When 'never' happens: what two wrong-side nerve blocks taught us about patient safety

Summary

In healthcare, we often talk about 'never events'—serious incidents that should not occur if appropriate systems are in place. But what happens when they do occur?

I recently had the great pleasure of working with a group of anaesthetic resident doctor colleagues on a patient safety project that began with exactly that question. Within a short period in 2025, our large UK teaching hospital experienced two wrong-sided peripheral nerve blocks after six years without a single reported incident. We wanted to understand why.

Content

Looking beyond individual error

Both incidents occurred during a major transition: we were moving anaesthetic records, consent forms and safety checklists from paper to digital. At first glance, the timing felt more than coincidental.

After initial governance processes were completed, our team used the Patient Safety Incident Response Framework (PSIRF)[1] to explore what had happened. Introduced in the NHS in 2022, PSIRF promotes a systems-based approach rather than searching for a single 'root cause'. It examines how elements such as people, tasks, tools and technology, environment and organisational factors interact to increase risk.

For us, this shift in perspective proved crucial. Instead of asking “who made this mistake?”, we were able to consider “what conditions made this error more likely?”.

What we found: small gaps in a complex system

We brought together a multidisciplinary 'learning MDT', combining insights from staff interviews and systems analysis. A clear pattern emerged: no single failure caused these incidents. Instead, multiple small vulnerabilities aligned.

One issue stood out. In our previous paper-based system, clinicians used a 'Stop Before You Block' (SBYB) sticker—a simple but effective visual cue prompting a final safety pause before performing a nerve block. During the digital transition, this physical prompt disappeared.

Other contributing factors reinforced the problem:

• Staff worked under cognitive overload, juggling interruptions, changing plans and high-acuity patients.
• Digital consent processes made SBYB checks feel more cumbersome, drawing attention away from the patient and towards the computer.
• Poor visibility of surgical site markings increased the barriers to performing SBYB.
• Ergonomic challenges in anaesthetic rooms made equipment setup frustrating.
• Time pressure on theatre lists encouraged task compression.

In both cases, clinicians skipped the SBYB pause entirely—not out of negligence, but because the system no longer reliably supported it.

These events didn’t reflect individual failure. They reflected a system under strain during organisational change.

From insight to action: designing safer systems

We knew we couldn’t eliminate complexity from clinical environments, but we could design systems that make the safe action the easy action. We developed a multi-faceted improvement plan.

1. Strengthening standards and education

We updated our local guidance, aligning it with national recommendations from the Safe Anaesthesia Liaison Group and Regional Anaesthesia UK.[2] We rebranded it as the 'Prep Stop Block LocSSIP' (Local Safety Standard for Invasive Procedures).

We promoted this through clinical governance meetings and delivered targeted teaching to consultants, trainees and anaesthetic practitioners. To support sustainability, we embedded a training video into the anaesthetic resident doctor induction programme and uploaded it to our intranet.

2. Fixing friction in the system

We addressed practical barriers:

• Improved access to longer ultrasound cables.
• Standardised surgical site markings to improve visibility.
• Explored integrating anaesthetic complexity into theatre scheduling.
• Trialled LED signs to indicate when the anaesthetic room is in use; thus creating a 'sterile cockpit' by discouraging interruptions during anaesthetic procedures.
• Introduced electronic tablets so consent forms could be viewed alongside the patient and checklist.

Each of these changes aimed to reduce cognitive load and create space for safer practice.

3. Introducing a physical safety barrier

Our most impactful intervention was the 'Prep Stop Block Lid'. We designed a lidded box displaying a safety infographic. Clinicians place prepared local anaesthetic inside and cannot access it until they complete the SBYB pause. This shifts safety from memory to physical design, creating a clear pause point in the workflow. We refined the intervention through Plan–Do–Study–Act (PDSA) cycles with frontline feedback before wider rollout.

What we’ve learned so far

Early data show improvements in process measures, including increased visibility of the SBYB step. Audits of Prep-Stop-Block compliance suggest an improvement from 34% during digital transition to 100% at most recent review. However, we remain cautious.

We are still in a 'zone of vulnerability', where changes are ongoing and their full impact is unclear. Because never events are (fortunately) rare, it will take time to determine whether these interventions reduce harm.

That said, several key lessons have already emerged:

• Never events are rarely about individuals. They arise from system conditions that make errors more likely.
• Digital transformation can unintentionally remove safety cues. We must actively design these back into new systems.
• Education and policy are necessary but insufficient. The most reliable safety interventions are embedded into workflow, especially physical or procedural 'forcing functions'.

A call to action

If your department is undergoing digital transformation, take a moment to ask: “What safety cues might we be losing—and how will we replace them?”

We need to move beyond simply digitalising existing processes. Instead, we should use these transitions as opportunities to design safer, more resilient systems from the ground up. Because when it comes to patient safety, 'never' is not a guarantee, it’s a goal we must actively work towards.

References

1. https://www.england.nhs.uk/long-read/patient-safety-incident-response-framework/
2. https://www.salg.ac.uk/salg-publications/stop-before-you-block/

About the Author

Victoria Prabhu is an ST7 anaesthetics resident doctor at Oxford University Hospitals NHS Foundation Trust. She has undertaken Special Interest Area modules in regional anaesthesia and obstetric anaesthesia, in addition to a Quality Improvement Fellowship and QI Leaders course. She has been involved in numerous quality improvement projects alongside her anaesthetic training and has seen that clinical staff play a vital role in translating patent safety initiatives into frontline practice.