Paliatívna medicína a liečba bolesti 2/2012

Peripheral nerve blocks under ultrasound guidance Ultrasound-guided peripheral nerve blocks

USRA – ultrasound guided regional anesthesia is a technique used by the anesthetist and pain physician. This means injecting local anesthetic in the vicinity of a peripheral nerve under ultrasound guidance and creating a temporary conducting block for the purpose of acute and chronic pain management. The use of ultrasound for regional anesthesia is relatively new, but interest in this technique is growing rapidly. Ultrasound guided nerve blocks were first described in 1978. It wasn't until the advent of modern ultrasound technology in the 1990s that interest in USRA increased significantly. Conventional techniques and neurostimulation guided peripheral nerve blocks, which are performed without visual guidance, are highly dependent on surface anatomical landmarks for locating the target nerve. These techniques have a failure rate of up to 20 %. More trial and error during the localisation of the target peripheral nerve can be painful or lead to iatrogenic injury, especially in patients with anatomical variations. Other options, such as MRI and CT scans, can successfully be utilized to visualize the nerve tissue. However, ultrasound imaging is the most practical tool for regional nerve blocks. It is portable, relatively easy to learn, less expensive and possesses no radiation hazard. Ultrasound provides real-time visualisation of the block procedure and has virtually no contraindications comparing to CT or MRI imaging.

Keywords: pain, peripheral nerve block, ultrasound, neurostimulation, cardiotoxicity.