II. Indications
- Rib Fracture related pain
- Regional Anesthesia for Chest Tube Placement
- Axillary abscess drainage
III. Preparation: Anesthetic
-
Bupivacaine
- Limit Bupivacaine max dose to 2.5 mg/kg or 175 mg for a 70 kg person (risk of LAST Reaction)
- Bupivacaine 0.5% concentration is 5 mg/ml (for a 70 kg person, max of 35 ml Bupivacaine 0.5%)
- Bupivacaine 0.25% concentration is 2.5 mg/ml (for a 70 kg person, max of 70 ml Bupivacaine 0.25%)
- Limit Bupivacaine max dose to 2.5 mg/kg or 175 mg for a 70 kg person (risk of LAST Reaction)
- Dilute in Saline
- Combine Bupivacaine and Normal Saline for a total volume of 30 ml
IV. Preparation: Other Materials
- Linear, high frequency Ultrasound probe
- Sterile Ultrasound cover (gel inside of cover) and sterile gel over surface
- Position Ultrasound machine on opposite side of patient
- Needles (choose one)
- Specific Nerve Block needle (magnetized, more easily seen on Ultrasound)
- Blunt tipped spinal needle with IV Line extension tubing
- Syringe (30 ml)
- Second operator to inject Anesthetic
- First operator will hold needle in position
- Skin preparation
- Chlorhexidine (Hibiclens)
- Povidone Iodine (Betadine)
- Sterile Gloves
V. Technique: Ultrasound Guided Serratus Anterior Nerve Block
- Images
- Landmarks: Serratus Anterior insertion site
- Identify rib spaces 4-5 at mid-axillary line (Nipple line in men)
- Ultrasound appearance (from superficial to deep)
- Skin
- Latissimus Dorsi Muscle
- Serratus Anterior Muscle
- Ribs (shadowing) interspersed with intercostal muscles
- Patient positioning: Lateral decubitus with unaffected side down (preferred)
- Ultrasound probe placed in horizontal, transverse position over landmark
- Needle directed inline toward table and medial chest
- Patient positioning: Supine
- Ultrasound probe placed in horizontal, transverse position over landmark
- Needle directed inline toward lateral chest
- Needle Insertion
- Direct needle toward a rib (acts as a stop in case of patient movement)
- Injection while inserting needle (hydrodissection) identifies the needle tip location on Ultrasound
- Injection depth should be between Latissimus Dorsi Muscle and Serratus Anterior Muscle
-
Anesthetic Injection
- Inject between Latissimus Dorsi Muscle and Serratus Anterior Muscle
- Creates a hypoechoic collection of fluid along the planar surface of the Serratus Anterior Muscle
VI. Resources
- Ultrasound Guided Serratus Anterior Blocks (Stat Pearls)
- Serratus Plane Block for Rib Fractures (Highland Ultrasound)
VII. References
- Avila in Herbert (2020) EM:Rap 20(8); 1
