The effects of longacting paracervical block anesthesia on the abortifacient efficacy of intra-amniotic PGF2alpha and hypertonic saline

Abstract

A comparative study was conducted to evaluate the effects of repeated, longacting paracervical blocks on the abortifacient efficacy of intraamniotic prostaglandin F2alpha (PGF2alpha)-40 mg initially and an additional 20 mg after 24 hours--and hypertonic saline augmented with intravenous oxytocin, for patients at 16 to 20 weeks' gestation. Patients were randomly assigned to the 2 abortion procedures, and one half (50) of the patients induced with each procedure received serial, longacting paracervical blocks. For those patients aborted with saline, the rates of complications, side effects, incomplete abortion, and cumulative abortion were similar for patients whether they did or did not receive paracervical blocks. Among the PGF2alpha-treated patients who were administered paracervical blocks, there was a significant reduction in the rates of gastrointestinal side effects and incomplete abortion and a significant differences in the cumulative abortion rates. Within 32 hours of the initial PGF2alpha, instillation, 98% of the patients who received paracervical blocks aborted compared to 70% of those who did not receive paracervical blocks. Although the cumulative abortion rates of PGF2alpha-treated patients with paracervical blocks and saline-treated patients were similar, the rate of incomplete abortion for the PGF2alpha-treated patients was significantly lower. Additional studies will be necessary to evaluate the safety and advantages of using paracervical block anesthesia as an adjunct to midtrimester abortion procedures.

PIP: 200 women pregnant for 16-20 weeks were aborted either 1) by 40 mg prostaglandin F2a (PGF2a) with an additional 20 mg at 24 hours if necessary, or 2) by saline plus oxytocin; 1/2 of the patients in each group were given a paracervical block (PCB) of lidocaine with epinephrine. Side effects were lower (p .1) in the PGF2a patients receiving the PCB than in those who did not. Also, abortion under PGF2a plus PCB was complete (without retained placenta) more often than under PGF2a alone. Regardless of PCB use, the instillation-to-labor interval was lower in the PGF2a group than in the saline group, (p .1). PCB was not found to improve the efficacy of the saline abortions in any respect. It is suggested that the PCB may act by enhancing cervical compliance.