Anaesthesia has same climate change effect as 1,000,000 cars

Thursday, January 06, 2011 by: Penny Forham
Tags: anesthesia, climate change, health news

(NewsTarget) Inhaled anaesthetics used to put patients to sleep during surgery are a big contributor to global climate change.

A recent study published in Anaesthesia & Analgesia in July 2010 found that, depending on the type of anaesthesia used, the effect of the surgeries conducted in the US alone could be as great as 1 million passenger cars per year. In fact 1kg of anaesthetic gas has the same effect as 1,620kg of CO2. Even though the effect is so great however, there is no obligation to report these gases in the same way as CO2 or refrigerants.

The three major inhalation anaesthetic gases are isoflurane, desflurane, and sevoflurane. These fluranes are recognised as greenhouse gases, but they have received little attention due to the fact that they are used in small amounts for each patient and are seen as medically necessary gases. When the number of surgeries are taken into account however, the effect becomes substantial. The gases are known as halogenated compounds, which are from the same family as the chemical which damaged the ozone layer back in the 1980s.

The gases are mainly unchanged by the body and are exhaled from the patient in almost the same form as they are inhaled. The chemists from the University of Copenhagen and NASA, in collaboration with anaesthesiologists at the University or Michigan, measured the infrared spectrum of the anaesthetics and calculated the wavelength of absorption. Desflurane remains in the atmosphere for 10 years, compared with 3.6 years for isoflurane and 1.2 years for sevoflurane. Although all 3 gases are more harmful than CO2, in relation to warming, they are not equally harmful. When the study authors factored in how the anaesthetics are used, they calculated that desflurane has about 26 times the global warming potential as sevoflurane and 13 times the potential of isoflurane. According to the study, use of desflurane for one hour is equivalent to 235 to 470 miles of driving.

The study concluded, "We estimate that the global emissions of inhalation anaesthetics have a climate impact which is comparable with that from the CO2 emissions from one coal-fired power plant or 1 million passenger cars."

Science Daily suggests that unless there are therapeutic reasons for using all 3, sevoflurane should be the only legal anaesthetic gas. The effect of anaesthetic gases on the atmosphere is just one more reason to look after your own health and avoid surgery.

References
http://www.ncbi.nlm.nih.gov/pubmed/20935004
http://www.health24.com/news/Anaesthesia/1-1...
http://www.sciencedaily.com/releases/2010/12...

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