All the steps in instrument reprocessing are important. Failure in any single one can result in a failed process, meaning an unsafe instrument—one not suitable for use on the next patient.
There are two basic methods to insure that instruments are getting clean. The first is to verify that the cleaning equipment is working properly. The second is to directly inspect instruments for cleanliness.
Verify Proper Working Order
There are two methods to verify the performance of equipment, and these are not mutually exclusive either and both should be done.
Parameters: In sterilization, we often speak about monitoring parameters of sterilization, including temperature, pressure, steam quality, time, etc. The same should be done with cleaning equipment. The key parameters of cleaning are:
1. Water quality and water temperature
2. Concentration of cleaning solution (detergent and/or water),
3. Adequate time for each stage of the cycle for the cleaning solution to breakdown and remove the target soil,
4. Proper mechanical action (i.e., spray arms spinning in a washer, cavitation energy in a sonic),
5. The human factor - proper loading of instruments in the equipment.
Surrogate challenge device: Use a suitable surrogate device to test the overall cleaning performance of the equipment. A suitable surrogate is based upon the kind of surgical instrument and the kind of soil the instrument is likely to be contaminated with from clinical use. For instance, most surgical instruments are:
1. Manufactured of stainless steel
2. Are soiled with blood
3. Provide a physical challenge to cleaning, such as hinges, crevices, lumens, etc.
The surrogate device should as closely as possible simulate these features of a surgical instrument. The surrogate should be run in the same cleaning cycle(s) as the surgical instrument. A passed test (e.g., all test soil is removed) will indicate that equipment is working properly. Failure will indicate some key parameter(s) (see above) is not right and further investigation is need.
There are two methods for direct inspection and again, these methods are not mutually exclusive and both should be done.
Visual inspection: For the longest time, the only standard in the healthcare industry was “visually clean.” By that it was meant that at the completion of the cleaning process, direct visual inspection of the instrument for residual soil be done. Today, AAMI, AORN and other key industry groups recommend that additional testing should be done (such as testing equipment performance described above). This recommendation comes from the realization that visual inspection is subjective and also today’s complex instruments often do not allow direct visual inspection (such as flexible endoscopes). This does not mean, however, that visual inspection should be abandoned. Quite the contrary. It is still vital that each instrument be directly inspected by sterile processing staff prior to preparation for sterilization. This is the last line of defense. Inspection can be done unaided, but increasingly optical inspection tools, such as desktop magnifying glasses, USB microscopes, are being used to aid the naked eye in visual inspection. Tools, such as fiberscopes, are the newest tools in this regard. These thin fibered scopes allow for visual inspection inside of lumened devices such as suctions, shavers and the like.
Chemical analysis: Beyond visual inspection, chemical analysis can be conducted. Various simple and rapid reagent tests for blood, protein, carbohydrates and other organic residuals are available. Typically, these tests involve swabbing a surface or flushing water through a channel and then testing that recaptured sample for residual organic soils. Like the surrogate challenge device, the best choice for a reagent test is one which is sensitive to the organic soil(s) the surgical instrument is likely to come in contact with during clinical use. Again, a common one again is blood, but depending on the area of the body, may be some other soil such as carbohydrates.