Dr. Bhavin Brahmbhatt :: Kidney Dialysis

Meaning and Indication

Dialysis is a procedure by which waste products and excess water that accumulate in renal failure are removed from the body artificially. It is a life-saving technique for patients with End Stage Kidney Disease (ESKD) or Acute Kidney Injury.

How does dialysis help people with severe kidney failure?

Dialysis helps the body by performing the following functions of failed kidneys:

Purification of blood by removal of waste products such as creatinine, urea etc.
Removal of excess fluid and maintenance of the right amount of water in the body.
Correction of electrolyte and acid-base balance disturbances.

However, dialytic therapy cannot replace all the functions of a normal kidney such as production of the hormone erythropoietin needed to maintain hemoglobin levels.

When is dialysis needed?

When the kidney function is reduced by 85-90% from the normal (ESKD) waste products and fluids build up in the body. The accumulation of toxins such as creatinine and other nitrogenous waste products leads to symptoms such as nausea, vomiting, fatigue, swelling and breathlessness. These are collectively termed as uremia. At this point, medical management becomes inadequate and the patient will need to start dialysis.

Can dialysis cure chronic kidney disease?

No. Chronic kidney disease is irreversible and once a patient reaches Stage 5 (ESKD), lifelong dialysis treatments will be needed unless successful kidney transplantation is performed. On the other hand, a patient with AKI may need dialysis support only for a short period until kidney function recovers.

Types of Dialysis

What are the types of dialysis?

There are two main types of dialysis : hemodialysis and peritoneal dialysis

Hemodialysis:

In hemodialysis (HD), waste products and excess fluids are removed from the blood by passing the blood through a special filter or artificial kidney called a dialyzer, aided by a dialysis machine.

Peritoneal dialysis:

In peritoneal dialysis (PD), a soft tube or catheter is inserted through the skin, into the abdominal cavity and dialysis solution is infused into the abdominal cavity to remove waste products and excess fluid from the body. This is done at home, usually without a machine.

Hemodialysis

In hemodialysis, blood is purified with the help of dialysis machine and dialyzer.

How is hemodialysis done?

Most of the time, hemodialysis is performed in hospitals or free standing dialysis centers, under the care of doctors, nurses and dialysis technicians.

The dialysis machine pumps blood from the body to the dialyzer through flexible blood tubings. Heparin infusion or continuous saline flushing is done to prevent clotting of blood.
The dialyzer (artificial kidney) is a special filter through which blood flows which removes extra fluids and waste products.
Dialyzer purifies blood with the help of special solution called dialysate which is prepared by a dialysis machine.
Once the blood is cleaned, the machine sends it back to the body.
Hemodialysis is carried out usually three times per week and each session lasts for about four hours.

How is the blood withdrawn for purification and returned back to the body in the process of hemodialysis?

The three most common types of vascular access for hemodialysis are central venous catheters, native arteriovenous (AV) fistulas and synthetic grafts.

Peritoneal Dialysis & IPD

Peritoneal dialysis (PD) is another form of dialysis modality for the patients with kidney failure. It is widely accepted and effective. It is the most common method of dialysis done at home.

What is peritoneal dialysis?

The peritoneum is a thin membrane that lines the inner surface of the abdominal cavity.
The peritoneal membrane is a natural semi-permeable membrane which allows waste products and toxins in the blood to pass through it.
Peritoneal dialysis is a process of purification of blood through the peritoneal membrane.

Dialysis