Ultrasound placement of needle in three‐in‐one nerve block

Ultrasound placement of needle in three‐in‐one nerve block

Report by R Williams, Specialist Registrar in Accident and Emergency

Checked by B Saha, Specialist Registrar in Anaesthesia

Oldham Royal Infirmary

Abstract

A short cut review was carried out to establish whether ultrasound placement of three‐in‐one block is better than placement using a nerve stimulator. 137 papers were found, of which two presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. The clinical bottom line is that ultrasound guidance is better than electrical nerve stimulation at obtaining a good quality three in one femoral block.

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 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 has been used as an alternative to nerve stimulators in this setting.

Search strategy

Medline using Ovid interface 1966–March 2006, CinAHL using Ovid interface 1982 to March Week 2 2006 and 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

137 papers were found through Medline, of which two were relevant to the three part question (see table 2). No additional papers were found in CinAHL or the Cochrane Librayry.

Table 2.

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.	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
	Quality of block was assessed for one hour at 10 min intervals using a pin prick test.		Subjective quality of analgesia	Better for USS. US 95% v 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 groups20 mls 0.5% bupivicaine under US guidance (A), 20 mls 0.5% bupivicaine and nerve stimulator (B), 30 mls 0.5% bupivicaine and nerve stimulator (C)	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
			Time to onset of block (mins)	Best with USS. A 13+/−6, B 27+/−12, C 26+/−13. p<0.01	No power study
	Quality of block assessed for one hour using pin prick test at 10 min intervals		Overall success rate	Best for USS. US 95% v NS 85%	Unclear if validated rating tool
			Complications	US None NS 2 (vascular puncture)	Not performed in the emergency department

Cochrane: 21 citations found but no new papers.

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 three‐in‐one 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 three in one femoral block.