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Wrong site nerve block | Signal

Reference number
1293 D
Issue date29 October 2010

This Signal is about the risk of administering a nerve block to the wrong site perioperatively.

A sample incident reads:

“It was realised that blocks were being inserted on the wrong side. Femoral and sciatic blocks were inserted on the correct side ... The wrong block persisted, delaying the patient mobilisation by approx 24hrs. ... Already careful to check: the side, the mark and ask the patient before anaesthesia. On this occasion I was distracted by a member of staff coming into the room and asking a question.”

Regional nerve blocks are given by injection around nerves for perioperative analgesia or anaesthesia. A variety of methods are used to locate the nerve including ultrasound. As the nerves have normal structure and function, abnormal features cannot be used to identify the site for blocking.

A search of the National Reporting and Learning System (NRLS) identified 67 further reports of wrong site block in a period of 15 months. The majority of blocks were administered by anaesthetists.

Issues identified included distraction of the anaesthetist, lack of mark specific to the block, lack of anaesthetic time-out and discrepancy between operating list and mark or consent form. Some reports stated the site was marked but either covered up by drapes or obscured when the patient was positioned. This is particularly likely if the surgical site mark is distant from the nerve block site. The Surgical Safety Checklist Alert (2009) contains the supporting information, “The anaesthetist should only proceed with a regional block when he/she has confirmed that the site for surgery has been marked.” Further guidance on the marking of the site is in the appendix.

Please contact us with your initiatives to reduce risks in this area. We can share them in appropriate forums for example the Safer Anaesthesia Liaison Group (SALG).

Signals are notifications of key risks emerging from review of serious incidents and shared by the NPSA.