The Debate Over Femoral Nerve Blocks

    Pain management in orthopaedic surgery remains a conundrum: What is the best way to provide pain relief?

    Femoral nerve blocks are very effective for pain control, but they have drawbacks. At the ICJR South/RLO Course, Joseph Rodrigo, DO, Director of Regional Anesthesia at Roper Hospital in Charleston, South Carolina, and Kirby Hitt, MD, Director of Adult Reconstructive Surgery at Scott & White Memorial Hospital and Clinic in Temple, Texas, debated the issue of using femoral nerve blocks for orthopaedic procedures.

    Pro: Joseph Rodrigo, DO

    At Roper Hospital, Dr. Rodrigo and his team have started more than 5,000 continuous femoral nerve blocks since the start of the hospital’s pain management program in 2008, including total joint, manipulation, and anterior cruciate ligament repair patients.

    With a highly efficient and experienced anesthesia team, block time at Roper is 4.5 minutes from skin preparation until the patient is ready for the operating room, which keeps the surgeons happy, Dr. Rodrigo said.

    According to Dr. Rodrigo, continuous femoral nerve blocks simply work in managing post-surgical pain. The advantages include:

    • Decreased pain scores
    • Decreased length of stay
    • Decreased opioid use
    • Decreased nausea and vomiting
    • Decreased PACU stay
    • Increased patient and surgeon satisfaction

    Dr. Rodrigo shared data on Roper’s pain scores. Prior to use of continuous femoral nerve blocks at the hospital, patients reported their post-surgery pain as an average of 7.9 on a scale of 1 to 10. After implementing continuous femoral nerve blocks as a part of multimodal therapy, the pain score average dropped to 1.7.

    The current pain score average has risen a bit, to 2.5 on the first post-operative day, because Dr. Rodrigo and his team had to “pull back” on their use of gabapentin and oxycodone due to the side effects of these drugs, including over sedation, respiratory distress, and ataxia.

    Length of stay at Roper has been decreased, from an average of 3.4 days pre-continuous femoral nerve blocks to 2.2 days post-continuous femoral nerve blocks. This has decreased hospital costs and increased bed availability, resulting in increased hospital revenue.

    Importantly, patient satisfaction scores at Roper have increased from an average of 18% of patients satisfied with their pain management pre-continuous femoral nerve blocks to 95% post-continuous femoral nerve blocks.

    This has translated to the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey as well: Roper patients’ pain is well controlled 75% of the time, compared with the national average of 68% and the South Carolina average of 70%.

    Dr. Rodrigo’s presentation can be found here.

    Con: Kirby Hitt, MD

    “I just like to have happy patients with no pain,” Dr. Hitt said, in opening his presentation.

    He agreed with Dr. Rodrigo that femoral nerve blocks achieve excellent pain relief, and he congratulated Dr. Rodrigo on his program at Roper. But as he noted, most hospitals do not have the luxury of such dedicated resources. And that may be one of the biggest issues with routinely using femoral nerve blocks with orthopaedic patients.

    Dr.Hitt enumerated the drawbacks of femoral nerve blocks:

    • They require catheter insertion expertise.
    • They take extra time to place and cause discomfort for the patient.
    • They require an additional capital investment.
    • They put the patient as higher risk for complications.

    So, do the benefits of femoral nerve blocks outweigh these issues? No, said Dr. Hitt.

    Looking at the literature, Dr. Hitt cited a study that compared femoral nerve block and peri-articular infection of pain medication with peri-articular injection alone. No differences were observed in pain, SF-36, WOMAC, or Oxford scores. Another study showed showed no difference in morphine consumption or functional outcomes between peri-articular injection and continuous femoral nerve block.

    One study also showed that peri-articular injection in patients undergoing knee arthroplasty increases quadriceps function. Opioid consumption in that study was also lower in the peri-articular injection group versus the femoral nerve block group in the first 8 hours post-surgery; opioid consumption and pain reports were similar up to 120 hours after surgery.

    According to Dr. Hitt, complications with femoral nerve blocks include:

    • Risk of falls (2.5% greater risk with nerve blocks)
    • Buckling
    • Risk of permanent nerve injury
    • Vascular punctures and injury
    • Bacterial colonization
    • Compartment syndrome
    • Periprosthetic fracture
    • Wrong-site catheter placement

    As part of the Rapid Recovery Joint Program at Scott & White, Dr. Hitt tells patients that after surgery, they will be up and moving and progressing fast, without a knee immobilizer and without limitations on activities because of the risk of falls – all because he does not use femoral nerve blocks.

    Dr. Hitt’s final thought: “Trash the femoral nerve block, get out the syringes, and start injecting.”

    Dr. Hitt’s presentation can be found here.