SGEM#496: Hangin’ Tough after a Nerve Block for Pediatric Femur Fractures

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Reference: Binder ZW et al. “Ultrasound-Guided Nerve Block for Pediatric Femur Fractures in the Emergency Department: A Prospective Multi-Center Study.” Academic Emergency Medicine, 2025.

Date: November 24, 2025

Guest Skeptic: Dr. Lauren Westafer is an Associate Professor in the Department of Emergency Medicine at the University of Massachusetts Medical School, Baystate. She is the co-founder of FOAMcast and a researcher in pulmonary embolism and implementation science.  Dr. Westafer serves as the research methodology editor for Annals of Emergency Medicine. 

Case: A 9-year-old boy presents to the emergency department after a trampoline injury. He was at a party with his friends and they were all bouncing together and competing to see who could bounce the highest. The boy fell down on his right leg and a friend accidentally landed on it. On your exam, the boy is in significant pain and has a deformity of his right leg. You do not note any additional injuries. X-rays confirm a mid-shaft femur fracture. You administer some IV morphine, but the boy is still whimpering in pain. One of the other attending physicians on shift who happens to be an ultrasound enthusiast, suggests using an ultrasound-guided nerve block as a way to manage the boy’s pain. The boy’s parents ask “What is that?”

Background: Femur fractures are one of the most painful injuries in pediatric patients and frequently require hospital admission for definitive treatment, often with long ED stays prior to operative management. Traditional pain management for these injuries relies heavily on IV opioids, which have well-documented side effects including nausea, respiratory depression, and sedation. Increasing public awareness of the opioid crisis has also led to growing parental concern over opioid exposure in children. There is growing interest in opioid-sparing pain control methods.

The fascia iliaca compartment nerve block (FICNB) is a regional anesthesia technique that targets the femoral nerve and adjacent sensory nerves to provide localized pain relief. While landmark-based FICNB techniques have been used successfully in adult patients, recent studies suggest that ultrasound guidance improves the accuracy and safety of these procedures. However, evidence on the effectiveness and safety of ultrasound-guided FICNB in pediatric patients, particularly when performed by emergency physicians in real-world ED settings, remains limited. 

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Clinical Question: In children with femur fractures, is ultrasound-guided FICNB more effective at reducing pain compared to systemic analgesia?

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Reference: Binder ZW et al. “Ultrasound-Guided Nerve Block for Pediatric Femur Fractures in the Emergency Department: A Prospective Multi-Center Study.” Academic Emergency Medicine, 2025.

• Population: Children aged 4–17 years presenting to the ED with isolated, acute femur fractures.
  • Excluded:  Patient with neurovascular compromise, multi-trauma, GCS ≤13, bilateral fractures, allergy to anesthetics, prisoners, pregnancy.

• Intervention: Ultrasound-guided fascia iliaca compartment nerve block (FICNB) performed with ropivacaine or bupivacaine

• Comparison: Systemic analgesia administered at discretion of ED treating team

• Outcome:

• • Primary Outcome: Reduction in pain intensity at 60 minutes using the Faces Pain Scale–Revised (FPS-R).

• • Secondary Outcomes: Reduction in pain at 240 minutes, opioid consumption (oral morphine equivalents per hour), occurrence of adverse events, and emergency department (ED) length of stay.

• Trial: Prospective multi-center observational study conducted at 12 pediatric emergency departments in the US and Australia. Some sites performed FICNB. Other sites did not.

Guest Author: Dr. Zachary Binder is a pediatric emergency medicine attending physician at UMass Memorial Health and Associate Professor at UMass Chan Medical School. He is the Director of Point-of-Care Ultrasound for the Department of Pediatrics and the medical school.

Authors’ Conclusions: Children who received FICNB had greater reductions in pain intensity and required less opioid medication than those who did not. This is the largest prospective study evaluating the ultrasound-guided FICNB performed on children in the ED, and its findings support the procedure’s use for pediatric femur fracture pain management.

Quality Checklist for Observational Study:

1. Did the study address a clearly focused issue? Yes
2. Did the authors use an appropriate method to answer their question? Yes
3. Was the cohort recruited in an acceptable way? Yes. 
4. Was the exposure accurately measured to minimize bias? Yes
5. Was the outcome accurately measured to minimize bias? Yes
6. Have the authors identified all-important confounding factors? Yes
7. Was the follow up of subjects complete enough? Yes. 
8. How precise are the results? Fairly precise
9. Do you believe the results? Yes
10. Can the results be applied to the local population? Unsure
11. Do the results of this study fit with other available evidence? Yes. 
12. Funding of the Study: No financial conflicts of interest

Results:

They included a total of 114 participants (54 in the FICNB group and 60 in the non-FICNB group).  The mean age was ~10 years old, with ~20% female. Fractures were mostly displaced (91% vs 83%), while open fractures were rare (~2%). Most had received opioids before enrollment (96% vs 88%).  FICNBs were performed by attendings (37%), fellows (33%), or residents (30%) under supervision. Half were performed or supervised by attendings with advanced POCUS training.

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Key Results: Children who received FICNB had greater reduction in pain compared to those who did not, without more adverse events or longer ED LOS.

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Primary Outcome (Pain reduction at 60 min)

There was a mean decrease of 3.8 points (95% CI, 3.1 to 4.6) in the FICNB group compared to a decrease of 0.8 points in the non-FICNB group (95% CI, -0.2 to 1.9). 

That was a difference of 3.0 (95% CI, 1.7 to 4.3). 

Secondary Outcomes

When it came to pain reduction at 240 min, there was a mean decrease of 3.6 points (95% CI, 2.6 to 4.5) in the FICNB group vs. 1.7 points (95% CI, 0.7 to 2.7) in the non-FICNB group. That was a difference of 1.9; (95% CI, 0.5 to 3.2).

The FICBN also received less opioids after enrollment measured as oral morphine equivalents per hour (OME/hr). This was 0.3 in the FICBN group vs. 1.1 in the non-FICBN group). This was a difference of 0.8 (95% CI, 0.4 to 1.1).

ED length of stay in both groups was 6.1 hours with overlapping 95% CI.

There was not much difference in adverse events between the two groups (5.6% FICNB vs 8.3% non-FICNB), with no serious complications attributable to FICNB. One patient in the FICNB group had apnea but had also received ketamine, fentanyl and midazolam. 

 

Listen to the SGEM podcast to hear Zack respond to our five nerdy points.

Selection Bias

Twelve sites were included. The proportion of physicians able to perform the nerve block ranged from 25-100% of the faculty. There were four sites that did not routinely perform FICNB. For the sites that did perform the nerve block, it was only performed when someone trained to do it was on shift (which makes sense). Patients may also have been missed for other reasons such as maybe it was too busy on shift or there was a fast disposition from ED to the operating room. However, this also means that there is a group of eligible kids that may have been missed with this convenience sampling.

How do you think this selection bias may have impacted the results of the study?

Performing FICNB

We can’t imagine that a young child is going to be thrilled seeing a long needle being introduced to the leg that is already broken.

How do you do this practically? Are you having to give any additional medications for anxiolysis prior to this? Are you worried about the patient moving during this process?

Any tips on how to fit this into the workflow of a busy ED shift?

One other thing that we were looking for was whether or not all of these blocks were successfully placed on the first attempt or did some require multiple attempts?

Ultrasound Training and Competencies

We were impressed that in this study, the nerve block was performed by a mix of attending physicians (37%) and fellows and residents under supervision.

What does it take to train someone to perform this nerve block? How do you determine they are capable enough to be credentialed?

Generalizability

It’s mentioned in the paper that four of the 12 sites involved in this project did not routinely perform FICNB. It’s also mentioned that at some of these sites, not performing FICNB would be considered substandard care. This is quite a variation even amongst academic children’s hospitals which may make this practice less generalizable to the community or rural settings. 

What do you think are some of the biggest barriers and challenges in having this practice be adopted more widely? Is it the lack of trained staff? Buy-in from orthopedic colleagues?

Patient and Family Experience

While the primary outcome of pain reduction was very patient-oriented, we can’t help but wonder, did you collect any additional data about the experience of patients or families? Were they overall satisfied with the care they received nerve block or not? Did any express preference for nerve block or systemic analgesia?

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We agree with the authors’ conclusion.

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SGEM Bottom Line: Ultrasound-guided fascia iliaca compartment nerve blocks were associated with clinically meaningful pain reduction and less opioid use for pediatric femur fractures in the ED without prolonging length of stay.

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Case Resolution: After discussing the different options available for pain control with the family, they consent to their son receiving an ultrasound-guided FICNB. Since you have never performed one before, you ask your ultrasound-trained colleague for help, and she happily agrees. As she sets up for the nerve block, you contact the orthopedic team.

Clinical Application: At institutions with trained ultrasound faculty who can perform FICNB for children with femur fractures, the nerve block is a reasonable and effective option for pain control.

What Do I Tell My Patient/Family? 

Your son has broken a big bone in his leg, and this is very painful. There are a few different ways we can manage your child’s pain. We can give medicine for pain through an IV, these are typically opioid medications like morphine. We can also use an ultrasound-guided injection that numbs the nerves of the thigh. Some kids who get this nerve block may have better relief in pain and need fewer IV pain medications. Would you like to try that for your son?

Now it is your turn, SGEMers. What do you think of this episode on nerve blocks for femur fractures in pediatric patients? What questions do you have for Zack and his team? Post your comments on social media using #SGEMHOP. The best social media feedback will be published in AEM.

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Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

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References: