Nerve stimulator-assisted femoral nerve block in the emergency department

Abstract

Objective: To describe the technique of femoral nerve block using a nerve stimulator to locate the nerve, and to report the success rate of its use by junior and senior doctors in the emergency department. Method: Standardized protocol and patient selection criteria were formulated for the performance of femoral nerve block on patients with femoral neck or shaft fractures using a nerve stimulator to locate the femoral nerve and confirm deposition of local anaesthetic agent close to the femoral nerve. Femoral nerve blockade was assessed before and after femoral nerve block by testing for altered sensation in the cutaneous distribution of the femoral nerve. Pain was assessed before and after femoral nerve block using a visual analogue scale. The use of supplementary analgesics was recorded. Results: A successful femoral nerve block was obtained with the nerve stimulator in 19 of 22 attempts (86%) at femoral nerve block. Success was unrelated to seniority of staff. Femoral nerve block was the only analgesia required in 17 patients (77%). Femoral nerve block was the only analgesia required for 100% for femoral shaft fractures and 75% and 73%, respectively, for extra-capsular and intracapsular fractures of the femoral neck. Conclusion: The femoral nerve was accurately located using the nerve stimulator irrespective of seniority of staff performing the procedure. Femoral nerve block using the nerve stimulator was effective analgesia for femoral shaft fractures and the majority of both intra- and extra-capsular femoral neck fractures.