الفهرس 
Nerve supply of upper limbOnly 14 pages are availabe for public view
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Abstract
Summery
Knowledge of anatomy remains the cornerstone of regional anesthesia. Newer imaging modalities have allowed improved characterization of anatomic relationships. For successful nerve blockade in various positions along the brachial plexus and its terminal nerves. Real-time ultrasonography may be particularly useful in characterizing local anatomy, demonstrating nerve positions and detecting anatomic variations that may affect block success or compromise patient safety.
The implementation of ultrasound into clinical anesthesia practice has been undertaken with the goal of advancing patient care through improvements in regional anesthesia effectiveness and reducing morbidity. Although those who are accomplished with the technology have realized these improvements, the introduction of ultrasound for regional anesthesia and vascular access requires a well-considered approach to initial learning. This presentation is directed towards highlighting the concepts for successfully integrating ultrasound into anesthesia practice to ensure that the ultimate goals of improved effectiveness and safety of regional anesthesia remains the focus all over our work .
As this new technology becomes an increasingly important link between patient and clinician, it requires understanding the equipment for its strengths and limitations to avoid compromising our goals of improved patient outcomes and safety.
Access to brchial plexus is commonly approached from an interscalene, supraclavicular, infraclavicular, or axillary location.
The interscalene approach to the brachial plexus requires initial anatomical reference to the clavicle, carotid artery, sternocleidom –astoid muscles, anterior scalene muscles, as well as cricoid cartilage.
The ultrasound approach to the interscalene block is very distinct from classical anatomical or neve-stimulation based techniques: needle introduction does not follow the same ‘perpendicular to skin planes’path as conventionally taught to avoid inadvertent central vascular or neural injection.
the ultrasound –guided approach to the supraclavicular block is significantly different from those typically described for anatomical and nerve –stimulation based approaches. with ultrasound technique, the transducer is oriented longitudinally along the posterior margin of the clavicle, and the needle is introduced superficially with either a lateral to medial or medial to lateral trajectory.
The classical infraclavicular approach has been associated with a minimal risk of pneumothorax and good reliability, but has never been popular after use of ultrasound guidance.
Also axillary block and the ulnar, median, radial and the medial, lateral and posterior cutaneous nerve of forearm have become easier and more safe.
The regional anesthesiologist is at a distinct advantage when the target nerve is surrounded by tissue that has different acoustic impedance.
Doppler technology allows for the identification and quantification of blood flow. The most important application of Doppler technology for the regional anesthesiologist is to confirm the absence of blood flow in anticipated trajectory of the needle, rather than the quantification of the actual velocity or direction of this flow. Doppler information is complicated by the frequent occurrence of artifact generation.
Efficacy of ultrasound-guided regional anesthesia depends critically on image quality of the target organ, the needle, and of the ultrasound (US) devices themselves.
The use of ultrasound also allows successful nerve blockade with lower volumes of local anesthetics.
Ultimately, ultrasound allows the consideration of multiple blocks on the same patient without as much concern for local anesthetic toxicity.
Ultrasound guidance compared with neurostimulation may reduce patient discomfort during axillary blocks compared with neurostimulation. Intra-epineural injections are common during an interscalene blockade, but the incidence of neurological injury remains low.
In the future, as ultrasound continues to be studied and used, even more information will be learned that will advance the field of regional anesthesia and be applicable to peripheral nerve blocks, whether performed with ultrasound guidance or not.