PT - JOURNAL ARTICLE AU - Diwan, Sandeep AU - Gupta, Anju AU - Shivamallappa, Shivprakash AU - Timane, Rasika AU - Pai, Pallavi TI - OP063 Anatomic evaluation to compare the dye spread with ultrasound-guided pericapsular nerve group (PENG) injection with or without an additional suprainguinal fascia iliaca (SIFI) injection in soft embalmed cadavers AID - 10.1136/rapm-2023-ESRA.61 DP - 2023 Sep 01 TA - Regional Anesthesia & Pain Medicine PG - A38--A38 VI - 48 IP - Suppl 1 4099 - http://rapm.bmj.com/content/48/Suppl_1/A38.1.short 4100 - http://rapm.bmj.com/content/48/Suppl_1/A38.1.full SO - Reg Anesth Pain Med2023 Sep 01; 48 AB - Please confirm that an ethics committee approval has been applied for or granted: Yes: I’m uploading the Ethics Committee Approval as a PDF file with this abstract submission Application for ESRA Abstract Prizes: I don’t wish to apply for the ESRA PrizesBackground and Aims Novel interfascial plane blocks like PEricapsular Nerve Group(PENG) and SupraInguinal Fascia Iliaca(SIFI) blocks have shown promise for hip fracture pain but the extent of local anaesthetic spread and the nerves involved is not clear. We compared the nerves stained and flow distribution of the dye injected in the PENG block with and without SIFI block.Methods Twenty-four designated dye injections were performed in eight soft-embalmed elderly cadavers. Using a linear probe, ultrasound-guided PENG block procedure was followed to inject 20ml green ink bilaterally and SIFI block technique was performed to deposit 30ml methylene blue dye on the right side. The cadavers were dissected 24 h later to assess extent of dye spread and nerves stained.Results An extensive spread and a mix of green and blue dyes were seen both above and below the iliacus muscle on right side. The proximal femoral (blue), subcostal and iliohypogastric, accessory Obturator(ON), anterior ON, distal femoral, and femoral cutaneous(green) were stained. On the left side, accessory ON, FCN, the anterior ON and femoral nerves were stained in majority, while subcostal and iliohypogastric nerves were stained in 3/8 cadavers. Main trunk of ON was not stained on either side. (figure 1 and 2)Abstract OP063 Figure 1 Cadaveric dissection findingsAbstract OP063 Figure 2 Dye distribution patternConclusions The study findings indicate that combined PENG + SIFI injections lead to an extensive cranio-caudal and longitudinal spread above and below iliacus muscle involving most nerves innervating hip region. We perceive that to have a superior clinical outcome probably the combination of these two injections would be optimum.