A practical solution for preventing wrong‐side blocks

Moppett and Shorrock's editorial 1 (accompanying Hopping et al.'s paper 2) makes some interesting points about how to practically prevent wrong-side blocks, above and beyond the admirable aims of the ‘Stop Before You Block’ (SBYB) campaign. We would like to share a development we have been working on and would welcome views as to whether this might be another avenue by which to tackle the problem. We recognise and agree with the significant role that human factors and ‘varieties of human work’ play in the event of a wrong-sided block. The SBYB campaign advocates a check just before needle insertion, but this is commonly a time of high cognitive load for all staff involved, and a difficult time to remember to perform the check. Accordingly, we have devised, coded and built an electronic ‘proof of concept’ device using open-source hardware (ArduinoTM, https://www.arduino.cc/en/Trademark/HomePage) which plugs in, and is powered by, the USB port found on the side of all new modern ultrasound machines. This device attaches to the nerve stimulator port of the block needle. The device then senses when the needle touches the skin (or, indeed the ultrasound gel in contact with the skin) and issues a final verbal cue to ‘check side of block’ just before needle insertion. This message is repeated until a confirmation button is pressed. It appears to be a highly reliable and reproducible addition to existing checks. We hope that by instigating this step, the final check will be more readily carried out. We would encourage industry to consider implementing such technology. With the relatively cheap cost of internet-enabled devices, it would be relatively simple to adapt this device to ‘log’ that a check had been carried out at a particular time and location, or to produce a simple printout to supplement the anaesthetic record, confirming that a check had taken place. Although this type of technology is unlikely to fully eliminate all wrong-sided blocks, we think it would serve as a final reminder at the time advocated by the SBYB campaign.