II. Indications
- Regional Anesthesia covering proximal femur (anterior medial thigh) to knee
- Also provides Regional Anesthesia to medial lower leg and ankle
- Femoral Neck Fracture
- Mid-shaft Femur Fracture (also covered by Femoral Nerve Block)
III. Contraindications
- Coagulopathy (e.g. Warfarin, Rivaroxaban, Clopidogrel)
- Multi-system Trauma
- Compartment Syndrome
IV. Anatomy: Landmarks
- Iliacus muscle
- Originates at the ilium and joins with the psoas to form the iliopsoas muscle
- Iliopsoas muscle runs under the inguinal ligament and inserts on the lesser trochanter of the femur
- Iliacus and iliopsoas muscles are covered in a dense fascia (Iliacus Fascia)
- Femoral nerve
- Originates from the L2 to L4 nerve roots
- Travels under the superficial fascia lata and the deeper fascia iliaca
- Accompanies lateral femoral cutaneous nerve and the obturator nerves
- Injection into the space beneath the Iliacus Fascia
- Provides anesthesia for all branches of the the L2 to L4 nerve roots
- Injection landmarks
- Divide inguinal ligament into three equal parts
- Mark lateral border of pubic symphysis (0 cm)
- Mark at one third (approximately 3 cm)
- Mark at two thirds (approximately 6 cm)
- Mark anterior superior iliac spine or ASIS (approximately 9 cm)
- Injection site should be near the two thirds mark
- Mark approximaly 5-7 cm mark (or 2-4 cm from the lateral margin)
- Confirm position by palpating the femoral artery
- Femoral Artery should be at least 2 fingerbreadths medial to the injection site
- Divide inguinal ligament into three equal parts
-
Ultrasound-Guidance (preferred)
- Identify femoral artery and vein in short axis
- Femoral nerve will be lateral to femoral artery
- Slide Ultrasound probe laterally to 2 hyperechoic lines/planes overlying iliacus muscle
- Fascia lata (superficial)
- Fascia iliaca (deeper, injection is deep to this fascia)
- Iliacus muscle (deepest)
- Identify femoral artery and vein in short axis
- Images
V. Preparation
- Local anesthetic
- Lidocaine 1% for skin and superficial anesthetic
- Regional anesthetic
- Anesthetic options
- Bupivacaine (0.5%): Maximum dose of 2 to 2.5 mg/kg or
- Ropivacaine: Maximum dose of 2 mg/kg
- Dilute anesthetic to 25-30 cc
- Anesthetic options
VI. Technique
- Use Ultrasound-Guidance as above
- Raise a skin wheel with the local anesthetic over the injection site
- Use an 18 gauge needle to break the skin (do not insert deeply - just make a hole)
- Insert an 18 gauge blunt needle through this hole and insert straight down (or in-plane with Ultrasound probe)
- Slowly insert needle until a pop is heard or felt as the needle breaches the fascia lata plane
- Slowly insert needle until a second pop is heard or felt when the needle breaches the fascia iliaca
- Ultrasound can be used for localization, but it is not mandatory
- Aspirate to confirm not in vessel
-
Ultrasound confirmation of position
- Inject an initial 1 to 2 ml anesthetic
- Anesthetic will track toward femoral nerve on Ultrasound
- Do NOT inject adjacent to femoral nerve (this is a compartment block)
- Inject the 20-30 cc of diluted anesthetic
- Injection should flow very easily (as if injecting into an IV)
- Withdraw or advance the needle 1-2 mm if resistance is met
- No swelling should be seen
VII. Efficacy
- Highly effective and reproducible (even without Ultrasound) as target is
- Will not achieve complete anesthesia in the leg
VIII. Resources
IX. References
- Eicken and Rempell (2016) Crit Dec Emerg Med 30(4):3-11
- Mason and Capagne in Herbert (2018) EM:Rap 18(9): 2-3
- Sacchetti in Herbert (2012) EM:RAP 12(2): 4
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| Concepts | Body Part, Organ, or Organ Component (T023) |
| English | Fascia of iliacus, Iliacus fascia |
