Ultrasound-guided regional nerve block (interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Ultrasound-guided regional nerve block

Regional anaesthesia is used to enable surgery to be performed on specific parts of the body while the patient remains awake. Ultrasound-guided regional nerve block uses ultrasound to facilitate easy and accurate positioning of the needles that deliver the anaesthetic drugs close to the nerves.

The National Institute for Health and Clinical Excellence is examining ultrasound-guided regional nerve block and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about ultrasound-guided regional nerve block.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

comments on the preliminary recommendations
the identification of factual inaccuracies
additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows.

The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the Institute's website (www.nice.org.uk/ipprocessmanual).

NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and how it might be improved.

Closing date for comments: 26 August 2008
Target date for publication of guidance: December 2008

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

1	Provisional recommendations
1.1	Current evidence on the safety and efficacy of ultrasound-guided regional nerve block appears adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance, consent and audit.
1.2	Clinicians wishing to perform this procedure should be experienced in the administration of regional nerve blocks and trained in ultrasound guidance techniques.

2	The procedure
*2.1*	*Indications* *and current treatments*
2.1.1	Regional nerve block is used for anaesthesia during surgery or to manage chronic pain. It is delivered with a needle in close proximity to the target nerve, usually via 'blind' insertion using anatomical landmarks. Some techniques also involve the detection of a 'click' when fascia is breached to guide the needle's position, or use of nerve stimulation to help confirm that the nerve has been correctly identified.

*2.2*	*Outline of the procedure*
2.2.1	Ultrasound imaging is used to visualise the target nerve and to guide accurate needle placement adjacent to the nerve. Ultrasound imaging allows visualisation of both superficial tissues and musculoskeletal structures. Ultrasound also allows the location of injected anaesthetic solution to be seen: the needle can be repositioned if the solution is placed incorrectly.

Sections 2.3 and 2.4 describe efficacy and safety outcomes which were available in the published literature and which the Committee considered as part of the evidence about this procedure. For more details, refer to the Sources of evidence.
*2.3*	*Efficacy*
2.3.1	Success of the regional nerve block technique was defined differently across the studies identified, in terms of sensory and motor function, making comparison of outcomes difficult.
2.3.2	A randomised controlled trial (RCT) of 188 patients reported that nerve block was more often successful with ultrasound guidance (83%, p = 0.01) or with combined ultrasound and nerve stimulation guidance (81%, p = 0.03) than with nerve stimulation guidance alone (63%) (absolute numbers not reported).
2.3.3	A second RCT of 60 patients reported nerve block failure in 5% (1/20) of patients following ultrasound-guided regional nerve block for hip surgery compared with 10% (2/20) of patients receiving the same volume of anaesthesia with nerve stimulation guidance (level of significance not reported).
2.3.4	A third RCT of 40 patients reported that nerve block was significantly more successful with ultrasound guidance than with anatomical landmark guidance (p = 0.003), and that the onset of block was significantly faster (p = 0.011) (absolute numbers not reported). This study reported conversion to general anaesthesia in 5% (1/20) of patients in the ultrasound-guided group and 10% (2/20) of patients in the landmark-guided group.
2.3.5	A fourth RCT of 100 patients having ilioinguinal and iliohypogastric nerve blocks reported that a significantly lower mean volume of anaesthesia (0.19 ml/kg) was required to produce an effective block when using ultrasound guidance than when using anatomical landmark guidance with fascial click (0.3 ml/kg) (p < 0.0001). In this study, a smaller proportion of patients required postoperative analgesic in the ultrasound-guided group (6%) than the anatomical landmark group (40%) (p < 0.0001) (absolute numbers not reported).
2.3.6	A non-comparative trial of 248 patients treated with peripheral nerve blocks at different sites reported nerve block failure in 2% (3/124) of patients treated with combined ultrasound and nerve stimulation-guided block compared with 6% (8/124) of patients treated with nerve stimulation-guided block alone (not statistically significant, p = 0.334).
2.3.7	In two case series of 1146 and 520 patients a successful block was recorded in 99% (1138/1146, upper limb or hand surgery) and 94% of patients (absolute numbers and location of block not reported in the series of 520 patients).
2.3.8	The Specialist Advisers considered key efficacy outcomes to include success of the blocks, volume of anaesthesia required, speed of onset of analgesia and pain score.

*2.4*	*Safety*
2.4.1	The RCT of 188 patients reported transient paraesthesia (up to 5 days) in 20% (13/64) of patients treated with ultrasound-guided block, 21% (13/62) of patients who received nerve stimulation-guided block and 15% (9/62) of patients who received combined ultrasound- and nerve stimulation-guided block (level of significance not reported).
2.4.2	A case series of 620 patients treated with ultrasound-guided catheter insertion reported nerve injury in fewer than 1% (2/620) of patients. In one patient the resulting weakness and sensory loss had resolved spontaneously at 6-week follow-up. The other patient was reported to have developed symptoms consistent with complex regional pain syndrome, with burning pain in the foot and allodynia. These symptoms reportedly resolved 2 weeks later, following three sympathetic blocks of the lower extremity.
2.4.3	The RCT of 60 patients reported vascular puncture causing haematoma in 0% (0/20) of the 20 patients treated with ultrasound-guided nerve block and in 10% (4/40) of patients following nerve stimulation-guided block (level of significance not reported).
2.4.4	The RCT of 40 patients reported arterial puncture in 0% (0/20) of the 20 patients treated with ultrasound-guided block, and 15% (3/20) of patients treated with anatomical landmark-guided block (not statistically significant). The same study reported that incidence of paraesthesia was significantly higher in the landmark-guided group than in the ultrasound-guided group (p = 0.012) (absolute numbers not reported).
2.4.5	The Specialist Advisers considered anecdotal adverse events to include organ damage, pneumothorax, nerve damage, intravascular injection, bleeding, systemic toxicity and intraneural injection. They considered theoretical adverse events to include inability to identify structures, misplacement, pain, paraesthesia and risks associated with the use of ultrasound energy at high frequencies.

3	*Further information*
3.1	NICE has published interventional procedures guidance on ultrasound-guided catheterisation of the epidural space (www.nice.org.uk/IPG249).

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
July 2008

Appendix:	Sources of evidence

The evidence considered by the Interventional Procedures Advisory Committee is described in the overview, available at: www.nice.org.uk/ip661overview.

This page was last updated: 30 March 2010