Research done at the Children's National Medical Center has revealed that young children are exposed to high levels of carbon monoxide during routine, general anesthesia. In specific cases, infants and children can suffer CO exposure during these procedures resulting in a rise in the child's carbon monoxide blood levels.

 

Carbon monoxide, a poisonous gas that causes many deaths each year, sometimes is generated as a byproduct of anesthesia. There are specific procedures that can limit its production during anesthesia, but still it is frequently present in the bloodstream of young children after surgery. A team of anesthesiologists lead by Richard J. Levy, the center's chief of cardiac anesthesiology, identified certain conditions in which carbon monoxide might be inhaled during a procedure.

 

Studies demonstrated a number of different facts and correlations.

 

First, carbon monoxide was found in increased amounts in the blood of children 2 years and older when it was also detected in the breathing circuit. Second, patients who exhaled carbon monoxide may re-breathe it during low-flow procedures. Low-flow procedures are the current standard, and feature a slow flow of gasses into the circuit.

 

"The main goal is to provide the safest environment for young patients who require surgery," Levy says. "We have identified tangible ways to reduce the risk of carbon monoxide exposure, and our hope is that these changes will be implemented internationally."

 

The effects of low doses of carbon monoxide on developing brains remain largely unknown. There are studies that suggest some effect, such as one recent study linking exposure to hearing defects. However, these studies are still not conclusive; much remains to be done. However, the team does recommend two immediate changes that can help eliminate some of the risk of CO exposure in young children.

 

First, the anesthesia machine should use carbon dioxide absorbents that lack a strong metal alkali. These will not degrade the inhaled anesthetics, meaning they will not contribute to the production of carbon monoxide. Second, the profession should switch to higher-flow anesthesia for children, which will reduce the CO rebreathing risk substantially.