Comparison of Combined Spinal-epidural Analgesia Versus Epidural Analgesia for Pain Management During Labor

Experimental: Combined spinal-epidural analgesia

The combined spinal epidural analgesia technique was used to maintain analgesia for parturients in the combined spinal-epidural analgesia group. First, the investigator injected a dose of 5 ug sufentanil into cerebrospinal fluid. If no adverse effects were observed 10 minutes after the first dose, the parturient then received mixed liquids of 0.075% ropivacaine and 0.2ug/ml sufentanil citrate through a patient-controlled epidural analgesia (PCA) pump, which provided patients themixed solution at 8-10ml/h to optimize their pain relief until the delivery of neonates.

Procedimiento: Combined spinal-epidural analgesia

Combined spinal-epidural analgesia during labor is a labor analgesia technique which reported maybe associate with a shorter labor duration compared to the traditional epidural labor analgesia.

Otro: Epidural analgesia

The epidural analgesia technique was used to maintain analgesia for parturients in the epidural analgesia group, which involved placing a thin catheter through a needle inserted into the epidural space. First, the investigator injected a test dose of 5ml 1% lidocaine through it. If not adverse effects were observed 10 minutes after the test dose, the parturient then received a bolus injection of an initial dose of 8-10 ml mixed liquids of 0.075% ropivacaine and 0.2ug/ml sufentanil citrate. We then connected the catheter with a patient-controlled epidural analgesia (PCA) pump, which provided patients the same mixed solution at 8-10ml/h to optimize their pain relief until the delivery of neonates.

Procedimiento: Epidural analgesia

Epidural analgesia is a well-accepted technique using for pain relief during labor.

Labor duration

Duration of three stages of labor

The mode of delivery

Including spontaneous vaginal delivery, vacuum- and forceps-assisted delivery, cesarean delivery

1 minute and 5 minutes Apgar scores

Neonatal Apgar scores at the first and fifth minute.The score indicates the infant s' conditions, including heart rate, breathing, muscle tone, reflex response, color. Each characteristic is given an individual score; two points for each of the five categories if all is completely well; then all scores are totaled. The score is from 0 to 10.

Visual Analogue Scores(VAS)

VAS is the most common pain scale for quantification. The score is higher, the patient will be more painful. That will indicate if the analgesia is effective. Visual analog scale (VAS) ranging from 0 to 10 (with 10 representing the worst pain imaginable) to measure the degree of pain for participants.

Modified Bromage scores

The modified Bromage score is the most frequently used measure of motor block. In this scale, the intensity of motor block is assessed by the patient's ability to move their lower extremities(0: no motor paralysis; 1: inability to raise extended leg, but able to move knee and foot; 2: inability to raise extended leg and to move knee, but able to move foot; 3: inability to raise extended leg or to move knee and foot).