From the *Department of Anesthesia and Surgical Intensive Care, Mansoura University Hospitals, Mansoura, Egypt; and †Department of Obstetrics and Gynecology, Mansoura University Hospitals, Mansoura, Egypt.
Anesth Analg. 2017 Mar;124(3):851-856. doi: 10.1213/ANE.0000000000001325.
Preprocedural ultrasound may improve the efficacy and safety of epidural catheterization, especially in difficult cases. Most studies of ultrasound-assisted epidural catheterization in the obstetric population are dated and nonblinded with inconsistent designs. This double-blind, randomized controlled study aimed to compare the ultrasound-assisted with the conventional palpation techniques for epidural catheterization in parturients undergoing cesarean delivery. We hypothesized that the use of preprocedural ultrasound would increase the success rate of epidural catheterization at the first needle pass.
Eligible subjects were American Society of Anesthesiologists physical status II parturients with full-term singleton pregnancy undergoing elective cesarean delivery using double-interspace combined spinal-epidural anesthesia. Exclusion criteria were age <19 or >40 years, body mass index ≥35 kg/m, women presenting in labor or having any contraindication to neuraxial anesthesia, marked spinal deformity, previous spinal surgery, or impalpable anatomical landmarks. One hundred ten patients were randomly allocated into 2 equal groups (palpation and ultrasound groups). All procedures were performed by a single experienced anesthesiologist. Patients and investigators assessing the outcome data were blinded to group allocation. A systematic spinal ultrasound assessment and a sham procedure were performed in the ultrasound and palpation groups, respectively, before attempting epidural catheterization. The primary outcome was the rate of successful epidural catheterization at the first needle pass. Secondary outcomes were the rate of successful epidural catheterization at the first skin puncture, number of performed needle passes and skin punctures, duration of the epidural procedure, patient satisfaction from the procedure, and complications of the procedure (incidence of unintentional dural and vascular punctures, failed block, unilateral or patchy block, and backache).
Data from 108 patients (55 patients in the palpation group and 53 patients in the ultrasound group) were analyzed. The rate of successful epidural catheterization at the first needle pass was 60% in the palpation group and 58.5% in the ultrasound group (95% confidence interval of the difference in proportions between groups is -18.5% to 21.6%; P > 0.99). There were no significant differences between the 2 groups in the success rate at the first skin puncture, the number of needle passes and skin punctures, or patient satisfaction. The median (range) duration of the epidural procedure was 185 (57-680) seconds in the ultrasound group and 215 (114-720) seconds in the palpation group (P = 0.036 with the Mann-Whitney U test and P = 0.083 with the Student t test with unequal variances). The overall rate of complications of the procedure was low in both groups.
For experienced anesthesiologists, it remains unclear whether preprocedural ultrasound improves the epidural catheterization technique in parturients with palpable anatomical landmarks undergoing cesarean delivery.
在硬膜外导管插入术之前进行超声检查可能会提高其效果和安全性，尤其是在困难的情况下。大多数针对产科人群中超声辅助硬膜外导管插入术的研究都是过时的、非盲法的，设计也不一致。本双盲、随机对照研究旨在比较超声辅助与传统触诊技术在接受剖宫产的产妇中进行硬膜外导管插入术的效果。我们假设在第一次进针时使用术前超声会增加硬膜外导管插入术的成功率。
符合条件的研究对象为美国麻醉医师协会（ASA）身体状况为 II 级、足月单胎妊娠、行双间隙联合脊麻-硬膜外麻醉的产妇。排除标准为年龄<19 岁或>40 岁、体重指数≥35 kg/m、临产或有任何神经轴麻醉禁忌证、明显脊柱畸形、既往脊柱手术或触诊解剖标志不明显的产妇。110 名患者被随机分为 2 组（触诊组和超声组）。所有操作均由一名经验丰富的麻醉医师进行。评估结果数据的患者和研究者均对分组情况不知情。在尝试硬膜外导管插入术之前，超声组和触诊组分别进行了系统的脊柱超声评估和模拟操作。主要结局是第一次进针时硬膜外导管插入术的成功率。次要结局为第一次皮肤穿刺时的成功率、进针和皮肤穿刺次数、硬膜外操作时间、患者对操作的满意度以及操作相关并发症（意外刺破硬脊膜和血管、阻滞失败、单侧或斑片状阻滞、腰痛的发生率）。
108 名患者（触诊组 55 名，超声组 53 名）的数据被纳入分析。触诊组第一次进针时硬膜外导管插入术的成功率为 60%，超声组为 58.5%（两组间差异的 95%置信区间为-18.5%至 21.6%；P>0.99）。两组间第一次皮肤穿刺成功率、进针和皮肤穿刺次数或患者满意度均无显著差异。超声组硬膜外操作的中位数（范围）时间为 185（57-680）秒，触诊组为 215（114-720）秒（Mann-Whitney U 检验 P=0.036，Student t 检验 P=0.083，方差不齐）。两组操作相关并发症的总发生率均较低。
对于经验丰富的麻醉医师来说，在可触及解剖标志的产妇中，术前超声是否能改善硬膜外导管插入术的效果仍不清楚。
