The lifesaving medical procedure known as hemodialysis has been made possible due to advancements in water treatment solutions that have bought the cleanest and purest form of water known to us, provided a safe and viable method of combating kidney failure, and improved the quality of life for many.
However, not many know how the dialysis water treatment systems work, nor do they understand how they need to change and evolve, especially when considering environmental sustainability. So, let’s take a look now.
The Lifesaving Water Treatment System
Dialysis water treatment systems play a crucial role in the field of hemodialysis, a medical procedure used to filter and cleanse the blood of individuals with kidney failure or chronic kidney disease. The success of hemodialysis depends heavily on the quality of the water used in the process, as any impurities in the water can pose serious health risks to patients. Unlike something such as the hydro water system we see in municipal plants, this water needs to be super clean, called ultrapure water.
But first, let’s give an overview of the system to provide a fundamental understanding of this treatment mechanism, its components, and its significance in ensuring the safety and effectiveness of dialysis treatment.
The Critical Aspects of Water Treatment in Dialysis Machines
The system typically starts with a raw water source, which can be tap water or well water. This source water is the initial input into the treatment process. We’ll talk more later about the types of water and their importance, but let’s go about the rest of it first.
Next comes the pre-treatment stage. This is the first step in the purification process. It involves removing large particles, sediments, and contaminants through mechanisms like sediment filters and activated carbon filters. This helps protect the subsequent treatment stages and extend the life of the system.
The stages progress as follows:
- Pre-Treatment: When water is gathered from a source, it may contain any number of impurities, so an initial filtration step is required to remove the less fine particles, such as relatively large bodies of debris and other objects.
- Reverse Osmosis (RO): The heart of most dialysis water treatment systems is the reverse osmosis unit. RO uses a semi-permeable membrane to remove ions, particles, and impurities from the water, ensuring it meets strict water quality standards. This removes impurities we cannot see through the naked eye, and can even be microscopic in size.
- Deionization: Following RO, the water passes through deionization beds, which remove any remaining ions and impurities. This stage further polishes the water, making it suitable for dialysis. Removing ions is particularly necessary for more than just dialysis, as it removes the conductivity of the water.
- Ultrafiltration: Some systems incorporate ultrafiltration to provide an additional level of water purity. Ultrafiltration removes larger particles and endotoxins, ensuring the water is free from contaminants. It acts as an additional filter, in a sense.
- Disinfection: To prevent bacterial contamination, water treatment systems often include ultraviolet (UV) or chemical disinfection methods.
- Storage and Distribution: Treated water is stored in a reservoir and then distributed to dialysis machines through a network of pipes and tubing.
The significance of high-quality water in dialysis cannot be overstated. Patients undergoing hemodialysis are exposed to large volumes of water during each treatment session, as the process injects water into the bloodstream. Moreover, dialysis is an ongoing process, and is not exclusively for failed kidneys, but also for failing kidneys.
To put things in perspective, patients that undergo dialysis consume more water in three to six weeks of treatment than an average person consumes in their entire lifetime. If this water contains impurities, microorganisms, or endotoxins, it can lead to serious complications and infections. Dialysis patients are often immunocompromised, making them more vulnerable to contaminants. Poor water quality can result in adverse reactions, infections, and, in severe cases, patient hospitalization or death.
Regulatory Standards
Hemodialysis machines and the treatment process itself are subject to strict regulatory standards and guidelines. Organizations like the Association for the Advancement of Medical Instrumentation (AAMI) set specific water quality standards for dialysis facilities. Compliance with these standards is mandatory to ensure patient safety, especially as dialysis requires ultrapure water as a minimal necessity rather than an optional benefit.
The Types of Water Used and Their Importance
Dialysis treatment isn’t just something reserved for the most top-of-the-line hospitals. It can be done in clinics, and even at home. This is largely due to regulatory standards making it compulsory for dialysis machines to provide everything necessary for a patient in a single unit. That means home dialysis machines can be used for the full treatment procedures as well.
That is why the choice of water source is so critical, as it means that the source water may or may not be the cleanest source, but the most readily available one.
Municipal Tap Water
Many dialysis facilities use treated municipal tap water as their water source. This is a convenient and readily available option. However, tap water often contains various minerals and impurities that need to be removed or reduced to meet dialysis water quality standards, something that home dialysis patients might not know, and not account for. Therefore, extensive pre-treatment and purification processes are typically required.
Well Water
Some dialysis clinics, especially those in rural areas, may use well water as their source. Well water quality can vary significantly depending on the location and local geology. Well water typically requires more extensive pre-treatment and purification compared to municipal water to meet dialysis standards.
Reverse Osmosis (RO) Water
In some cases, dialysis facilities use a dedicated RO water purification system as the primary source of water. RO systems can generate high-purity water from a variety of source waters, including tap water, well water, or even partially treated water from other sources. The RO process removes a wide range of contaminants, making it suitable for use in dialysis. It adds the benefits and the drawbacks of using a mixture of these sources as a whole.
Central Dialysis Water Systems
Large healthcare facilities or multi-center dialysis providers may have central water treatment systems that produce high-quality water and distribute it to multiple dialysis units. These systems often use RO as a primary purification method. However, the way the water is distributed can also matter, as copper and lead pipes can be chipped away by the water and be added as microparticles into the water system.
The Limitations of Producing Ultrapure Water
Producing ultrapure water for dialysis is essential to ensure the safety and well-being of patients undergoing hemodialysis. However, there are certain limitations and challenges associated with the production of ultrapure water for dialysis, and most of these challenges do not have a viable solution just yet.
- Maintaining an ultrapure water system can be expensive. The equipment required for water purification, such as reverse osmosis units, deionization tanks, and monitoring systems, can be costly to purchase and maintain. Moreover, high electricity consumption can add to the price for each individual dialysis procedure, leading at-home patients and smaller clinics into greater financial burdens and a higher carbon footprint.
- Components like RO membranes and activated carbon filters need periodic replacement, and any breakdowns or malfunctions in the system can disrupt dialysis treatments and pose a risk to patients. This isn’t just optional or best practice, but necessary, which calls for better quality dialysis machines and improved systems of transporting water to reduce wear and tear.
- We’ve already talked about the water source and their variability, but that also adds the limitation of maintaining microbiological control. Ultrapure water requires a strict maximum threshold of bacteria (because getting it down to zero is nearly impossible), and the variance can add complexity in monitoring those levels.
- From removing chloramines that are used to disinfect the water to the constant maintenance is required, regulation is understandable. However, the technology of current dialysis machines makes it very costly and very difficult to maintain these standards, especially as monitoring for the levels of purity is nearly impossible due to technological limitations.
- The water purification processes, particularly those involving reverse osmosis, generate a lot of wastewater as a byproduct. For every gallon of ultrapure water, five gallons of wastewater are produced. Managing and disposing of this waste can be environmentally challenging, and regulation adds complication to managing this aspect.
Saving Lives is a Difficult Process
Despite these limitations, the production of ultrapure water and the dialysis medical procedure remains critical in improving quality of life and advancing modern medicine. Healthcare facilities continually work to overcome these challenges through proper management, monitoring, and the use of advanced technology and best practices in water treatment and providing healthcare.