Renal replacement therapies

Once the stage of End Stage Kidney Disease is reached the treatment options are broadly classified as Renal Replacement Therapies. They include dialysis (hemodialysis/ peritoneal dialysis) and kidney transplantation.

Dialysis can replace some functions of healthy kidney, it does not cure kidney disease. It is important to understand that dialysis does not replace the endocrine functions of failed kidneys. Therefore patients need to take additional medications and precautions as well.

What is hemodialysis?

Hemodialysis is the process of artificially eliminating waste products and excess water from blood. Patient’s blood is processed in special filters; exposed to a specially created fluid (dialysate) across a semi permeable membrane; thus helping to filter out the waste products. Each session lasts approximately 4 hours and international guidelines recommend at least 12 hrs of treatment per week.

What is peritoneal dialysis?

Peritoneal dialysis is based on the concept of diffusion where the inner lining of the abdomen (peritoneum) is used as the semi permeable membrane. A specially created fluid is put in the abdomen where it gets exposed to the blood in the vessels supplying the peritoneum, facilitating movement of molecules from blood to dialysate.

It closely mimics physiological function because it is a continuous process.

What preparation is needed prior to initiation of dialysis?

In order to remove and return the blood from the patient’s body in hemodialysis, an access is required. The various options in decreasing order of preference are AV Fistula, AV Graft, Permanent and Temporary Catheters.

In patients opting for peritoneal dialysis a catheter has to be placed in the abdomen.

All accesses need time to mature before being usable e.g. 4-6 weeks in AV fistula, 14 days before using a PD catheter. Vascular catheters can be used immediately, but are avoidable as they have significant long term complications.

What is transplant?

Kidney from a matched healthy donor is surgically placed in the groin. This kidney takes over all the functions (excretory/ endocrine) of the native kidneys and the recipient can lead a near normal life. Medications (immunosuppressants) have to be taken lifelong.

Renal transplantation is the treatment of choice for patients with ESRD. Over the years there has been marked improvement in patient and graft survival, thus making transplant a cost effective alternative. Barriers of HLA and blood group have been breached, making transplant a reality for more and more people worldwide.