AIRBORNE INFECTION CONTROL
in all the risk assessments they undertook for managing disease, and focusing particularly on those at the top of the list. She said: “Right at the top of the pyramid is ‘Elimination’, i.e. preventing somebody infectious being in the building, but we all know that this is not going to be possible in a hospital.” She continued: “It’s important to note here that ‘Engineering Controls’ sit firmly in the middle, above Administrative Controls and PPE, so we should really be ensuring we have these things in place – not only screens, barriers, and automatic doors, but also ventilation – before the rest, simply because the engineering controls don’t rely on the human behaviour to be effective. Of course this is such an infectious disease that PPE also becomes really important.”
Reducing the source of the pathogen Following on, and thinking about how healthcare engineers might best prioritise interventions, one of the first steps was to remove/reduce the source of the pathogen, for example via isolating infected patients, implementing effective testing, and using zoning, as well as making mask wearing mandatory for all staff. Prof. Noakes said: “Thinking about engineering though, I would always put ventilation top of the list; it’s essential for health and well-being – not just for COVID – and should be the first thing we implement to control the risks in a room. Your ultimate risk control, of course, is respiratory protection. Certainly when somebody is very close to others during aerosol-generating procedures, you need that, but in the corridor, for example, there should be less of a need; your ventilation should be managing your airborne risks here.”
Installed single pass Local single pass
Upper room – UV
Room reactor
Figure 4: Various room approaches for the use of air cleaning equipment. Flagging the difference
Here, the speaker said she was keen to ‘flag’ the difference between ventilation and air cleaning – the first was ‘certainly not a substitute’ for the second. She elaborated: “Your ventilation is there for multiple reasons – obviously to control infection, but also other contaminants, and also part of your thermal comfort strategy and control for humidity and odour. The air cleaning and disinfection approaches, meanwhile, are only about contaminant reduction; not all the other parameters. I would reiterate that air cleaning is no substitute for ventilation, although it can play a valuable role in hospital locations where the ventilation
Medical Engineering
APPRENTICESHIPS •
WE ARE P
WE ARE PROUD TO ANNOUNCE OUR PAR ANNOUNCE OUR PARTNERSHIP WITH DUDLEY COLLEGE OF TECHNOLOGY IN T DELIVERY OF APPRENTICESHIP
OANNOUNCEOURPA DELIVERY OF APPRENTICESHIPS •
• •
Level 4 Healthcare Science Apprenticeship Le v el 2 Healthcare Science Apprenticeship
(Selected trainers at NHS Nightingale Hospitals) World class tuition on medical devices from Avensys
In partnership with Dudley College of Technology - Rated Ofsted Outstanding
• Fees drawn from the Apprenticeship Levy •
Dev elop the knowledge and skills of your EBME staff
For an info-pack or to discuss how we can help develop your depa rtment: - suitable for new starters and experienced staff
01562 745 858 training@av
ensysmedical.co.uk April 2021 Health Estate Journal 27 P OGY IN THE PA NOW IN
PARTNERSHIP WITH
isn’t ideal, and where it is difficult to increase ventilation rates without substantial building works.”
Moving next to ‘touch on definitions’, Professor Noakes said the sector tended to focus on air change rates as a key parameter in describing hospital ventilation, but an air change rate would not remove all contaminants in the air. Each time the air was changed – given a mixed ventilation environment – it removed about 63 per cent of the aerosols; thus in a room subject to a single air change/hour, only 63 per cent were removed, whereas with six air changes/ hour, almost 99.5 per cent are removed. Turning to log reductions, she said: “Quite
©Professor Cath Noakes, University of Leeds
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
