Single, double or multiple-injection techniques for non-ultrasound guided axillary brachial plexus block in adults undergoing surgery of the lower arm

  • Review
  • Intervention

Authors


Abstract

Background

Regional anaesthesia comprising axillary block of the brachial plexus is a common anaesthetic technique for distal upper limb surgery. This is an update of a review first published in 2006 and updated in 2011.

Objectives

To compare the relative effects (benefits and harms) of three injection techniques (single, double and multiple) of axillary block of the brachial plexus for distal upper extremity surgery. We considered these effects primarily in terms of anaesthetic effectiveness; the complication rate (neurological and vascular); and pain and discomfort caused by performance of the block.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE and reference lists of trials. We contacted trial authors. The date of the last search was March 2013 (updated from March 2011).

Selection criteria

We included randomized controlled trials that compared double with single-injection techniques, multiple with single-injection techniques, or multiple with double-injection techniques for axillary block in adults undergoing surgery of the distal upper limb. We excluded trials using ultrasound-guided techniques.

Data collection and analysis

Independent study selection, risk of bias assessment and data extraction were performed by at least two investigators. We undertook meta-analysis.

Main results

The 21 included trials involved a total of 2148 participants who received regional anaesthesia for hand, wrist, forearm or elbow surgery. Risk of bias assessment indicated that trial design and conduct were generally adequate; the most common areas of weakness were in blinding and allocation concealment.

Eight trials comparing double versus single injections showed a statistically significant decrease in primary anaesthesia failure (risk ratio (RR 0.51), 95% confidence interval (CI) 0.30 to 0.85). Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique.

Eight trials comparing multiple with single injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.25, 95% CI 0.14 to 0.44) and of incomplete motor block (RR 0.61, 95% CI 0.39 to 0.96) in the multiple injection group.

Eleven trials comparing multiple with double injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.28, 95% CI 0.20 to 0.40) and of incomplete motor block (RR 0.55, 95% CI 0.36 to 0.85) in the multiple injection group.

Tourniquet pain was significantly reduced with multiple injections compared with double injections (RR 0.53, 95% CI 0.33 to 0.84). Otherwise there were no statistically significant differences between groups in any of the three comparisons on secondary analgesia failure, complications and patient discomfort. The time for block performance was significantly shorter for single and double injections compared with multiple injections.

Authors' conclusions

This review provides evidence that multiple-injection techniques using nerve stimulation for axillary plexus block produce more effective anaesthesia than either double or single-injection techniques. However, there was insufficient evidence for a significant difference in other outcomes, including safety.

Plain language summary

Anaesthesia for hand and forearm surgery via single, double or multiple injections placed close to nerves in the armpit

A common method of regional anaesthesia for hand, wrist or forearm surgery is to inject local anaesthetic into the tissues surrounding nerves in the armpit. This is because in the armpit (axilla) the key nerves for the lower part of the arm are close together and are easier to locate. This type of anaesthesia is called axillary brachial plexus block. Successful blocking of the nerves produces a numb and limp arm that enables pain-free surgery. This review compared the effects of single, double and multiple (three or four) injections of local anaesthetic.

We searched the literature up until March 2013 and identified 21 randomized controlled trials for inclusion in the review. These trials involved a total of 2148 participants who were given regional anaesthesia for hand, wrist, forearm or elbow surgery. The trials used methods that were generally adequate and did not affect the validity of the findings. Eight trials compared double versus single injections. These found that fewer people in the double injection group required additional anaesthesia. However, the effect was more certain in the four trials where the nerves were located using the precise technique of neurostimulation. In the eight trials comparing multiple with single injections, and the 11 trials comparing multiple with double injections, there were significantly fewer people needing extra anaesthesia in the multiple injection groups. In addition, fewer patients in the multiple-injection group experienced tourniquet pain compared to the double-injection group. There were no other statistically significant differences in complications or patient discomfort between the two groups for any of the three comparisons. Single and double injections took less time to perform than multiple injections, but this did not reduce the total time required for adequate surgical anaesthesia to be established.

Overall, the evidence from these trials showed that injections of anaesthetic close to three or four nerves in the armpit provide more complete anaesthesia for hand and forearm surgery than one or two injections. There was, however, not enough evidence to determine if there was a significant difference in the other outcomes, including safety.