Hong Kong Green Healthcare
Green Solutions
Climate-Smart Anaesthetic Care
Hitting the gas for sustainable anaesthetic practice
Nitrous Oxide
100-year GWP
298
Sevoflurane
100-year GWP
130
Desflurane
100-year GWP
2540
GWP = Global warming potential; 100-year GWP of CO2 is 1
Anaesthetic gases are
potent greenhouse gases
Anaesthetic gases are potent greenhouse gases. After administration to patients, they are minimally metabolized and exhaled into the atmosphere. The heat-trapping property of these agents is reflected in its global warming potential (GWP), which is a measure of the specific agent's radiative efficiency and atmospheric lifetime relative to CO2.
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This means the global warming effect of releasing 1 unit of desflurane into the atmosphere is equivalent to releasing 2540 units of carbon dioxide.
It has been estimated that the use of volatile anaesthetics in human healthcare is the same as having 1 million cars on the road. This is why institutions are actively looking for ways to reduce its use.
Because of its high global warming potential, hospitals in Australia are eliminating their desflurane use. 6 hospitals have joined the #ditchthedes pledge to take desflurane off the formulary by 2025
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Total intravenous anaesthesia
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Regional anaesthesia
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Low flow anaesthesia
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Avoid use of desflurane
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Waste anaesthetic gas capture and destruction
Some practical ideas
Successful stories
Capture and destroy
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Nitrous oxide (N2O) is an anaesthetic gas commonly used in obstetric wards for mothers in labour. Because it is delivered in an open system, there will be significant levels of N2O accumulated in the delivery room. Chronic exposure has been associated with reproductive problem and liver disorders, which constitutes an occupation hazard to staff.
In 2002, the Stockholm County Council in Sweden decided to lower N2O emission by installing capture and destruction systems in 12 hospital units. Double face masks are used to deliver N2O to patients and also collect the waste N2O exhaled. The gas is then destroyed by catalytic splitting.
Source: Mattias Ahlm, Greenhouse Gases
Reduced nitrous oxide emission
by 52% in 2010
Awake and safe​
The ophthalmology team at the Whipps Cross University Hospital in the UK started a green initiative 'Keeping patients awake and safe for eye surgery', in which clinical staff were encouraged to question the need for general anaesthesia (GA) at various stages of patient encounter.
Over a 6-week period, 9 operations were converted from using GA to local anaesthesia.
Eliminates general anaesthetic risk
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Saves pre-operative assessment and investigations
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Reduces operative waiting time
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770g less waste for each operation
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Projected annual carbon emission reduction 3,704kg CO2 equivalent
Projected annual savings about £161,000
Making the facts known
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Anaesthetists in the University Hospitals Bristol and Weston NHS Foundation Trust developed engagement tools to encourage coworkers to reduce desflurane usage. That includes placing prompt cards on anaesthetic machines that makes clear the environmental impact of various anaesthetic gases. QR codes on the machines would direct the reader to website resources for more information.
This intervention had led to significant reduction in the use of desflurane.
Reduced emission by 30,000kg CO2 equivalent per month
Ideas and challenges
What is the culture of desflurane use in my department? Can a survey be done? How much desflurane is being used?
Can we stop using desflurane altogether?
How can I engage my coworkers in the sustainability discussion?
Anaesthetists
Obstetricians & midwives
Is the occupational exposure of our staff to nitrous oxide above the safety limit?
Can we install capture and destruction systems to reduce nitrous oxide emission?
Surgeons
Can the operation be done under local anaesthesia or regional anaesthesia?
Facilities managers
Is there any leakage in the manifold that leads to wastage of piped nitrous oxide?
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