Suprainguinal Fascia Iliaca (SIFI) Block
Indications:
Provides analgesia to anterior-lateral thigh, knee and most importantly the hip, for the following surgeries:
· Unilateral hip/pelvic osteotomy
· Surgeries of lateral thigh including graft sites
· Femur fractures with proximal repair
Special Considerations:
Since, the SIFI block may cause motor blockade of the femoral nerve, it is best suited for procedures where the patient will not need to ambulate, due to activity restrictions or casting. The block is best suited for hip surgeries and is a simple way to block the complex mix of nerves that supply various parts of the hip and surrounding pelvic structures. Utilizing ultrasound ensures that the local anesthetic is injected truly supra-inguinal to encourage medication to be within the pelvic brim thus avoiding femoral nerve blockade, if the goal is to preserve motor function of the leg.
Patient Position:
Supine position with hip extended
Technique: Probe – Linear; Needle – In-plane
The technique for identifying appropriate ultrasound sonoanatomy is based on the original paper as described by Hebbard et al1:
· With patient in supine position with hip extended, palpate the anterior superior iliac spine (ASIS) and visualize the location of the inguinal ligament extending from ASIS to the pubic tubercle
· Place the linear probe in a cephalad-caudad orientation just infero-medial to the ASIS and perpendicular to the inguinal ligament, which should result in the probe being rotate slightly clockwise, towards the umbilicus, so that the probe is oriented in such a way that the cephalad end is pointing to the 1 o’clock position
· The probe is then slid in a medial direction and to obtain the “bow-tie sign”, in order to obtain a view of the internal oblique muscle on the cephalad side and the sartorius muscle on the caudad side2 (Figure needed)
· Identification of the deep circumflex artery, which is found superficial to the fascia iliaca, is an important landmark to utilize for confirmation of the correct plane
· A needle is then inserted from the caudad end of the probe, so that the tip is pointing cephalad towards the pelvis, thus encouraging local anesthetic to be directed above the inguinal ligament and into the pelvic brim
· As the local anesthetic hydro-dissects the appropriate plane, it is important to confirm that the deep circumflex artery is displaced superficially as the fascia iliaca plane zippers open, to confirm appropriate needle position
· The needle can be further advanced as the plane expands to encourage cephalad movement of the medication, thus ensuring adequate anterior lumbar plexus coverage
· Given that this is a fascial plane block, high volumes are needed, and we recommend 0.5-0.8 ml/kg [DK1] of either 0.2% ropivacaine or 0.25% bupivacaine; addition of adjuvants such as dexmedetomidine and dexamethasone can potentially prolong the block to provide more than 20 hours of analgesia that will extend into post-operative day 1
Coverage:
· Lateral femoral cutaneous nerve (LFCN)
· Obturator nerve
· Femoral nerve
Potential Complications:
Intravascular injection or injury
Bleeding / infection at needle insertion site
Local anesthetic systemtic toxicity (given that SIFI is a volume-based block)
Bowel perforation
Literature Discussion
The supra-inguinal fascia iliaca (SIFI) block, with ultrasound guidance, was first described in
2011 cadaveric study1 which demonstrated that local anesthetic injection would anesthetize
the femoral nerve, lateral femoral cutaneous nerve and ilio-inguinal nerve. Given, that it can
anesthetize several nerves innervating the hip and leg, it is considered to an anterior approach to the lumbar plexus.
Previous, to this study, infra-inguinal fascia iliac block was performed using landmarks and tactile feedback with the needle entering through the fascial planes producing a decipherable “2-pop”sensation. The landmark-based fascia iliac block was a more established technique that deposited local anesthetic caudad to the inguinal ligament, as a method to anesthetize the lateral thigh by blocking the lateral femoral cutaneous nerve and femoral nerve. Introduction of ultrasound has provided for more precise performance of nerve blocks, and a supra-inguinal approach allows for visualization and avoidance of vital structures while also allowing for injection of local anesthetic deep into the pelvic brim.
SIFI is considered as an anterior approach to the lumbar plexus, thus providing a method of reaching many nerves to anesthetize the hip and leg, in a simpler fashion than the more complex lumbar plexus block. A randomized control trial comparing the lumbar plexus block to SIFI for total hip arthroplasty found no difference in analgesia or opioid consumption, and also found that SIFI provided longer sensory block, given that the psoas muscle within which the lumbar plexus lies, is more vascular thus leading to quicker resorption of local anesthetic3.
Thus, SIFI is a fantastic core block and when compared to lumbar plexus block is a) less complex to perform, b) with less risk of penetrating deep anatomical structures and c) with a steeper learning curve given that structures are superficial, thus making it a technique that can easily integrated into daily clinical practice when caring for children and youth.
REFERENCES
1. Hebbard P, Ivanusic J, Sha S. Ultrasound‐guided supra‐inguinal fascia iliaca block: a cadaveric evaluation of a novel approach. Anaesthesia. 2011;66(4):300-305. doi:10.1111/j.1365-2044.2011.06628.x
2. Desmet M, Vermeylen K, Van Herreweghe I, et al. A Longitudinal Supra-Inguinal Fascia Iliaca Compartment Block Reduces Morphine Consumption After Total Hip Arthroplasty: Reg Anesth Pain Med. 2017;42(3):327-333. doi:10.1097/AAP.0000000000000543
3. Bravo D, Layera S, Aliste J, et al. Lumbar plexus block versus suprainguinal fascia iliaca block for total hip arthroplasty: A single-blinded, randomized trial. J Clin Anesth. 2020;66:109907. doi:10.1016/j.jclinane.2020.109907
[DK1]Is 1 ml/kg too crazy lol? that’s what i do and so far no one has died
