Labor Anesthesia & Analgesia pt2

Question 1

Preeclampsia and hypertension prevent the use of this drug.

Answer 1

Ketamine: causes increases in HR and BP

Question 2

What is the obstetric dose of ketamine?

Answer 2

0.2 - 0.5 mg/kg

Question 3

What is the IV onset & duration of ketamine?

Answer 3

Onset: 30 seconds
Duration: 5-10 min

Question 4

What is the IM onset & duration of ketamine?

Answer 4

Onset: 6 min
Duration: 10 - 20 min

Question 5

What is the ketamine infusion loading dose and rate?

Answer 5

Loading: 0.2 mg/kg (over 30 min)
Infusion: 0.2 mg/kg/hr

Question 6

What are the neonatal consequences of benzodiazepines?

Answer 6

Cross placenta easily

• Neonatal respiratory depression
• Neonatal hypotonicity
• Neonatal impaired thermoregulation

Question 7

What is the IM dose of meperidine?

Answer 7

50 - 100mg IM q4hours

Question 8

What is the IV dose of Meperidine?

Answer 8

25 mg IV q2-4 hours

Question 9

What is the weight based dose of IV morphine?

Answer 9

0.05 - 0.1 mg/kg IV

Question 10

What is the weight based dosing of IM morphine?

Answer 10

0.1 - 0.2 mg/kg IM

Question 11

What is the active metabolite of morphine than can accumulate in the neonate?

Answer 11

Morphine-6-glucuronide: can accumulate and lead to respiratory depression

Question 12

What is the PCA dosing of remifentanil?

Answer 12

20 - 40mcg (lockout of 2-3 min)

Question 13

What is the IV/IM dose of butorphanol (stadol)?

Answer 13

1-2mg IV/IM q3-4 hours

half life 4.6 hours

Question 14

What is the dose of nalbuphine (nubain)?

Answer 14

5 - 20 mg IV/IM/SQ

half life 5 hours

Question 15

What opioid can result in significant fetal bradycardia?

Answer 15

Nalbuphine (nubain)

Question 16

Why is toradol typically not used in labor?

Answer 16

• Suppresses uterine contractions
• Premature constriction of DA
• Inhibits PLT aggregation => bleeding

Question 17

What nerve block is typically provided by the OBGYN during the 1st stage of labor to provide short term pain relief with cervical dilation?

Answer 17

Paracervical Block

Question 18

What are the two fetal complications that can occur with paracervical block?

Answer 18

• Fetal LAST (more severe)
• Fetal Bradycardia (more common)

risk of injection into fetal scalp

Question 19

What nerve block is an alternative to pharmacologic pain management in the 2ⁿᵈ stage of labor?

Answer 19

Pudendal nerve block

Question 20

What form of anesthesia completely covers both 1st and 2ⁿᵈ stage of labor?

Answer 20

Neuraxial techniques

Question 21

Epidural veins are decompressed in what position?

Answer 21

Lateral lying

Harder to place.

Question 22

Why is there an increased risk for cephalad spread of neuraxial LA in pregnant patients?

Answer 22

Due to apex of thoracic curvature shifting from T8 to T6.

Also from epidural vein engorgement.

Question 23

What are absolute contraindications to neuraxial anesthesia?

Answer 23

• Refusal
• Uncooperative patient
• Uncontrolled hemorrhage w/ ↓volume
• Epidural site infection
• Bleeding issues/disorder
• Anticoagulated

Question 24

What are the risks associated with epidural placement that is too early in labor?

Answer 24

• ↑ risk for instrumented delivery
• Prolonged 2ⁿᵈ stage of labor
• Risk of ineffective epidural and need for replacement

Question 25

Does meperidine cross the placenta?

Answer 25

lipid soluble - crosses placenta readily

Question 26

What metabolite issues may arise with meperidine administration

Answer 26

Normeperidine active metabolite: can cause seizures

Question 27

What is notable about the lipid solubility of morphine?

Answer 27

hydrophilic, slower onset

Question 28

What is the obstetric infusion dose of fentanyl?

Answer 28

50-100mcg/hr

Question 29

What is notable of the lipid solubility of fentanyl?

Answer 29

Lipophilic, crosses placenta readily, but works quickly

Question 30

Remifentanil is metabolized by?

Answer 30

plasma esterases, and is ultra short acting

Question 31

What are the primary downsides of a pudendal nerve block?

Answer 31

* minimizes urge to push * risk for LAST (injection into pudendal artery) * risk for fetal injection

Question 32

What preanesthetic checks should be made prior to neuraxial anesthesia?

Answer 32

* NPO status * informed consent * IV access * Intralipids and vasopressors/emergency meds * Labs (plt)

Question 33

Studies have typically shown which to be better: coloading or preloading with fluids prior to neuraxial anesthesia?

Answer 33

Co-loading with fluids

Question 34

Blood pressure monitoring should be adjusted to what with the administration of neuraxial anesthesia?

Answer 34

* cycle 1-5 minutes during intial stage of dosing * change to 15 minutes after initial 20-30 min *EKG typically not required*

Question 35

What are risks associated with epidural placement that is too late?

Answer 35

* Pt no longer able to get in good position * pt no longer able to sit still *somewhat uncooperative*