Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Excellence in Osteology Research and Training Center (ORTC), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Reg Anesth Pain Med. 2021 Sep;46(9):757-762. doi: 10.1136/rapm-2021-102563. Epub 2021 Apr 28.
This cadaveric dose-finding study investigated the minimum effective volume of dye in 90% of cases (MEV90), required to stain the femoral, lateral femoral cutaneous and obturator nerves for ultrasound-guided suprainguinal fascia iliaca block (SIFIB).
In cadaveric specimens of the lower limb, the block needle was advanced, medial to the anterosuperior iliac spine, until its tip was positioned between the internal oblique and iliacus muscles underneath the fascia iliaca. The dye was injected inside the fascia iliaca compartment. Volume assignment was carried out using a biased coin design, whereby the volume of dye administered to each cadaveric specimen depended on the response of the previous one. In case of failure, the next one received a higher volume (defined as the previous volume with an increment of 2.5 mL). If the previous cadaveric specimen had a successful block, the next one was randomized to a lower volume (defined as the previous volume with a decrement of 2.5 mL), with a probability of =0.11, or the same volume, with a probability of 1-=0.89. Success was defined as the staining of the femoral, lateral femoral cutaneous, and obturator nerves on dissection.
Thirty-six cadavers (60 cadaveric specimens) were included in the study. Using isotonic regression and bootstrap CI, the MEV90 for ultrasound-guided SIFIB was estimated to be 62.5 mL (95% CI 60 to 65).
For ultrasound-guided SIFIB, the MEV90 of dye required to stain the femoral, lateral femoral cutaneous and obturator nerves is 62.5 mL. Further studies are required to correlate this finding with the MEV90 of local anesthetic in human subjects.
本尸体剂量发现研究旨在确定在超声引导下股外侧皮神经-股神经阻滞（SIFIB）中，染色股神经、股外侧皮神经和闭孔神经所需的染料最小有效体积（MEV90）。
在下肢尸体标本中，将阻滞针从前上棘内侧进针，直至针尖位于阔筋膜张肌和髂腰肌下方的阔筋膜下间隙。将染料注入阔筋膜下间隙。采用偏倚硬币设计进行容量分配，即每个尸体标本的染料注射量取决于前一个标本的反应。如果前一个标本阻滞失败，则下一个标本注射更高的剂量（定义为前一个剂量增加 2.5ml）。如果前一个尸体标本阻滞成功，则下一个标本随机分配到较低的剂量（定义为前一个剂量减少 2.5ml），概率为=0.11，或者相同的剂量，概率为 1-=0.89。成功定义为解剖时染色股神经、股外侧皮神经和闭孔神经。
本研究纳入了 36 具尸体（60 个尸体标本）。使用等渗回归和 bootstrap CI，超声引导下 SIFIB 的 MEV90 估计为 62.5ml（95%CI 60 至 65）。
对于超声引导下 SIFIB，染色股神经、股外侧皮神经和闭孔神经所需的染料的 MEV90 为 62.5ml。需要进一步的研究来将这一发现与人体局部麻醉剂的 MEV90 相关联。
