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Water loss

Insensible (non-sensible) water loss

Society needs to work towards sustainable health and social care for all, now more than ever. One particular aspect of sustainability is to recognise the importance of the environment and our place within it. 

As anaesthetists and intensivists, we work on the front line of the NHS and have the ability to influence greatly the impact we have on the environment. Whether that be encouraging the use of recycling, or turning off electricals when not in use, we can all make a difference. 

We decided to look at the use of water in our Trust because one of our group was frustrated at seeing leaking theatre taps every day. We thought this was wasteful, so decided to quantify the problem with a small study.

The NHS uses a vast amount of water, around 40 million m3 in 2007/2008. With over 7 million operations a year, and at least two people scrubbed for each, the potential for water wastage is large. 

Our Trust alone spends over £134,000 each year for roughly 139,000 m3 of water. 

The Sustainable Development Unit requires all NHS organisations to measure and monitor annual water consumption, to improve efficiency and lower their environmental impact. 

We placed measuring jugs under each lever tap in theatres, and measured the 'as found' water for three minutes. We then turned them off and repeated the measurement. We did this twice a day for eight weeks. 

The total water wasted 'as found' was 11.4 litres. This was reduced to around 1.3 litres by simply turning off the taps: a nearly 90% reduction. 

The worst offending theatres were orthopaedics.

These numbers don't sound vast, but this is just for the taps in six theatres for six minutes of a day. Imagine this problem scaled up to all the taps in the hospital, to all the hospitals in the country, all day. 

In the worst three-minute collection period over the study, we collected 2.2 litres of water. That’s 45 litres/hour of water literally going down the drain.

What our small dataset indicated was that human behaviour was the key. Taps just weren't being turned off. 

We presented our data at various audit meetings to get the message across to the groups who use theatres. People had been intrigued as to what we had been doing with measuring jugs and stopwatches in the sinks for the past few months and seemed receptive to the idea. 

Some of the problem was clearly mechanical. We still had a litre of water wasted despite taps being optimally 'off', so we discussed getting the faulty taps fixed with Estates.

Like all good researchers, we wanted to see if our interventions had made a difference. We repeated the study, using the same methodology, and found some improvement. 

We hadn’t managed to get anywhere with maintenance yet, but people were taking note and trying to turn taps off. We found we had reduced 'as found' wastage from 11.4 litres to just under 9 litres, a modest but statistically significant reduction. 

Unfortunately, we still found we could reduce this by nearly 80% simply by turning taps off. 

What did we learn and what could be changed? We considered that tap design was a problem. The operators and scrubbed staff cannot de-sterilise by turning taps off. Some units have used foot-operated taps to reduce water use, with good effect

Other hospitals use sensors to provide water only when hands are under the tap. 

These are big investments and clearly disruptive to implement. A continued cycle of education should help promote good practice and maybe a few washers to tighten up the leaky taps. 

Written by:

  • P Douglass - CT2 Anaesthetics, North West London rotation
  • L Jeanes - CT2 Anaesthetics, North West London rotation
  • SM Yentis - Consultant Anaesthetist, Chelsea and Westminster Hospital, London

 This article first appeared in the May 2018 edition of Anaesthesia News

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