Emergency Medicine

FEMORAL NERVE BLOCK

Practical Procedures 489

9 Continuously monitor the cuff pressure for leakage. Keep the cuff inf lated
for a minimum of 20 min to ensure the prilocaine is fully tissue bound, and
for a maximum of 45 min (usually not tolerated longer).

10 Wait at least 5 min before performing the manipulation after confirming the
adequacy of the block. Request a check X-ray and repeat the manipulation
immediately if reduction is unsatisfactory.

11 If satisfactory, def late the cuff then re-inf late for 2 min observing for signs of
local anaesthetic toxicity, although, as the maximum safe dosage of
prilocaine is 6 mg/kg (over double the amount used in the block), toxicity is
rare.

COMPLICATIONS

1 Local anaesthetic toxicity from cuff failure – never use bupivacaine.

2 Transient peripheral nerve neurapraxia.

FEMORAL NERVE BLOCK

INDICATIONS

1 Analgesia for femoral shaft fracture, particularly prior to dynamic splintage.

2 Analgesia for femoral neck fracture, particularly if significant quadriceps
spasm.

3 Analgesia for surgery on the anterior thigh, knee, quadriceps.

4 Postoperative pain management after femur and knee surgery.

CONTRAINDICATIONS

1 Local infection.

2 Femoral vascular graft (relative).

TECHNIQUE

1 Use either 0.5% bupivacaine 10 mL (total of 50 mg: maximum safe dosage
2 mg/kg), or 1% lignocaine (lidocaine) 10 mL (total of 100 mg: maximum
safe dosage 3 mg/kg).

2 Palpate the femoral artery and insert a 21-gauge needle with syringe perpen-
dicular to the skin, lateral to the artery and just below the inguinal ligament
(see Fig. 18.6).