Magnesium-sulfate as Adjuvant in Prehospital Femoral Nerve Block for Patient With Diaphysial Femoral Fracture.

Prehospital management of traumatic pain is commonly based on morphine while loco-regional analgesia techniques, especially the femoral nerve block (FNB), can be safely and efficiently used. Adjuvants uses can reduce local anesthetic doses and decrease their related risk. The aim of the study was to assess the analgesic effect of Magnesium sulfate (Mg S) when used as adjuvant in prehospital FNB. This is a randomized double-blinded trial conducted in a prehospital medical department of an academic hospital. Patients with isolated diaphysial femoral fracture and eligible to participate were randomized into 2 groups. The Group Placebo had a FNB with 15 ml of lidocaine with epinephrine (300 mg) and 3 ml of normal saline. The Group Magnesium had a FNB with 15 ml of lidocaine with epinephrine (300 mg) and 3 ml of Mg S 15% (450 mg). The FNB was performed according to the WINNIE technique. Primary endpoints were morphine consumption and pain intensity during the first 6 hours. Secondary end-points were the duration of the sensitive block, time to the first analgesic request, side effects occurrence.