[Analgesia after hip fracture repair in elderly patients: the effect of a continuous femoral nerve block: a prospective and randomised study].

INTRODUCTION: The usefulness of peripheral femoral nerve block for pain management after hip fracture has been established. This prospective and randomised study compared the analgesia effect of a continuous femoral nerve block (CF) versus two conventional analgesia procedures after hip fracture.

PATIENTS AND METHODS: Patients. (n=62) scheduled for surgery under spinal anaesthesia were prospectively included. After surgery, analgesia (48 hours) was randomised: group FC (femoral catheter, anterior paravascular approach, initial bolus followed by continuous infusion of ropivacaine 0.2%), group P (iv 2 g propacetamol/6 hours), group M (sc morphine, 0.05 mg/kg per 4 hour). Intravenous morphine titration was performed, followed by subcutaneous (sc) morphine every 4 hours according to the VAS score. The primary end-point was the morphine requirements. Secondary end-points were VAS score, side effects, and mortality.

RESULTS: Demographic data and surgical procedures were similar between groups. After morphine titration, the VAS pain score did not differ between groups. All patients in-group M received additional morphine. Morphine mean consumption was increased in CF group: 26 mg (5-42) versus P: 8 mg (3-12) (p=0.0001) or M: 19 mg (8-33) (p<0.006) while constipation was decreased in P group vs CF. Percentage of patients requiring no morphine was similar between P (n=6; 28%) and CF (n=6; 28%) and greater than M (n=0; 0%). Hospital discharge, cardiovascular or pulmonary complications and mortality after 6 months showed no statistical difference.

CONCLUSION: Continuous femoral nerve block provided limited pain relief after hip fracture did not reduced side effects and induced an expensive cost.