Lesson 7

Lesson 7

Neuraxial Analgesia in Obstetrics

  • Common Local Anesthetics:

    • Bupivacaine

    • Ropivacaine

    • Lidocaine

    • 2-Chloroprocaine

  • Bupivacaine Concerns:

    • 0.75% bupivacaine is contraindicated via epidural due to IV toxicity risk.

  • Ropivacaine Benefits:

    • Lower CV toxicity risk compared to bupivacaine.

  • Neuraxial Opioids Benefits (when administered alone):

    • No loss of sensation or proprioception.

    • No sympathectomy, maintaining hemodynamic stability.

    • Does not impair maternal ability to push.

    • Meperidine has local anesthetic properties.

  • Side Effects of Neuraxial Opioids:

    • Pruritus (most common)

    • Nausea/Vomiting

    • Sedation

    • Respiratory depression

    • Minimal fetal depression.

  • Downsides of Neuraxial Opioids (when alone):

    • Poor perineal relaxation.

    • Lesser analgesia than local anesthetics.

Dosing Regimens for Labor Analgesia

Local Anesthetics:

  • Spinal Bolus:

    • Bupivacaine: 1.25 - 2.5 mg

    • Ropivacaine: 2-3.5 mg

    • Lidocaine: 1.25 - 2.5 mg

    • Levobupivacaine: 2 - 3.5 mg

  • Epidural Bolus:

    • Bupivacaine: 0.0625 - 0.125%

    • Ropivacaine: 0.08 - 0.2%

    • Lidocaine: 0.0625 - 0.125%

    • Levobupivacaine: 0.05 - 0.125%

  • Epidural Continuous Infusion:

    • Bupivacaine: 0.5 - 1%

    • Ropivacaine: 0.08 - 0.2%

    • Lidocaine: not typically used for continuous infusion due to tachyphylaxis

    • Levobupivacaine: 0.05 - 0.125%

Opioids:

  • Dosing:

    • Fentanyl: 15-25 mcg

    • Sufentanil: 1.5 - 5 mcg

    • Morphine: 125-250 mcg

    • Meperidine: 10 - 20 mg

Adjuncts:

  • Epinephrine:

    • Dose: NA

  • Clonidine:

    • Dose: 25 - 75 mcg

  • Neostigmine:

    • Dose: 75-100 mcg

  • General Notes:

    • Dosing may vary among sources.

    • Lidocaine crosses the placenta more than alternatives and is noted for tachyphylaxis.