Dialysis: Types, How It Works, Procedure, and Side Effects

Asian Institute of Nephrology and Urology | February 12, 2024

Dialysis: Types, How It Works, Procedure, and Side Effects

Dialysis is a medical term that most people have come across in their lifetimes. There is ageneral awareness that dialysis is a procedure that helps kidney patients. But many people are not aware of the nitty-gritty of the dialysis procedure. In this post, we will check out the A to Z of dialysis, including its type, functioning, and side effects.

What is dialysis treatment?

Healthy kidneys regulate the human body’s water and minerals and remove waste. However, people with failed or damaged kidneys have difficulty eliminating waste and unwanted substances from their blood. This is known as kidney failure and occurs when the human kidney can only perform less than 15 percent of its essential function.

In such a context, dialysis serves as an artificial way of filtering out extra fluid and byproducts from the blood. Dialysis treatment substitutes for the organic function of the kidneys and is hence known as renal replacement therapy (RRT). It was first used successfully in the 1940s and became a standard treatment for kidney failure in the 1970s. Since then, millions of people have been saved by the treatment. Without dialysis waste products accumulate in the blood of a person with damaged kidneys and harm other organs of the body.

It is essential to remember that, along with regulating water and waste from the body, the kidneys also secrete products that are important for metabolism. A hormone called erythropoietin made by the kidney, helps maintain normal level of hemoglobin in the body. A dialysis procedure cannot emulate the latter function. Hence, this hormone is given to patients on permanent dialysis to maintain a normal range of hemoglobin.

How does dialysis work?

Dialysis can be done in a hospital, a dialysis center, or even at home. Some of the kidney functions that a dialysis treatment emulates are:

• Removing waste and extra fluids from the body to maintain body fluid balance.
• Keeping safe levels of minerals, like potassium, sodium, calcium, and bicarbonate, in the body
• Removing excess fluid helps control blood pressure.

Why is dialysis needed?

Many people often wonder: Who needs dialysis? Well, people who have kidney failure or end stage renal disease (ESRD) need dialysis.

People who develop sudden,severe kidney injury (termed severe acute kidney injury) may sometimes require dialysis. However, with timely and adequate care, most patients recover from it and a substantial proportion of these patients are off dialysis.

Types of Dialysis

There are three main approaches to dialysis: intermittent hemodialysis (IHD), peritoneal dialysis (PD), and continuous renal replacement therapies (CRRT). Let us break down these three types of dialysis in detail.

1. Intermittent hemodialysis

Hemodialysis involves a machine that gently takes blood from your vein, filters it through a dialyzer(filter), and returns it to the patient. It is a 4-hour process that may take place in a hospital or dialysis center three times a week. It is possible to do at-home hemodialysis, and some people even choose to do the process at night while they sleep.

2. Peritoneal Dialysis

It is a dialysis procedure wherein a sterile dialysate solution full of glucose and minerals goes through a silicone tube placed in the abdomen. The fluid gets in contact with a special membrance called peritoneum that lines the inner wall of the abdomen and the surface of abdominal organs. The peritoneal membrane acts as a natural ‘filter’ and fliters out metabolic waste and excess water into the abdominal cavity. The waste and excess water collected in the abdomen is periodically removed. This is called Peritoneal Dialysis.

the Peritoneal dialysis takes place at home, and there are two ways to do the treatment:

• Automated peritoneal dialysis that uses a machine called a cycler.
• Continuous ambulatory peritoneal dialysis (CAPD) that takes place manually.

Peritoneal dialysis, if done properly, will ensure greater freedom to patients and allow them to visit their Nephrologist just once a month. However, patient education of the procedure and caregiver support are important caveats of a successful peritoneal dialysis program.

3. CRRT or Continuous renal replacement therapy

Dialysis can be continuous or intermittent. An intermittent dialysis session lasts up to six hours, but continuous renal replacement therapy (CRRT) is designed for 24 hours. There are multiple types of CRRT, and they can involve filtration and diffusion. CRRT is used in critically ill patients that require tailored dialysis therapy suiting their specific needs. These patients frequently have a very low blood pressure for which CRRT is ideal.

Side Effects Associated with Dialysis

All three types of dialysis carry certain risks.

The potential side effects of hemodialysis include:

• Low blood pressure
• Anaemia
• Muscle cramps
• Bleeding
• Chills
• Fever Fever and chills are very rare with modern dialysis technology and single use dialysis.
• Irregular heartbeat

The possible side effects linked to peritoneal dialysis are:

• High blood sugar
• Infection – Peritonitis / Skin Infection
• Hernia

Side effects linked to CRRT.

• Hypothermia
• Bleeding
• Low blood pressure
• Electrolyte disturbances

Wrapping It Up

Hemodialysis is a painless, lifesaving therapy which involves blood purification by a dialysis machine. The process is very effective and allows patients to maintain an active lifestyle. In most cases, it involves a thrice weekly schedule of 4 hours each.

Peritoneal dialysis involves a small, silicone tube placement in the abdomen, that allows instillation of special dialysis solution into the abdomen. The solution aids the peritoneal lining membrane in filtering excess fluid and metabolic waste. This procedure allows the patient to be independent of any health care provider. In most cases, when done in a safe and hygienic manner, the patient needs to follow up with a Nephrologist only once a month.

Frequently Asked Questions

1. How long does dialysis treatment last?

Ans. A dialysis treatment lasts for three to four hours per session.

2. Is dialysis painful?

Ans. No, dialysis is not painful.

3. Can the kidneys fully recover after dialysis?

No, kidneys do not recover after dialysis. Only a fraction of the patients witnessed recovery.

4. What is the first stage of kidney failure?

Ans. The first stage of kidney failure includes mild damage or physical damage to the kidney. At this stage, the patient has a normal estimated glomerular filtration rate (eGFR) of 90 or higher, but there is protein in the urine.

5. What foods help repair the kidneys?

Ans. Superfoods like avocados, cranberries, cauliflower, etc. are helpful for kidneys. The key is to have a balanced diet.