Methods
Study Design and Population
In this retrospective, single-center case-control analysis, a total of 360 cases of voluntary acceptance of painless childbirth pregnant from October 2017 to August 2018 in the Beijing Obstetrics and Gynecology Hospital were selected in this study retrospectively. The inclusion criteria were: (1) primiparous women; (2) at first full-term pregnancy, singleton pregnancies; and (3) cephalic, and had no spinal deformity. Exclusion criteria were: (1) pregnant women who had contraindication to epidural anesthesia; (2) pregnant women who had signs of fetal distress; (3) pregant women with contraindications for vaginal delivery. The subjects were divided into observation group and control group according to anesthetic method (n = 180 in each group, control: case were 1:1). For the observation group, combined spinal-epidural anesthesia (CSEA group) was used. Cases in control group received continuous epidural anesthesia (CEA group). Ropivacaine combined with sufentanil were used in all subjects. All subjects were American Society of Anesthesiologists (ASA) physical status class I or II. One hundred forty-two subjects in CSEA group and 133 subjects in CEA group were class I and 18 subjects in CSEA group and 27 subjects in CEA group were class II.
Anesthetic Method
After entering the clinical delivery, the routine monitoring was established for all women, including blood pressure (BP), heart rate (HR), pulse oximetry (SpO2) and electrocardiography (ECG). Oxygen therapy by nasal catheter venous access and fetal heart monitoring was given. In terms of labor analgesia, the impact on the patient's circulation and other aspects is very small since the dosage of CSEA injected into the subarachnoid space is only 1/5–1/10 of normal CSEA anesthesia. In addition, CEA and CSEA were performed in patients with normal coagulation function. Therefore, there is no obvious tendency in the selection of indications. Both CEA and CSEA were routinely used in our department and the method was chosen according to the anesthesiologist's personal anesthesia operation habits.
For CEA group, pregnant women were placed in the left lateral position. After successful epidural puncture at L2–3 or L3–4 interspace, 3 mL of 0.5% ropivacaine (Naropin; AstraZeneca Co., Ltd.; 10 ml/100 mg; Registration number: H20140763) were slowly injected. If no occurrence of adverse reactions were observed 10 min later, pre-configured 10 mL of analgesic pump solution were given from the epidural space and epidural analgesia analgesia pump (PCEA) was then connected. The formula of analgesic pump solution was: 10 ml of l% ropivacaine combined with 0.3–0.4 μg/ml sufentanil (Eurocept BV Trapgans 51,244 RL Ankeveen, The Netherlands; 75 μg/1 ml; Batch number: 170553) diluted to 100 ml with 0.9% sterile saline. The analgesic pump parameters were set as follows: continuous background infusion of 5 ml/h, single additional dose (PCA) of 7 ml/time, interval lockout time of 15 min and total amount of 100 ml.
For pregnant women in CSEA group, after successful epidural puncture at L2–3 or L3–4 interspace, a 25-G lumbar puncture needle was inserted through the epidural needle (Xinxiang Camel Medical Devices Co., Ltd.; Batch number: 1310015). After the cerebrospinal fluid was seen 2–3 mg of 0.1% ropivacaine (diluted to 2–3 ml with sterile saline) was then injected into the subarachnoid space. After 3–4 cm of epidural catheter was set to the head side, subjects in both groups were placed in the supine position. Ten minutes later, epidural analgesia analgesia pump (PCEA) was connected after no occurrence of adverse reactions were observed. The formula of analgesic pump solution and analgesic pump parameters were the same as CEA group.
For both groups, the heart rate, blood pressure and fetal heart rate of the pregnant women were closely monitored during the process of analgesia and childbirth. After the uterine cervix was opened, the pump fluid infusion was stopped, and the epidural catheter was pulled out 2 h after delivery.
Observation Indexes
The onset time of analgesia, T1, T2, T3, total labor time and doses of ropivacaine and sufentanil in two groups were recorded. Pain was assessed by visual analog scale (VAS)[10] scores at four time points: (1) T0, stage before analgesia; (2) T1, from the beginning of uterine contractions to cervical dilatation of 10 cm; (3) T2, from cervical dilatation of 10 cm to the delivery of the baby; (4) T3, From the delivery of the baby to the delivery of the placenta. The T0, T1, T2 and T3 in this study were defined according to the guidelines from the National Institute for Health and Clinical Excellence.[11]
The Apgar scores were assessed at 1, 5, and 10 min after birth.[12] Apgar scores of 8–10 points were considered normal for newborns; 4–7 points indicated mild asphyxia; and 0–3 points suggested severe asphyxia.
Maternal satisfaction evaluation were performed based on subjects' feelings during different labor periods on labor analgesia (80–100: very satisfactory; 60–80: general satisfactory; below 60: unsatisfactory).
Finally, the adverse pregnancy outcomes and adverse drug reactions were observed.
Statistical Analysis
All statistical analyses were conducted with SPSS software, version 18.0 (SPSS Inc., Chicago, USA). PP plot (probability-probability plot) indicates the normal distribution of data. Values are presented as mean ± standard deviation (SD) or number (percentage) at appropriate. Quantitative variables (VAS scores, labor time, apgar scores and doses of ropivacaine and sufentanil) were compared by Student's t test and χ2 test was used for categorical variables (adverse pregnancy outcomes and adverse drug reactions). Repeated-measures ANOVA were used for the comparison of different time points within the group. All reported P values are two-sided, and P value of less than 0.05 was considered statistically significant.
BMC Anesthesiol. 2020;20(1) © 2020 BioMed Central, Ltd.
