ATP bioluminescence test can aid in endoscope decontamination

Last Updated: 2016-11-24

By Reuters Staff

NEW YORK (Reuters Health) - Adenosine triphosphate (ATP) bioluminescence can inexpensively detect microbial residue in endoscopes, and when used in conjunction with retraining may help minimize the risk of spreading infections via the instruments, new findings show.

Reprocessing flexible endoscopes requires several steps, and the manual cleaning component may be the most error-prone, Dr. Subhas Banerjee and colleagues at Stanford University School of Medicine note in Gastrointestinal Endoscopy, online November 3.

There are currently no recommendations for microbial surveillance of endoscopes in the United States, they add, largely because infection transmission had been thought to be rare. But recent outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) infection linked to duodenoscopes have shown that such surveillance programs are needed.

ATP bioluminescence testing can identify microbial and biological residue in endoscopes, the researchers note, and is "practical, rapid and low-cost."

In the new study, the team measured ATP bioluminescence in endoscopes after pre-cleaning, manual cleaning and high-level disinfection (HLD), and re-measured it after endoscopy staff had been re-trained in endoscope cleaning. They also tested after devices had undergone either two cycles of precleaning and manual cleaning and a single cycle of HLD, or two cycles of precleaning, manual cleaning and HLD.

Before training, suction-biopsy channel rinsates from all endoscopes achieved the benchmark of fewer than 200 relative light units (RLUs) after manual cleaning, but nine of 10 duodenoscope elevator channel rinsates did not. After training, RLUs in duodenoscope elevator channel rinsates were reduced from 23,218 to 1,341 RLUs, while levels after HLD were 177 before training and 12 afterwards.

Duodenoscope elevator channel RLU levels reached near-sterility with two cycles of manual cleaning and HLD, the researchers found.

"Despite completion of manual cleaning by dedicated SPD (sterile processing department) personnel, we found that median ATP bioluminescence values from elevator channels of both linear echoendoscopes and duodenoscopes remained above the ideal ATP benchmark before HLD," the researchers note.

"Even after completion of HLD, this benchmark was not achieved in 9 of 20 elevator channel rinsates," they add. "This inability to adequately clean elevator channels of both duodenoscopes and linear echoendoscopes implicates their current physical design."

While performing an additional HLD cycle adds 45 to 60 minutes to reprocessing time, the authors note, "it nevertheless offers endoscopy units a cost effective alternative to culturing/quarantining duodenoscopes and sterilization with ethylene oxide."

ATP bioluminescence testing could also be performed on duodenoscopes before patient use, they add, to confirm adequate decontamination.

Dr. Banerjee did not respond to an interview request by press time.

SOURCE: http://bit.ly/2fVykf8

Gastrointest Endosc 2016.