II. Indications

  1. Regional Anesthesia covering proximal femur (anterior medial thigh) to knee
  2. Also provides Regional Anesthesia to medial lower leg and ankle
  3. Consider in mid-shaft Femur Fracture

III. 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 Iliacus Fascia
      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 crest/spine (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. Identify femoral artery and vein in short axis
      1. Femoral nerve will be lateral to femoral artery
    2. Slide Ultrasound probe laterally to 2 hyperechoic structures overlying iliacus muscle
      1. Fascia lata (superficial)
      2. Fascia iliaca (deeper)
      3. Iliacus muscle (deepest)
  5. Images
    1. fasciaIliacaBlock.jpg

IV. Preparation

  1. Local anesthetic
    1. Lidocaine 1% for skin and superficial anesthetic
  2. Regional anesthetic
    1. Anesthetic options
      1. Bupivacaine (0.5%): 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

V. Technique

  1. Use Ultrasound-Guidance as above
  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 - just make a hole)
  4. Insert an 18 gauge blunt needle through this hole and insert straight down (or in-plane with Ultrasound probe)
    1. Slowly insert needle until a pop is heard or felt as the needle breaches the fascia lata plane
    2. Slowly insert needle until a second pop is heard or felt when the needle breaches the fascia iliaca
    3. Ultrasound can be used 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
    2. Anesthetic will track toward femoral nerve on Ultrasound
    3. Do NOT inject adjacent to femoral nerve (this is a compartment block)
  7. Inject the 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

VI. Efficacy

  1. Will not achieve complete anesthesia in the leg

VIII. References

  1. Eicken and Rempell (2016) Crit Dec Emerg Med 30(4):3-11
  2. Sacchetti in Majoewsky (2012) EM:RAP 12(2): 4

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Ontology: Fascia of iliacus (C0933960)

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