Ultrasound Imaging for Regional Anesthesia. a Practical Guide

Description

The use of ultrasound for regional anesthesia is relatively new, however interest in this application is growing rapidly. Ultrasound guided nerve blocks were first described as early as 1978, but it was not until the advent of advanced ultrasound technology in the 1990's that interest in this field grew. Published reports of ultrasound guided regional anesthesia have largely focused on brachial plexus blockade in the interscalene, supraclavicular, infraclavicular and axillary regions. Recent studies examining the efficacy of ultrasound guidance for femoral, sciatic, psoas compartment, celiac plexus and stellate ganglion blocks are promising, while ultrasound visualization of the epidural space can facilitate neuraxial blockade in children, adults and parturients.

This manual describes both the techniques for single shot and continuous nerve blocks of the brachial plexus and lumbosacral plexus, as well as techniques for neuraxial blockade. Each technique is described in an easy step-by-step manner and is accompanied by a list of selected references. The goal of this manual is to impart a greater understanding of ultrasound imaging for regional anesthesia to anesthesia practitioners and pain management clinicians. Conventional peripheral nerve block techniques that are performed without visual guidance are highly dependent on surface anatomical landmarks for localization of the target nerve. It is therefore not surprising that regional anesthetic techniques are associated with a reported failure rate of up to 20% presumably because of incorrect needle and/or local anesthetic placement. Multiple trial-and-error attempts to locate the target nerve can lead to operator frustration, unwarranted patient pain, and time delay in the operating room, especially in patients with difficult anatomical landmarks. Imaging technology such as MRI and CT scan can successfully localize neural structures. However, ultrasound is the most practical imaging tool for regional anesthesia as it is portable, relatively easy to learn, moderately priced, and does not pose any radiation risk. Ultrasound provides real time imaging guidance during a nerve block procedure.

Table of Contents

• Introduction
• Potential Advantages of Ultrasound
• Terminology
• Basic Principles & Physics of Ultrasound Characteristics of Ultrasound
• Generation of Ultrasound
• Generation of an Ultrasound Image
• Ultrasound Tissue Interaction
• Tissue Echogenicity
• Image Resolution
• Color Doppler.
• Image Artifacts
• Ultrasound Equipment
• Transducer Selection
• Optimizing Image Quality
• Preparing the Transducer & a Sterile Field.
• Transducer Handling
• Transducer & Image Orientation.
• Nerve Localization Strategy
• Needle Selection
• Nerve Block Approaches
• Needle Handling & Body Ergonomics.
• Needle Localization Strategy
• Nerve Injection Techniques
• Continuous Catheter Techniques
• Phantom Practice.
• Outcome Data
• The Brachial Plexus
• Interscalene Region.
• Supraclavicular Region
• Infraclavicular Region.
• Axillary Region
• Mid Humeral Region.
• Peripheral Nerves
• The Lumbar Plexus
• Psoas Compartment
• Femoral Nerve
• Saphenous Nerve
• Obturator Nerve
• Lateral Femoral Cutaneous Nerve
• Ilioinguinal & Iliohypogastric Nerves
• The Sacral Plexus & Sciatic Nerve
• Gluteal Region (Labat)
• Subgluteal Region
• Proximal Thigh Region
• Popliteal Region
• Ankle Region.
• The Neuraxial Space (Adult)