The influence of the bupivacaine epidural anesthesia on the rabbit myometrium contractile activity and the functional state of the fetuses in induced labor

Abstract

The influence of bupivacaine (0.5% - 1 ml) epidural anesthesia (EA) on 15 pregnant rabbit females induced in labor by oxytocin on the 30th day of pregnancy in chronic experiment was conducted. 26 pregnant rabbit females took part in the investigation. 11 females were included in the control group and 15--to the main group. Both groups retrospectively were divided in two on the fact of the delivery during the experiment. For each 5-minute interval the contractile activity of the myometrium (number of uterine contractions, duration and amplitude of the one uterine contraction), functional state of fetuses and female (ECG) were evaluated. Registration of the parameters was carried out simultaneously with the help of electrodes which were administrated in the myometrium, to the fetuses and females on the 28th day of pregnancy. It was shown that EA influence on the myometrium contractile activity and functional state of fetuses and female depends on the female delivery readiness. In the case of the optimal one short-term increase of the contractile activity (on the 15th minute after EA) with no significant fetal heart rate changes were observed. In the case of its absence no significant influence was revealed. Moderate female tachycardia in both groups under EA was registered more pronounced in delivery one group.