Department of Anesthesia, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
Anesthesiology. 2011 Jul;115(1):94-101. doi: 10.1097/ALN.0b013e31821a8ad4.
Poor surface anatomic landmarks are highly predictive of technical difficulty in neuraxial blockade. The authors examined the use of ultrasound imaging to reduce this difficulty.
The authors recruited 120 orthopedic patients with one of the following: body mass index more than 35 kg/m² and poorly palpable spinous processes; moderate to severe lumbar scoliosis; or previous lumbar spine surgery. Patients were randomized to receive spinal anesthetic by the conventional surface landmark-guided technique (group LM) or by an ultrasound-guided technique (group US). Patients in group US had a preprocedural ultrasound scan to locate and mark a suitable needle insertion point. The primary outcome was the rate of successful dural puncture on the first needle insertion attempt. Normally distributed data were summarized as mean ± SD and nonnormally distributed data were summarized as median [interquartile range].
The first-attempt success rate was twice as high in group US than in group LM (65% vs. 32%; P < 0.001). There was a twofold difference between groups in the number of needle insertion attempts (group US, 1 [1-2] vs. group LM, 2 [1-4]; P < 0.001) and number of needle passes (group US, 6 [1-10] vs. group LM, 13 [5-21]; P = 0.003). More time was required to establish landmarks in group US (6.7 ± 3.1; group LM, 0.6 ± 0.5 min; P < 0.001), but this was partially offset by a shorter spinal anesthesia performance time (group US, 5.0 ± 4.9 vs. group LM, 7.3 ± 7.6 min; P = 0.038). Similar results were seen in subgroup analyses of patients with body mass index more than 35 kg/m and patients with poorly palpable landmarks.
Preprocedural ultrasound imaging facilitates the performance of spinal anesthesia in the nonobstetric patient population with difficult anatomic landmarks.
体表解剖标志不明显预示着神经轴阻滞技术难度大。作者研究了使用超声成像来降低这种难度。
作者招募了 120 名骨科患者，这些患者具有以下特征之一：体重指数（BMI）大于 35kg/m²，棘突触诊不明显；中重度腰椎侧凸；或有腰椎手术史。患者随机接受传统体表标志引导下的椎管内麻醉（LM 组）或超声引导下的椎管内麻醉（US 组）。US 组患者在术前进行超声扫描，以定位和标记合适的进针点。主要结局是首次进针时硬膜穿破的成功率。正态分布数据用均数±标准差表示，非正态分布数据用中位数（四分位数间距）表示。
US 组首次进针成功率明显高于 LM 组（65% vs. 32%；P<0.001）。US 组的进针次数（1 [1-2] vs. LM 组 2 [1-4]；P<0.001）和进针次数（6 [1-10] vs. LM 组 13 [5-21]；P=0.003）均为 LM 组的两倍。US 组建立体表标志所需时间更长（6.7 ± 3.1 分钟；LM 组 0.6 ± 0.5 分钟；P<0.001），但椎管内麻醉操作时间更短（US 组 5.0 ± 4.9 分钟；LM 组 7.3 ± 7.6 分钟；P=0.038），这部分弥补了建立体表标志所需的时间。在 BMI 大于 35kg/m²的患者和体表标志触诊不明显的患者亚组分析中，也观察到了类似的结果。
术前超声成像有助于在体表解剖标志不明显的非产科患者中进行椎管内麻醉。
