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In Sault Ste. Marie, Ontario, 250 patients at the Group Health Centre were tested for HIV and/or hepatitis infection after a mistake was made during the sterilization of an older type of endoscope. An additional 20 patients were advised that they should be tested for tuberculosis (TB). At Tulane University Hospital and Clinic in New Orleans, eight patients were notified that they could contract Creutzfeldt-Jacob disease (CJD) because instruments used on a CJD patient were subsequently used on them.
Although at press time, no cases of transmission had been reported by either institution, it raises new questions about what is considered adequate sterilization of instruments.
At Group Health Centre, an employee who wasn’t accustomed to sterilizing older types of equipment left a cap on one of the ports during sterilization, according to Elizabeth Bodnar, spokeswoman for the facility.
Tulane officials said the surgical instruments used on the CJD patient were put through "normal’’ washing and sterilization procedures. Officials there said that the risk of CJD is "reduced by washing but not eliminated by normal sterilization procedures." Tulane destroyed the instruments as soon as officials realized the first patient had died from CJD.
Tulane might have its sterilization techniques called into question, says Greig Coates, MD, JD, partner at Mithoff and Jacks in Austin, TX. "It’s one of the cracks that this case could have fallen through," Coates says. "It might be laid at the feet of whether this is adequate sterilization." Tulane officials didn’t respond to a request for an interview.
Same-day surgery providers should be particularly concerned about transmission of CJD because they perform so many eye procedures, and corneal tissue can be infectious, points out Victoria M. Steelman, RN, PhD, CNOR, advanced practice nurse in the perioperative division at the University of Iowa Hospital in Iowa City.
CJD is a rare, fatal brain disorder that causes a rapid, progressive dementia and associated neuromuscular disturbances, according to the Creutzfeldt-Jakob Foundation in Miami. (Web: www.cjdfoundation.org.) The disease often is referred to as a subacute spongiform encephalopathy because it usually produces microscopic vacuoles in neurons that appear "sponge-like," resulting in progressive dementia and loss of physical functions. Patients usually die within a year of the first symptoms. The disease usually affects men and women ages 50 to 75. The disease strikes about 6,000 people a year.
Traditional methods of disinfecting endoscopes, such as soaking them in glutaraldehyde, might actually make decontamination of instruments used on a CJD patient more difficult by hardening the patient material, according to David L. Lewis, PhD, research microbiologist at the Environmental Protection Agency’s (EPA) National Exposure Research Laboratory in Athens, GA. Lewis is on assignment to the University of Georgia in Athens to study infection control with dental and medical devices. His views don’t represent official views of the EPA. "My main point is that CJD should be the deathblow for glutaraldehyde in endoscopy," he says. "We can’t afford to keep using a chemical that makes it more difficult to clean scopes."
The cause of CJD is the subject of scientific debate. CJD might be transmitted by "prions," proteinaceous infectious particles, according to the Creutzfeldt-Jakob Foundation. Prions are thought to transform normal protein molecules into infectious, deadly ones by altering the shape of the molecules, according to the foundation.
"Endoscopes can’t withstand the high temperatures necessary to destroy prions, and we have no reliable means of determining whether chemically treated prions are no longer infectious," Lewis says.
Furthermore, in CJD transmission cases, "often instruments are cleaned inappropriately, often not meeting minimal standards, and used on additional patients," says Bill Jarvis, MD, associate director for program development at the Centers for Disease Control and Prevention (CDC) in Atlanta.
Flexible endoscopes are particularly difficult to clean, because most models still have air-water channels that are inaccessible to brushing, Lewis says. To ensure you don’t run the risk of infecting patients with tainted surgical instruments, follow these steps:
• Identify patients at risk for CJD. Don’t wait until the diagnosis of CJD is made, or the instruments might have been already used on other patients, warns Steelman. Identify upfront what patients will be at high risk, and treat them with special precautions, she says. The University of Iowa Hospitals and Clinics doesn’t use any reusable biopsy needles, hollow bore needles, or suction tips.
"For the precautions, the most important thing is adequate decontamination of surgical instruments," Steelman says. Soiled reusable surgical instruments are opened, wiped off with a dry cloth or sponge, and placed in the basket of a metal steam sterilization container. Instruments are not immersed in liquid or scrubbed with a brush. The container is sealed and steam sterilized in a pre-vacuum cycle at 135 degrees Celsius for 18 minutes. When the cycle is finished, at least two people verify the parameters. (To see Infection Control Policies and Procedures: CJD Precautions, click here.)
Eighteen minutes is more than four times the typical sterilization time, Steelman points out. If the sterilizer is gravity displacement, the sterilization time is 60 minutes, which is six to 20 times the normal time used in facilities. Subsequently, the instruments are put through a washer decontaminator, packaged, and sterilized again, she says.
• Consider changing your traditional sterilization methods or equipment. Glutaraldehyde is ineffective to sterilize endoscopes that have been used on CJD patients, Steelman maintains. Lewis agrees and, in fact, he advises providers to never use glutaraldehyde to disinfect endoscopes.
The FDA recommends sterilizing endoscopes whenever possible and using a 45-minute exposure time for high-level disinfection with 2% glutaraldehyde, he points out. "I’m not saying that these procedures destroy prions, " he says. "In practice, however, few medical facilities have time to soak scopes for 45 minutes." CDC officials think the 45-minute standard only applies to scopes that have not been manually pre-cleaned, Lewis says. "This is a common misconception The 45 minutes is actually based on the amount of time it takes for 2% glutaraldehyde to kill Mycobacterium [TB]," he says.
When possible, same-day surgery programs should use automatic endoscope reprocessors relying on peracetic acid, hydrogen peroxide, or other chemicals proven to dislodge or dissolve patient materials; or use endoscopes equipped with disposable sheaths and channels in which contaminated surfaces are discarded after each use, Lewis advises.
Coates agrees that disposable instruments should be used, at least with suspected CJD cases. "At the end of the day, I think that everyone would want to err on the side of safety," he says. "Go ahead and swap out instruments instead of having the assumption that they are not heat-resistant, for a modest savings, and foist the risk on patients."
These changes are more critical now that the Tulane incident has been publicized, Coates says. "From a pure risk management standpoint, I would say you are tempting fate if it turns out, at the end of the day, prions withstand autoclaving, if for any reason — heaven forbid, cost — you haven’t changed your policy of reusable instruments during brain surgery" or eye surgery, he adds.
• Allow adequate time for cleanup in suspected CJD cases. At the University of Iowa Hospitals and Clinics, unnecessary equipment is removed from the OR before the beginning of a procedure on a suspected CJD patient to make it easier to clean up. Sodium hydroxide is used to decontaminate surfaces that become contaminated during the procedure, Steelman says.
Two hours is the allotted time for cleanup. "That contact time is prolonged, so two hours in our protocol ensures staff will not comprise the cleaning," Steelman says. "We write it in there to make sure there’s not undue pressure on the staff to cut corners."
• Consider a ban on some instruments in suspected CJD cases. The University of Iowa bans certain instruments, such as power instruments, in procedures performed on suspected CJD patients in its hospitals and clinics. Power instruments splatter and can expose a health care worker’s mucous membranes, Steelman says. "And it’s impossible to decontaminate," she says. "We don’t know how long you’d have to sterilize them to effectively deactivate the agent. If we were able to sterilize them long enough, it likely would destroy the equipment."
The number of variant CJD cases, which is caused by eating meat contaminated with mad cow disease (bovine spongiform encephalophy), has been increasing in the United Kingdom, Steelman reports. With the rise in these cases, precautions against transmission of CJD will become increasingly important, she predicts. "We potentially could see patients with variant CJD," which would need the same precautions as the traditional CJD cases, she warns.
• Greig Coates, MD, JD, Partner, Mithoff and Jacks, 111 Congress Ave., Suite 1010, Austin, TX 78701. Telephone: (512) 478-4422. Fax: (512) 478-5015.
• Bill Jarvis, MD, Hospital Infections Program, Mail Stop E69, Centers for Disease Control and Prevention, Atlanta, GA 30333. Telephone: (404) 639-6413. Fax: (404) 639-6459.
• Victoria M. Steelman, RN, PhD, CNOR, Advanced Practice Nurse, Perioperative Division, The University of Iowa Hospital, 200 Hawkins Drive, Iowa City, IA 52242. E-mail: email@example.com.