The topic of disinfection processes has always been central to prevention in the health and social care setting and even more so in the clinical setting. These measures are implemented to reduce the level of microbial and pathogenic contamination in hospitals, polyclinics, and clinics.

In the latter, it is the most vulnerable subjects that are most exposed to the risk of contamination, as in the case of infections contracted by hemodialysis patients, which we will discuss shortly.

We at AMIL Care think it is essential to reflect on the topic of infections in hemodialysis patients. For this reason, we have decided to dedicate an article to you, designed to assist the work of professionals such as purchasing managers in hospitals, medical equipment management managers, clinical engineers (AIIC), safety and hygiene managers (HSE), clinical risk management managers (i.e., risk managers).

What is hemodialysis?

We proceed step by step. First of all, hemodialysis mainly concerns the dialysis of patients suffering from renal failure. Once the kidneys are no longer able to carry out their functions of regulation, waste elimination, and hormone production, it is necessary to intervene to avoid irreversible damage to the body. This is where hemodialysis comes in to replace the functions performed naturally.

Thus, hemodialysis acts as an “extrarenal” method of blood purification. More technically, the process takes place through a membrane that plays the role of an “artificial kidney,” which allows the removal of “contaminated” fluid and its subsequent reintroduction into the body.

This requires flawless disinfection of instruments, liquids, and membranes, as well as the clinical environment itself.

The importance of disinfection of hemodialysis equipment

Especially in the world of hemodialysis, a treatment that requires the use of external tools, healthcare-associated infections (HAIs) pose a significant risk. These can be endogenous (internal to the body) or exogenous (external), but it is the latter that makes hemodialysis patients particularly vulnerable.

HAI transmission can occur in many ways, ranging from airborne contamination to the use of non-sterile instruments. So, while new medical technologies are crucial for treating serious conditions, they must not become a source of further complications.

Consequently, the places where hemodialysis is performed, starting from outpatient clinics, hospital structures, and more generally specialized clinics, must all undergo a scrupulous disinfection procedure that can avoid the onset of microbial and pathogens. While HAIs are not entirely preventable, proper sanitization, sterilization, and monitoring of dialysis equipment can dramatically reduce the likelihood of exposure to such infections.

The first step towards optimal disinfection

Considering the increased vulnerability of hemodialysis patients and the places where it is performed, the first step might seem trivial, but it is crucial: wash your hands. This simple gesture can significantly reduce the risk of re-contamination of already sterilized instruments.

A further fundamental step is the use of advanced technology. The new generation instruments, equipped with systems that prevent contamination, such as the ‘no touch’ technology, which eliminates any physical contact, are essential to preserving the sterilized environment.

What are the central processes of dialysis equipment disinfection?

First, the processes can be divided into physical, chemical, and mechanical. The application of these processes is generally divided into the so-called ‘disinfection phases’. Let’s see them in more detail.

The physical process of disinfection

The ‘physical’ process of disinfection refers, for example, to the use of heat as a disinfectant factor. In practice, it is a question of making the water circulate in the hydraulic branches of the instruments at a temperature exceeding 85°C. Furthermore, the creation of vapor allows for reaching points inaccessible by liquid alone.

The use of heat can also be associated with chemical elements for greater effectiveness. In particular, heat can be combined with Citric Acid, a solution that allows effective descaling of the equipment.

 The chemical process of disinfection

Disinfection by means of a “chemical” process, on the other hand, allows for specific results, depending on the agent used or the qualities of the substance applied. Nonetheless, an appropriate ratio of dilution and distribution of such products, as well as their placement, is necessary. Therefore, different types of disinfectant products can be used. It is also advisable to pay attention to the use of these chemicals: some can damage equipment due, for example, to the difficulty of removing them from the circuits during the washing phase. For this reason, manufacturers of hemodialysis equipment have compiled a classification of disinfection products in their manuals.

However, as regards the protection of hemodialysis instruments from airborne contamination, hydrogen peroxide, is essential. The use of this substance allows the elimination of all types of microorganisms, such as bacteria, viruses, spores, fungi, TB, and biofilm. The active ingredients, concentration, contact times, and methods of use of these substances must in any case strictly comply with what is reported in the manuals.

The mechanical process of disinfection

The third type of disinfection is called a ‘mechanical’ process. This term refers to the management procedures of the equipment which allow their automatic disinfection. First of all, the timing of the mechanical process is fundamental: the disinfection process must take place at the end of each session, before starting a new one, and after a period of non-use. Furthermore, the operator plays a crucial role by monitoring and verifying the automatic disinfection cycle and the consequent washing cycle.

In addition to this, to avoid any type of contamination of the hydraulic circuits themselves, the ultrafilters with which each appliance is equipped must be checked regularly, both on the inlet and outlet membranes of the liquids. For this reason, it is recommended to check in advance the tolerance of the filters to the type of disinfectant used, as specified in the equipment manuals. Even if often overlooked, the water supply branch requires thorough disinfection.

Following these disinfection procedures, whether physical, chemical, or mechanical, it is advisable to carry out scrupulous checks on the residues of the disinfectant substances in the equipment itself. To this end, there are specific systems and tools for detecting the traces indicated in the instructions for the use and management of dialysis equipment.

The importance of disinfecting external surfaces

Last, but not least, is the disinfection of the external surfaces of the equipment. The routine cleaning of the surface of the equipment and the correct disinfection before and after the single treatment is of primary importance to prevent the onset of infections in hemodialysis. In addition, because the dialysis monitor is considered to be a medical device in all respects, it must be properly disinfected and sterilized, paying attention to the chamber supports and pressure transducer connections as well.

The implementation of these ideal procedures for accurate disinfection aimed at protecting hemodialysis patients and improving the effectiveness of the treatment itself allows to significantly reduce, if not eliminate, the risks of exposure to contamination in a clinical setting.

Of course, to implement safe and risk-free disinfection for equipment, operator, and patient, the protocols to be followed must be coupled with careful verification of results. In particular, it is advisable to periodically check the quality of the treated water. Furthermore, the reference to the European guidelines regarding quality standards, protocols to be followed, and their frequency, can guarantee a strong safety and efficacy of the disinfection phases in a clinical setting, particularly in very vulnerable patients, such as those in hemodialysis.