Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, and the Department of Anesthesiology, MetroHealth Medical Center, Cleveland, Ohio.
Obstet Gynecol. 2017 Dec;130(6):1366-1376. doi: 10.1097/AOG.0000000000002326.
To test the hypothesis that increasing the intravenous fluid bolus volume at the time of epidural placement in women with narrow pulse pressure would reduce postepidural fetal heart rate (FHR) abnormalities, hypotension, and resuscitative obstetric interventions.
We performed a single-center randomized controlled trial. Eligible participants were normotensive with a nonanomalous singleton gestation at or after 35 weeks and with a narrow pulse pressure (less than 45 mm Hg) on admission. Enrolled patients remained eligible for randomization at epidural request if they were within 6 hours of admission and the FHR remained category 1. Patients were allocated to a 500-mL (institutional standard) or 1,500-mL intravenous fluid bolus at epidural placement. A reference group with admission pulse pressure 50 mm Hg or greater was also evaluated. The primary outcome was a category 2 or 3 FHR pattern within 60 minutes after the epidural test dose. Evaluated secondary outcomes included maternal hypotension and composite resuscitative interventions to correct FHR abnormalities or hypotension. We calculated that 276 women (138/group) would provide 80% power to detect a relative 50% reduction in the occurrence of the primary outcome from 27% in the 500-mL group to 13.5% in the 1,500-mL group (two-sided α=0.05).
From October 2015 to November 2016, 276 women were allocated to receive a 500-mL (n=139) or 1,500-mL (n=137) fluid bolus. One hundred thirty-eight women were evaluated in the reference group. Demographic, obstetric, and labor characteristics were similar between groups. The 1,500-mL group had significantly fewer postepidural FHR abnormalities (38.0% compared with 51.8%, relative risk 0.73, 95% CI 0.56-0.96, P=.02). Maternal systolic hypotension (10.2% compared with 34.5%, relative risk 0.30, 95% CI 0.17-0.51, P<.001) and composite postepidural interventions (18.3% compared with 44.2%, relative risk 0.42, 95% CI 0.28-0.62, P<.001) were also less frequent in the 1,500-mL group. Fetal heart rate abnormalities remained significantly less frequent in the reference group than among women with a narrow pulse pressure on admission for delivery.
A 1,500-mL intravenous fluid bolus in women with a narrow pulse pressure decreases the risk of postepidural FHR abnormalities (number needed to treat=7), results in less frequent postepidural hypotension, and reduces the need for resuscitative interventions. Admission pulse pressure may be used to individualize intrapartum fluid management at the time of initiation of neuraxial labor analgesia.
ClinicalTrials.gov, NCT02565485.
检验假设，即在脉压较窄的产妇行硬膜外置管时增加静脉输液量，是否能减少硬膜外后胎儿心率（FHR）异常、低血压和复苏性产科干预。
我们进行了一项单中心随机对照试验。入选标准为血压正常、单胎妊娠且无异常，且入院时脉压小于 45mmHg。如果产妇在入院 6 小时内且 FHR 仍为 1 类，仍有资格接受随机分组。产妇如果在硬膜外请求时处于入院时脉压 50mmHg 或更高，则被分配至 500ml（机构标准）或 1500ml 静脉输液。还评估了入院脉压 50mmHg 或更高的参考组。主要结局为硬膜外试验剂量后 60 分钟内出现 2 类或 3 类 FHR 模式。评估的次要结局包括产妇低血压和为纠正 FHR 异常或低血压而进行的综合复苏性干预。我们计算出，276 名女性（每组 138 名）将提供 80%的效力，以检测主要结局的发生率从 500ml 组的 27%降低至 1500ml 组的 13.5%（双侧α=0.05）。
2015 年 10 月至 2016 年 11 月，276 名女性被分配至接受 500ml（n=139）或 1500ml（n=137）的液体冲击。138 名女性被分配至参考组。组间的人口统计学、产科和分娩特征相似。1500ml 组的硬膜外后 FHR 异常明显较少（38.0%与 51.8%，相对风险 0.73，95%CI 0.56-0.96，P=0.02）。产妇收缩压低血压（10.2%与 34.5%，相对风险 0.30，95%CI 0.17-0.51，P<.001）和综合硬膜外后干预（18.3%与 44.2%，相对风险 0.42，95%CI 0.28-0.62，P<.001）也较少。参考组的 FHR 异常也明显少于入院时脉压较窄的女性。
在脉压较窄的女性中，1500ml 静脉输液可降低硬膜外后 FHR 异常的风险（治疗需要数=7），导致较少出现硬膜外后低血压，并减少复苏性干预的需要。入院时的脉压可能可用于指导在开始分娩时的椎管内分娩镇痛时的围产期液体管理。
ClinicalTrials.gov，NCT02565485。
