LAUSR

We thank Pollard et al. for observations on our letter [1] and agree with the Health Service Investigation Branch (HSIB) concerns about practice variability in stop before you block. The HSIB chose as an index case an example of wrong side block from a Trust that used a sticker, but where this was not applied [2]. The HSIB might equally have used an index case where a sticker was applied on the wrong side, which led to wrong-side block. Pollard et al. readily concede that stickers have been ineffective in their experience, so it is unclear if they are defending this practice. Additional marks/stickers have caused wrong side blocks and are contrary to other guidance cited, which states the only mark should be the surgical site mark [3]. Pandit et al. have speculated (before the most recent discussions, and to embrace a wide range of views) about the use of a sign or a sticker, but, crucially, only if these are applied within the sterile field, after skin prep and immediately (just seconds) before needle injection [4]. The alternative described by Pollard et al. involves non-sterile stickers applied long (many minutes) before injection. This cannot serve as a stop moment, but rather only as a reminder. As Hopping et al. discovered, it is not just a case of what forces the stop moment, but when this is applied [5]. Pollard et al. refer to some international literature, but since practices differ, extrapolation is difficult, especially as Never Events are unique to NHS England [6]. The radiology and other society guidance referred to concerns situations where the block is the sole intervention. That the correspondents extrapolate this to blocks for surgery represents another source of confusion. The HSIB has now asked the Safe Anaesthesia Liaison Group to review the guidance to resolve inconsistencies. We cannot prejudge the outcome of that review, but checklist fatigue will be one consideration [7]. Mock Before You Block (a personal behavioural barrier) or ultrasound screens (aides memoire) are harmless, at least [1]. It is more difficult to identify those measures that are both harmless andproven effective [8].