Step and repeat: Understanding device reprocessing

Knowing what's involved when medical devices are reprocessed can help manufacturers understand what’s needed in the design and material choice. Stephen Spiegelberg, Cambridge Polymer Group, explains

Reusable medical devices are designed to be used to treat multiple patients with appropriate reprocessing between each patient. Initially, these devices were relegated to surgical tools, such as scalpels, retractors, and suction tubes, and examination equipment, such as stethoscopes and blood pressure cuffs, but now extend to endoscopy equipment, infusion pumps, biopsy equipment, and respiratory equipment. Reprocessing of these devices saves hospitals between $0.5 to $2M annually through reduced original equipment purchasing and through reduction in tonnes of medical waste disposal. The reprocessing is typically performed at either central facilities within hospitals or by third party processors. The reprocessing medical device market in the United States was $0.78B in 2013 and is anticipated to reach $2.58B by 2020.

Reprocessing reusable devices involves cleaning and disinfection/sterilisation (or generally ‘microbicidal’ process). The principle risk involves transferring organic soil and/or micro-organisms from one patient to another due to incomplete cleaning or microbicidal processing.  In 2015, the FDA published a guidance document for reprocessing medical devices. The document places the responsibility of reducing this risk on:

1. the original manufacturers of the medical devices, who should design the devices for easy disassembly and cleaning, and for providing adequate instructions for cleaning;
2. the reprocessors (either the central facilities at the hospitals or third party reprocessors) for properly cleaning and microbicidal processing the devices, and for validating these processes; and
3. the FDA, for examining the documentation on the previous two entities and ensuring the devices are safe and effective as originally manufactured and following cleaning.

Reprocessing reusable medical devices involve three main steps, each of which is equally important in reducing risk of transmission of organic soils, such as blood, fecal soils, soft and hard tissues, as well as microorganisms, such as bacteria and fungi, to a patient. The first step begins at the clinical setting, or point of use of the medical device upon completion of the procedure. The reusable device should be separated from the disposable medical waste, wiped clean if possible, and placed in an appropriate container or transport so that it is kept moist and free of damage while it is transported to the cleaning area. Keeping the device from drying out is important, as it becomes substantially more difficult to clean dried organic soils.

The second step involves cleaning the medical device. For some devices, some disassembly is required to expose internal channels to the cleaning process, and to remove parts of the device, such as electronics, that may be sensitive to more rigorous cleaning steps. The original equipment manufacturer should provide easy-to-understand directions for disassembling the equipment and for cleaning the part, including what size brushes to use and what cleaning agents are appropriate. The instructions should also include directions for reassembly. The cleaning should minimide transmission of organic soils from one patient to another, and prevent accumulation of soils during repeated uses/cleaning cycles. Additionally, the soil removal aids in microbicidal processing by ensuring the sterilisation or disinfecting agents can contact the micro-organisms.

The reprocessing instructions should be validated to ensure they will consistently reduce the soils and bioburden levels to safe levels. Whereas there are currently no standards for validating reprocessing procedures for reusable devices, several ASTM and AAMI standards may be applied. These standards provide guidance on test assays to measure protein, carbohydrate, endotoxins, and other markers for organic soils, and also recipes for artificial test soils to challenge and validate the cleaning process.

The third step in reprocessing is to disinfect or sterilise the device. The appropriate microbicidal process depends on the intended use of the device, along with the construct of the device. For critical devices where the device is in contact with blood or sterilised tissue, such as surgical instruments, sterilisation is required, often through autoclaves, ethylene oxide, or gas plasma. Semi-critical devices where the device is in contact with mucous membranes or non-intact skin should undergo high-level disinfection, normally with chemical disinfectants that reduce all microorganisms except for some bacterial spores. Non-critical devices which contact intact skin, such as pressure cuffs and bed rails, can undergo low-level disinfection.

When designing a re-usable medical device, the equipment manufacturer selects materials and designs that take into account ease of cleaning and the number of times the device can be successfully reprocessed (reuse life). With thoughtful consideration of these factors, devices can undergo multiple processing steps, helping to reduce healthcare costs while still providing safe and effective treatment for the patients.