Anaesthesia and the Environment

Question 1

Environmental impacts of vets.

Answer 1

Construction.
Energy.
Engagement.
Procurement.
Paper.
Drugs.
Water.
Active travel.
Conferences / education.
Domestic waste.
Healthcare waste.
Client interaction.

Question 2

Triple threat to the ecosystems?

Answer 2

• Global heating.
  – emissions e.g. VAs, F-gases from refrigerant and MDIs, transport.
  – Embedded carbon.
• Biodiversity loss.
  – Ecosystem damage e.g. eutrophication, ocean acidification, microplastics, extreme weather events, ozone depletion (N2O), air pollution.
  – Persistence, accumulation and biotoxicity of drugs.
• Resource scarcity.
  – Pharmaceuticals and medical equipment.
  – Construction materials, land, water, food.

Question 3

1. Average C footprint of a UK citizen.
2. What C footprint do we want to move towards and by when? – aim of this?

Answer 3

1. 10t CO2 per annum.
2. 2.5t CO2 per annum by 2030. – limit global temperature increases to 1.5C.

Question 4

1. What is the main contributing factor of vet practice C footprint?
2. Second?
3. third?
4. Fourth?
5. Fifth?
6. Sixth?

Answer 4

1. Nitrous oxide.
2. electricity.
3. VA – iso/sevo.
4. fuels.
5. Fleet.
6. Waste.

Question 5

Why is it so important to control anaesthetic gases?

Answer 5

They have a relatively low carbon emission.
But they are disproportionately effective as GHGs.
They absorb radiation in the atmospheric window which is usually used by the earth to cool itself.
Anaesthetic gases responsible for 10-15% of total anthropogenic radiative forcing of the climate since before the industrial era.

Question 6

1. Which VA has the highest global warming potential?
2. Which VA has the lowest global warming potential?
3. How is nitrous oxide so damaging?

Answer 6

1. Desflurane (2540).
2. Sevoflurane (130).
3. Nitrous oxide has a much lower potency so more used, and has atmospheric persistence of over 100yrs. Also strongly ozone depleting.

Question 7

High energy users in the ops room.

Answer 7

Oxygen concentrator.
Forced warm air unit (i.e. Bair hugger).
Active gas scavenging.
Air conditioning.

Question 8

Alternative anaesthetic maintenance?

Answer 8

TIVA (total intravenous anaesthesia).
E.g. propofol and fentanyl.
10 X lower C footprint.
Majority C footprint now from energy e.g. lighting, pumps, air con, machines. And then commuting.

Question 9

Does TIVA still have an environmental impact?

Answer 9

In production of drugs, up to 100kg (average 40kg) waste per kg pharmaceutical can be generated.
Life cycle carbon emissions for 20 common anaesthetic drugs calculated as up to 3000kg per kg of drug.
Carbon costs in delivery systems (energy and embedded), sterilisation and packaging.
Info available on persistence, bioaccumulation and toxicity of some anaesthetic agents.
Unaware of effects of drugs making it into the aquisystems, active drugs and metabolites.
Significant training / equipment development needed e.g. TCI (target controlled infusion) pumps.
Questions as to whether PIVA or regional anaesthesia actually reduces VA that much.

Question 10

Summary for lower carbon anaesthesia.

Answer 10

Stop using nitrous oxide.
Avoid prolonged or unnecessary anaesthesia.
Regularly check and service GA machine, vaporiser and breathing systems.
Use VA-sparing drugs and techniques.
Consider use of TIVA or PIVA.
Consider sevo over iso.
Encourage use of perioperative enteral medication.
Don’t open kit you don’t need / draw up more than you need.
Use lower flow anaesthetic techniques.

Question 11

1. What is ‘low flow’?
2. Practicalities?
3. Pros of ‘low flow’?
4. Cons of ‘low flow’?

Answer 11

1. Technical term defined by FGF 0.5-1L/min.
2. Need circle rebreathing system, rotameters and vaporisers which work under 1L/min, understanding/training, and need monitoring of fresh inspired O2 (FiO2) and end tidal (ET) agent.
3. • As reduce FGF by any amount, use proportionately less anaesthetic = save £ and reduce GHG emissions.
     - Conserve temperature and humidity w/in system = patient safety.
4. • Dilution of anaesthetic = patient wakes up.
     - Slower onset/offset time = patient wakes up or won’t sleep; need higher FGF when changing depth of anaesthesia.
     - Hypoxic mixtures (usually <0.5L/min) for prolonged periods, or when using N2O (reason to monitor FiO2).

Question 12

Waste hierarchy.

Answer 12

Prevention/reduction.
Preparing for re-use.
Recycling.
Other recovery.
Disposal.

Question 13

What is EWC?

Answer 13

European waste code.
For segregation of waste.

Question 14

Examples of reduction/prevention.

Answer 14

‘turn off light’ signs.
Use of Sterillium to scrub hands to save water and use less chemical.
Food waste to anaerobic digestor to turn into biogas and fertiliser.
Bio-bins (cardboard bins to put pharmaceutical waste into.
Environmentally friendly swaps e.g. wooden toothbrushes, PVC free plastics.
Cytotoxic bags to reduce plastic as opposed to hard.
Syringes that use 30% less plastic than regular syringes.
Steam cleaners reduce the amount of water needed by ~90%.

Question 15

Examples of reuse.

Answer 15

Reusable water bottles for staff.
Reusable clinical waste, sharps and pharmaceuticals bins.
Reusable, washable Bair hugger blankets.
Reusable gowns and drapes.
Reusable silicone scrub brushes for cleaning patient bowls.
Bank pens.
Reusable surgical tins (last ~20yrs).
Silicone lids for food tins and bottles etc.

Question 16

Pros of reuse.

Answer 16

• Lower C footprint and lifecycle impacts across equipment and textiles.
• Supports supply chain resiliency.
• Use of plastic may give false sense of security; consider other infection ctrl:
  – Staff compliance w/ aseptic processes, optimising patient health status, design of theatre environment, eco-cleaning systems e.g. steam, UV, ozone-based, reusable wipes.

Question 17

Cons of reuse.

Answer 17

• Hospital acquired infections carry a large carbon cost.
• Infection risk may depend on age of fabric, but microfibre shed may be less.
• Many devices labelled as single use so that the liability for device failure / infection risk rests w/ the user.

Question 18

Examples of recycle.

Answer 18

Always ensure infectious, clinical, pharmaceutical, sharps waste etc goes where it needs to go!
Where uncontaminated waste is labelled as recyclable, should looks to recycle it e.g. fluids bottles.
Products that are made from recycled materials are available to buy.
Sites and information pages for recycling waste available. e.g. recyclenow, Recoup, Terracycle, WarpIt.
Under Commercial law for domestic waste and under Hazardous Waste Regulations for most medical waste so need to comply.

Question 19

Disposal…
1. Black.
2. Yellow/black.
3. Orange.
4. Yellow.
5. Purple.
6. Blue.

Answer 19

1. Domestic municipal waste.
   – Recyclable waste should be segregated.
   – Energy from waste (EfW).
   – Landfill.
2. Offensive waste.
   – Recycling at approved facilities.
   – EfW.
   – Landfill/
3. Clinical infectious waste (or sharps).
   – Alternative treatment plant (then landfill or EfW).
   – Incineration.
4. Clinical infectious waste (or sharps) and pharmaceuticals/chemicals.
   – Incineration only.
5. Cytotoxic/cytostatic waste (or sharps + pharmaceuticals).
   – Incineration only.
6. Medicinal (pharmaceutical) waste.
   – Incineration only.