The first time I hear about femoral nerve block for hip fracture was in my early years of residency. I found an article that I presented to an anesthesia journal club. MISTAKE! They all criticized the anatomy non-sense, the emergency department irrelevance, and most importantly, my choice of article! I felt exactly if I was in a discussion with radiologists about POCUS 10 years ago. And like I predicted, the evidences of the femoral nerve block benefits for patient with hip fracture became more and more abundant.
First, I will remind you (and myself) the procedure of an effective femoral block.
Indication in the ED: Hip and femoral fracture. This procedure will block the femoral, obturator and lateral femoral cutaneous nerves.
Contre-Indication: Allergies, anatomy distortion, severe anticoagulation, overlying skin infection.
- Ultrasound + material to use it in a sterile fashion
- Disinfectant, sterile gloves, sterile fields
- 75cm 25 or 22 gauge needle (Lumbar puncture needle)
- 1 connector + small extension (from the needle to the syringe)
- 10cc lidocaine 2% + 10cc buvicaine 0.25%
- Place the patient in a supine position and prepare the skin.
- Use an ultrasound to localize the femoral nerve 1-2 cm distal to the inguinal ligament (from lateral to medial: Nerve, Artery, Vein). The nerve will look like a funny honeycomb oval.
- Insert your needle at 30 degrees and reach the femoral nerve, have a second person to press on the syringe (so you have perfect control of your needle). Inject the anesthetics all around the femoral nerve.
Now, lets review what are the evidences. Anesthesiologists, we are coming to get you!!!!
A very recent randomized controlled study evaluated the performance of the regional femoral nerve block (done by ED physicians) in terms of pain management on a 10 points scale. They found a significant difference (3.5 vs 5.3 p=0.02) after 2 hours. (Morrison, 2016)
Also this year, a systematic review what published, interestingly they targeted older adults’ population. The femoral block did appear to have some benefit by decreasing the amount of pain and opioid use. (Riddel, 2016).
I did a rapid screening of many other study results and they are all in favor of doing this block. I even found one about what would be the impact on the efficacy if its done by a junior physician. There was no difference. (hogh, 2008)
But is there any risk of doing this? According to studies, there were no significant adverse reactions. One study reported more nausea in the femoral block group. (Lee, 2014)
Even if we lower the pain and the opioid use, is there any other outcome that has been evaluated? I found this study about delirium. They divided the participant in 3 groups (low, intermediate and high risk of delirium) and they either received the femoral block or placebo. The femoral block significantly reduced the incidence of delirium in the intermediate group only. But, the mean duration of the delirium was significantly shorter in the femoral block group. This study was not designed for the ED and they have a very strange delirium management plan. Anyway, interesting! (Mouzopoulos, 2009)
The bottom line, I did not find anything against this block.
I will conclude this post by quoting Hogh: The femoral nerve block “is easy to perform, requires minimal introduction, no expensive equipment and is connected with a minimal risk approach.”
Now, get out there and start doing it!