P264 Modified sub-tenon’s block (STB) in anterior segment eye surgery: retrospective analysis of a ropivacaine-dexmedetomidine LA-mixture

<h3></h3> <b>Please confirm that an ethics committee approval has been applied for or granted</b>: Yes: I’m uploading the Ethics Committee Approval as a PDF file with this abstract submission Application for ESRA Abstract Prizes <h3>Background and Aims</h3> Eye surgery is increasingly taking place without anaesthesiologists. Providing safe and cost-effective analgesia, avoiding the risks of traditional sharp-needle blocks is important. This study explores a safe tangential sharp-needle approach for STB, screening for complications and inadequate analgesia through VAS/PROM screening <h3>Methods</h3> In 2023, a representative demographic cohort (&gt;18 y) of consenting ASA 1–2 patients (n=907) (median-age 75.5 y) scheduled for anterior chamber eye surgery (refractive, glaucoma and iris surgery) received STB-injection of 1–1.5 ml ropivacaine 2% containing 50 μg dexmedetomidine. STB injected at 8 mm lateral limbus, lateral M rectus inf. insertion (see figure 1) <h3>Results</h3> - STB-onset averaged 4 min, -STB-duration &gt; 3 h, - small sub-conjunctival hemorrhage 42%, - conjunctival chemosis 19.4% -18% of the patients demanded additional analgesia iv (2 γ/kg fentanyl + 1 mg midazolam), reporting VAS scores &gt;/= 3 during surgery <h3>Conclusions</h3> Anterior sharp-needle STB is a valid alternative to blunt-cannula post-aequator STB or epi-caruncular sharp-needle STB in anterior segment eye surgery. 82% of the 907 patients were able to undergo interventions on lens, capsula, cornea, iris and trabeculae without additional systemic analgesia. No grave sharp-needle complications (bulbar perforation, intraorbital bleeding, brainstem anaesthesia, strabism) occurred due to the needle-trajectory running parallel to the scleral surface. Conjunctival hemorrhage and negligible chemosis were comparable to other STB-techniques.