Many patients with neck of femur fractures get some form of a nerve block in the Emergency Department. This is most often a single injection and wears off in several hours. Would a continuous block via infusion be better?
This UK single centre trial randomised patients to standard care vs. a continuous infusion of 0.2% ropivacaine at 5ml/hour for 48 hours. The medication was delivered by perineural catheter placed by experienced anaesthesia doctors.
Included patients had to be >70 years old, without cognitive impairment, live at home and independently mobilise. Yikes! This obviously limited the number of eligible patients and made this study less feasible to undertake.
The two primary outcomes were the Cumulated Ambulation Score and Dynamic Pain Score score over three days. Whatever those are...
111 patients with fractures underwent analysis.
It is no surprise no difference was found. (Other than a secondary outcome of improved pain at rest) With these small numbers, the researchers had low statistical power and could only hope to find a big difference. In addition, there were several issues that may have drawn the conclusion to the null hypothesis.
Many questions remain; did they use the right dose, did they do the correct block, were the primary outcome scores appropriate & relevant, etc.
In the end, the jury is still out. Despite the negative conclusion, the research question really remains unanswered. If there was a longer delay to theatre, one would hope a continuous infusion would be better than standard care… but who knows, there still is clinical equipois
Rowlands M, van de Walt G, Bradley J, et al. Femoral Nerve Block Intervention in Neck of Femur Fracture (FINOF): a randomised controlled trial. MJ Open 2018;8:e019650. doi: 10.1136/bmjopen-2017-019650