Neuraxial skin preparation…
time to rethink applying the Pink!

Author: Dr Julia Morch-Waldock, Consultant Anaesthetist, Royal Victoria Infirmary, Newcastle upon Tyne, UK

Introduction
Skin preparation guidelines for neuraxial block are focussed on prevention of infection and arachnoiditis, both very rare catastrophic events1.
The ‘spray, wipe, spray’ application method of Hydrex™️ Pink (Ecolab) is commonplace.
Chemical burns to women from this practice could be more common than previously understood2, estimate prevalence 1/1000

Case report
32 year P1 woman, BMI 33 had an epidural inserted 9 hours into labour. 
When her back was sprayed with Hydrex™️ she complained of pain, exacerbated when the area was wiped and resprayed. 
Catheter insertion was uneventful and it was secured with a LockIt Plus®, Tegaderm™ and Leucoplast® Hypafix® . 
Routine follow up revealed an area of skin damage over her epidural insertion site consistent with a chemical burn and dressing removal damage (Figure1).
We were reassured by the manufacturer’s quality controls that the appropriate mixture was in the bottles. Bottle/woman usage was untraceable in our system.
Allergy testing was negative. 
Institution investigation revealed one similar case and two others of skin blisters in a ‘drip cake’ pattern around the natal cleft. 
Observation of typical Hydrex spray application revealed coalescing droplets descending to the natal cleft followed by a vigorous wiping of the target area and respraying. The lumbar area was allowed to dry by evaporation but the natal cleft often remained wet allowing prolonged contact when the woman was laid down.
The incidents were reported to the MHRA.

Discussion
Labouring women are at increased risk of pressure sores, all NHS settled claims for pressure lesions (2000-18) involved epidurals3. The role of chlorhexidine is absent from causation narrative which focuses on mobility restriction. 
Both our women complained of pain when sprayed which is a red flag.
’Spray, wipe, spray’ is embedded practice but work as done is not work as prescribed. The manufacturers of Hydrex™️ do not recommend wiping skin. The 2nd spray is perceived as beneficial yet not evidenced or recommended1. 

Recommendations
Revise skin preparation application guidance
Consent for skin damageBibliography
1. Campbell JP, Plaat F, Checketts MR, et al. Safety guideline: skin antisepsis for central neuraxial blockade. Anaesthesia 2014;69(11):1279-86. doi: https://doi.org/10.1111/anae.12844
2. Blake SC, O'Dea S, Murrell DF. A chlorhexidine conundrum after an epidural delivery: The difficulty of differentiating between chlorhexidine burns and hypersensitivity reactions. Int J Womens Dermatol 2019;5(4):269-70. doi: 10.1016/j.ijwd.2019.04.023 [published Online First: 20190502]
3. NHS R. Did you know? Maternity pressure ulcers. 2018. https://resolution.nhs.uk/wp-content/uploads/2018/10/Did-you-know-Maternity-Pressure-Ulcers.pdf (accessed 30/01/26).