Cleaning is a critical part of endoscope processing. It sounds obvious, but the chemicals we use for cleaning will not function as designed unless used correctly. So, let’s review the factors that might compromise our path to a clean endoscope.
Detergents are cleaning agents that dislodge soils and dissolve or suspend them in the solution so they can be removed by washing and rinsing. They are less likely than soap to form films (soap scum) or to be affected by the minerals in hard water.
No single cleaning agent can remove all types of soils or is safe on all materials. Virtually all manufacturers of surgical instruments and devices recommend using a neutral-pH detergent for cleaning.
Several factors affect cleaning but the selection and use of detergents is one of the most critical steps. So, how do we ensure this is being done?
Steps for Effective Cleaning
Step 1: Obtain the most current manufacturer’s instructions for use (IFU) for the scope or device to be processed. IFUs are updated by manufacturers on a routine basis, so it is important to update your IFUs on a routine basis. Frequency should be specified in a department policy.
Step 2: Review the IFU for any changes from the IFU you currently have on file. Review the entire IFU for any new chemicals validated for use, new cleaning equipment or implements, changes in the water quality for cleaning and/or rinsing, etc.
Step 3: Changes in any recommendations need to be brought to the attention of the department manager and the Infection Pre- vention Department. If the changes differ from the current policy for processing flexible and semi-rigid endoscopes, the zpolicy should be updated and processing staff trained in the changes.
Step 4: If no changes are indicated, then obtain a current copy for any detergent(s) you are currently using to process your endoscopes and accessories (manually and/or mechanically).
Step 5: Review the detergent IFU for information regarding shelf life. (NOTE: The date of manufacturer and lot number are usually printed on the bottle or container.) The chemicals usually have a lot number, manufacture date and expiration date. The chemical should be used before the expiration date. I suggest you document the information on a log form in the event of a problem with the chemical and/or a recall from the manufacturer.
While reviewing the IFU of the detergent, look for information about the concentration needed (e.g., one (1) ounce per gallon of water). Enzymatic detergents (neutral pH) are most commonly used because of their ability to break down soils, making them easier to remove, and because of their wide material compatibility. They are the detergent of choice for flexible endoscopes as well.
Step 6: Review the enzyme detergent manufacturer’s IFU to determine whether the enzyme is affected by water temperature and if so, what recommended temperature range should be used. If the manufacturer has specific recommendations about water temperature, processing staff should ensure a thermometer is installed in the sink or basin. During use, monitor compliance with the water tempera- ture specified in the IFU. The thermometer should be durable and easy to keep inside the sink or basin. Temperatures higher than those recommended by the enzyme manufacturer can coagulate protein and break down and/or destroy the enzymes, making cleaning more difficult.
Temperatures below the recommended limit can result in sluggish enzymes, reducing their effectiveness. Thermometers should be cleaned as recommended in the IFU, calibrated annually or replaced.
Step 7: No matter which device is used for dispensing detergents, it should be maintained to ensure correct dilution. If measuring cups are used, they should be cleaned between uses to prevent buildup of the detergent inside the cup, which could affect the correct amount being dispensed. Another method is using a manual pump on the detergent bottle. The pump should be cleaned routinely to prevent buildup of detergent at the dispensing spout; in addition, the amount of solution dispensed should be checked routinely to ensure it has not changed. For example, if one pump should dispense one ounce of detergent, this is easily verified by checking the measuring cup when the detergent is dispensed. However, if the amount of detergent in the cup is less than an ounce, the pump needs to be cleaned. Too much detergent is as bad as too little. Either scenario can impair the effectiveness of the cleaning process.
If an automated system is used to deliver the detergent, it should be routinely calibrated and maintained by the manufacturer. The amount of detergent dispensed should also be verified routinely or as recommended by the manufacturer. Processing staff should be trained in the operation, care and maintenance of this system.
Excessive detergent can also result in incomplete rinsing of the detergent, which can build up over time and interfere with high-level disinfection or sterilization of the endoscope.
Step 8: Comply with the water-quality recommendations in the IFU. Impurities (e.g., calcium/magnesium) in water can adversely affect the cleaning process. Management should ensure the department’s water quality has been analyzed and that the water used for cleaning, as well as the initial and final rinses, meets current standards (Association for the Advancement of Medical Instrumentation ST-108 Water for Processing of Medical Devices 2023). If not, management should work to attain compliance with the standard.
Summary
Cleaning medical devices requires knowledge, education, the recommended chemicals, using those chemicals according to the IFU, and monitoring compliance with the IFU. The device manufacturer is responsible to validate which chemical(s) have been tested for efficacy on their devices. But endoscopy technicians must comply with the IFU for the chemical selected. In addition, for staff safety, PPE should be worn when working with cleaning chemicals. However, check with the detergent IFU and Safety Data Sheet to see if any special PPE is required. If so, it should be purchased and staff trained in its use. Cleaning can be adversely affected when we do not comply with the device and chemical IFUs. Compliance will ensure staff safety and facilitate the cleaning process for devices being processed.
