“Doctor, please tell me about peritoneal dialysis vs hemodialysis. Which one is better for me?”, is a question that patients about to start dialysis at our dialysis center often ask me.
There are two major types of dialysis: hemodialysis and peritoneal dialysis. Knowing the differences between hemodialysis and peritoneal dialysis can come in handy in choosing the right one for you or a loved one. Through this article, I will try to explain the pros and cons of both hemodialysis and peritoneal dialysis.
But before moving to the differences, let’s briefly learn about each of them:
The most common type of dialysis is hemodialysis. A hemodialyzer or an artificial kidney is used to remove wastes from the body. The work of the artificial kidney is the same as a normal kidney which is filtering the blood removed from the body. The dialysis machine’s job is to return the filtered blood in the body. This process needs blood to be removed from the body at rates of 200-400 ml/minute. This amount of blood flow can be achieved by what is called as dialysis vascular access.
The access can be of three types-
- Arteriovenous (AV) fistula- This is the preferred option. This connects an artery and a vein. If a person receives AV fistula, she is healed two to three months after the surgery and could start the hemodialysis treatment.
- AV graft- This type is a looped artificial tube. It is designed in a manner that it could be used for long-term dialysis treatments. Both AV graft and AV fistula need the insertion of dialysis needles to get the required blood flow. Because of this, there can be pain during dialysis for a few seconds when the needles are being inserted.
- Vascular access catheter- This is inserted into a large vein in the neck. Catheters are specifically designed for temporary or short term use when an AV fistula/graft hasn’t been created well in time.
- Peritoneal dialysis:
A surgery is involved in peritoneal dialysis to implant a peritoneal dialysis (PD) catheter in the abdomen. A PD catheter is an artificial tube which facilitates performance of peritoneal dialysis. The abdomen is lined by a membrane called the peritoneum and the catheter is placed within the cavity formed by the peritoneum without harming other abdominal organs like intestines, liver, etc.
The blood is filtered through the peritoneum. A special fluid called dialysate is infused into the peritoneum during the treatment. The function of dialysate is to absorb wastes from the blood. Dialysate is drained from the abdomen once it draws waste out of the bloodstream. This process is repeated 3-4 times per day and takes a few hours each time. The fluid exchange process can be followed while the person is sleeping or awake.
There are several different types of peritoneal dialysis but the main ones are-
- Continuous ambulatory peritoneal dialysis (CAPD)- In this method, the abdomen is filled and drained multiple times a day. The person must be awake while performing this method and a machine is not required. This is the commonest type.
- Continuous cycling peritoneal dialysis (CCPD): A machine is used to cycle the fluid in and out of the abdomen in this method. This method is usually performed at night while the person is asleep.
- Intermittent peritoneal dialysis (IPD): This method is usually performed in the hospital but it can be performed at home. The machine used is the same as CCPD but the process takes longer.
Now that we know about them in brief, let’s learn a few points of difference between hemodialysis and Peritoneal Dialysis.
In hemodialysis, an artificial kidney or a hemodialyzer is connected to the patient’s blood vessels via a fistula or a graft by a doctor surgically. Blood enters the dialyzer, dialysis occurs and the blood is returned to the body. It is the commonest type of dialysis. On the other hand, as the name suggests, peritoneal dialysis occurs when a catheter is attached to the belly (peritoneal cavity) of the patient, and a dialysing solution is poured in. After some time, the solution is drained and blood is cleared.
In hemodialysis, the waste elimination is done by a machine so the person needs to visit a hospital or a dialysis center on a set schedule. Hemodialysis is done three days each week and takes around four to five hours per session. During an emergency, HD is preferred because of higher efficiency in a short time.
In the case of peritoneal dialysis, no such heavy equipment is used so the person can undergo the treatment even at home or while traveling. Peritoneal dialysis is done three to four times per day.
AS you can see, PD is better suited for the following type of patients :
- Very active lifestyle/work- For people with an active lifestyle, PD provides an option to get dialysis done as and where they are and they don’t have to go to the hospital everyday.
- For people who have difficulty in moving around, peritoneal dialysis saves the daily trip to the hospital
- Children- PD can be easily carried out in school or at home, making it the more convenient choice
- Peritoneal dialysis procedure is carried out in a gentler way, implying that there is no pumping of blood unlike in hemodialysis. This makes it a better suited option for heart patients.
- For patients who live in remote areas like hilly areas etc.., it is difficult to find access to healthcare. Peritoneal dialysis proves to be a well suited choice for them.
However, for people with low social support or the elderly who can’t perform the process themselves, hemodialysis remains as the only viable option.
Risk of infections:
Both hemodialysis and peritoneal Dialysis patients are prone to infections but of different types. Bloodstream infections are more common in hemodialysis due to various catheters and instruments. Also viral infections like hepatitis B, hepatitis C and even HIV can spread in a dialysis unit because so much blood is pumped in and out.
On the other hand, patients of peritoneal dialysis are at risk of peritonitis which is infection of the peritoneum.
It is often observed that the risk of infections in PD is overplayed while that in hemodialysis is underplayed. We must always remember that both carry their own sets of risks.
The cost of a single session of peritoneal dialysis is less than that of a single session of hemodialysis. However, dialysis is not a single time procedure. It can continue for months to years. If we factor in cost of transportation of patients or the number of times the procedure is carried out, the cost may become almost equal. Sometimes PD may in fact work-out cheaper for patients if transportation is difficult or long distance.
Hemodialysis involves pumping of blood out of the body, into the dialyser and then back in. This dynamic process may not be so gentle to some people, like those with a history of heart problems. Peritoneal dialysis, thus, is a gentler option for such people.
Hemodialysis also puts patients at a risk of low BP, cramps, blood loss, low sugar, nausea, vomiting and weakness. It is tougher on the heart, as already discussed.
On the other hand, the dialysing fluid used in peritoneal dialysis is rich in sugars and lipids and could contribute to elevated blood sugar and lipid levels. Also after a period of time, the efficacy of peritoneal dialysis reduces.
Life expectancy/mortality :
In both HD and PD, mortality rates are similar. Studies done don’t show a huge difference in life expectancy.
Patients undergoing hemodialysis or peritoneal dialysis have to take a high protein diet because of the loss of proteins in the process. The protein needs of patients on both HD and PD are high.
However, PD is a continuously done process and thus dietary restrictions are less as compared to HD.
So, finally which is better for me/family member?
Choosing between hemodialysis and peritoneal dialysis can be difficult and confusing. Both of them have certain advantages over the other.
Each patient and her family circumstances are unique. The final decision needs to be made after a thorough discussion with your nephrologist. To start with one can choose PD or HD.
Sometimes hybrid procedures are done that use both hemodialysis and peritoneal dialysis. For example, three sessions of PD per day and one session of HD in a week.
But over time, one may need to shift from one type of dialysis to another because of circumstances. For patients who started with peritoneal dialysis, its reduced efficiency can be a reason for switching. For hemodialysis, patients have to regularly visit the hospital and thus, reduced motility or transport costs can be potential reasons for switch to peritoneal dialysis.
To conclude, we can say that hemodialysis and peritoneal dialysis complement each other. Over the course of time, switching between the two can be really helpful for a patient. The best advice for you or a family member comes by considering all the different factors like conveyance, cost, previous medical history etc. I hope this article was helpful in providing you a basic idea about key differences between hemodialysis and peritoneal dialysis. All the best!