Ultrasound-Guided Nerve Blocks: The Real Position of the Needle Should Be Defined

Department of Anesthesiology and Critical Care Medicine, Lapeyronie University Hospital and Montpellier 1 University, Montpellier, France. x-capdevila@chu-montpellier.f.
Anesthesia and analgesia (Impact Factor: 3.47). 05/2012; 114(5):929-30. DOI: 10.1213/ANE.0b013e31823207b9
Source: PubMed
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    ABSTRACT: Currently, the most commonly used techniques to perform peripheral nerve blockade are ultrasound-guided regional anesthesia (UGRA) and nerve stimulation (NS). Since its introduction in the 1990s, the use of ultrasound has gained popularity. In the beginning, it was used together with NS to confirm identification of nerve structures, once the learning curve has reached its end, there is a trend to use UGRA alone. In this article, we discuss the pros and cons of performing RA procedures with NS, UGRA, or a combination of both, which we call stimulated and ultrasound-guided regional anesthesia (SUGRA). Even though the use of SUGRA does not seem to improve the success rate of the nerve blocks, does not shorten the time to perform them, and does not shorten the onset time, it does help to avoid intraneural injection without increasing patient's discomfort. The use of SUGRA with low-intensity current and without a generation of motor response, would allow positioning of the needle tip close to the nerve avoiding intraneural injection and nerve damage.
    No preview · Article · Jul 2012 · Techniques in Regional Anesthesia [amp ] Pain Management
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    ABSTRACT: Data now exist describing the appropriate positioning of the needle tip and pattern of local anaesthetic spread after injection. The recent literature has been analysed in search of studies on the optimal procedure for common approaches centred on block efficacy, performance time, and safety. Large peripheral nerves are surrounded by a gliding layer, the adventitia or paraneurium. Ultrasonically, a circumneural spread corresponds to adventitial extraneural injection. Nerve expansion with fascicular separation matches intraneural injection. Deliberate intraneural injection remains controversial, and is not advisable at the present time. For popliteal sciatic nerve blocks, positioning the needle in the common nerve sheath between the tibial and peroneal components and obtaining a circumneural spread surrounding both divisions predict rapid surgical anaesthesia. Using axillary and infraclavicular approaches, ultrasound-guided perivascular injection aiming at circumferential spread around the artery appears a valuable alternative to individual targeted nerve injections. For single injection interscalene block, an injection into the fascial sheath but far from the plexus proved to be as effective as an injection adjacent to the nerve structures. Fascial plane approaches are appealing alternatives for thin nerves that run between muscles and cannot be regularly visualized with the current resolution of ultrasound systems. The ultrasound appearance of nerves and target injections are better understood. The specific distributions of local anaesthetic spread that predict success are significantly different from one anatomical site to another. It seems advisable to avoid intraneural injection.
    No preview · Article · Jul 2012 · Current opinion in anaesthesiology
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    ABSTRACT: Significant improvements have been made in the quality of ultrasound imaging, and it is now much easier to see nerves. However, the key to safe ultrasound-guided regional anesthesia is to be able to direct the needle to the target. This relies on good needle visibility. We review the recent advances that have been made in this crucial area. Echogenic needles can improve shaft and tip visibility independent of experience level, compensate for suboptimal scanning technique, allow steeper insertion angles, reduce technical difficulty, and increase both confidence and satisfaction by anesthesiologists. An echogenic needle encourages holding the probe in one place on the patient, only advancing the needle when it can be seen, hence reducing the likelihood of quality-compromising behaviors. The poor visibility of nonechogenic needles when inserted at steeper angles commonly causes the observer to underestimate the insertion depth of the needle. Significant differences in echogenicity are found when comparing the currently available needles. Good echogenic needles should increase safety, efficacy, and simplicity, and hopefully further drive the adoption of ultrasound-guided techniques, to the benefit of our patients.
    Full-text · Article · Jul 2012 · Current opinion in anaesthesiology
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