What is peritoneal dialysis?

The abdominal organs are covered by a thin membrane called peritoneum. An empty space exists between the abdominal organs called peritoneal cavity. Peritoneal Dialysis is performed by introducing a dextrose and salt solution into the peritoneal cavity. Waste material and water moves across the peritoneal membrane into this fluid which is drained out.

What is the physiological basis for performing peritoneal dialysis?

Two main ways in which dialysis takes place in peritoneal dialysis.

• Diffusion.
• Ultra filtration.

Diffusion: Diffusion is the principal mechanism in which peritoneal dialysis removes waste products. It is the process in which the peritoneal membrane acts as an semi permeable membrane and diffusion occurs down the concentration bleeding from the blood into the dialysis solution.

Ultra filtration : Ultra filtration is defined as the movement of water across semi permeable. Ultra filtration is the mechanism where by fluid is removed in Peritoneal Dialysis. The dialysis solutions contains glucose and this acts as an effective osmotic agent to draw water across the semi permeable membrane. Along with water some solutes are dragged across.

What is the typically composition of dialysis solution for Peritoneal Dialysis?

The Dialysis solution normally contains:
Sodium:
132 miliquirents /liter Potassium zero. It is added as needed Chloride 96 to 102 miliquirents /liter, Calcium 3.5 or 2.5 miliquirents /liter, Magnesium 0.5 or 1.5 miliquirents /liter.

Bicarbonate is in the form of lactate. The normal dialysis solution lactate is 35 to 40 miliquirents /liter Glucose in the form as dextrose

How is peritoneal dialysis done?

Peritoneal dialysis requires the insertion of a catheter into the abdomen. Peritoneal dialysis solution, which is provided in plastic bags (Usually 2 – 2.5L at a time) is connected to the catheter and fluid is inserted into the abdomen. The fluid is allowed to remain in the abdomen for some time after which it is drained out.

What is an exchange in peritoneal dialysis?

First, any residual fluid in the abdomen is drained out. The bag containing the PDExchange in Peritonial Dialysis fluid is then connected to the catheter and fluid is allowed to run in. The bag is disconnected from the catheter (possible with Y–set). This is called an exchange. The fluid is allowed to remain in the abdomen for a few hours before it is drained out again.

How much time is required to do an exchange?

Usually about 30–45 min.

What is CAPD?

CAPD is Continuous Ambulatory Peritoneal Dialysis. PD fluid is always present in the abdomen. Typically 4–5 exchanges are done during the daytime. The abdomen is left filled with peritoneal dialysis fluid overnight and drained out in the morning.

What is CCPD?

CCPD is Continuous Cycler Peritoneal Dialysis. In this method the dialysis is done at night time with the help of a machine. The bags are hooked up to the machine at bed time and the machine automatically fills and drains the abdomen as programmed. In the morning the patients disconnects from the cycler leaving a fresh exchange of dialysis solution in the abdomen which is drained prior to being hooked up to the cycler.

Is CCPD better than CAPD?

Both CCPD and CAPD achieve adequate dialysis. However with CCPD, since no exchanges are done during the daytime it gives more freedom to the patient. It is important that CCPD depends on the characteristics of the peritoneal membrane judged by a test called the PET (Peritoneal Membrane Equilibration) Test.

How many liters of Peritoneal solutions is required for a week?

In both CAPD and CCPD about 56 – 60 liters of fluid per week is required.

Which is a better method of Dialysis– Hemodialysis or Peritoneal dialysis?

The numerous studies have been done which have shown conflicting results between outcomes of peritoneal and hemodialysis. However there is a consistent opinion that during the first 2 or 3 years the Peritoneal Dialysis patients do as good or sometimes even better than Hemodialysis patients. The decision to do Hemodialysis or peritoneal dialysis should be judged individually.

What are the advantages of the Peritoneal Dialysis?

Freedom to do the exchanges at home. Gives the patient more autonomy.
Water intake restriction not as rigid as in Hemodialysis.
No restriction on potassium intake.

What kind of catheters are used in peritoneal dialysis?

The catheters generally used for chronic peritoneal dialysis are usually made of silicon rubber or polyurethane. The name of some catheters used are Tenckhoff, Toronto western and Life cath.

What kind of anesthesia is required for insertion of Peritoneal Dialysis catheter?

Usually it is done under local anesthesia by using a laparoscope by making a small incision on the abdomen, near the umbilicus.

How long after insulation of the cathedra can it be used for dialysis?

It normally takes around 2 to 3 weeks for the cathedra to be used after insulation.

What are the complications of peritoneal dialysis?

Leakage of dialysis solution which is usually due to loosening of the catheter.

Problems with flow of dialysis solution into and out of the abdomen. Many times it is related to constipation and clears with laxatives. Infections of the catheter (exit site infections) or peritoneum (peritonitis).

A patient doing peritoneal dialysis complained of the fluid being cloudy. What does it signify?

Normally PD fluid is colorless. Cloudy fluid signifies peritonitis (inflammation of the peritoneal membrane). It usually manifest abdominal pain and change in the color fluid from clear to cloudy which can be easily noticed by the patient. It is extremely important to alert the nephrologist or the nurse who is taking care of the patient. The antibiotics are usually given in the peritoneal dialysis fluid itself for in which certain cases they may have to be given intravenously.

How is fluid removal regulated on peritoneal dialysis?

PD fluid dextrose concentration can be changed. The higher the dextrose concentration more is the fluid removal. PD fluid bags are available in concentrations of 1.25, 2.5, and 4.5%. Excess fluid removal can result in low blood pressure, and a change in concentration of the PD fluid is required.

“I have abdominal pain while doing my exchanges. What should I do?”

Abdominal pain which may be related to over distension of the peritoneal cavity which may need change in the amount of the dialysis fluid that is inserted.