Ford Simon, Dosani Maryam, Robinson Ashley J, Campbell G Claire, Ansermino J Mark, Lim Joanne, Lauder Gillian R
Department of Anesthesia, Morriston Hospital, Swansea, Wales, United Kingdom.
Anesth Analg. 2009 Dec;109(6):1793-8. doi: 10.1213/ANE.0b013e3181bce5a5.
The ilioinguinal (II)/iliohypogastric (IH) nerve block is a safe, frequently used block that has been improved in efficacy and safety by the use of ultrasound guidance. We assessed the frequency with which pediatric anesthesiologists with limited experience with ultrasound-guided regional anesthesia could correctly identify anatomical structures within the inguinal region. Our primary outcome was to compare the frequency of correct identification of the transversus abdominis (TA) muscle with the frequency of correct identification of the II/IH nerves. We used 2 ultrasound machines with different capabilities to assess a potential equipment effect on success of structure identification and time taken for structure identification.
Seven pediatric anesthesiologists with <6 mo experience with ultrasound-guided regional anesthesia performed a total of 127 scans of the II region in anesthetized children. The muscle planes and the II and IH nerves were identified and labeled. The ultrasound images were reviewed by a blinded expert to mark accuracy of structure identification and time taken for identification. Two ultrasound machines (Sonosite C180plus and Micromaxx, both from Sonosite, Bothell, WA) were used.
There was no difference in the frequency of correct identification of the TA muscle compared with the II/IH nerves (chi(2) test, TA versus II, P = 0.45; TA versus IH, P = 0.50). Ultrasound machine selection did show a nonsignificant trend in improving correct II/IH nerve identification (II nerve chi(2) test, P = 0.02; IH nerve chi(2) test, P = 0.04; Bonferroni corrected significance 0.17) but not for the muscle planes (chi(2) test, P = 0.83) or time taken (1-way analysis of variance, P = 0.07). A curve of improving accuracy with number of scans was plotted, with reliability of TA recognition occurring after 14-15 scans and II/IH identification after 18 scans.
We have demonstrated that although there is no difference in the overall accuracy of muscle plane versus II/IH nerve identification, the muscle planes are reliably identified after fewer scans of the inguinal region. We suggest that a reliable end point for the inexperienced practitioner of ultrasound-guided II/IH nerve block may be the TA/internal oblique plane where the nerves are reported to be found in 100% of cases.
髂腹股沟（II）/髂腹下（IH）神经阻滞是一种安全且常用的阻滞方法，超声引导的应用提高了其有效性和安全性。我们评估了在超声引导区域麻醉方面经验有限的儿科麻醉医生正确识别腹股沟区域内解剖结构的频率。我们的主要结果是比较腹横肌（TA）识别正确的频率与II/IH神经识别正确的频率。我们使用了两台功能不同的超声机器，以评估设备对结构识别成功率和结构识别所需时间的潜在影响。
7名在超声引导区域麻醉方面经验不足6个月的儿科麻醉医生，对麻醉儿童的II区进行了总共127次扫描。识别并标记肌肉平面以及II和IH神经。由一位不知情的专家对超声图像进行审查，以标记结构识别的准确性和识别所需时间。使用了两台超声机器（均为来自华盛顿州博塞尔的索诺声公司的Sonosite C180plus和Micromaxx）。
TA肌肉识别正确的频率与II/IH神经识别正确的频率相比无差异（卡方检验，TA与II比较，P = 0.45；TA与IH比较，P = 0.50）。超声机器的选择在提高II/IH神经识别正确方面确实显示出一种无显著意义的趋势（II神经卡方检验，P = 0.02；IH神经卡方检验，P = 0.04；经Bonferroni校正后的显著性为0.17），但对肌肉平面（卡方检验，P = 0.83）或所需时间（单因素方差分析，P = 0.07）无此趋势。绘制了随着扫描次数增加准确性提高的曲线，TA识别的可靠性在14 - 15次扫描后出现，II/IH识别的可靠性在18次扫描后出现。
我们已经证明，尽管肌肉平面识别与II/IH神经识别的总体准确性没有差异，但在对腹股沟区域进行较少次数的扫描后就能可靠地识别肌肉平面。我们建议，对于超声引导II/IH神经阻滞经验不足的从业者来说，一个可靠的终点可能是TA/腹内斜肌平面，据报道在100%的病例中神经位于此平面。
