Nerve block site marking

Abstract

Pandit et al. caution against site marking for nerve blocks [1]. National Health Service Trusts around the country (including our own) have developed local adaptations to the Stop Before You Block (SBYB) procedure, as advocated in the original document [2]. In Oxford, as in other Trusts, we chose to provide a sticker for anaesthetists to use just before performing the procedure as an additional reminder of the site of the block [3] (e.g. if the surgical site mark is distant from the point of insertion of the block). The process we designed seeks to reinforce the vigilance and teamwork within the anaesthetic room when doing the WHO checks. The Healthcare Safety Investigation Branch (HSIB) index case [4] described a wrong site block that occurred in a hospital where the local policy was to mark the site with blue tape, but in this case the tape was not applied. This does not provide evidence that applying the mark can lead to wrong site block, but does support the premise put forward by James Reason, that ‘misuse of a good rule can lead to error’ [5]. The HSIB concluded that ‘the current variability of how SBYB is understood and practised means that SBYB does not always form a strong systemic protective barrier to wrong site blocks occurring’.Our own experience in Oxford and evidence from others would support this statement: our current procedures are insufficient to prevent wrong-sided blocks. It is important to consider what constitutes an ‘invasive procedure’ and, therefore, how one defines the operator. The 2015 NatSSIPs [6] document states: ‘3.4.2 Invasive Procedure: All surgical and interventional procedures performed in operating theatres outpatient treatment areas, labour ward delivery rooms, and other procedural areas within an organisation’. In the case of nerve blocks it is commonly an anaesthetist who is the operator responsible for the procedure and, therefore, also responsible for ensuring all sensible measures are taken to perform the block on the correct side. This may include making an additional mark. In the UK, site marking was one of the proposals first made by French et al. [2] who stated ‘suggested adjuncts include block side marking by anaesthetists at the time of theWHO sign in’. Others have similarly recommended marking of the block site by the anaesthetist to help prevent error, including the Faculty of Pain Medicine at the Royal College of Anaesthetists [7], the American Society for Regional Analgesia [8], the Joint Commission [9], and, most recently, in a systematic review of wrong site blocks by Deutsch et al. [10]. It was also suggested by Professor Pandit that modifications of ‘mock before you block’ might include signing the site with one’s own signature (or other unique mark), or applying a sterile label/dressing to remark the site [11]. Furthermore, colleagues in interventional radiology have considered the problem of how to ensure procedures are carried out on the correct side such that both the Royal College of Radiologists [12] and the Society of Interventional Radiology [13] recommend sitemarking.We, therefore, feel that to caution clinicians against site marking now is unhelpful, risking further confusion, and potentially a backward step in attempts to minimise human errors. The Canadian Root Cause Analysis Framework states ‘from a human factors standpoint, the strongest interventions are physical rather than procedural and permanent rather than temporary’ [14]. As yet there is no physical intervention that would absolutely prevent a wrong site nerve block and well-designed, standard procedures usedproperly by everyone are the next best thing. We conclude that at the heart of these exchanges of opinion is the desire to ensure that we get it right first time, every time, for our patients and that the available evidence would suggest that a collaborative, multimodal approach will be vital in achieving that end.