**5. Considerations to be highlighted with respect to the training models on ultrasound-guided vascular access**

Ultrasound-guided vascular access is a tool to decrease the probability of making errors, the risk of complications, and the number of attempts when performing a vascular access [10, 12, 13, 32].

This technique requires a proper training in order to optimize the learning curve which is characteristic of every invasive procedure [17, 18].

Every simulation model, even the most rudimentary and crude, is a useful tool to improve the results of ultrasound-guided vascular access. It will make it possible to minimize the probability of complications and, with respect to the professionals performing this technique, their trust in this technique performance will be increased [11, 14, 24].

The simulation model described by our research team to perform ultrasoundguided vascular access has been used in more than 800 punctures [8, 17, 18]. After testing most of the previously described models, it could be said that the structure provided by this model is closely similar to pediatric patient's muscular and vascular structures, and that it resembles these patients' vessels anatomy, depth, and diameter with respect to the children's weight. This model improves the learning curve to acquire the skill required by this technique when it is performed by doctors trained in vascular access by following the instructions of the classical technique ("blindly" oriented by anatomic references), by doctors not trained in vascular access or by nurses to cannulate peripherally inserted central catheter [14, 24].

This model is inexpensive, easy to prepare and transportable, and it permits the visualization of the vascular structures, the measurement of these structures, the ultrasound-guided cannulation, and the visualization of the needle from the different ultrasound axes. It also permits maneuvering in response to access difficulties, such as needle replacement/reinsertion, and checking the correct cannulation by visualizing the guide inside the vascular structure [8].

In addition, this model reproduces the different depth and diameter ranges of children's vessels. So, taken together with the above, each simulation performed by using this model can be used to develop the skills required to perform ultrasoundguided vascular accesses [19, 20].

*Ultrasound Imaging - Current Topics*
