Why reducing anesthetic gas during surgery is beneficial

By Alice Clifford via SWNS

Reducing anesthetic gas during surgery could cut greenhouse gas emissions without affecting patient care.

Inhaled anesthetics are estimated to be responsible for 0.01 percent to 0.1 percent of total worldwide carbon dioxide equivalent emissions.

An hour's surgery using this type of anesthetic has the same impact as driving up to 470 miles.

While most general anesthesia procedures require high fresh gas flow (FGF) at the beginning and end of the procedure to achieve the desired effect quickly, it is safe and effective to lower the flow during the rest of the surgery.

Desflurane is a commonly used anesthetic and produces the most significant carbon dioxide emissions in comparison to other inhaled anesthetics.

Carbon dioxide is the primary greenhouse gas that traps heat in the Earth’s atmosphere, contributing to global warming.

Dr. Mohamed Fayed, senior anesthesia resident at Henry Ford Health in Detroit and lead author, said: “Global warming is affecting our daily life more and more, and the reduction of greenhouse gas emissions has become crucial.

“No matter how small each effect is, it will add up.

“As anesthesiologists, we can contribute significantly to this cause by making little changes in our daily practice — such as lowering the flow of anesthetic gas — without affecting patient care.”

The researchers educated anesthesiologists at their institution about the benefits of dialing down the anesthetic gas flow during procedures.

They put on departmental presentations, created newsletter articles, put up posters in work areas and sent emails.

They also removed desflurane from their operating rooms.

The team studied more than 13,000 patients.

They set a goal of an average FGF of three liters per minute or less for procedures to try and reduce greenhouse gases.

In March 2021, before their intervention, the team found that in many cases FGF was five to six liters per minute.

Only 65 percent of cases achieved an FGF of three liters per minute or less.

By July 2021, 93 percent of cases used an average FGF of three liters per minute or less.

The team is now aiming to reduce the FDF to less than two liters per minute throughout the system.

The initiative is part of a quality improvement project called the Multicenter Perioperative Outcome Group.

The project includes more than 60 anesthesia practices.

The ultimate goal is to measure actual carbon footprints from anesthetic agent waste for each surgical case. However, achieving this will require significant modifications and costs.

Provided through a mask, inhaled anesthetics such as desflurane, sevoflurane and isoflurane are given to patients during general anesthesia so they are unconscious during a major operation, such as open-heart surgery.

Another inhaled anesthetic, nitrous oxide, is sometimes given during childbirth or during dental procedures.

Inhaled anesthetics are not used for patients who undergo sedation, which is typically used for minimally invasive procedures, such as colonoscopies.

Nor is it used during regional anesthesia, which is used for childbirth or surgeries of the arm, leg or abdomen and numbs only part of the body with the patient remaining awake.

Dr. Fayed said: “For a long time, there was a notion that the greenhouse effect caused in health care settings was an inevitable and unavoidable cost of providing patient care.

“But we have learned that reducing anesthetic gas flow is one of the many ways health care can lessen its contribution to the global warming crisis, along with reducing waste, turning off lights and equipment when not in use and challenging practice habits, as long as they don’t compromise patient care.”

The research will be presented at the American Society of Anaesthesiologists' ADVANCE 2023: The Anaesthesiology Business Event. It will run from January 27 to 29 in Orlando, Florida.