PT  - JOURNAL ARTICLE
AU  - Perada Kantakam
AU  - Naraporn Maikong
AU  - Apichat Sinthubua
AU  - Pasuk Mahakkanukrauh
AU  - De Q Tran
AU  - Prangmalee Leurcharusmee
TI  - Cadaveric investigation of the minimum effective volume for ultrasound-guided suprainguinal fascia iliaca block
AID  - 10.1136/rapm-2021-102563
DP  - 2021 Mar 24
TA  - Regional Anesthesia & Pain Medicine
PG  - rapm-2021-102563
4099  - http://rapm.bmj.com/content/early/2021/03/24/rapm-2021-102563.short
4100  - http://rapm.bmj.com/content/early/2021/03/24/rapm-2021-102563.full
AB  - Background 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).Methods 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 b=0.11, or the same volume, with a probability of 1–b=0.89. Success was defined as the staining of the femoral, lateral femoral cutaneous, and obturator nerves on dissection.Results 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).Conclusion 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.All data relevant to the study are included in the article.