Impact of preoperative continuous femoral blockades on morphine consumption and morphine side effects in hip-fracture patients: A randomized, placebo-controlled study.

BACKGROUND: Upon arrival at the emergency department, hip-fracture pain relief is usually carried out via systemic opioids. Continuous nerve blocks are efficient in the postoperative period, but have not been evaluated preoperatively. This study compared the reduction in morphine consumption and related side effects of a continuous femoral block with a single shot block in hip-fracture patients.

METHODS: Hip-fracture patients admitted to the emergency department received a femoral nerve catheter, with a single lidocaine injection. They were then randomized to ropivacaine (group R) or saline continuous infusion (placebo, group P) in a double-blind manner. Morphine consumption and side effects were prospectively collected until the 24th postoperative hour.

RESULTS: Sixty patients were included and 55 analyzed. There were no significant differences between the 2 groups regarding fracture types, delay before surgery (median [Q1-Q3]: 21.3 [14.5-29.4] versus 20.8 [15.7-36.2] hours for groups R and P, respectively; P=0.87) and catheter duration (47.5 [39.8-52.4] versus 42.5 [32.1-50.5] hours, P=0.29). Total morphine consumption was not significantly decreased in group R (5 [0-14] versus 8 [4.5-11] mg, P=0.3) and pain scores were similar (mean±SD; VAS 29±15/100 versus 33±13, P=0.3). We observed a significant reduction in morphine adverse effects (31% versus 69% for groups R and P, respectively; P<0.01), mainly nausea (31% versus 59%, P=0.03). One morphine side effect could be avoided for every 5 patients treated.

CONCLUSION: Preoperative continuous femoral blockades using ropivacaine reduce morphine side effects (mainly nausea) in hip-fracture patients without reducing morphine consumption.