T. Fowles, P. Arnold

Alder Hey Children's NHS Trust, Liverpool, UK


Performance of a regional anaesthetic block at an incorrect site is undesirable and can be associated with patient harm. Wrong sided blocks are considered a ‘Never Event’ in current NHS England Serious Incident Framework(1). Historically a ‘stop before you block’ (SBYB) policy has been in place in our hospital for several years following an initial incident. In accordance with national guidance this consisted of a pause prior to performing the block and additional checks conducted by anaesthetists and anaesthetic practitioners (2).


Following a further incorrect side block an attempt was made to improve this process. An audit was instigated to monitor compliance with completion of the SBYB and with the recommended procedure. Initial attempts at this audit had poor compliance and proved time consuming.

Strategy For Change

Following engagement and discussion with anaesthetists and anaesthetic practitioners, posters and teaching were distributed to reinforce the correct process. In addition, a modified approach to the audit utilising electronic forms (assessed using a QR code displayed in all anaesthetic rooms) and cross validation with electronic patient records. Emphasis was placed on:

  • nerve block was highlighted in the morning/afternoon huddle.
  • that SBYB must be performed for all cases.
  • that SBYB should occur immediately before needle insertion.
  • that the surgical site mark is marked and checked against consent.

Measure of Improvement

In December and January, there were a total of 274 nerve blocks performed. In 230 of these an audit form was completed (response of 84%). 225 (98%) of the blocks were highlighted in the huddle, all but one (99%) of SBYB’s occurred immediately before needle insertion and in all cases the consent form was checked. Site markings were checked in 76% whilst 24% it was confirmed the site marking was not appropriate (i.e. bilateral truncal blocks). In only one case was the site marking not checked. Of the 44 cases in which an audit form was not completed the majority were blocks placed by surgeons within the field. However, in 7 cases these were Quadratus Lumborum blocks placed by anaesthetists.

Conclusions and lessons learnt

Compliance with the SBYB process was high. This was achieved by a process of engagement, publicity, and education. Wrong sided blocks are rare and we cannot comment from this audit on the success at avoiding wrong sided blocks.  There is a need to consider how compliance with this process when blocks are performed by the surgical team is recorded.

The use of combined methods and interdisciplinary cooperation, reporting by anaesthetic support staff using a QR code and recording by anaesthetists on the anaesthetic record, allowed us to describe this level of compliance successfully. This is potentially a model for future collaborative service evaluations and quality improvement.


  1. Never Events list 2018 (updated February 2021): NHS England; 2021 [Available from: https://www.england.nhs.uk/publication/never-events/] Accessed 6/2/2024
  2. Haslam N, Bedforth N, Pandit JJ. 'Prep, stop, block': refreshing 'stop before you block' with new national guidance. Anaesthesia. 2022;77(4):372-5.
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