Hazard Report: New Primer on Deadly Dirty Scopes

Dirty duodenoscopes can be lethal. The ECRI Institute, a nonprofit research and testing lab, today put out a “high priority hazard report” on procedures for cleaning the devices. There have been at least 7 hospital outbreaks of carbapenem-resistant enterobacteriaceae (CRE) infections traced to these instruments.

The devices are used for endoscopic retrograde cholangiopancreatography procedures meant to diagnose a variety of ailments of the gall bladder and pancreas.

The prevalence of these infections “appears to be increasing” the research institute said in its report.

Most recently two patients at UCLA Ronald Reagan Medical Center in Los Angeles, CA died of CRE infections and 180 patients there may have been exposed to the dangerous bacteria. One was a 48-year-old woman recuperating from a liver transplant.

Though that UCLA outbreak has been blamed by some on devices made by one manufacturer, Japan-based Olympus Corp, ECRI said all duodenoscopes are prone to resisting cleaning.

“We believe this is a generic hazard and that most, if not all duodenoscope models in use are susceptible,” ECRI continued.

The CRE infections are lethal in an estimated 44% of infected patients.

There are two basic ways to clean the devices, using a liquid chemical germicide (LGG) in an automated reprocessor, or ethylene oxide (EtO).

But neither approach will be effective if there is still “bioburden” such as fecal material still attached to the scope. Because the scopes have tiny stents and tubes to clear blockages in the digestive tract, it is easy for such matter to remain after cleaning, giving bacteria a place to grow.

To combat that contamination, ECRI said, after initial thorough cleaning and rinsing, the channels in the scopes should be flushed with alcohol, dried with filtered compressed air possibly by using HEPA-filtered forced air drying cabinets with channel connectors.

Even that is not enough, ECRI said. Hospitals and other facilities using the devices should also culture them after cleaning to make sure there are no microbes lurking. Since that process takes 48 hours, hospital may have to take some of the duodenoscopes temporarily out of service, and buy extras (at about $40,000 each.)

If that’s not feasible, ECRI recommends culturing weekly. “Culturing at the end of day of Fridays may be the least disruptive approach,” though it “will not provide the high degree of assurance that culturing after each reprocessing cycle provides.”

Should the cultures come back positive, the contaminated duodenoscope should be retired or sent back to the manufacturer.

If multiple scopes repeatedly test positive for contamination, it is possible the reprocessing equipment itself is contaminated.

Problems with reprocessing of endoscopes has appeared on the ECRI’s annual Top 10 Health Technology Hazards list for the past six years.

The full report is here. ECRI is based in Plymouth Meeting, PA.