Catheter Over Needle (CON) vs Catheter Through Needle (CTN).

This is a randomized clinical trial with the objective of comparing the time of insertion of two types of perineural catheters in shoulder surgery. These devices are thin lines that have to be inserted over a needle or throw a needle, depending of the type of catheter that is used. The hypothesis is: the installation of Contiplex C or catheter over needle (CON) is faster than a normal contiplex catheter or Catheter throw needle (CTN) at same rate of effectivity.

In the market, there is currently two types of catheter to perform a continuous nerve block. One is called Contiplex throw needle catheter that is the most used device and other needle available for performing this block called the Contiplex® C Set, which uses a different method called Catheter over Needle (CON). This method involves advancing the catheter immediately along with the needle upon puncture, and once it reaches the target site, the needle inside the catheter is removed, leaving the catheter in its final working position. This eliminates the step of threading the catheter through the needle. Additionally, this technique allows for the visualization of the final catheter site in vivo with a single operator. Considering the differences between both techniques, the hypothesis proposed in this study is that in adult patients undergoing shoulder and proximal humerus surgery requiring anesthetic/analgesic management with inter-scalene catheters, the use of the Catheter over Needle (CON) technique results in shorter installation time and similar effectiveness compared to the conventional technique of catheter insertion through the needle (CTN) with tunnel fixation. The primary objectives will be to compare the block execution times between the CTN and CON techniques, as well as the effectiveness rate of both catheters