Nerve Blocks

Nerve BlocksDenise Ammon T4

Anesthesia2/23/12

Brachial Plexus

Anatomy Union of the anterior primary divisions

of C5-8 and the T1 nerve.› C4 and T2 may contribute as well.

Roots Trunks Divisions Cords Terminal nerves (branches). “Robert Taylor Drinks Cold Beer”.

Terminal Branches: Axillary, Radial, Median, Musculocutaneous, and Ulnar. “ARM MU”.

Picture

Interscalene Block Performed at the C6 level (cricoid cartilage

level).› Ask patient to turn head to side.› Locate groove.

Between the anterior and middle scalene muscles.› The anterior scalene is an important landmark that

should be identified. Posterior to the posterior aspect of the SCM at the

level of the cricoid. Enter behind the External Jugular at 45 degrees

caudad and posterior.

Supraclavicular Block Needle enters 1.2cm above the middle

of the clavicle. Administer anesthetic while advancing

needle towards the first rib. › Anterior-posterior direction until

parasthesias are elicited.

Sciatic Nerve

Sciatic Nerve Block L4-5 and S1-3

› Runs between the ischial spine and greater trochanter of the femur.

› Becomes superficial at the base of the gluteus maximus. Cutaneous innervation to posterior thigh and all of

the leg below the knee minus a small medial strip. Two approaches: Posterior and Anterior. Usually block is combined with femoral, obturator,

or lateral fem cutaneous nerve blocks. Disadvantages: technically difficult, painful,

possible hematoma, nerve damage, slight drop in BP due to blood pooling.

Posterior Approach Lateral decub position with leg to be

blocked flexed at the knee with the heel resting on the opposite knee.

Connect the posterior superior iliac spine with the greater trochanter with a drawing pen. Bisect this line perpendicularly, extending caudal.

Needle entry point: 3cm downward from the perpendicular line.

Anterior Approach Supine position. Line from ASIS to pubic tubercle. Mark

point 2/3 of the way. Draw parallel line from greater

trochanter. From point of first line, continue down

to second line. Inject at this site until bone is hit, then direct medially.