What is flexible endoscope cross contamination and why is it unsafe?
Every day flexible endoscopy procedures are a routine part of diagnosis in hospitals, ambulatory care facilities and private practices around the United States. However, in order to ensure patient safety and prevent cross contamination, endoscopes need to be carefully cleaned and disinfected or sterilized between each patient use. Moreover, endoscopes that come in contact with mucous membranes or sterile tissue need to be sterilized before each use.
If endoscopes and their accessories are not scrupulously cleaned, cross contamination between body fluids and tissues can occur, possibly resulting in transmission of bloodborne pathogens such as hepatitis and HIV to other patients. Sometimes cross contamination can result in large-scale infection of patients who may need to be contacted and brought back to the hospital for testing. In fact, cross contamination from flexible endoscopes was identified by the ECRI as the number three hazard among medical technology risks for 2011.
Instances of cross contamination can occur due to reuse of accessories designed for single use, using improper accessories for endoscopy irrigation set-ups, failure to adequately clean reusable endoscopy accessories, using damaged or malfunctioning reprocessing equipment, and failure to follow the manufacturer’s instructions for endoscope reprocessing.
Due to the difficulty in adequately sterilizing and disinfecting endoscopes and their accessories, medical facilities need to develop and implement a model-specific reprocessing protocol for each endoscope in order to minimize risks of cross-infection. Such a protocol would typically involve a multi-step procedure for cleaning and disinfection.
Procedures to minimize risks
Various steps can be taken to minimize the risk of cross-contamination between patients. As well as establishing a protocol, written procedures need to be drawn up. Employees need to be trained how to set up, sterilize, disinfect and store endoscopy equipment, together with periodic retraining. Staff need to be instructed to read and follow the manufacturer’s instructions for each endoscope.
A typical reprocessing protocol would include the following steps:
Cleaning and disinfection are two distinct processes. First, the endoscope should be subjected to pre-cleaning using an enzymatic detergent solution. This should be used to flush all channels and wipe down the exterior of the endoscope.
Leak testing should be carried out by submerging the endoscope in water to check for damage. If air bubbles are observed, the endoscope needs to be removed from service and sent for repair.
Next, after immersion in an enzymatic detergent solution, the endoscope needs to be meticulously cleaned and flushed of any tissue or debris. The importance of this step cannot be over-emphasized because gross contamination will prevent the germicidal agent used during disinfection from contacting the surfaces.
This should be followed by high-level disinfection or sterilization, either carried out manually or using an automatic endoscope reprocessor (AER) using a germicidal agent. When using an AER, ensure that it properly fits the endoscope, as sterilizers and AERs are only designed to process certain makes and models of endoscope. Compatibility of the germicidal agent with the particular endoscope must also be verified.
After use of a germicidal agent, the endoscope needs to be rinsed with filtered water. This is followed by forcing pressurized air through the scope to remove remaining water. With high level disinfection, the endoscope is finally flushed with isopropyl or ethyl alcohol and dried with forced air. This can be done manually or using an AER.
Finally, correct storage of the flexible endoscope is also important. Following high-level disinfection the endoscope should be stored vertically with its accessories and other components removed. It can either be stored in a well–ventilated area or wrapped to ensure sterility, according to the manufacturer’s recommendations.