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Ultrasound-Guided Nerve Block for Pediatric Femur Fractures: A Secondary Analysis of Needle Tip Distance
Antonio Riera1, Simone L Lawson2, Nicole Klekowski3
1Department of Pediatrics, Yale University School of Medicine, New Haven, CT.
Background:
Fascia iliaca compartment nerve blocks (FICNB) have been shown to be an effective management strategy for pediatric femur fractures in the emergency department, but they can be performed using different techniques. Our main objective was to evaluate the association between needle tip distance to the femoral nerve and pain score reduction following ultrasound-guided FICNB in pediatric patients with acute femur fractures.
Methods:
We conducted a secondary analysis of a prospective, multicenter observational study conducted in the United States and Australia. Participants were children aged 4 to 17 years with isolated femur fractures who received a FICNB, divided into 2 groups based on ultrasound visualization of needle tip distance from the femoral nerve: ≥5 mm or <5 mm. The main outcome was a comparison of the mean pain score reduction between groups using the Faces Pain Scale-Revised (FPS-R). The FPS-R is a validated 0 to 10 continuous scale in which participants self-report their pain intensity. Pain scores were taken immediately before the nerve block (t 0 ) and 60 minutes postprocedure (t 60 ). In addition, adverse events were recorded. Differences in mean pain scores were analyzed using t tests, and categorical variables were compared with Fisher exact test.
Results:
Of the 54 participants who received a FICNB (31 with needle tip ≥5 mm from the femoral nerve, 23 with needle tip <5 mm), 49 had a t 60 pain score available for analysis (30 in the ≥5 mm group, 19 in the <5 mm group). Pain scores at t 0 were similar between both groups. Both groups experienced a reduction in mean pain score at t 60 [≥5 mm group 3.5 vs <5 mm group 4.6, difference between groups: 1.1 (95% CI, -0.6 to 2.7)]. No serious adverse events were reported.
Conclusion:
In pediatric patients with acute femur fractures, needle tip distance from the femoral nerve does not seem to be associated with a difference in pain score reduction or the occurrence of serious adverse events.
