Brachial plexus block

The axillary block (also axillary brachial plexus block, axillary brachial plexus block ) is a regional anesthesia procedure that allows surgery on the arm. The nerves of the brachial plexus ( median nerve, ulnar nerve, radial nerve, musculocutaneous nerve ) are reversibly blocked by the injection of local anesthetic in the area of the armpit. The axillary block is a relatively easy to perform and little side effects method. A disadvantage compared to the infraclavicular plexus block is partially inadequate elimination of Innervationsgebietes the radial nerve ( " Radialislücke " ), but there is no danger of causing a pneumothorax.

Areas of application

The axillary plexus block allows operations at the lower (distal) upper arm, elbow, forearm and hand. Also a pain therapeutic use, such as neuralgia, CRPS, or phantom limb pain is possible. Here, in the context of the puncture, a catheter is often inserted, can be injected continuously over the anesthetics.

Contraindications ( contraindications ) are infections or tumors in the arm, broken bones and refusal or lack of cooperation by the patient. Blood clotting disorders or taking anticoagulant drugs represent a relative contraindication

Implementation

The patient's arm is bent at the shoulder and the elbow at 90 °, so that the hand is next to the head. The implementation is done under sterile conditions. The puncture site is located above the axillary artery (Figure ).

The identification of the nerves in the armpit can be done by different approaches. Usually the exploration is carried out by means of a neurostimulator which is connected to the end of the puncture needle. The position of the needle tip in the vicinity of the nerve if it is considered by muscle spasms in the forearm. Also, an ultrasound- guided puncture is possible, and wins because of the high reliability and lower failure rate more and more important. Other, less reliable methods are the trans arterial puncture, in the punctured through the axillary artery, and the landmark- oriented ( "blind" ) puncture, which is based on a "click" when passage of the surrounding connective tissue.

When using the nerve stimulator about 40 ml of local anesthetic is injected. Targeted ultrasound blockages can be performed with 15-24 ml of local anesthetic suffizient. It is preferred to use longer-acting local anesthetics such as ropivacaine. To accelerate the onset of action, which takes 20-30 minutes, also fast and short effective substances such as prilocaine or mepivacaine are used in combination occasionally.

Side effects

Side-effects are rare. Nerve damage can be caused by local anesthetics that are injected accidentally in the nerve ( intraneural ) by direct injury to the cannula or by toxic effects. This damage can be avoided during the implementation through the use of blunt needles and the failure of injections in paresthesia ( paraesthesia). By Accidental injection into blood vessels ( intravascular ) effects on the cardiovascular system (bradycardia, hypotension, cardiac arrest at high doses ) or central nervous system ( seizures, loss of consciousness) are possible.