By Sara Cooper
Lastyear, fears that improperly cleaned endoscopes may have infected hundreds ofpatients with HIV or hepatitis A, B or C swept through a Canadian healthcarecenter, drawing dozens of patients in for blood tests, according to newsreports.
The problem, officials said, was that some older iscopes were cleaned using aprocess usually reserved for newer models. About 250 patients were examined overa 60-day period and follow-up tests were scheduled.
Nosocomial infection is a problem that may not be fully recognized amongendoscopy professionals for the reason that it is infrequently reported byhospitals and clinics.1 According to the U.S. Food and DrugAdministration (FDA), healthcare worker (HCWs) are at a greater risk of beinginfected by patients than vice versa.2 The hepatitis B virus HBV --more common and more easily transmitted than HIV -- is estimated by the Centersfor Disease Control and Prevention (CDC) to infect about 250,000 Americansannually; about 10,000 of them are HCWs.2
Since 1990, when news reports first suggested HIV could be transmitted from ahealth-care provider to a patient, federal agencies and professionalorganizations have worked to assure patients the risk is small and providehealthcare facilities with better, more thorough infection-control precautions.
Pat Tydell, RN, MSN, MPH, risk manager at North Chicago VeteransAdministration Medical Center (VAMC) in North Chicago, emphasizes that any timenurses are exposed to mucous membranes or bodily fluids, as in an endoscopyprocedure, they are putting themselves at risk for infection. The general rule,therefore, is to treat all patients as if they are infectious.
"If [nurses] know they have an infectious patient, they are verycareful. But they are never sure what the patient has," she says.
This is particularly true with a greater emphasis on patient confidentialityand protecting medical information, she adds.
Instrumentdesign is a central component to preventing contamination that leads toinfection. The Association for Professionals in Infection Control andEpidemiology (APIC) reports that while recent design advances have improved thecapabilities of flexible endoscopes, there have been relatively few improvementsthat better facilitate cleaning and disinfection.1
Tydell says the best endoscopic instruments have few moving parts, crevices,hollows, tubes or cavities. A retractor, for example, has no enclosed areas inwhich tissue can hide. Tydell says tissue or blood that has not been completelyremoved from an instrument can protect bacteria and allow it to grow. In othercases, foreign proteins from the patient's body may remain on an instrument,causing a localized allergic reaction in a subsequent patient. Endoscopes andaccessories should be cleaned promptly after use so that secretions do not dry.
Maureen Cain, manager of gastrointestinal (GI) endoscopy at the Mayo Clinicin Scottsdale, Ariz., emphasizes that once a procedure is finished, before thescope is processed, staff should perform a leak test to check for damage to thescope. "This should be routine practice in all endoscopy centers," sheadds.
Nurses at the Mayo Clinic have been using disposable forceps for some time.The concern with reusable forceps was that the spike used to grab tissue couldprick a staff member during cleaning, resulting in infection.
Currently most of the accessories used in therapy at the Mayo Clinic, such assnares, are disposable. Because disposable devices can be more costly, manyhospitals still opt for reusable devices. Cain has seen this become an issue ina number of facilities where cutting costs is a primary concern. She points out,however, that there are costs involved in reprocessing as well.
Meticulousendoscope cleaning by trained professionals is crucial to preventing the spreadof infections such as hepatitis B and HIV. According to APIC, there continues tobe variations in techniques hospitals use to clean and disinfect endoscopes.1Because manually cleaning and disinfecting endoscopes can be complex and timeconsuming, the use of automated endoscope reprocessing machines has increased inthe United States.3
Improperly functioning machines can be a source of contamination. A 1991report by the CDC described two hospitals that found contamination in automatedreprocessing machines, specifically in water-holding tanks, water hoses and airvents. The CDC linked the problem to ineffective machine design the reuse ofdetergent, disinfectant and tap water in the auto disinfector and reservoirs andtubing that remained moist or filled with fluid for extended periods.3
In April 1990, the Olympus Corporation mailed a safety alert to allconsignees of particular machine models recommending all endoscope channels berinsed with 70-percent isopropyl alcohol and suctioned with forced air aftermachine processing. At the time of the report, the CDC said such precautionsstill did not ensure elimination of contamination.
Tydell says a number of factors can affect cleaning effectiveness, from abreak in technique to machine malfunction. Cain points out that newer scopemodels may have attachments that do not fit properly into older machines,causing openings such as biopsy channels to be blocked during cleaning. Whenevera hospital or clinic gets a new scope, she recommends checking with themanufacturer to ensure the facility has the means to process it correctly.
Cain says a misconception is that hospitals can sterilize scopes. The processused in GI centers, she says, is called high-level disinfection. At the MayoClinic, trained professionals first clean scopes manually, brushing eachchannel, then attach them to the machine, which runs a cycle of soaking andflushing with water, and a 30-minute glutaraldehyde soak.
Proper cleaning prevents infection, and can eliminate instrumentdeterioration and malfunction.
At the North Chicago VAMC, Tydell says personnel test reprocessing unitsdaily, keeping logs of infection-related information that is reported to theinfection control nurse.
For many years, glutaraldehyde has been the disinfectant solution of choicewithin healthcare facilities. The non-corrosive solution does not damageendoscopes, and is highly resistant to neutralization by organic soil. Theproblem with the solution, however, is the health risks it can present to staff.Cain says nurses exposed to the caustic solution have complained of headachesand skin reactions. Breathing problems also have been reported in somefacilities.
Tydell says a number of disinfectants can be dangerous to HCWs, and stressesthe importance of personal protective equipment (PPE) and proper ventilationwhere chemicals are used. Every hospital should have an accessible safety datasheet describing the risks of handling chemicals. APIC suggests installingexhaust hoods for tubs if at all possible.1
FDA regulations state: "Devices that do not penetrate the skin or comein contact with normally sterile areas of the body, such as several types ofendoscopes, must be disinfected, at a minimum, with an Environmental ProtectionAgency (EPA-) registered and FDA-cleared disinfectant. The disinfectant selectedmust be of appropriate strength to kill the types of organisms that maycontaminate the particular device.2"
According to APIC, use of a disinfectant solution for extensive periods oftime can result in dilution.1 For this reason, commercial test kitsare available for chlorine, hydrogen peroxide,and glutaraldehyde solutions todetermine whether an effective concentration of active ingredients is present.
Protection of HCWs
While vaccinations are more readily available than ever, many HCWs are notvaccinated. In 1990, the FDA estimated that about 250 HCWs die annually fromcomplications of HBV acquired on the job. Tydell says that while it is crucialthat nurses receive at least annual health surveillance, some hospitals arecutting down on employee health functions because of cost. She adds thatemergency room (ER) staff should have access to stool sample testing and X-rayson a regular basis.
Taking measures to protect the clinician will also protect the patient.2PPE should be worn by all endoscopy personnel and readily accessible in theendoscopy area. Protective attire includes gloves, masks, eye protection andmoisture-resistant gowns or aprons.
The FDA and the CDC identify other safety practices including: caution inhandling sharp instruments, proper disposal of sharp instruments; in labeled,puncture-resistant containers and immediate handwashing following exposure tobodily fluids.
HIV and hepatitis are among nurses' primary concerns when it comes toendoscopy-related infection, Tydell says. Tuberculosis (TB) is the main concernsurrounding bronchoscopy. In a 1992 American Hospital Association (AHA)/CDCsurvey, 90 of 729 respondents reported nosocomial TB transmission to HCWs.4
In1994, the Occupational Safety and Health Administration (OSHA) revised andpublished guidelines regarding the responsibility of employers in preventing thetransmission of TB. The guidelines identify several control methods, includingearly identification, isolation and treatment of persons with TB, use ofengineering and administrative procedures to reduce exposure, and the use ofrespiratory protection.
Tydell says some procedures will present greater risk than others. Ifendoscopy complications such as perforation arise, for example, excessivebleeding may occur. As long as the staff is practicing the right precautions anddo not break technique, she says they are not in serious danger.
There is a level of infection control awareness that is yet to be attained,Tydell says. "The general public is very lackadaisical about infections.They figure we have something to cure them and they won't get sick or die fromthese things anymore," she says. "It is really hard to convince peoplethat these bugs are still out there and they are much better at causing diseasethan we are at stopping it."
Since 1987, the CDC has identified universal precautions for all HCWs toprevent the spread of HBV, HIV and other blood-borne infections. The mostfundamental precaution is the assumption that the "blood and body fluids ofall patients may be infectious, and measures to protect against exposure must beobserved at all times."2
The CDC and FDA are continually working to assess the frequency and level ofendoscope contamination within hospitals and clinics. Healthcare professionalsare asked to report episodes of endoscopy-related infection in patientsundergoing gastrointestinal endoscopy or bronchoscopy directly to their countyor state health departments, or to internal safety, infection control andrisk-management programs.
If it is suspected that infection is being transferred through contaminatedendoscopy equipment, it is useful to maintain a logbook that includes eachpatient's name and medical record number, the procedure, the endoscopist and theserial number of the endoscope, according to APIC.