Paracervical block with 2-chloroprocaine.

Thirty healthy term gravidas in active labor received a paracervical block (PCB) with the ester-type local anesthetic, 2-chloroprocaine (2CP). Good to excellent pain relief resulted in all but 1 case. The duration of action was short (mean 38.9 min), requiring repeat blocks in 6/30 cases. Fetal heart rate and uterine contractions were electronically monitored, and fetal acid-base status was periodically checked by fetal scalp pH measurements. PCB-related fetal bradycardia was observed in 3 cases, but in only 1 case was PCB the only cause for the bradycardia. Fetal acidosis was not observed. No instance of neonatal depression or acidosis as expressed by the 1- and 5-minute Apgar scores and cord blood acid-base evaluation was observed. No maternal complications were observed. It is concluded that paracervical block using 2CP is an effective though short-acting method of pain relief which, when properly monitored, is safe for both mother and fetus.