A study published in the Emergency Medicine Journal and authored by Cody Vaughn Gibson at the Department of Natural Sciences, Calhoun Community College in Alabama, investigated whether emergency medical services oxygen (O2) equipment aids the transmission of the ‘superbug’ MRSA.

Researchers tested nine O2 tanks carried by three ambulances based at an emergency medical services (EMS) station in Alabama. They found MRSA, or methicillin-resistant Staphylococcus aureus, on all nine tanks. They also swabbed O2 tanks in a storage area, finding MRSA on 96% of the stored cylinders.

MRSA infections are difficult to treat because the bacteria are resistant to common antibiotics. Although usually mild, MRSA infections still cause thousands of deaths each year.

The presence of MRSA on the tanks could be due to a lack of universal disinfection protocols for O2 equipment.

Cody Gibson, Researcher, Department of Surgery

Cody Gibson, Researcher, Department of Surgery at the University of Alabama

“The focus of the study is on O2 cylinders because they require exchange during the refilling process, which could potentially result in the spread of MRSA over large geographical areas,” Gibson told gasworld.

Most ambulance equipment is disinfected after each patient because of company protocol or as directed by regulatory authorities, but O2 cylinders could oftentimes be overlooked.

“A universal protocol would be beneficial as it would outline an evidence-based method for disinfection which would also avoid compromising the integrity of the O2 cylinder,” Gibson explained.

Gibson interviewed EMS personnel and found the staff were not aware of when the O2 cylinders were last disinfected, while other surfaces that patients contacted were regularly decontaminated with disinfectants.

“I think it is an issue which is overlooked because it is well known that ambulances are reservoirs for MRSA, so O2 cylinders tend to be grouped with other MRSA contaminated equipment. But, the key difference between O2 cylinders and other medical equipment is that during the refilling process, O2 cylinders, potentially MRSA contaminated, are transported to and from refilling facilities and possibly exchanged between healthcare facilities.”

“Educate the purchasers of medical gas cylinders about the need to disinfect cylinders…”

Cody Gibson, Researcher, Department of Surgery at the University of Alabama.

When asked what the providers of medical gas cylinders could do to help ameliorate this problem, Gibson answered, “Educate the purchasers of medical gas cylinders about the need to disinfect cylinders: A process which includes removing all organic matter and using a suitable disinfectant. Additionally, O2 cylinders could be disinfected at the refilling facilities, perhaps by using UV light.” 

The study didn’t look at actual transmission rates, so it’s unclear whether anyone actually became infected from bacteria on these tanks. Also, Gibson points out, the samples only came from a single EMS station, and at only one point in time.

“In my opinion, this requires a follow-up study to increase the sample size, randomise samples, and show trends over time. I would like to see this study conducted on a large scale with many O2 cylinders in numerous healthcare settings.”

He concludes, “My hope is that EMS providers, O2 refilling companies, biologists, and other personnel will acknowledge this study and work toward a plan to address these issues.”

Cody Vaughn Gibson is a Researcher in the Surgery Department at the University of Alabama at Birmingham. At the time of the study, Gibson was employed at Calhoun Community College in the Department of Natural Sciences. His education background is in cellular and developmental biology, and he is also a Nationally-Registered Advanced-Emergency Medical Technician.