Comparison Between Two Ultrasound Technologies for Ultrasound-guided Catheter Placement in Regional Anesthesia (eZono)

The use of ultrasound imaging techniques in regional anaesthesia is rapidly becoming an area of increasing interest. It represents one of the largest changes that the field of regional anaesthesia has seen. For the first time, the operator is able to view an image of the target nerve directly, guide the needle under real-time observation, navigate away from sensitive anatomy, and monitor the spread of local anaesthetic (LA).The key to successful regional anaesthesia is deposition of LA accurately around the nerve structures.

In the past, electrical stimulation which relied on surface landmark identification, was used for this. However, landmark techniques have limitations; variations in anatomy and nerve physiology , as well as equipment accuracy have had an effect on success rates and complications.

However, alongside the enthusiasm of ultrasound guidance in regional anaesthesia, there should be a degree of informed scepticism. The widespread use of the various techniques of ultrasound-guided regional blocks without adequate training raises the danger of malpractice and subsequent impaired outcome.

Adequate education in the use of regional block techniques under ultrasound guidance is essential. Recent technical developments have achieved higher ultrasound frequencies and better image resolution, as well as better post-processing and user-friendliness.

The purpose of this study is to determine whether new technical features such as reference images, higher ultrasound frequencies, better image resolution and smaller size and weight of the ultrasound probes may improve outcome (clinical benefits) and may show an increased efficacy and safety. And if the new technology of ultrasound images improves the training quality of trainees and novices in the art of ultrasound-guided blocks.