Scoping Infectious Patients
By Sara Cooper
Last year, fears that improperly cleaned endoscopes may have infected hundreds of patients with HIV or hepatitis A, B or C swept through a Canadian healthcare center, drawing dozens of patients in for blood tests, according to news reports.
The problem, officials said, was that some older iscopes were cleaned using a process usually reserved for newer models. About 250 patients were examined over a 60-day period and follow-up tests were scheduled.
Nosocomial infection is a problem that may not be fully recognized among endoscopy professionals for the reason that it is infrequently reported by hospitals and clinics.1 According to the U.S. Food and Drug Administration (FDA), healthcare worker (HCWs) are at a greater risk of being infected by patients than vice versa.2 The hepatitis B virus HBV -- more common and more easily transmitted than HIV -- is estimated by the Centers for Disease Control and Prevention (CDC) to infect about 250,000 Americans annually; about 10,000 of them are HCWs.2
Since 1990, when news reports first suggested HIV could be transmitted from a health-care provider to a patient, federal agencies and professional organizations have worked to assure patients the risk is small and provide healthcare facilities with better, more thorough infection-control precautions.
Pat Tydell, RN, MSN, MPH, risk manager at North Chicago Veterans Administration Medical Center (VAMC) in North Chicago, emphasizes that any time nurses are exposed to mucous membranes or bodily fluids, as in an endoscopy procedure, 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 very careful. But they are never sure what the patient has," she says.
This is particularly true with a greater emphasis on patient confidentiality and protecting medical information, she adds.
Instrument design is a central component to preventing contamination that leads to infection. The Association for Professionals in Infection Control and Epidemiology (APIC) reports that while recent design advances have improved the capabilities of flexible endoscopes, there have been relatively few improvements that 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 in which tissue can hide. Tydell says tissue or blood that has not been completely removed from an instrument can protect bacteria and allow it to grow. In other cases, foreign proteins from the patient's body may remain on an instrument, causing a localized allergic reaction in a subsequent patient. Endoscopes and accessories should be cleaned promptly after use so that secretions do not dry.
Maureen Cain, manager of gastrointestinal (GI) endoscopy at the Mayo Clinic in Scottsdale, Ariz., emphasizes that once a procedure is finished, before the scope is processed, staff should perform a leak test to check for damage to the scope. "This should be routine practice in all endoscopy centers," she adds.
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 could prick a staff member during cleaning, resulting in infection.
Currently most of the accessories used in therapy at the Mayo Clinic, such as snares, are disposable. Because disposable devices can be more costly, many hospitals still opt for reusable devices. Cain has seen this become an issue in a number of facilities where cutting costs is a primary concern. She points out, however, that there are costs involved in reprocessing as well.
Meticulous endoscope cleaning by trained professionals is crucial to preventing the spread of infections such as hepatitis B and HIV. According to APIC, there continues to be variations in techniques hospitals use to clean and disinfect endoscopes.1 Because manually cleaning and disinfecting endoscopes can be complex and time consuming, the use of automated endoscope reprocessing machines has increased in the United States.3
Improperly functioning machines can be a source of contamination. A 1991 report by the CDC described two hospitals that found contamination in automated reprocessing machines, specifically in water-holding tanks, water hoses and air vents. The CDC linked the problem to ineffective machine design the reuse of detergent, disinfectant and tap water in the auto disinfector and reservoirs and tubing that remained moist or filled with fluid for extended periods.3
In April 1990, the Olympus Corporation mailed a safety alert to all consignees of particular machine models recommending all endoscope channels be rinsed with 70-percent isopropyl alcohol and suctioned with forced air after machine processing. At the time of the report, the CDC said such precautions still did not ensure elimination of contamination.
Tydell says a number of factors can affect cleaning effectiveness, from a break in technique to machine malfunction. Cain points out that newer scope models may have attachments that do not fit properly into older machines, causing openings such as biopsy channels to be blocked during cleaning. Whenever a hospital or clinic gets a new scope, she recommends checking with the manufacturer to ensure the facility has the means to process it correctly.
Cain says a misconception is that hospitals can sterilize scopes. The process used in GI centers, she says, is called high-level disinfection. At the Mayo Clinic, trained professionals first clean scopes manually, brushing each channel, then attach them to the machine, which runs a cycle of soaking and flushing with water, and a 30-minute glutaraldehyde soak.
Proper cleaning prevents infection, and can eliminate instrument deterioration and malfunction.
At the North Chicago VAMC, Tydell says personnel test reprocessing units daily, keeping logs of infection-related information that is reported to the infection control nurse.
For many years, glutaraldehyde has been the disinfectant solution of choice within healthcare facilities. The non-corrosive solution does not damage endoscopes, and is highly resistant to neutralization by organic soil. The problem with the solution, however, is the health risks it can present to staff. Cain says nurses exposed to the caustic solution have complained of headaches and skin reactions. Breathing problems also have been reported in some facilities.
Tydell says a number of disinfectants can be dangerous to HCWs, and stresses the importance of personal protective equipment (PPE) and proper ventilation where chemicals are used. Every hospital should have an accessible safety data sheet describing the risks of handling chemicals. APIC suggests installing exhaust hoods for tubs if at all possible.1
FDA regulations state: "Devices that do not penetrate the skin or come in contact with normally sterile areas of the body, such as several types of endoscopes, must be disinfected, at a minimum, with an Environmental Protection Agency (EPA-) registered and FDA-cleared disinfectant. The disinfectant selected must be of appropriate strength to kill the types of organisms that may contaminate the particular device.2"
According to APIC, use of a disinfectant solution for extensive periods of time can result in dilution.1 For this reason, commercial test kits are available for chlorine, hydrogen peroxide,and glutaraldehyde solutions to determine whether an effective concentration of active ingredients is present.
Protection of HCWs
While vaccinations are more readily available than ever, many HCWs are not vaccinated. In 1990, the FDA estimated that about 250 HCWs die annually from complications of HBV acquired on the job. Tydell says that while it is crucial that nurses receive at least annual health surveillance, some hospitals are cutting down on employee health functions because of cost. She adds that emergency room (ER) staff should have access to stool sample testing and X-rays on a regular basis.
Taking measures to protect the clinician will also protect the patient.2 PPE should be worn by all endoscopy personnel and readily accessible in the endoscopy area. Protective attire includes gloves, masks, eye protection and moisture-resistant gowns or aprons.
The FDA and the CDC identify other safety practices including: caution in handling sharp instruments, proper disposal of sharp instruments; in labeled, puncture-resistant containers and immediate handwashing following exposure to bodily fluids.
HIV and hepatitis are among nurses' primary concerns when it comes to endoscopy-related infection, Tydell says. Tuberculosis (TB) is the main concern surrounding bronchoscopy. In a 1992 American Hospital Association (AHA)/CDC survey, 90 of 729 respondents reported nosocomial TB transmission to HCWs.4
In 1994, the Occupational Safety and Health Administration (OSHA) revised and published guidelines regarding the responsibility of employers in preventing the transmission of TB. The guidelines identify several control methods, including early identification, isolation and treatment of persons with TB, use of engineering and administrative procedures to reduce exposure, and the use of respiratory protection.
Tydell says some procedures will present greater risk than others. If endoscopy complications such as perforation arise, for example, excessive bleeding may occur. As long as the staff is practicing the right precautions and do 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 from these things anymore," she says. "It is really hard to convince people that these bugs are still out there and they are much better at causing disease than we are at stopping it."
Since 1987, the CDC has identified universal precautions for all HCWs to prevent the spread of HBV, HIV and other blood-borne infections. The most fundamental precaution is the assumption that the "blood and body fluids of all patients may be infectious, and measures to protect against exposure must be observed at all times."2
The CDC and FDA are continually working to assess the frequency and level of endoscope contamination within hospitals and clinics. Healthcare professionals are asked to report episodes of endoscopy-related infection in patients undergoing gastrointestinal endoscopy or bronchoscopy directly to their county or state health departments, or to internal safety, infection control and risk-management programs.
If it is suspected that infection is being transferred through contaminated endoscopy equipment, it is useful to maintain a logbook that includes each patient's name and medical record number, the procedure, the endoscopist and the serial number of the endoscope, according to APIC.