Effect of Different Labour Analgesics on Maternal and Fetal Blood Flow Observed by Doppler Ultrasonography

Study intervention At the time of request for labor analgesia, patients were randomized to receive either sufentanil 5 μg (Group S) and ropivacaine 3mg (Group R) into the subarachnoid space. All groups received the standard epidural solution that contained 0.1% ropivacaine with 0.25 μg/ml sufentanil. Routine obstetric and anaesthetic monitoring was given after maternal entered the delivery room. An experienced the anesthesiologist select L3-4 lumbar vertebra clearance to puncture with standard sterile technique using loss of resistance when the puerpera palace has expanded to about 3 cm. After the puncture reached the epidural space, a 25-gauge lumbar anesthesia needle was used to puncture into the subarachnoid space. 2 mL of anesthetic drug as determined by her group randomization were administered into the cavity through the lumbar anesthesia needle after cerebrospinal fluid flow out. A 19-gauge spring-wound catheter was threaded 4-6 cm into the epidural space. All patients received a test dose of 3 ml of 1.5% lidocaine followed by an initial loading dose of 5 ml of the standard epidural solution. Epidural catheters into vessels or subarachnoid space were excluded. An analgesic pump (PCEA pump, 100ml) containing standard epidural solution was then connected to the epidural catheter at a background continuous infusion rate of 5 mL/h. The visual analogue score for pain (VAS) was performed 15 minutes after the injection dose, and if the VAS score fell below 3, the case was included in the study.

An anesthesia provider assessed the adequacy of analgesia for the patients throughout the duration of labor. Any breakthrough pain was managed with a physician-administered epidural bolus. All obstetric analgesia procedures were performed by the same anesthesiologist to reduce errors due to technical reasons.