Dialysis Overview

Our kidneys regulate body levels of water and minerals, and remove waste products. The kidneys also produce hormones like erythropoietin and 1, 25-dihydroxycholecalciferol (calcitriol).

Hemodialysis is the process of artificially eliminating waste products and excess  water  from the blood
for patients who either have acute kidney injury or those who have permanently lost kidney function (Stage 5 chronic kidney disease). In other words, dialysis is a form of renal replacement therapy, the alternative being kidney transplant.

Hemodialysis is a technique whereby the patient’s blood is processed in special filters; where they are exposed to a specially created fluid (dialysate) against a semipermeable membrane; thus helping to filter out the waste products from the blood via the process of diffusion. The process of removal of excess fluid from the body is known as ultrafiltration. Both the process happen simultaneously, the processed blood is then returned to the patient’s body. Each session lasts approximately 4 hours and about 65 – 75 ltr of blood is processed in each session. International guidelines recommend atleast 12 hrs of treatment per week.

In order to remove and return the blood from the patient’s body an access is required. The various access can be AV Fistula, Temporary and Permanent Catheters. The dialysate does not contain any of the uraemic  toxins viz Urea, Creatinine etc.. and so these molecules are easily removed from the blood. The composition of dialysate can be altered depending on the clinical condition of the patient. In one dialysis session approx 120 ltr of dialysate fluid is consumed.

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