For many individuals with renal problems, there's a time they do not forget – the day the doctor speaks to them about their dialysis needs for the first time. It may feel like your world has just collapsed. However, for many millions, that day marks not the end but a beginning because modern medicine offers something called renal replacement therapy.
If you have never had to learn about it, you may think that renal replacement therapy is complicated and difficult to understand. But in fact, renal replacement therapy is among the most convincing successes of modern medicine; using this technique gives a patient the chance to keep their blood clean, their body chemistry intact, and their life continuing.
Let’s take a closer look at what renal replacement therapy is, why people need it, and what kinds of it exist.
What Exactly Is Renal Replacement Therapy?
Kidneys are incredibly good at doing various things at once. They filter about 150 litres of blood daily, and they remove waste from it, neutralise electrolytes (such as potassium and sodium), control the liquids in organs, and support the process of controlling blood pressure. When the kidneys are unable to perform these functions properly due to low functionality, caused by chronic kidney disease, acute kidney injury, or complete kidney failure, toxin accumulation and fluid retention can be observed.
Renal replacement therapy refers to treatment methods that perform kidney function for the sick kidneys. Renal replacement therapy cannot treat kidney disease, but it can perform its function and help patients live longer.
Doctors usually decide to initiate renal replacement therapy if kidney function drops to 10-15% of the normal value or even sooner in case of the appearance of particular (dangerous) symptoms.
Why Would Someone Need It?
There are two general cases in which renal replacement therapy is required.
One is the case of acute kidney injury, an abrupt loss of kidney function often observed in critical patients after undergoing major surgeries, experiencing infections, physical trauma, and hypotension. In such cases, renal replacement therapy is just a temporary solution to keep the patient alive while waiting for the kidneys to regain their functioning capacity by themselves.
The other is that of chronic kidney disease leading to end-stage renal disease. In such cases, the cause of renal failure is often attributed to chronic problems such as diabetes, hypertension, glomerulonephritis, or polycystic kidney disease that have affected the kidneys over time. Unlike acute renal failure, renal replacement therapy in this case is a long-term procedure unless there is an option for a kidney transplant.
The Main Renal Replacement Therapy Types
This is the point where things become very intriguing, because "renal replacement therapy" is not a single type of treatment, but rather a group of treatment techniques, which are best suited for various conditions, ways of living and health conditions. Knowing about the most common renal replacement therapy types makes it easier to understand the actual meaning of a diagnosis.
Hemodialysis
This is how most people envision dialysis. Hemodialysis works by taking blood from the body, running it through a machine that has a semi-permeable filter called a dialyser, and returning it to the body after it has been cleaned of any impurities. Access to the patient’s blood is usually from a surgically created connection in their arm (an arteriovenous fistula or graft) or, for short periods of time, a central venous catheter.
Most patients undergo hemodialysis three times a week, with each session lasting three to five hours; while most of this takes place in a dialysis centre, home hemodialysis is becoming increasingly popular for those who are eligible. Hemodialysis is a safe and effective practice; however, it means patients have to go to the facility at set times for their sessions.
Peritoneal Dialysis
Peritoneal dialysis employs a less aggressive method. Rather than filtering blood using a machine, peritoneal dialysis uses the body’s peritoneum, which is the membrane surrounding the abdominal cavity, as a natural filter. In peritoneal dialysis, a specially designed fluid, known as dialysate, is inserted through a catheter into the abdominal area and, after a certain period, it removes waste products and excess fluids from the body via the peritoneum.
It may either be performed continuously during the day (Continuous Ambulatory Peritoneal Dialysis) or continuously during the night by means of a machine known as a cycler (Automated Peritoneal Dialysis). It offers greater freedom as compared to hemodialysis since it can be done anywhere, including homes, workplaces or while travelling.
Continuous Renal Replacement Therapy (CRRT)
The technique of CRRT can be referred to as the dialysis used in ICU’s. Unlike dialysis, which is done for a few hours in a day, CRRT is done continuously and for 24 hours, which is very helpful in gently eliminating wastes and fluids from the body. This is obviously an advantage for patients suffering from low blood pressure or heart diseases, where rapid changes in the body will cause disturbances. There are a few types of CRRT, including CVVH, where hemodialysis takes place continuously and CVVHDF, which uses filtration and diffusion of CRRT.
Kidney Transplantation
Kidney transplantation is considered a variant of renal replacement therapy even though it is not precisely the same. Indeed, transplantation is seen as the best renal replacement therapy since it does not solely substitute kidney function but restores it entirely. The healthy kidney from a donor, either a living or deceased donor, is implanted surgically, and after that, it becomes capable of full kidney function with the support of some lifelong immunosuppressive medication.
Indeed, kidney transplantation is said to be the best option in terms of both quality of life and survival; however, not all patients meet the criteria to be suitable candidates for the transplant, and sometimes donor kidneys may not be available.
Read Also:Understanding Stage 5 Kidney Failure Life Expectancy
Preparing for Renal Replacement Therapy
The preparation process differs according to which route a patient chooses. In the case of hemodialysis, this will entail surgery several weeks or even months prior to the procedure to create a fistula or graft that should be allowed time to mature. When it comes to peritoneal dialysis, the placement of a catheter in the abdomen is done surgically well before the commencement date. Transplant patients undergo compatibility testing and health screenings, in addition to waiting for a suitable organ to become available.
Besides the physical preparation, almost all patients are counselled on their diet (balancing their intake of potassium, phosphorus, sodium, and fluids on a daily basis), medications, and, equally importantly, emotionally and psychologically prepared. It truly is a major adjustment, adapting to a new lifestyle centred on treatment schedules.
Risks and Realities
There is always a certain amount of risk involved in any kind of medical intervention, and this is certainly true for renal replacement therapy. Hemodialysis involves the risk of hypotension during the procedure, infection at the access site, and cardiovascular stress as a result of repeated treatment sessions. Peritoneal dialysis also comes with the risk of developing peritonitis if the process isn't strictly sterile. CRRT is conducted in patients who have already been critically ill; therefore, some of the risks associated with the procedure are related to their primary condition, while there is also the risk of bleeding due to anticoagulation.
All of this doesn't mean that renal replacement therapy is dangerous – on the contrary, it just means that a clear understanding of its risks and benefits is necessary. Renal replacement therapy has become incredibly safe and efficient, and the risks involved are significantly less serious than the consequences of the failure to undergo the treatment.
Living Well With Renal Replacement Therapy
The first and foremost thing that should be understood here is that a diagnosis of renal replacement therapy doesn't mark the end of a full and productive life; it marks the beginning of the next phase. Dialysis patients work, travel, raise children, engage in recreational activities, and develop healthy routines despite the treatments they have to undergo. Developments in home therapy, flexible scheduling options, and improved technologies have facilitated the process of integrating the treatment into a patient's life rather than having his or her life dictated by it.
For those who find themselves on this path or for their loved ones and close friends, perhaps the best initial action to take is to talk to a nephrologist about what sort of renal replacement therapy works better for their unique medical condition and lifestyle. The right choice here is highly subjective and individual.
The kidneys are small organs; yet, their lack is felt very strongly. Fortunately, science has found multiple ways to replace what these vital organs can no longer do – and that has made a huge difference for many.
Read Also: Kidney Transplant Criteria: Who Qualifies and What It Really Takes
Frequently Asked Questions (FAQs)
What are the four types of renal replacement therapy?
The four main forms of RRT include hemodialysis, peritoneal dialysis, continuous renal replacement therapy (CRRT), and kidney transplantation. The first two involve filtering the waste products and fluids at scheduled intervals in outpatient and home settings, while CRRT offers 24-hour filtration of the blood in unstable ICU patients, and kidney transplantation involves replacing the failed kidneys with a new organ.
What are renal replacement therapies?
Renal replacement therapy (RRT) is a form of treatment that takes the place of nonfunctional kidneys by performing vital actions that would otherwise be done by the kidneys. RRT removes metabolic wastes from the body, manages fluid balance in the body, controls electrolyte levels, and maintains acid-base balance of the body.
What is a 24-hour dialysis machine?
A continuous dialysis machine is a particular CRRT machine used in the ICU for filtering the blood continuously for 24 hours a day. It contrasts with the normal dialysis machine, where the process of filtering blood takes only 3 to 4 hours. The continuous machine works in such a way that it extracts waste and extra fluid from the body at a very slow pace.
What are the treatment options for kidney failure?
The main methods of treatment of kidney disease include hemodialysis, peritoneal dialysis, CRRT (continuous renal replacement therapy – used for ICU patients), kidney transplantation, and conservative treatment. The best method should be chosen based on the nature of the disease being acute or end-stage chronic, as well as individual health conditions.
What is the rule of 7 in hemodialysis?
When doctors create a hemodialysis plan, they often use something called the "rule of 7" to set the potassium level in the dialysate. It’s simple: they take the patient’s blood potassium before dialysis, add it to the dialysate potassium, and shoot for a total of around 7. So, if someone starts with 4.5 mEq/L in their blood, the doctor might pick a dialysate with 2.5 mEq/L. The whole point is to drop the potassium back to a safe range and prevent serious heart rhythm problems.
What are the four principles of CRRT therapy?
Diffusion, ultrafiltration, convection, and adsorption are the four basic physical principles of CRRT (continuous renal replacement therapy). Diffusion is responsible for elimination of solutes based on a concentration gradient. Ultrafiltration entails removal of excess fluid with hydrostatic pressure, while convection eliminates solute particles along with ultrafiltrate. Adsorption entails binding certain inflammatory proteins or toxins to the filter membrane.
What are the two types of kidney transplants?
There are two major types of kidney transplant surgery, which include living-donor transplantation and deceased-donor transplantation. In living-donor transplantation, the kidney is taken from a living donor who may be a relative, spouse, or altruistic donor of the patient, offering the patient longer survival of the organ as well as reduced waiting time for the transplantation procedure.
What are the two types of dialysis treatments?
There are two conventional types of long-term dialysis, which include hemodialysis and peritoneal dialysis. Hemodialysis involves pumping blood through an external machine with an artificial filter, while peritoneal dialysis involves the use of the body's abdominal lining (peritoneum) as the filter, using a special cleansing solution infused and drained via a catheter.
Read Also:Life After Kidney Transplant: How Long Can You Really Live