الفهرس 
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Abstract
Summary
Ultrasound-guided nerve block first step is to visualize all the anatomical structures in the target area. All adjustable ultrasound variables, i.e. penetration depth, the frequencies, and the position of the focal zones, must be optimized for the type of block to be performed. Both the skin and the ultrasound probe need to be disinfected. Most conventional disinfectants can be used on ultrasound probes. A sterile ultrasound jelly will provide aseptic conditions for the nerve block (a jelly for urinary catheters can also be used). Alternatively, the probe can also be wrapped in a sterile glove.
The next step is to perform subcutaneous infiltration in order to render the procedure painless. Needle usually used is 22-gauge 40–80 mm needles with a facette tip. Depending on the type of nerve block, the puncture will be performed 5–10 mm distal or proximal to the probe with ultrasound imaging in the transverse plane. The identification of the needle is only possible when the needle crosses the ultrasonographic level of the probe. The needle itself is identified as a hypoechoic structure and a dorsal acoustic shadow is generated by the needle.
The equipments needed for ultrasound guided nerve block are ultrasound system, ultrasound transducer, 13-6 MHz linear array with variable resolution settings, Stimulating needles, ultrasound gel (sterile and non-sterile), Sterile transducer cover and nerve block kit containing sterile drape, skin wheal needles, extension tubing, and syringes of choice.
Advantages of Ultrasound are revealing the nerve location and the surrounding vascular, muscular, bony, and visceral structures, providing
real-time imaging guidance during needle advancement allowing for purposeful needle movement and proper adjustments in direction and depth, Imaging the local anaesthetic spread pattern during injection. improving the quality of sensory block, the onset time, and the success rate compared to nerve stimulator techniques (as shown in some clinical studies), reduces the number of needle attempts for nerve localization which may prove to reduce the risk of nerve injury, differentiating extra vascular injection from unintentional intravascular injection and differentiating extraneural injection from unintentional intraneural Injection.
Every nerve block should document all of the following; Approach, Needle type ,Local anaesthetic used and additives, if any, Description of the paresthesias elicited, Any vascular puncture or injection pain, Hematoma formation, Any supplementation and Tourniquet duration.