USMLE Step 2 CK Lecture Notes 2019: Obstetrics/Gynecology (Kaplan Test Prep)

OB TRIAD

Paracervical    Block   Effect

Paracervical block is a mode of conduction anesthesia that involves bilateral
transvaginal local anesthetic injection to block Frankenhauser’ ganglion lateral
to the cervix. It is administered in the active phase of labor. Disadvantages
include temporary high levels of local anesthetic in the uterus that may lead to
transitory fetal bradycardia, which is managed conservatively.

Pudendal block is a mode of conduction anesthesia that involves bilateral
transvaginal local anesthetic injection to block the pudendal nerve as it passes by
the ischial spines. It is administered in stage 2 of labor to provide perineal
anesthesia.

Term    pregnancy   in  active  labor

Local   anesthetic  injection   into    cervix

Immediate   fetal   bradycardia