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Three Part Question

In patients [undergoing "3-in-1" nerve block for femoral neck fractures] is [ultrasound scanning as efficatious as nerve stimulation] for [confirmation of needle placement and reducing complications]?

Clinical Scenario

A 77-year old woman presents to the Accident and Emergency department following a simple fall in which she has sustained a fractured neck of femur. You have recently completed a secondment in anaesthetics and consider a "3-in-1" block for pain relief. One of the consultants with whom you worked stated that to perform a nerve block without using a nerve stimulator would be poor clinical practice. When you gave the example of nerve blocks in fractured neck of femur he commented that ultrasound (US) has been used as an alternative to nerve stimulators (NS) in this setting.

Search Strategy

Medline using Ovid interface 1966 – March 2006
CinAHL using Ovid interface 1982 to March Week 2 2006
Cochrane: via NELH 2006 Issue 1. "femoral and ultrasound and anaesthesia"
Medline: {[(Exp. Ultrasonography or ultrasound$.mp or sonographic guidance.mp) or (electrical nerve stimulator$.mp or electrical nerve stimulation.mp)] and (exp. Nerve block$ or femoral nerve block$.mp or 3-in-1 block.mp or three in one block$.mp or three-in-one block$.mp or triple block.mp or lateral cutaneous nerve block$.mp or obturator nerve block$.mp)} (limited to human, English and abstracts in Medline but not in CinAHL).
Cochrane: "femoral and ultrasound and anaesthesia"

Search Outcome

Medline: 137 papers were found of which 2 were relevant to the three part question.
CinAHL: 26 papers were found. None of which were relevant to the three part question.
Cochrane: 21 citations found but no new papers.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Marhofer P et al 1997 Austria	40 patients (ASA II or III) undergoing hip surgery after trauma. Randomisation to either nerve stimulator (n=20) or ultrasound guided (n=20) three in one block. Quality of block was assessed for one hour at 10 min intervals using a pin prick test.	PRCT	Quality of block as assessed by block rating scale (0 to 100) expressed as percentage of initial value.	Better for USS. US 15% +/- 10%, NS 27% +/- 14% p<0.05	Unblinded No power study Small group Unclear if validated rating tool Matching of groups not explicit for fracture or procedure Not performed in the emergency department
			Time to onset of block (mins)	Better with USS. US 16 +/-14, NS 27+/-16 p<0.05
			Subjective quality of analgesia	Better for USS, US 95% vs NS 85%
			Complications Arterial puncture	Better for USS, US 0, NS 3
Marhofer P et al 1998 Austria	60 patients undergoing hip surgery following trauma. Randomly assigned into one of three groups20mls 0.5% bupivicaine under US guidance (A), 20mls 0.5% bupivicaine and nerve stimulator (B), 30mls 0.5% bupivicaine and nerve stimulator (C) Quality of block assessed for one hour using pin prick test at 10 min intervals	PRCT	Quality of block as assessed by block rating scale (0 to 100) expressed as percentage of initial value	Best for USS. A 4% +/-5%, B 21% +/-11%, C 22% +/- 19%. p < 0.01	Unblinded No power study Unclear if validated rating tool Not performed in the emergency department
			Time to onset of block (mins)	Best with USS. A 13+/-6, B 27+/-12, C 26+/-13. p<0.01
			Overall success rate	Best for USS. US 95% vs. NS 85%
			Complications	US None NS 2 (vascular puncture)

Comment(s)

Conformation of needle placement in regional anaesthesia is seen by many as a vital part of the procedure. Many anaesthetists would argue that to perform such procedures without a nerve stimulator is not best practice, and has implications within clinical governance. In the emergency department the use of a nerve stimulator for three-in-one blocks would result in muscular contraction that would cause increase pain and risk fracture displacement. Although the trials are small, the data presented would suggest that ultrasound guide 3-in-1 block may be an alternative to nerve stimulation in the emergency department.

Clinical Bottom Line

Ultrasound guidance is better than electrical nerve stimulation at obtaining a good quality 3 in 1 femoral block.

References

1. Marhofer P. Schrogendorfer K. Koinig H Ultrasonographic guidance improves sensory block and onset time of three-in-one blocks. Anaesthesia and Analgesia 85(4):854-7, 1997 Oct.
2. Marhofer P. Schrodendorfer K. Wallner T. et al. Ultrasonographic guidance reduces the amount of local anaesthetic for 3-in-1 blocks. Regional Anaesthesia and Pain Medicine 23(6):584-8,1998 Nov-Dec.