Nerve blocks are a medical technique used to manage pain or provide anesthesia by temporarily numbing a specific area of the body. They involve injecting medication near nerves to interrupt pain signals. As regional anesthesia, they target specific nerve groups. Nerve blocks offer significant relief for both acute and chronic pain, and enhance recovery after surgical procedures.
Understanding the Axillary Brachial Plexus Block
An axillary brachial plexus block targets the brachial plexus, a network of nerves originating from spinal nerves in the neck (C5-T1) that extends into the arm, forearm, and hand. The “axillary” approach means the local anesthetic is administered in the armpit region, near the axillary artery. This targets the musculocutaneous, median, ulnar, and radial nerves, which are the main nerves of the arm and hand.
The axillary brachial plexus block provides anesthesia and pain relief for procedures primarily affecting the limb below the shoulder. It is a relatively safe approach compared to other brachial plexus blocks due to its distance from structures like the lungs, reducing the risk of complications such as pneumothorax. The block offers comprehensive coverage for the arm, forearm, and hand.
Applications of the Block
The axillary brachial plexus block is commonly used for surgical procedures involving the elbow, forearm, wrist, and hand, including carpal tunnel release, fracture repair, and tendon repair. It allows these surgeries to be performed without general anesthesia, benefiting patients with health conditions like heart or breathing problems.
Beyond surgery, this block is also used for acute pain management following injuries or conditions affecting the upper limb. It provides effective pain relief for conditions like shoulder dislocations, rotator cuff injuries, or elbow tendonitis. Sustained pain relief facilitates earlier physical therapy and improves overall recovery. It also aids in managing chronic pain affecting the upper extremity.
The Procedure and Patient Experience
Before the procedure, patients are positioned on their back with the arm to be blocked abducted about 90 degrees and the elbow flexed. The skin around the armpit is cleaned with an antiseptic solution. Ultrasound guidance is often used to visualize nerves and surrounding structures, ensuring accurate needle placement and anesthetic distribution.
Local anesthetic is first injected to numb the skin at the insertion site, minimizing discomfort. A fine needle is then advanced, often with ultrasound guidance, to deposit anesthetic around the targeted nerves. Patients may feel pressure or a tingling sensation as the needle approaches, followed by a warm, heavy feeling as numbness sets in. The procedure typically takes 10 to 20 minutes for the arm to become numb enough for surgery.
Recovery and Important Considerations
After an axillary brachial plexus block, the arm, forearm, and hand will remain numb and weak for several hours. The block’s duration varies, typically 4 to 24 hours (average 10-12), depending on the anesthetic and patient. As sensation returns, patients may experience a tingling or “pins and needles” feeling.
During numbness, protect the affected limb from accidental injury, as sensation and movement control will be limited. A sling is often provided to support the arm. Patients should avoid heavy lifting or operating machinery until full strength and sensation have returned. While generally safe, contact a healthcare provider for persistent pain, unexpected weakness, signs of infection at the injection site, or other concerning symptoms.