Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland.
Anaesthesia. 2011 Nov;66(11):1023-30. doi: 10.1111/j.1365-2044.2011.06855.x. Epub 2011 Aug 18.
The extent of analgesia provided by transversus abdominis plane blocks depends upon the site of injection and pattern of spread within the plane. There are currently a number of ultrasound-guided approaches in use, including an anterior oblique-subcostal approach, a mid-axillary approach and a more recently proposed posterior approach. We wished to determine whether the site of injection of local anaesthetic into the transversus abdominis plane affects the spread of the local anaesthetic within that plane, by studying the spread of a local anaesthetic and contrast solution in four groups of volunteers. The first group underwent the classical landmark-based transversus abdominis plane block whereby two different volumes of injectate were studied: 0.3 ml.kg(-1) vs 0.6 ml.kg(-1). The second group underwent transversus abdominis plane block using the anterior subcostal approach. The third group underwent transversus abdominis plane block using the mid-axillary approach. The fourth group underwent transversus abdominis plane block using the posterior approach, in which local anaesthetic was deposited close to the antero-lateral border of the quadratus lumborum. All volunteers subsequently underwent magnetic resonance imaging at 1, 2 and 4 h following each block to determine the spread of local anaesthetic over time. The studies demonstrated that the anterior subcostal and mid-axillary ultrasound approaches resulted in a predominantly anterior spread of the contrast solution within the transversus abdominis plane and relatively little posterior spread. There was no spread to the paravertebral space with the anterior subcostal approach. The mid-axillary transversus abdominis plane block gave faint contrast enhancement in the paravertebral space at T12-L2. In contrast, the posterior approaches, using both landmark and ultrasound identifications, resulted in predominantly posterior spread of contrast around the quadratus lumborum to the paravertebral space from T5 to L1 vertebral levels. We concluded that the pattern of spread of local anaesthetic differs depending on the site of injection into the transversus abdominis plane. This may have important implications for the extent of analgesia produced with each approach.
腹横肌平面阻滞的镇痛范围取决于注射部位和在该平面内的扩散模式。目前有多种超声引导的方法在使用，包括前斜肋下途径、腋中线途径和最近提出的后途径。我们希望通过研究 4 组志愿者中局部麻醉剂在腹横肌平面内的注射部位是否会影响该平面内局部麻醉剂的扩散，来确定局部麻醉剂在腹横肌平面内的注射部位是否会影响其扩散。第一组接受经典的基于解剖标志的腹横肌平面阻滞，研究了两种不同体积的注射量：0.3ml/kg 和 0.6ml/kg。第二组采用前肋下途径行腹横肌平面阻滞。第三组采用腋中线途径行腹横肌平面阻滞。第四组采用后途径行腹横肌平面阻滞，在该途径中，将局部麻醉剂沉积在竖脊肌前外侧缘附近。所有志愿者在每个阻滞完成后 1、2 和 4 小时进行磁共振成像，以确定局部麻醉剂随时间的扩散情况。研究表明，前肋下和腋中线超声方法导致对比剂溶液在腹横肌平面内主要向前扩散，而后部扩散相对较少。前肋下途径无向椎旁间隙扩散。腋中线腹横肌平面阻滞在 T12-L2 椎旁间隙有微弱的对比增强。相比之下，使用解剖标志和超声识别的后途径导致对比剂主要在后侧围绕竖脊肌扩散到 T5-L1 椎体水平的椎旁间隙。我们得出结论，局部麻醉剂的扩散模式取决于腹横肌平面内的注射部位。这可能对每种方法产生的镇痛范围有重要影响。
