Hemodynamic Changes Associated with Uterine Contraction under Obstetric Analgesia

Chung, Sung Won; Cheun, Jae Kyu

Abstract

BACKGROUND: Continuous epidural analgesia is the most widely used technique in obstetric analgesia today. Hemodynamic changes during pregnancy were most remarkable during the uterine contractions of the first stage of labor. The aim of this study was to compare the difference in hemodynamics between two groups with and without obstetric analgesia.
METHODS
Twenty healthy parturients were divided into two groups as follows: Group 1; 10 parturients under epidural analgesia, Group 2; 10 parturients without epidural analgesia,and hemodynamic changes were monitored throughout labor. For the purpose of analysis, the course of labor was divided into three categories according to the degree of dilation of the cervix: 4 cm, 4~7 cm and above 7cm. Hemodynamic parameters were obtained during and in-between contractions over the course of labor through transcutaneous impedence cardiography and a noninvasive automatic blood pressure monitor.
RESULTS
Heart rate (HR) in Group 2 were more increased than that in Group 1 during uterine contraction. In Group 1, the end-diastolic volume index (EDVI) and stroke volume index (SVI) at 4 cm dilation and SVI at above 7 cm dilation of the cervix were increased during the contraction. In Group 2, HR increased throughout the first stage of delivery and systolic blood pressure (SBP), EDVI at 4~7 cm and above 7 cm dilation and SVI at above 7 cm dilation were increased during contractions.
CONCLUSIONS
Our study showed more stability in hemodynamic parameters in parturients under epidural analgesia as compared to those without analgesia. From these results, we conclude that continuous epidural analgesia is very safe to the fetus as well as mother since the technique dose not cause significant hemodynamic change during uterine contractions.