Wrong-sided nerve blocks: a preventable error

As practising anaesthetists, in recent years with the advent of systems and programmes for incident awareness and reporting, we have seen a number of previously unnoticed problems brought to our attention.

Performing peripheral nerve blocks on the wrong side or at the incorrect site is one issue that was previously ‘tolerated’ without the due recognition, reporting and scrutiny undertaken to minimise or even eradicate this simple error which can be associated with significant morbidity.

An indefensible claim

While most patients will not suffer any long-lasting damage from a wrong-sided nerve block, if a patient suffers, for example, a nerve injury as a result of a wrong-sided nerve block, any claim will be indefensible and will be settled. Avant takes the view that claims such as these should be settled as wrong-sided nerve blocks are a preventable medical error.

How common are wrong-sided blocks?

While wrong-sided nerve blocks are a relatively rare event, estimated at 0.04% in Australia and New Zealand, with the increasing use of peripheral nerve blockade (particularly with the greater access to ultrasounds to guide nerve blocks), we may find that future statistical reports show a higher incidence of wrong-sided nerve blocks.

Risk factors

The consequences of performing wrong-sided nerve blocks can include complications such as neuropraxia, arterial puncture or injury, inadvertent IV injection or pneumothorax etc arising from the unnecessary block itself. It also carries the additional risk associated with the administration of extra local anaesthetic to the patient, should the nerve block have to be performed again on the correct side.

A UK study found femoral, interscalene and ilio-inguinal blocks were most commonly involved in wrong-sided nerve blocks being performed.

Factors pointing to an increased risk of performing a wrong-sided nerve block include:

• significant time delays between ‘check in’ and the block performance
• distraction in a busy anaesthetic room or theatre
• push for fast turnover times
• no marking of the surgical (or block) side/site
• turning of patients may cover side/site markings
• lower limb nerve blocks may have surgical site arrow covered

‘Stop before you block’ approach

Recognition of this issue has seen the development of international initiatives to help anaesthetists avoid this preventable medical error.

Australia, New Zealand, the USA and United Kingdom have adopted a regional nerve block pre-procedural checklist dubbed the ‘Stop before you block’ campaign, to reduce the potential for wrong-sided/site nerve blocks. Posters advertising the initiative have been developed to help lift awareness and compliance with this quality and safety measure.

Anaesthetists and anaesthetic assistants should follow the ‘Stop before you block’ process in addition to the World Health Organisation [WHO] Surgical Safety Checklist which requires sign in before induction.

According to this process:

• The WHO sign in is performed as usual. Patient identity, consent and marking of the correct surgical site are confirmed.
• A STOP moment must take place immediately before inserting the block needle.
• The anaesthetist and anaesthetic assistant must double-check:     - the surgical site marking      - the site and side of the block

The Australian and New Zealand College of Anaesthetists’ (ANZCA) guidelines support this process with the requirement to perform a ‘time out’ before skin incision.

Key lessons

• Wrong-sided nerve blocks are a preventable medical error; claims resulting from wrong-sided blocks are considered indefensible and in most cases will be settled.
• Anaesthetists can eliminate the risk of making this simple error by adhering to initiatives such as the WHO Surgical Safety Checklist and the ‘Stop before you block’ approach and by being aware of the risk factors associated with wrong-sided blocks listed above.

You may also be interested in…

Our article, ‘WHO Surgical Safety Checklist: is it working?’

Viewing our new Risk IQ webinar ‘Creating a just culture’ to obtain CPD points. This popular webinar explores the creation of a just culture and provides lessons learned from the aviation industry to reduce medical errors.