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Three Part Question

In [children with traumatic mid-shaft femur fractures] does [ultrasound guided femoral nerve block] [improve the quality of the block and allow smaller doses of local anaesthesia to be used]

Clinical Scenario

A 4 year-old is brought into the Emergency Department after a fall from a slide in a playground. The clinical diagnosis of a left mid-shaft femoral fracture is confirmed by X-ray. Having become familiar with regional anaesthesia techniques during a recent placement it is decided to carry out a femoral nerve block prior to placing the child’s leg in a Thomas’ splint. Can the departmental ultrasound machine be of assistance when compared to the anatomical or nerve stimulator techniques?

Search Strategy

Medline 1966-08/07 and EMBASE using the National Library for Health (UK) interface, Cochrane library 2008: [(exp ultrasonography OR ultrasound.mp) AND (exp femoral nerve OR exp nerve block)].
Search supervised by Clinical Outreach Librarian Queen Alexandra Hospital, Portsmouth, Fran Lamusse.

Search Outcome

17 Papers were found of which only one was clinically relevant. This of sufficient quality to be included in this review (see table 1)

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
U. Oberndorfer et al. June 2007 South Africa	46 children up to 8 years old undergoing elective surgery of one lower extremity	Randomised Controlled Trial	Mean volume of local anaesthetic used. Increase of heart rate 15% above baseline during surgery analgesia considered insufficient. Duration of nerve block measured using OPS score.	No ultrasound blocks failed, 2 nerve stimulator blocks failed. Duration of analgesia was increased and volume of local anaesthetic used was lower in the ultrasound group	Setting is elective surgery. Mainly Sciatic nerve blocks evaluated. Investigators had substantial expertise in regional anaesthesia.

Clinical Bottom Line

The use of ultrasound has been shown in one small randomised controlled trial to prolong the duration of femoral nerve blocks and allow lower volumes of local anaesthetic to be used when compared to nerve stimulator techniques, in the setting of elective surgery. The current published evidence may support the use of ultrasound for placement of femoral nerve blocks for children in the Emergency Department though more research is required.

References

1. U. Oberndorfer; P. Marhofer; A. Bosenberg; H Willschke et al. Ultrasonographic guidance for sciatic and femoral nerve blocks in children. British Journal of Anaesthesia 98 (6): 797-801