Guidance on ventilation revised and updated

Speaking in the ‘System Governance’ stream on the first day of last October’s IHEEM Healthcare Estates 2021 conference, consulting engineer, Malcolm Thomas, the main author of the 2021 version of HTM 03-01, Specialist Ventilation for Healthcare Premises, published last June, explained the background to, and aims behind, the HTM’s revision, and highlighted some of the major changes that those responsible for ventilation plant in hospitals and other healthcare facilities need to be aware of. HEJ editor, Jonathan Baillie, reports.

Malcolm Thomas was the lead author for both editions (published in 2007 and last year) of HTM 03-01, and also of the ventilation-related HTM 2025 that preceded them. Also the lead author of the engineering section of several HBNs, he has worked in the healthcare sector for over 40 years – both within and outside the NHS. He is President of the Specialised Ventilation for Healthcare Society, and a visiting lecturer at the University of Leeds. Welcoming attendees to his presentation, he explained that as the lead author of HTM 03-01 (2021), he would explain some of the main thinking behind it, and set out the reasons for a number of key changes in the ‘rewritten version’. He began: “As some background to where the HTMs and other guidance on ventilation originated, back in 1972 Dr Owen Lidwell led a Joint Working Party on ventilation and operating suites, and this was the foundation of all the guidance that has emerged since. Many people have asked me,” he continued,” why we bother with material that is ‘so old’? The reason is that when this work was done, it was very evident what worked well in practice, and what didn’t, in a way that’s no longer nearly so clear. When you have significant infection rates in operating theatres, it’s quite easy to see whether – if you change the colour of the paintwork – it makes any difference. Conversely, with very small infection rates – which fortunately we have now – it’s very difficult to know whether changing the surgeons’ gowns, the air change rate, or the colour of the walls, or putting carpet in, makes any significant difference. We’re talking about low percentage changes. We’re in a situation now where people think changes will improve things, but they don’t actually know, and it’s hard to prove what is a good or a bad thing. Back when Owen Lidwell did this work, it was relatively easy, there were step-changes, and he was able to conduct a number of trials.” 

Comparative trials