Nerve Block: Serratus Anterior

Overview

• Injection of local anesthetic around the thoracic intercostal nerves to provide regional anesthesia to the anterolateral chest wall

Indications

• Rib fractures
• Rib contusions

Contraindications

• Overlying soft tissue infection
• Allergy to local anesthetic

Equipment Needed

• Ultrasound (linear transducer) w/ sterile probe cover
• Sterile gloves
• Chlorhexidine or betadine solution
• 1% lidocaine with epinephrine in syringe with 27-gauge needle (for skin wheel)
• 0.5% or 0.25% bupivacaine in 30 ml syringe.
• 18 gauge blunt needle
• 22-25 gauge peripheral nerve block needle with extension tubing
  • Alternatively, 22g spinal needle with IV extension tubing

Procedure

• Position patient in supine or lateral decubitus position (injured side up)
• Sterilize skin w/ antiseptic solution
• Inject wheal of lidocaine into injection site
• Place ultrasound probe lateral to the nipple in transverse orientation
• Find the serratus anterior muscle overlying the ribs in the lateral chest wall
• Using the in-plane technique, advance needle with dominant hand
• Identify the pleural line prior to inserting the needle
• Advance the needle toward the rib (you will feel a pop once through the fascia)
• Connect tubing to needle and syringe.
• Push 2-3 cc to confirm placement between the serratus anterior and latissimus dorsi. The two should separate freely.
• Inject the remaining anesthetic