Aligning Vascular Access Choices with NAP6 Safety Principles

The Sixth National Audit Project (NAP6)¹ was the largest UK study on perioperative anaphylaxis, reviewing over three million anaesthetics across all NHS hospitals between 2015 and 2016. Its findings were significant: approximately one in 10,000 anaesthetics resulted in life-threatening anaphylaxis. While neuromuscular blockers and patent blue dye were common triggers, chlorhexidine emerged as a notable cause of severe reactions.

However, chlorhexidine-related sensitivity and anaphylaxis remain largely under-reported and poorly recognised, with the true prevalence still uncertain. In the original NAP6 study, it highlighted research that identified that during a ten-year period up to 2004, only 50 cases of IgE-mediated reactions were reported in the medical literature. Following this 10-year period, 104 cases were documented from four UK specialist centres between 2009 and 2013². Despite a national alert issued by the MHRA in 2012 warning about chlorhexidine-containing medical products and devices, awareness among clinical staff remains low.

NAP6 also highlighted gaps in recognition and management, including delayed administration of adrenaline, incomplete investigations, and missed allergy referrals. Although most patients survived, ten deaths were reported, with poor outcomes linked to age, obesity, and chronic illness.

Current Evidence and Practice Trends

According to a 2025 qualitative study, NAP6 recommendations have influenced practice significantly. NAP6 has:

• Raised awareness of perioperative anaphylaxis.
• Improved allergy referral processes.
• Lead to the development of penicillin allergy de-labelling initiatives.
• Updated national guidelines and departmental alerts.

The Resuscitation Council, and Association of Anaesthetists, have published guidelines to help raise awareness of the importance in recognising and preventing chlorhexidine-related reactions. Both agree this has made a huge difference for patient outcomes.^3,4 However, despite progress since NAP6, several challenges remain in implementing allergy-safe practices,^5,6 such as:

• Limited access to allergy clinics, making timely diagnosis and follow-up difficult.

• Misalignment between clinical disciplines, which can lead to gaps in communication and inconsistent approaches.
• Difficulty removing incorrect allergy labels, which can persist in patient records and affect care decisions.

These barriers highlight the need for continued education, collaboration, and system-level improvements to fully realise the safety principles outlined by NAP6.

Aligning Vascular Access Choices with NAP6 Safety Principles

Moving from the NAP6 and local audit findings to practical action may mean applying NAP6 recommendations to procurement decisions.

For clinicians and purchasing teams, it is important to align vascular access choices with NAP6 safety principles to support patient care.

Ebo, as quoted in the NAP6 Report¹, says: It may not be immediately obvious that these products contain chlorhexidine, which has been called “the hidden allergen” (Ebo 2004).

This means choosing vascular access devices which reflect best practice, reduce the risk of “the hidden allergen”, and maintain better infection control standards.

Antimicrobial silver ion based technology offers an effective CLABSI prevention without relying on chlorhexidine. While it is not possible to eliminate the risk of allergic reactions for every individual, the potential adverse effects linked to chlorhexidine can be significant. When safer options exist, prioritising products with a lower risk profile is a responsible approach, and such alternatives could be made readily accessible to support patient safety and informed clinical decision‑making.

This technology can deliver protection against microbial contamination when compared to chlorhexidine coatings. Therefore, using chlorhexidine-free catheters, integrated with alternative antimicrobial technology can provide effective infection prevention without introducing the potential for chlorhexidine related anaphylaxis.

Practical implications

Translating NAP6 findings into everyday practice means making informed choices about vascular access devices. Clinicians can take practical steps to minimise allergy risk while maintaining infection prevention and control:

• Check product composition: Increase awareness around products so clinicians know which devices contain chlorhexidine.
• Consider allergy risk in procurement: Selecting chlorhexidine-free CVC options reduces the likelihood of severe reactions.
• Follow MHRA guidance: Stay informed about alerts and recommendations for safe device use.

Conclusion

NAP6 highlighted the importance of recognising and preventing perioperative allergens such as chlorhexidine. Its findings have driven changes in UK guidelines and clinical practice, emphasising alternative product choices. Advanced vascular access solutions, which incorporate antimicrobial technology design and offer infection prevention and control, may be recommended. These features align with NAP6 safety principles, supporting clinicians in delivering high-quality, allergy-safe care, helping to improve patient safety.

References

1. Cook TM, Harper N, editors. Anaesthesia, Surgery and Life‑Threatening Allergic Reactions: Report and findings of the Royal College of Anaesthetists’ 6th National Audit Project: Perioperative Anaphylaxis. London: Royal College of Anaesthetists; May 2018. ISBN: 978‑1‑900936‑18‑7. Available from: https://www.rcoa.ac.uk/sites/default/files/documents/2023-02/NAP6%20Report%202018.pdf (accessed 18 Dec 2025)
2. Egner W, Cook TM, Harper NJ, et al. Specialist Perioperative Allergy Clinic Services in the UK 2016: Results from the Royal College of Anaesthetists 6th National Audit Project. Clin Exp Allergy 2017; 47: 1318-30.
3. Resuscitation Council UK. Guidance: Anaphylaxis [Internet]. London: Resuscitation Council UK; [cited 2025 Dec 18]. Available from: https://www.resus.org.uk/library/additional-guidance/guidance-anaphylaxis.
4. Association of Anaesthetists. Anaphylaxis and allergies [Internet]. London: Association of Anaesthetists; [cited 2025 Dec 18]. Available from: https://anaesthetists.org/Home/Resources-publications/Safety-alerts/Anaesthesia-emergencies/Anaphylaxis-and-allergies.
5. Beecham E, Clark SE, Brady G, Brummell Z, Kane AD, et al. An evaluation of the impact of national recommendations on patient safety in perioperative care. BMJ Open Qual. 2025;14(Suppl 3):A69.
6. Rose MA, Garcez T, Savic S, Garvey LH. Chlorhexidine allergy in the perioperative setting: a narrative review. Br J Anaesth. 2019;123(1):e95–e103.