Climate change anaesthesia s part in the problem

Climate change – anaesthesia’s part in the problem Dr Stuart White Royal Sussex County Hospital, Brighton

Climate change is a fact.

Man is responsible for climate change.

Why? • • • Less/more expensive food Fewer/more expensive car journeys No air travel Higher taxes and costs Less ‘stuff’ Population restriction

Anaesthetists • Professional life • Personal life

Professional life • Do anaesthetic drugs harm the environment? • Does the conduct of anaesthesia harm the environment? • How can we minimise the impact of anaesthesia on the environment?

Anaesthetic gasses • Evidence limited • Langbein T et al. Volatile anaesthetics and the atmosphere: atmospheric lifetimes and atmospheric effects of halothane, enflurane, isoflurane, desflurane and sevoflurane. BJA 1999; 82: 66 -73 • IPCC • Summarised in Axelson U. Climate impact of anaesthetic gases 2008. http: //www. miljo. skane. se/eng/U 2237_translation. pdf

Langbein Inhalational anaesthetic agents contribute to two environmental problems • Direct depletion of the ozone layer • Infrared absorption and global warming

Oxygen-ozone cycle OO UV O OO OO UV OOO OO OO

l 100 400 MESOSPHERE STRATOSPHERE TROPOSPHERE

Ozone depletion potential Ozone depletion dependent on: - chlorine and bromine content - amount of agent that reaches the stratosphere - longevity of agent remains in the stratosphere Calculated contribution to stratospheric ozone depletion • halothane 1%, • isoflurane 0. 02% • sevoflurane 0% • desflurane 0%

Health effects of global warming • • Extreme weather Rising sea levels Drought Crop failure Resource conflict Disease Ozone depletion

Greenhouse gasses Global warming potentials (GWPs) • Measure of relative contribution to global warming of a mass of gas to equivalent mass of CO 2 (GWP 1) • Calculated according to - (high) absorption of infrared radiation - (wide) spectral location of absorbing wavelengths - (long) atmospheric lifetime • Absorption not always linear

Greenhouse gasses Gas Lifetime (years) Global warming potential (time horizon, years) GWP 20 GWP 100 GWP 500 Carbon dioxide Variable 1 1 1 Methane 12 72 25 7. 6 HFC 23 270 12000 14800 12200 Sulphur hexafluoride 3200 16300 22800 32600

Anaesthetic gasses Gas Lifetime (years) Global warming potential (time horizon, years) GWP 20 GWP 100 GWP 500 Nitrous oxide (‘laughing gas’) 114 289 298 153 Isoflurane 2. 6 1230 350 106 Sevoflurane 5. 2 1980 575 175 Desflurane 2. 6 1230 1526 106

Axelson BUT. . .

So N 2 O is most pollutant, BUT Greenhouse gasses 6% Nitrous oxide 20% Anthropogenic N 2 O 4% Specific manufacture 90% Medicinal N 2 O

So N 2 O is most pollutant, BUT Greenhouse gasses 6% Nitrous oxide 20% Anthropogenic N 2 O 4% Specific manufacture 90% Medical N 2 O . . . equivalent to approximately • 1% atmospheric nitrous • 0. 07% global warming

So not much, BUT. . . • Avoidable • Secondary health benefits • I’ve stopped using it • BUT, have to use nasty gasses at higher MAC • + more oxygen/air

Adapted from Charlesworth M. How green is your gas? Anaesthesia News 2009; 267: 22 -23. Agent MAC in 100% O 2 GWP 100 Environmental factor, EF (GWPx. MAC) Relative EF Isoflurane 1. 3 350 455 1 Sevoflurane 2. 2 575 1265 2. 8 Desflurane 6. 0 1526 9156 20. 1

Oxygen production CO 2 cost of liquid oxygen • Air liquefaction • Cooling • Transport = 0. 4 g CO 2 per litre of oxygen • RAFT: Average amount of oxygen used per case is 594 litres = 238 g CO 2 • Hip # (GA) = 340 L = 136 g CO 2

Advice • • • Avoid nitrous oxide Avoid desflurane (+ energy cost of warming) Care prescribing oxygen Active scavenging? Low flow anaesthesia TIVA

Low flow anaesthesia Lockwood GG, White DC. Measuring the costs of inhaled anaesthetics. BJA 2001; 87: 559 -63. • NARKUP • Hip#, 50 kg, SV, CO 4. 5, MV 4. 5, FRC 1500 ml Cons Induct Time (min) LOS (min) 2 3 17 80 Flow Surg (l/min) Sevo Used (mls) Cost (£. p) 12/4% 1 Flow induct (l/min) 5/2% 109 53. 63 6/4% 3/2% 56 27. 55 6/2% 0. 6/2% 13 6. 40

TIVA Stockholm county council • janusinfo. se, pbtprofiler. net

TIVA (EPA) Drug PERSISTENCE BIOACCUMULATION Propofol P B T Alfentanil P B T Remifentanil P B T TOXICITY (fish)

What about regional anaesthesia? Drug PERSISTENCE BIOACCUMULATION Lignocaine P B T Bupivacaine P B T Levo P B T Ropivacaine P B T TOXICITY (fish)

RA v GA Also cheaper! Hip # Cost spinal anaesthesia, (£) Cost as % spinal total Cost GA (£) Cost as % GA total Group cost % total General equipment 66. 73 37 108. 15 42 40 Airway equipment 1. 81 1 25. 68 10 6 Personnel 92. 85 51 93. 71 36 43 Drugs 18. 94 10 25. 16 10 10 Gasses/ inhalational agents 0. 43 <1 6. 26 2 2 TOTAL 180. 76 257. 53*

Medical waste • double/triple/quadruple packaging! Argh! • • Costs of waste storage set to increase Incinerator £ 753/tonne Domestic £ 83/tonne Recycled cardboard, plastic, glass +£ 17/tonne

Some figures • • Europe 1. 3 bn tonnes solid waste (3. 5 t/person) UK 100 million tonnes solid waste 85% 9901 landfill sites Incineration limited by EU Directive NHS waste 408, 000 t/year (4%) 29% is clinical waste < 10% of total NHS waste is recycled.

Hutchins DCJ, White S. Coming round to recycling. BMJ 2009; 338: 609 • 2300 kg of anaesthetic waste/theatre/year • 40% of anaesthetic theatre waste is potentially recyclable • 4% of sharps bin waste was appropriate

Barriers Social Logistical Legal environment and wastes health and safety transport

6 R • • • Responsibility Reduce Reuse Recycle Rethink Research

Responsibility Central Professional Personal

Travel 2010 update of NHS Carbon Reduction strategy (NHS SDU) • 2004 18. 6 Mt CO 2 (25% public sector, 3% UK) • 2007 21 Mt CO 2 • 2008 Climate Change Act - reduce by 10% 2015 (19 Mt!) - reduce by 80% 2050 (4. 2 Mt)

22%

RAFT environmental audit Patient + theatre staff + anaesthetists = 108. 7 miles of car usage = 17. 2 kg CO 2 (+ the rest!)

Cycle/walk/run to work

ESA Milan 2009 • From LGW (BA)= 225 kg CO 2 (stratosphere) • Mean SE UK = 8. 8 t CO 2/person @ • ie 2. 5% of @ production in 0. 0006% of a year • ie 43 times the usual rate

ESA Amsterdam 2011

Research Update inhalational work Evaluate inhalational vs TIVA vs regional Life cycle analysis of anaesthetic equipment Evaluate the monetary and environmental cost of recycling equipment • Fully calculate the carbon cost of oxygen/air • Green alternatives • Decontamination and sterilisation • •

BUT 1 year Brighton East REC paper audit • 68 REC applications + research conduct of successful 55 • 176, 150 sheets of A 4 paper - 879 kg, £ 658, + £ 2078 PC • equivalent national annual estimate - 11. 5 m sheets A 4 - 88 tonnes - 2100 trees

Top tips • • Don’t use nitrous oxide Use low flow anesthesia Use regional anaesthesia REDUCE, reuse, recycle, responsibility Cycle to work Stay informed Agitate

igasbest@hotmail. com stuart. white@bsuh. nhs. uk