Disinfection of medical instruments is important for preventing the spread of disease. Cleaning and disinfecting reusable equipment after it comes into contact with patients can be expensive, both in the cost of the disinfection procedure, but also in terms of time away from the patients themselves.
Not all medical instruments can be fully sterilized after each use. Thankfully, not all reusable instruments need the highest level of disinfection. But how to determine the minimum level of disinfection in a given situation?
Enter the Spaulding classification
To better answer this question, Earle Spaulding, a researcher at Temple University in Philadelphia, Pennsylvania, developed a method for determining the appropriate level of disinfection based on the risk of transmission of infection.[i]
The Spaulding classification provides a general standard for the levels of disinfection required for medical devices. Since the original research published in 1939, this system has been used by standards organizations all over the world for developing recommended disinfection practices.
Overview of the Spaulding Classification
Spaulding recognized that the need for disinfection of equipment in medical settings ranged from non-critical to semi-critical to critical, depending on the likelihood of spreading disease.
For example, sterilization is necessary for equipment that comes into contact with a patient’s bloodstream or sterile tissue. This category of equipment, such as surgical knives, is designated “critical” because it presents a high risk of disease transmission from patient to patient.
Equipment that only touches healthy, unbroken skin presents a low risk of contamination because intact skin acts as an effective barrier to most microorganisms. Examples in this “non-critical” category include bedpans, blood-pressure cuffs, and bedrails.
In between those two scenarios, a “semi-critical” level of disinfection presents a medium risk of contamination. This would include equipment such as endoscopes used on mucous membranes or areas of broken skin.
Classifications range from low-level disinfection to sterilization
Spaulding divided the three levels of criticality into four classifications for disinfection or sterilization requirements:
- Sterilization – The highest level of decontamination requires that all microbes have been destroyed.
- High-level disinfection – HLD is considered semi-critical and requires the destruction of all bacteria, fungi, mycobacteria, and viruses, though small numbers of bacterial spores may remain.
- Intermediate-level disinfection – The ILD designation is considered non-critical, but requires the destruction of most bacteria, mycobacteria, and certain types of viruses, as well as some fungi. It is not required to destroy any spores.
- Low-level disinfection – LLD is also non-critical. This designation requires only the destruction of bacteria and enveloped viruses, as well as partially destroying fungi and non-enveloped viruses. It does not need to destroy spores or mycobacteria.
Achieve HLD with UV Disinfection
As Spalding noted, different kinds of medical equipment require different levels and methods of cleaning. For example, channel-less endoscopes and TEE probes require HLD level disinfection after each use. To accomplish HLD, standard reprocessing methods may take two to three hours after each patient and require a special cleaning center, copious amounts of water, and chemicals and disposables that negatively impact the environment.
A relatively new technology for disinfecting medical equipment uses ultraviolet light (UV) technology. UV-C is electromagnetic radiation with a wavelength in the ultraviolet spectrum spanning the 200-280 nm range, reaching peak effectiveness at a wavelength of 254 nm. This short wavelength causes DNA and RNA strands to break – inactivating dangerous microorganisms and rendering them harmless and unable to reproduce.
Thanks to its germicidal property UV-C is an effective method for rapid reprocessing of equipment such as endoscopes that require HLD. The UV Smart D60 uses ImpeluxTM UV-C technology for consistent and reliable disinfection of the full spectrum of microorganisms in just a few seconds.
UV-C light for HLD
Although UV-C disinfection technology for medical instruments was not yet invented when Spaulding created his classification system, recently national standards and guidance organizations have begun to recognize the capabilities of this technology to perform high-level disinfection.
Learn more about how UV Smart disinfection technology can achieve HLD and improve the practices and performance of medical offices and hospitals.