2014年2月4日星期二

Types Of Dialysis, Indications, Side-Effects And More

Dialysis is likely a dirty word to anyone who has ever had problems with their kidneys. You think, “If only I could avoid dialysis.” It is true that it is a complex, sometimes intrusive procedure, but it can actually save your life. You shouldn’t think of dialysis as something to be feared. Of course, it would be great if you could preserve your kidney function. Rather, you need a thorough understanding of what dialysis is and how it will affect your life.

What is Dialysis?

Now, let’s imagine here for a moment that your kidney is not working at all. I mean, it does so many useful things for your body: filtering wastes, controlling electrolytes, and balancing the water in your body. When you have failing kidneys, all these processes go haywire. What’s the solution? Simple: find something to take the place of the kidneys that can no longer do their job. One way – the obvious way, I suppose – is to simply put in another flesh and blood kidney to do the work. This is a great solution, but honestly, there just aren’t enough kidneys to go around.

In this modern age, to save lives that would otherwise be lost to complete kidney failure, someone invented a machine to do the exact same things that the anatomical kidneys do. Great age we live in, huh?

The dialysis machine:
• Takes all the blood from your body

• Filters the blood

• Removes water

• Balances electrolytes

• Returns that blood safely into circulation


Some systems, such as peritoneal dialysis, don’t require a machine, but a special catheter inside your abdomen. Even now, these machines are becoming so sophisticated that they have home hemodialysis machines. If you have kidney failure, you are in luck with these treatments around to help you.

Indications for Dialysis

You may wonder just what your doctor saw in your history to indicate that you need dialysis. Indications for dialysis are usually when your kidneys are at the end of their working life. You have reached a point called “end stage” kidney disease, which means that the organs are functioning at only 10 to 15 percent of their normal workload. Your doctor determines this mostly by lab work, such as:

• Blood urea nitrogen,

• Creatinine,

• Creatinine clearance

• Estimated glomerular filtration rate

These lab tests show how well your kidneys are able to remove wastes from the body and how well it filters your blood.

Among other indications for dialysis include physical symptoms, such as:

• Swelling and edema in your legs and hands.

• High blood pressure

• High Potassium

Swelling indicates that your kidneys are not adequately balancing the fluids in your body and allowing them to accumulate. Too much potassium can lead to deadly heart rhythm disorders, and a high blood pressure can result in stroke, in addition to weakening the heart muscle.

Types of Dialysis

The two most common types of dialysis are hemodialysis and peritoneal dialysis. However, home hemodialysis is now becoming an option with the advent of smaller, less expensive hemodialysis machines. For most patients, though, you will have to go to a hospital or hemodialysis center two to three times per week to remove fluid and filter your blood. If you miss your appointment for dialysis, it can cause a dangerous build-up of wastes and fluid.

Hemodialysis is the most common of all types of dialysis. It generally takes three to five hours because the entire volume of your blood is run through the machine. Peritoneal dialysis is another type of dialysis that is often used, and it is much more convenient than hemodialysis. You can actually perform peritoneal dialysis at home without the need for a dialysis center. It involves a catheter placed in your abdomen, and you essentially put the dialysis material into your body through this portal. The dialysate dwells in your body, exchanging fluids and wastes by osmosis, and then you drain the fluid out. Many more people are opting for peritoneal dialysis now that many of the peritoneal dialysis side effects have been addressed.

How Hemodialysis Works

Hemodialysis is a complex procedure, and it really is a wonder of modern medicine. Using an access port somewhere on the body, two needles are inserted to access the blood stream. One needle is the outflow needle, and the second needle returns the blood to the body in the hemodialysis procedure. The hemodialysis machine takes small amounts of your blood out from this access port, and it brings the blood into the machine.

Once the blood is in the machine, it runs through a series of tubes and filters to change the electrolyte balance in your body, remove waste, and take off some fluids. The blood passes through an apparatus known as a dialyzer, and this cartridge holds the dialysis solution, or dialysate. It is this solution that pulls the wastes and electrolytes from your body. It does this by the force of osmosis. Basically, this means that the concentration of the chemicals in the dialyzer is lower than the concentration in the blood. That difference causes the chemicals in your blood to move across a membrane with holes in it, and the dialysate catches the particles and holds them. The blood is then returned safely to your body through the return port. The machine removes blood and fluid very slowly to ensure that your blood pressure does not drop too low and you pass out.

Hemodialysis Side Effects

Hemodialysis side effects can be separated into two categories: short-term and long-term. In the short-term, the most common side effect is low blood pressure. When the machine pulls water out of your blood, your veins and arteries don’t have time to accommodate the drop in fluid. This causes you to have a “big container,” or your blood stream, and not enough fluid to fill it. Usually, your blood pressure will stabilize later in the day after dialysis, but it can be quite uncomfortable, inconvenient, and scary for some.

Other short-term dialysis side effects include:

• Nausea

• Vomiting

• Cramps

• Electrolyte imbalances

• Infection

• Bleeding at the access site

• An air bubble that makes it into your bloodstream

Your doctor can prescribe medications for nausea or you can use natural remedies, such as ginger. You might have cramps and electrolyte imbalances if the machine pulls off too much sodium or potassium. These can lead to irregular heartbeat, dehydration, and heart palpitations. On the whole, most people feel better after a dialysis run.

Long-term dialysis side effects include anemia, or a drop in the hemoglobin that carries oxygen to your cells. This is because the red blood cells get damaged from passing through the machine and are no longer usable. You might need a shot to help with anemia, iron transfusions, or even blood products.

Other long-term dialysis side effects include:

• Itching

• Weakening of the bones from calcium depletion

• Difficulty sleeping

Access for Hemodialysis

One of the most important cogs in the dialysis process is maintaining access for the blood transfer to occur. A few different ways exist to accomplish this task. One of the most popular is the arterio-venous fistula, or AV fistula. This is a vein in your arm that is surgically joined to an artery. It causes a rounded nub in your arm, usually at the bend of the elbow, which feels like a cat purring from the rush of arterial blood past it. AV fistulas are great because with just two needles, the dialysis nurse can quickly and easily establish access and perform dialysis. The problems with AV fistula are that they have to be surgically created, and sometimes they clot off and stop working. This can be very frustrating for dialysis patients because they have to resort to other methods to establish access.

Another way to gain access to the bloodstream is through an internal jugular vein catheter. This is a port that is placed just under your collarbone and has two floppy access ports protruding from it. Again, clotting of this catheter can happen, but it is not as common as with AV fistulas. With a dialysis catheter, you just get a new one placed. Unfortunately, these catheters are prone to infections that can lead to sepsis, or blood infection. This is a life threatening situation, and all precautions must be taken to avoid it. That is why the preferred method is the AV fistula.

Tips for Hemodialysis

If you are getting hemodialysis or want to know how to get through it a little easier, you should keep a few things in mind. You don’t want to eat foods that contain a great deal of potassium, such as bananas, oranges, and potatoes, because this only makes the levels of potassium higher in your blood. This can lead to you feeling sick, but it can also increase your risk for heart irregularities.

To raise your blood pressure post-dialysis, you could drink more water to add volume to your veins, but many kidney patients are on a fluid restriction. You should only do this if your doctor is okay with you drinking more water than your allowance. For problems with low blood pressure, change positions carefully. Sit up from a lying position then dangle your feet off the side of the bed for a few minutes. Stand up slowly and hold on to something stable. This should keep you from passing out.

When you have an AV fistula or access port, you have to take precautions to keep those access sites viable for dialysis. Without them, you would have no way to receive your life-sustaining treatment. With AV fistulas, make sure that you don’t allow anyone to take a blood pressure or draw blood from the arm that has the fistula. This can interfere with the blood flow and possibly lead to a clot. Also, don’t wear tight sleeves, tight jewelry, or anything restrictive on your fistula arm. With an access port, you should make sure that you and your caretakers wear a mask and gloves when accessing your port to prevent the spread of infection. Protecting your port from infection could save your life.

How Peritoneal Dialysis Works

Peritoneal dialysis is a whole different system. You would almost think that it wouldn’t work when you hear of it, but it is actually an effective way of cleaning and filtering the blood just like hemodialysis. The idea for peritoneal dialysis is based on the anatomical configuration of the abdomen. All of the organs in your belly – intestines, liver, and spleen – are covered with a thick membrane known as the peritoneum. This membrane is highly vascular, which means that it has a great deal of blood vessels running through it. It is also semi-permeable, which means that wastes, electrolytes, and fluid can pass easily through it.

When you get surgically set up for the peritoneal dialysis procedure, the surgeon inserts a catheter into this membrane and brings the hub of it to the surface. The hub is locked down under rigorous, anti-infective clamps to keep bugs out of your belly. For dialysis, you take the dialysate, much like the solution that is in the machine in hemodialysis, and allow the solution to drain into your abdomen by gravity. That solution sits inside your abdomen and pulls the wastes and fluid from your body by way of the blood that is coursing through the peritoneum. After five or six hours, you hook up to another bag and drain all of the solution out. You simply discard the bag. Most doctors want you to do four to six “exchanges” like this per day to maintain your health.

Peritoneal Dialysis Side Effects

The most common and severe peritoneal dialysis side effects are:

• Infection

• Weight gain

• Weakening of abdominal muscles

Since you have a port that is open to your abdomen – normally a sterile space – and the blood flow through it is so great, it is a place where bacteria can enter your body and quickly become a problem. As for your abdominal muscles, they become strained and give out from holding the fluid in your abdomen for hours at a time.

You may wonder if you are a good candidate for this type of dialysis. If you cannot handle the rapid fluid changes caused by hemodialysis, this may be an option for you. It is also a great alternative if you don’t want to upset your lifestyle and you are able to care for yourself. If you have scarring in the abdomen or are debilitated to the point that you cannot effectively care for yourself, then hemodialysis is the way to go. Talk to your doctor and see if peritoneal dialysis is right for your level of kidney function, overall health, and social constraints.

Access for Peritoneal Dialysis

Like the access with hemodialysis, a surgeon needs to establish your access for this type of dialysis. It will involve a short surgery, usually same day, and the surgeon will put the small catheter inside your abdomen. You will have a single port with a universal adapter on the end to attach to the dialysate bags for your exchanges. It is important to keep this area and the port scrupulously clean because any bacteria that get inside your peritoneum will wreak havoc with you system.

Be on the lookout for signs of infection, such as:

• Chills

• Fever

• Redness

• Swelling

• Drainage

• Nausea

• Vomiting


If you notice that the cuff from the port is pushed out, you need to let your doctor know you are having trouble with your dialysis.

When you are manipulating your port, such as taking the cap off, cleaning the cap, or attaching to the dialysate, be sure that you and those around you wear masks to prevent breathing bacteria onto the port. In addition, if you are doing the transfer, you should wear gloves and wash your hands prior to touching the port’s dressing. Keeping clean and maintaining a sterile environment is absolutely essential to effective, long-term, complication-free peritoneal dialysis.

Tips for Peritoneal Dialysis

Besides wearing a mask and gloves to take care of your exchanges, you can easily work peritoneal dialysis into your life. You can do this type of dialysis in two ways: continuous ambulatory peritoneal dialysis and continuous cycling peritoneal dialysis. With the ambulatory type, you drain in the dialysate and go about your daily life. With cycling, you are hooked up to a machine while you sleep and the machine does the cycling for you. Whatever method you and your doctor choose, it takes less time and inconvenience than hemodialysis.

When performing your exchanges, you should make sure you warm the bags of dialysate before allowing them to dwell. If the solution is cold or even room temperature, it can make your stomach cramp from the changes between room temperature and body temperature. Most doctors will also recommend that you change the universal adapter with every exchange to prevent it from harboring bacteria. When you are done with your exchange, you should weigh and record the weight of the discard bag. This is so that you and your doctor can keep track of how much fluid the solution is pulling from your body.

Peritoneal Dialysis vs. Hemodialysis

Now that you know a little about each type of dialysis, you might be wondering what the best dialysis is for you. What are the pros and cons when looking at peritoneal dialysis vs. hemodialysis? Hemodialysis is a gold standard for all dialysis. It is the best process and the one with the most data behind it. It is actually the dialysis most doctors prefer because the rates of peritoneal dialysis are not high. However, it is intrusive, inconvenient, and sometimes physically demanding. The change in blood pressure can sometimes cause side effects, such as vertigo and passing out, that make this type of dialysis contraindicated.

Peritoneal dialysis seems like the star. You can do it on your own time, when you want to, and you don’t have to be bothered with going to a dialysis center. However, sometimes it is easy to get lax with your exchanges and become non-compliant. In other words, you feel fine so you just stop doing it. This can lead to dangerous consequences, so if you are not responsible or able to perform the manual tasks on your own, you can end up risking your kidneys and your life. Peritoneal dialysis is also well known for infections, and for some patients, the risk of that is just too great to even try this type of dialysis.

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