Infraclavicular Block: Ultrasound, NYSORA Technique, Coverage & Space | Infraclavicular Nerve Block, Lymph Nodes,

Content

• What is Infraclavicular Block?
• Ultrasound
• NYSORA Technique
• Coverage & Space
• Infraclavicular Nerve Block
• Lymph Nodes

What is Infraclavicular Block?

An Infraclavicular Block is a type of regional anesthesia that targets the brachial plexus below the clavicle, usually at the level of the cords. It is commonly used for surgical anesthesia or postoperative analgesia for procedures involving the elbow, forearm, or hand. The block is performed by injecting a local anesthetic around the axillary artery in the infraclavicular fossa, ensuring that the lateral, posterior, and medial cords of the brachial plexus are adequately covered.

This block has several advantages over other brachial plexus approaches, such as the supraclavicular or axillary blocks. It provides reliable anesthesia for the entire upper limb below the shoulder and avoids some of the risks associated with more proximal approaches, like pneumothorax. It is particularly beneficial for patients undergoing longer surgeries, as it can accommodate the placement of a catheter for continuous infusion, providing extended postoperative pain control.

Ultrasound

Ultrasound guidance has significantly improved the safety and accuracy of infraclavicular blocks. By using a high-frequency linear transducer, clinicians can visualize the axillary artery, the surrounding cords of the brachial plexus, and nearby structures such as veins and pleura. The ultrasound probe is placed below the clavicle, oriented in a transverse or parasagittal plane, depending on the technique used.

Under ultrasound, the cords of the brachial plexus typically appear as hyperechoic structures surrounding the axillary artery. Real-time needle visualization allows the anesthetist to deposit local anesthetic precisely in the desired plane, minimizing the risk of vascular puncture or nerve injury. Ultrasound also allows for a lower volume of local anesthetic while achieving effective anesthesia, improving onset time and patient comfort.

NYSORA Technique

The NYSORA (New York School of Regional Anesthesia) technique for infraclavicular block emphasizes a standardized approach to improve block success rates. It involves patient positioning with the arm abducted and externally rotated, careful ultrasound scanning to identify anatomical landmarks, and in-plane needle advancement towards the posterior aspect of the axillary artery.

According to NYSORA guidelines, the key is to deposit local anesthetic in a circumferential pattern around the artery to ensure coverage of all three cords. The needle is advanced in-plane under ultrasound visualization, and local anesthetic is injected incrementally, with frequent aspiration to avoid intravascular injection. This technique is valued for its reproducibility, high success rate, and low complication profile, making it a preferred method in many institutions.

Coverage & Space

The coverage area of an infraclavicular block includes the entire upper limb below the shoulder, making it ideal for surgeries on the elbow, forearm, wrist, or hand. It effectively anesthetizes the musculocutaneous, median, ulnar, radial, and axillary nerve branches originating from the cords of the brachial plexus.

The infraclavicular space is located deep to the pectoralis major and minor muscles, just below the clavicle. Proper understanding of this anatomical space is crucial to avoid complications such as pneumothorax or vascular injury. Injecting local anesthetic within this confined space ensures close contact with the cords and efficient spread, resulting in dense and reliable anesthesia.

Infraclavicular Nerve Block

An infraclavicular nerve block specifically targets the cords of the brachial plexus as they surround the axillary artery. Unlike the axillary approach, which requires multiple injections to block different nerves, the infraclavicular block usually requires a single injection. This makes it efficient and particularly useful for continuous catheter placement for prolonged analgesia.

The infraclavicular block is well-suited for both adult and pediatric patients. It provides excellent coverage for upper limb surgeries while avoiding some of the risks associated with interscalene blocks, such as phrenic nerve paralysis. With ultrasound guidance, success rates exceed 95%, and the block has become a mainstay in regional anesthesia for upper extremity procedures.

Lymph Nodes

Lymph nodes are located in the infraclavicular and axillary regions, and their presence should be noted during ultrasound scanning for nerve blocks. While they typically do not interfere with the procedure, enlarged lymph nodes may indicate infection, malignancy, or inflammatory processes. Identifying these nodes helps clinicians avoid inadvertent needle puncture or misinterpretation of sonographic images.

In rare cases, prominent lymph nodes can alter the expected anatomy, making the procedure more challenging. Skilled ultrasound use allows practitioners to distinguish between neural, vascular, and lymphatic structures accurately. Awareness of lymph node locations also prevents complications and maintains aseptic technique during block placement.