Dr Lalit Kumar Agarwal, Consultant Nephrologist, Woodlands Multispeciality Hospital, Kolkata, elaborates on dialysis and how it is performed
The kidney plays various regulatory roles including water balance, control blood electrolyte, acid base balance, control of blood pressure, maintain haemoglobin level, keep the bones healthy and overall maintaining body homeostasis (balance). Most of the functions of the kidney are attained by simple methods namely secretion, filtration and reabsorption. Diverse range of causes can disturb the functioning of kidneys. When the kidney(s) fail to perform these functions, a substitute is required to fulfill many of its roles through an artificial set-up called dialysis.
What is dialysis?
Dialysis is a treatment procedure performed using artificial set-up or the lining of the abdomen (the peritoneum) as a filter to excrete the waste products from the blood, when the kidneys fail to perform its functions. Healthy kidneys remove harmful wastes, extra salts from the blood and maintain fluid balance in the body by adjusting urine output. Dialysis helps to replace some of these functions of a healthy kidney and hence it is called as an artificial kidney. Dialysis allows individuals to live productive lives, despite the kidneys not working adequately.
What are the types of dialysis?
There are mainly two types of dialysis.
Haemodialysis: It is an artificial set up to replace the kidney functions through an artificial machine. It involves transfer of blood into the dialysis machine through an access, which filters out the waste/ excess fluid and then returns back to the body. It takes four to five hours to complete the procedure. Patient undergoing haemodialysis has to undergo this procedure thrice a week.
Peritoneal dialysis: It involves the use of lining of the abdomen (Peritoneum) which contains tiny blood vessels to filter out the blood from the wastes. It involves insertion of a flexible tube in the abdomen followed by pumping of dialysis fluid to the peritoneal surrounding. When the blood passes through the peritoneum, waste and excess fluids get filtered into the dialysis fluid which is then drained away. This procedure has to be carried throughout the day.
When is the dialysis needed?
Most often, dialysis is required when accumulated waste products in the body become toxic and patient is symptomatic.
If excess water accumulates in the body and produces severe symptoms like shortness of breath, then dialysis may be indicated even though the creatinine
clearance is in normal range.
Is dialysis a procedure to cure the kidney disease?
Absolutely not, dialysis only performs some of the functions of normal kidney to keep the blood purified until your kidneys get recovered as in AKI or transplanted in CKD.