during pregnancy?

Answer 5

• Considered “full stomach” after 20 weeks gestation
  
  • Decreased gastric motility
  • Decreased LES tone
• Increased RBF and GFR

Question 6

Heme changes during pregnancy?

Answer 6

• Hypercoagulable
  
  • Increased fibrinogen, factors 7, 8, 9, 10, 12
• Dilutional anemia

Question 7

What is important to consider before epidural or spinal?

Answer 7

Platelet count

Are they pre-eclamptic?

Question 8

Drugs of choice for hypertensive crisis in pregnancy?

Answer 8

Labetolol
Hydralazine

Also Magnesium for seizure prevention (monitor for hyperreflexia)

Question 9

Agents to help induce uterine contraction post-delivery?

Answer 9

Oxytocin
Methergine
Hemabate

Question 10

What agent is contraindicated with maternal HTN?

maternal asthma?

Answer 10

Maternal HTN: Methergine (constricts vascular smooth muscle)

Maternal asthma: Hemabate (prostaglandin analogue)

Question 11

Labor dermatomes?

Answer 11

1st stage: T10-L1 (visceral - cervical dilation and contractions)

2nd stage: T10-S4 (somatic - pelvic/perineal structures)

Question 12

IV vs Epidural vs Intrathecal doses for morphine, hydromorphone, fentanyl?

Answer 12

Morphine: 10mg IV = 1mg epidural = 0.1 mg intrathecal
*1/10 dilutions

Hydromorphone: 1mg IV = 0.2mg epidural = 0.04mg intrathecal
*1/5 dilutions

Fentanyl: 100mcg IV = 33mcg epidural = 10mcg intrathecal
*1/3 dilutions