II. Indications

  1. Regional Anesthesia covering proximal femur (hip and anterior medial thigh) to knee
  2. Also provides Regional Anesthesia to medial lower leg and ankle
  3. Femoral Neck Fracture
  4. Mid-shaft Femur Fracture (also covered by Femoral Nerve Block)

III. Contraindications

IV. Complications

  1. Local Anesthetic Systemic Toxicity (LAST Reaction)
    1. Bupivicaine is typically used for this injection (Ropivacaine is safer if available)
      1. Bupivicaine may cause a fatal reaction if given intravascularly
      2. Do NOT use 0.5% for this injection (use 0.25%)
    2. Carefully identify landmarks by exam and Ultrasound
    3. Do not inject without first withdrawing and confirming the needle is not within a vessel
    4. Keep Intralipid nearby when performing this injection (see LAST Reaction for protocol)

V. Anatomy: Landmarks

  1. Iliacus Muscle
    1. Originates at the ilium and joins with the psoas to form the iliopsoas Muscle
    2. Iliopsoas Muscle runs under the inguinal ligament and inserts on the lesser trochanter of the femur
    3. Iliacus and iliopsoas Muscles are covered in a dense fascia (Iliacus Fascia)
  2. Femoral nerve
    1. Originates from the L2 to L4 nerve roots
    2. Travels under the superficial fascia lata and the deeper fascia iliaca
      1. Accompanies lateral femoral cutaneous nerve and the obturator nerves
    3. Injection into the space beneath the Iliacus Fascia
      1. Provides Anesthesia for all branches of the the L2 to L4 nerve roots
  3. Injection landmarks
    1. Divide inguinal ligament into three equal parts
      1. Mark lateral border of Pubic Symphysis (0 cm)
      2. Mark at one third (approximately 3 cm)
      3. Mark at two thirds (approximately 6 cm)
      4. Mark anterior superior iliac spine or ASIS (approximately 9 cm)
    2. Injection site should be near the two thirds mark
      1. Mark approximaly 5-7 cm mark (or 2-4 cm from the lateral margin)
      2. Confirm position by palpating the femoral artery
        1. Femoral Artery should be at least 2 fingerbreadths medial to the injection site
  4. Ultrasound-Guidance (preferred)
    1. Ultrasound probe positioned parallel to inguinal ligament
    2. Identify femoral artery and vein in short axis (transverse)
      1. Femoral nerve will be lateral to femoral artery
      2. Fascia iliaca will be a bright white line immediately deep to the femoral nerve
    3. Landmarks
      1. Inferior to the inguinal ligament
      2. Superior to the femoral artery bifurcation
      3. Lateral to the femoral nerve
      4. Medial to sartorius Muscle
    4. Slide Ultrasound probe laterally to 2 hyperechoic lines/planes overlying iliacus Muscle
      1. Fascia lata (superficial)
      2. Fascia iliaca (deeper, injection is deep to this fascia)
        1. Lies just deep to the femoral nerve
      3. Iliacus Muscle (deepest)
  5. Images
    1. fasciaIliacaBlockUs.jpg
    2. fasciaIliacaBlock.jpg

VI. Preparation

  1. Local Anesthetic
    1. Lidocaine 1% for skin and superficial Anesthetic
  2. Regional Anesthetic
    1. Anesthetic options
      1. Bupivacaine (0.25%): Maximum dose of 2 to 2.5 mg/kg OR
      2. Ropivacaine: Maximum dose of 2 mg/kg
    2. Dilute Anesthetic to 25-30 cc
  3. Blunt Needles
    1. 18 gauge blunt needle
    2. 21 gauge (10 cm) stimulation cannula with extension set (best visibility on Ultrasound)
    3. 20 gauge (3.5 cm) spinal needle with extension tubing

VII. Technique

  1. Use Ultrasound-Guidance as above
    1. Utrasound probe positioned parallel to inguinal ligament
  2. Raise a skin wheel with the local Anesthetic over the injection site
  3. Use an 18 gauge needle to break the skin (do not insert deeply - only make a hole)
  4. Insert a blunt needle (see options above) through this hole created by 18 gauge needle
    1. Direct needle, angled lateral to medial in-plane with Ultrasound probe
    2. Slowly insert needle until a pop is heard or felt as the needle breaches the fascia lata plane
    3. Slowly insert needle until a second pop is heard or felt when the needle breaches the fascia iliaca
    4. Ultrasound is preferred for localization (but it is not mandatory)
  5. Aspirate to confirm not in vessel
  6. Ultrasound confirmation of position
    1. Inject an initial 1 to 2 ml Anesthetic or saline deep to the fascia iliaca can widen the space (hydrodissect)
    2. Do not inject into Muscle
    3. Anesthetic will track toward femoral nerve on Ultrasound
    4. Do NOT inject adjacent to femoral nerve (this is a compartment block)
  7. Inject the 20-30 cc of diluted Anesthetic
    1. Injection should flow very easily (as if injecting into an IV)
    2. Withdraw or advance the needle 1-2 mm if resistance is met
    3. No swelling should be seen

VIII. Efficacy

  1. Highly effective and reproducible (even without Ultrasound) as target is
  2. Will not achieve complete Anesthesia in the leg

X. References

  1. Eicken and Rempell (2016) Crit Dec Emerg Med 30(4):3-11
  2. Herbert and Weingart in Herbert (2019) EM:RAP 19(7): 4, 8-9
  3. Mason and Capagne in Herbert (2018) EM:Rap 18(9): 2-3
  4. Sacchetti in Herbert (2012) EM:RAP 12(2): 4

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Related Studies

Ontology: Fascia of iliacus (C0933960)

Concepts Body Part, Organ, or Organ Component (T023)
English Fascia of iliacus, Iliacus fascia