Dave Mortimer, national sales manager for Vapac Humidity Control explains why hospitals are approaching the need for humidification from a scientific standpoint.
MRSA and the presence of other super bugs has put ventilation systems in hospitals up and down the country high on the agenda and renewed research is being carried out to investigate the benefits of humidification and how it might help counteract the spread of infection.

Researchers at Bradford University have already started a two-year programme examining the effects of humidity on hospital super bugs such as e.coli and have constructed one of the world's largest biological test chambers.

Professor Beggs, head of the Bradford Infection Group and professor of medical engineering at the University is spearheading the research and is keen to establish the extent humidity control might assist in the fighting infection.

Impact of humidity

Humidification has long been recognised as necessary and there are countless papers and articles written extolling its virtues. Dry eyes, sore throats and sick building syndrome can all be attributed to a lack of humidification. Until now there has been no scientific research carried out in the UK to substantiate a need for humidification.

Although there have been papers published looking at surgical applications there has until now been no extensive research looking at how it may be used to combat infection on hospital wards.

Researchers are modelling the impact of humidity on bacteria and looking at the impact of changes in room humidity on different pathogens and how humidity might be used to control the spread of infection via contaminated surfaces and air in hospital wards.

Air quality in hospitals is a very complex issue. Contaminants can be airborne; attracted to dust due to static; or carried by visitors; as well as originate inside the hospital and these threaten the quality of the environment. Ventilation and filtration provides a means of combating contaminants by diluting their concentration.

A high standard of air quality can be achieved by ensuring proper ventilation, adequate filtration and humidity management.

While it is recognised that maintaining a comfortable and safe working environment is important for operating teams and patients, for many surgical procedures a carefully managed environment can be critical. For example for many surgical procedures humidity is essential and cannot take place without it, ophthalmic surgery where the eye needs to be kept moist throughout the procedure, accounts for 7% of all surgery in the UK.

Effects of Humidity on Posterior Lens Opacification During Fluid Air Exchange published in the US says that the use of humidified air promotes better visualisation and enhances surgical performance.

There are many other procedures that require precisely controlled humidity including invasive surgery when tissue starts to deteriorate if there is not enough moisture in the air.

Here in the UK various papers have appeared in The British Journal of Anaesthesia and the Journal of Laryngology and Otology discussing humidification.

The NHS has recognised the importance of humidification for quite sometime as bodies can lose as much fluid in cold environments as in a hot one.

In an information leaflet 'Water for Health Hydration Best Practice Toolkit for Hospitals and Healthcare' it states that: 'In some environments there may be a risk of low humidity, for example if there is a poor ac system...This can dry the air to unacceptable levels...The RH for an office should be between 40-70% with the lower end being the most comfortable in warmer offices'.

Only last year the Spanish paper La Vanguardia reported that 619 employees were allegedly suffering from muscle lesions in Catalunya as a direct result of static build up in the work environment and that adequate humidification could have prevented the problem.

Humidification systems are already present in operating theatres where the control of air movement and humidity is essential. Theatres by their very nature have to be regarded as clean rooms and the cleanest area is working above floor level at the height of the operating table and at elbow height of the surgeon. Correctly balanced humidity helps keep contaminants at low levels.

The majority of humidity problems in hospitals tend to be as a result of poor applications, incorrect installation or lack of maintenance, rather than equipment. Only when manufacturers are called in to solve problems and/or retrofit systems is there an opportunity for a manufacturer to talk directly with the health engineers who have first hand experience of patients' well being.

By consulting directly with manufacturers who are experts in humidification, hospitals will have access to a vast untapped resource of knowledge. Systems will then be installed to meet a specific requirement and fit for purpose.

Most problems that occur tend to lie with the application and the wrong sizing of equipment. As a result manufacturers have developed selection software to guide FM's and health estate managers through the selection process. A number also offer selection software free. (Vapac provides demo disks and a 30-day free trial can be obtained at the Energy Exhibition in Birmingham and the London HEVAR.)

Ever mindful of variable water qualities and possible contaminants reverse osmosis systems are available. Using the latest technology these offer automatic flushing to avoid salt build up, pressure regulation for stable operation and an integrated pump, delivering a high flow rate and reduced maintenance thus extending the life of humidifiers.

Hospital environments and manufacturers are playing their part to ensure that health estate managers make the right selection. The findings of Bradford's research may well provide the industry with a welcome boost.

Vapac Humidity Control
01732 863447