EP025 Prediction of the nerves depth during limbs’ peripheral nerve blocks in children

<h3></h3> <b>Please confirm that an ethics committee approval has been applied for or granted:</b> Not relevant <h3>Background and Aims</h3> The Peripheral Nerve Blocks (PNB) are becoming a major analgesic technique for the children’s inferior/superior limbs surgery. The objective of this research is to design a formula which will help predict with accuracy the depth of the nerves according to the weight of patients benefitting from PNB. <h3>Methods</h3> This prospective and analytical study includes children that will undergo limbs surgery. The PNB were realized with a guided ultra-sound or a neurostimulation. Additionally, the Distance between the Nerve and the Skin (DNS) was measured in all children under study. The data were analyzed by SPSS ‘20’ as well as Stata software for a linear regression. <h3>Results</h3> 355 patients were included in this study. The average age was 9,29 ± 4,13 years old and the average weight was 34,7 ± 17 kg. The average DNS was 21,97 ± 10,02 mm. The findings also showed an average correlation R2= 0,48 between the DNS and the children’s weight (P &lt; 0,001). This enabled us to elaborate a formula to predict the length of the needle according to: the weight of the child, the detecting technique and the PNB type realized [DNS (DNP) = 4,33 + 5,48 (technique) + 0,23 (weight) + β (Corresponding to the type of block). <h3>Conclusions</h3> DNS measurement can be a good guide for needle placement in order to reduce the risk of nerves complications.