Obstetric Analgesia and Anesthesia

 

Visceral pain during labour from the uterus and cervix is transmitted by T10-L1. Somatic pain from pressure on the vagina and perineum is transmitted by the pudendal nerve (S2-S4).

Pain relief should be provided according to the mother's request. Absolute contraindications to regional anesthesia below.

 

option

indications

adverse effects

parenteral opioids

regional anesthesia not desired or contraindicated

limited effectiveness; decreased 5 min APGAR scores

epidural

effective pain control; also cesarean section

pruritus, fever, hypotension, FHR deceleration

spinal

rapid onset pain control; limited duration (20-30 min)

hypotension, postdural puncture headache, transient neurologic symptoms

combined spinal/epidural

rapid, continuous pain control

as above; increased risk bradycardia

local lidocaine, 2-chloroprocaine

pre-epistiotomy; pudendal block

rarely, seizures, hypotension, arrhythmias

general

emergent C-section, some cases fetal abnormality

maternal aspiration, neonatal depression, elevated rates of maternal morbidity

 

Absolute Contraindications to Regional Anesthesia