Defining “Clean” in Sterile Processing

Patient-Ready Scopes Remain Contaminated After Reprocessing

By Kelly M. Pyrek

Note: This is the second in a series of articles examining how “clean” is being defined in the healthcare environment.

For the last several years, researchers have been sounding the alarm about processed, presumably patient-ready endoscopes that have retained bioburden and pose a risk to patients. And the Food and Drug Administration (FDA) has been doubling down on its scrutiny of scope manufacturers since high-profile outbreaks and patient deaths linked to contaminated scopes have been making headlines.

The discovery of still-contaminated scopes coming out of sterile processing departments despite manual cleaning and high-level disinfection (HLD) cycles in automated endoscopic reprocessors (AERs) has changed everything we thought we knew about how to reduce and eliminate risk posed by invasive medical devices and instruments.

In 2014, Cori Ofstead, MSPH, president and CEO of Ofstead & Associates, and colleagues, presented a paper at the annual APIC meeting that alarmed the infection prevention community by its startling conclusion that despite guideline adherence by sterile processing technicians, endoscopes remained contaminated with debris and microorganisms. Furthermore, Ofstead, et al. (2014) found that visual inspections performed during manual cleaning did not identify the debris that researchers could visualize on white swabs during data collection, and rapid-indicator tests detected contamination on endoscopes with and without visible debris. Additionally, cultures confirmed viable microorganisms after manual cleaning and HLD.

In their study, endoscope reprocessing was directly observed during 60 encounters with 15 used colonoscopes and gastroscopes at a large tertiary-care medical center. Researchers documented adherence with guidelines. Surface swabs were used to sample distal ends, control handles, ports, caps, and buttons. Water samples were obtained from suction-biopsy channels and auxiliary water channels. Samples were tested for protein, blood, carbohydrates, and adenosine triphosphate (ATP) using rapid indicator tests. Aerobic cultures were performed, and positive cultures were sent to a reference lab for species identification. Researchers visually inspected 500 endoscope components and conducted 588 rapid indicator tests, including surface protein, surface ATP, water ATP and dipsticks for protein, blood, and carbohydrates. Cultures were performed on 88 channel effluent samples. No residue was visible on endoscopes after manual cleaning. Residue was seen on swabs or in effluent for 31 percent of post-manual cleaning samples and zero post-HLD samples. After manual cleaning, samples exceeded benchmarks for ATP (46 percent biopsy ports) and protein (75 percent handles). Post-HLD tests revealed persistent contamination (p<.05). Colony counts from bedside-cleaned channel samples were higher than manually cleaned and disinfected counts.

This study came on the heels of a 2013 Ofstead-produced paper tackling endoscopy-associated infection (EAI) risk estimates and their implications, which shattered any remaining complacency about scope-associated infections.

Read further from the November 2019 issue HERE