Fascia Iliaca Block

Indications

• Neck of femur fracture — NICE hip fracture guidance recommends considering nerve blocks such as the fascia iliaca block, alongside paracetamol, as part of a multimodal, opioid-sparing analgesia strategy from presentation onwards.
• Femoral shaft fracture — effective analgesia for the significant pain of femoral shaft injury, also easing positioning for traction splintage.
• Useful as an adjunct that reduces opioid requirement and its associated risks (sedation, delirium, respiratory depression), particularly valuable in frail or older patients.

Contraindications & cautions

Equipment

Landmark — inguinal thirds

Landmark technique — "two-pop"

1. Mark the line and entry point

   Draw a line from ASIS to pubic tubercle, divide into thirds; entry point is 1 cm caudal to the junction of the lateral and middle thirds.

2. Aseptic technique

   Clean the skin and use a sterile approach throughout.

3. Advance perpendicular to skin

   Insert the blunt-tipped needle perpendicular to the skin, feeling for two distinct "pops"/loss-of-resistance as the needle passes through fascia lata, then fascia iliaca.

4. Aspirate and inject

   Once through the second pop (needle tip now deep to fascia iliaca), aspirate to exclude vascular placement, then inject the calculated volume of local anaesthetic slowly, aspirating intermittently.

5. Assess

   Onset of sensory block over the anterior/medial thigh within 15–30 minutes confirms a successful block; reassess pain and consider a repeat/alternative approach if analgesia is inadequate.

Ultrasound-guided technique (preferred)

• Place the linear probe transversely just below the inguinal ligament to identify the femoral vessels, then slide laterally to visualise the fascia iliaca plane overlying iliopsoas, lateral to the femoral nerve/sartorius.
• Insert the needle in-plane (lateral to medial) and advance under direct vision until the tip lies deep to the fascia iliaca and superficial to iliopsoas.
• Inject slowly, watching for local anaesthetic spread lifting the fascia iliaca off the muscle — a "doughnut" or spreading hypoechoic pool confirms correct plane placement, more reliably than the landmark "two-pop" alone.
• Ultrasound guidance is preferred where available and where operator competence allows, as it directly confirms correct plane deposition and may reduce block failure and vascular puncture.

Local anaesthetic choice & dose

• Levobupivacaine is a commonly used agent for this block; maximum dose 2 mg/kg (a lower-cardiotoxicity enantiomer of bupivacaine). Calculate the maximum safe volume for the patient's weight before drawing up, and never exceed it regardless of "typical" volumes quoted in the literature.
• Typical injected volumes for an infra-inguinal approach are around 20–40 mL of dilute local anaesthetic (e.g. levobupivacaine 0.25%) — always confirm the calculated maximum dose is not exceeded for the specific concentration and volume used.
• Document the drug, concentration, volume, calculated maximum dose and patient weight in the notes.

Local anaesthetic systemic toxicity (LAST)

• Recognise early: perioral tingling, metallic taste, tinnitus, visual disturbance, agitation or drowsiness — progressing to seizures, arrhythmia, and cardiovascular collapse in severe cases.
• Stop injecting immediately, call for help, and manage the airway (100% oxygen) and any seizure in the standard way.
• Give lipid emulsion 20% (Intralipid) per the Association of Anaesthetists Quick Reference Handbook 3-10 (v2, June 2023): an initial bolus of 1.5 mL/kg over 2–3 minutes — about 100 mL in a 70 kg adult — followed immediately by an infusion at 15 mL/kg/hr. If cardiovascular stability is not restored, repeat the bolus at 5 and at 10 minutes (up to two further boluses) and double the infusion rate to 30 mL/kg/hr, subject to a maximum cumulative dose of 12 mL/kg (840 mL at 70 kg).
• In LAST cardiac arrest, use a reduced adrenaline dose of ≤1 microgram/kg — not the standard 1 mg, and avoid vasopressin. Full-dose adrenaline impairs lipid rescue in animal models of local anaesthetic cardiotoxicity. This is new since the withdrawn 2010 poster and is the change most likely to catch out anyone working from a laminate.
• Avoid hypercarbia — it worsens local anaesthetic cardiotoxicity. For seizures that do not settle, consider neuromuscular blockade to control muscle activity, acidosis and hypercarbia while you continue treatment.
• Continue conventional resuscitation (which may need to be prolonged) alongside lipid therapy; call the cardiac arrest team and involve cardiothoracic/extracorporeal support early in severe cases.

Documentation & monitoring

• Document indication, technique (landmark vs ultrasound), drug/concentration/volume/dose, any complications, and pain scores before and after the block.
• Monitor as for any local anaesthetic administration: continuous observation for at least 30 minutes post-injection, watching for early LAST symptoms.
• Warn the patient of expected numbness/weakness in the leg and appropriate precautions (fall risk once mobilising) as the block wears off.

References