Comparison of Analgesic Efficacy and Shortening of Labor Duration between L1 2 and L3 4 Epidural Blocks in Nulliparous Normal Vaginal Delivery

Kang, Kyu Sik; Lee, Sang Yoon; Kim, Jung Soon; Nam, Kae Hyun; Park, Wook

Abstract

BACKGROUND: Usually, lumbar epidural block is performed on the L3-4 interspace. This study was designed to evaluate the analgesic efficacy and shortening of labor duration comparing the L1-2 and L3-4 interspace epidural blocks in nulliparous normal vaginal deliveries and then investigates side effects following the blocks.
METHODS
Eighty healthy nulliparous women were divided into two groups, L1-2 (n = 40) and L3-4 (n = 40). Epidural blocks, lumbar epidural block were performed at the L1-2 and L3-4 interspace with a catheter advancing 3 cm cephalad. The initial dose of 12 ml (0.167% bupivacaine, fentanyl 50microgram and clonidine 75microgram) was injected epidurally at 4 cm dilatation of cervix and severe pain of labor. If a visual analogue scale (VAS) score was more than 4 points, an additional dose was administered epidurally using the same volume as the above mentioned, but with the exception that the bupivacaine was diluted to 0.1 percentage. The maternal blood pressure, pulse rate, respiration rate and fetal heart rate were measured at 10 min intervals for the first 30 min, at 15 min interval for the next 30 min and at 30 min interval for the last one hour following the blocks. The duration of the first (active) and second stages of labor was counted and the neonatal Apgar score was recorded at one and five min after delivery. The degree of motor block, pruritus, nausea and vomiting were also noted.
RESULTS
The patients in group L1-2 had lower pain scores than group L3-4 at 5, 20, 30, 60 mins. The duration of 1st and 2nd labor stage in the L3-4 epidural block were 272+/-33.5 min, 49.2+/-27.4 min respectively but those in the L1-2 epidural block were 253.5+/-32.5 min, 37.3+/-22.3 min, respectively.
CONCLUSIONS
We concluded the analgesic efficacy and shortening of labor duration in L1-2 epidural block was better than those in L3 4 epidural block. Maternal hemodynamic change, motor block. pruritus, nausea, vomiting and Apgar score showed no significant differences between the two groups.