What is Hemodialysis? Purpose, Procedure & Results

Hemodialysis is a medical treatment that cleans your blood when your kidneys can't do it properly anymore. Think of it as an artificial kidney that filters waste products, excess water, and toxins from your bloodstream using a special machine and filter.

This life-saving treatment becomes necessary when chronic kidney disease progresses to kidney failure, also called end-stage renal disease. While the idea of being connected to a machine might feel overwhelming at first, millions of people worldwide live full, meaningful lives with hemodialysis.

What is hemodialysis?

Hemodialysis is a kidney replacement therapy that does the job your kidneys normally handle. Your blood flows through thin tubes to a dialysis machine, where it passes through a special filter called a dialyzer.

The dialyzer contains thousands of tiny fibers that work like a sieve. As your blood moves through these fibers, waste products and extra fluid pass through the membrane while your clean blood cells and important proteins stay in your bloodstream.

The cleaned blood then returns to your body through another tube. This process typically takes 3-5 hours and happens three times per week at a dialysis center or sometimes at home.

Why is hemodialysis done?

Hemodialysis becomes necessary when your kidneys lose about 85-90% of their function. At this point, your body can't effectively remove waste products, excess water, and maintain the right balance of chemicals in your blood.

Without this treatment, dangerous toxins would build up in your system, causing serious complications. Your doctor will recommend hemodialysis when your kidney function drops to a level where your body can't maintain good health on its own.

The most common conditions that lead to needing hemodialysis include diabetes, high blood pressure, polycystic kidney disease, and autoimmune disorders that damage the kidneys over time.

What is the procedure for hemodialysis?

The hemodialysis procedure follows a careful, step-by-step process designed for your safety and comfort. Before your first treatment, you'll need a minor surgical procedure to create vascular access, which gives the dialysis machine a way to reach your bloodstream.

Here's what happens during each dialysis session:

1. Your dialysis team connects you to the machine using your vascular access
2. Blood flows from your body through tubing to the dialyzer
3. The dialyzer filters waste, toxins, and excess fluid from your blood
4. Clean blood returns to your body through separate tubing
5. The process continues for 3-5 hours while you rest, read, or watch TV

Throughout the treatment, machines monitor your blood pressure, heart rate, and the rate of fluid removal. Your dialysis team stays nearby to ensure everything runs smoothly and adjust settings if needed.

How to prepare for your hemodialysis?

Preparing for hemodialysis involves both physical and emotional readiness. Your healthcare team will guide you through each step, but understanding what to expect can help ease any anxiety.

First, you'll need to have vascular access created, which is usually done several weeks before starting dialysis. This might be an arteriovenous fistula, graft, or temporary catheter that allows blood to flow to and from the dialysis machine.

Before each treatment session, there are several things you can do to prepare:

• Take your medications as prescribed, unless your doctor advises otherwise
• Eat a light meal or snack before treatment to prevent low blood sugar
• Wear comfortable, loose-fitting clothing with sleeves that roll up easily
• Bring entertainment like books, tablets, or music for the 3-5 hour session
• Keep track of how much fluid you drink between treatments

Your dialysis team will also teach you about dietary changes that can help you feel better and make treatments more effective. This education process is gradual and supportive, giving you time to adjust.

How to read your hemodialysis results?

Understanding your dialysis results helps you track how well the treatment is working. Your healthcare team will explain these numbers in detail, but here are the key measurements they monitor.

The most important measurement is called Kt/V, which shows how effectively dialysis is removing waste from your blood. A Kt/V of 1.2 or higher indicates adequate dialysis, though your target may be different based on your individual needs.

Other important measurements include:

• URR (Urea Reduction Ratio): Should be 65% or higher
• Fluid removal rate: How much excess water is removed during treatment
• Blood pressure changes: Monitored before, during, and after treatment
• Laboratory values: Including potassium, phosphorus, and hemoglobin levels

Your dialysis team reviews these results regularly and adjusts your treatment plan as needed. Don't hesitate to ask questions about what these numbers mean for your health and well-being.

How to optimize your hemodialysis treatment?

Getting the most benefit from hemodialysis involves working closely with your healthcare team and making certain lifestyle adjustments. The good news is that small changes can make a big difference in how you feel.

Following your prescribed diet is one of the most important things you can do. This typically means limiting sodium, potassium, phosphorus, and fluid intake between treatments. Your dietitian will help you create meal plans that are both nutritious and enjoyable.

Taking your medications exactly as prescribed is equally important. These might include phosphate binders, blood pressure medications, or treatments for anemia. Each medication serves a specific purpose in keeping you healthy.

Regular attendance at dialysis sessions is crucial. Missing treatments or cutting them short can lead to dangerous buildups of toxins and fluid in your body. If you're having trouble with the schedule, talk to your team about possible solutions.

What are the risk factors for needing hemodialysis?

Several conditions and factors can increase your risk of developing kidney failure that requires hemodialysis. Understanding these risk factors can help with early detection and prevention when possible.

Diabetes is the leading cause of kidney failure in many countries. High blood sugar levels over time can damage the small blood vessels in your kidneys, gradually reducing their ability to filter waste effectively.

The most common risk factors include:

• Diabetes (especially when poorly controlled)
• High blood pressure that damages kidney blood vessels
• Family history of kidney disease
• Age over 60, as kidney function naturally declines
• Cardiovascular disease
• Obesity
• Smoking

Less common but important risk factors include autoimmune diseases like lupus, polycystic kidney disease, and certain medications that can harm kidneys over time. Some people may also have genetic conditions that affect kidney function.

What are the possible complications of hemodialysis?

While hemodialysis is generally safe and well-tolerated, like any medical treatment, it can have some side effects and complications. Most of these are manageable with proper care and monitoring.

The most common side effects happen during or shortly after treatment and usually improve as your body adjusts. These include muscle cramps, dizziness, nausea, and fatigue as your body adapts to fluid and chemical changes.

More serious but less common complications can include:

• Low blood pressure during treatment
• Infection at the access site
• Blood clots in the access
• Irregular heart rhythms
• Air embolism (very rare)

Access-related complications may require additional procedures to maintain or replace your vascular access. Your dialysis team monitors for these issues and takes steps to prevent them when possible.

Long-term complications can include bone disease, anemia, and cardiovascular problems. However, with proper treatment and lifestyle management, many people minimize these risks and maintain good quality of life.

When should I see a doctor about hemodialysis?

If you're already on hemodialysis, you should contact your healthcare team immediately if you experience certain warning signs. These might indicate complications that need prompt attention.

Call your dialysis center or doctor right away if you notice signs of infection at your access site, such as redness, warmth, swelling, or drainage. Fever, chills, or feeling unusually unwell should also prompt immediate medical attention.

Other situations that require urgent care include:

• Severe shortness of breath or chest pain
• Excessive bleeding from your access site
• Signs of blood clots, like swelling in your arm or leg
• Severe nausea, vomiting, or inability to keep fluids down
• Changes in your access site, like loss of the vibration feeling

For those not yet on dialysis, discuss the possibility with your kidney doctor if you're experiencing symptoms like persistent fatigue, swelling, changes in urination, or nausea. Early planning for dialysis, if needed, leads to better outcomes.