When end-stage renal failure occurs (that is, when the kidney function is irreversibly reduced to below 15% of normal), there are two treatment options: dialysis or a kidney transplant (also known as a renal transplant).
There are two types of dialysis: haemodialysis and peritoneal dialysis. This page deals with haemodialysis.
The word ‘haemo’ refers to blood. Haemodialysis is a process that balances blood chemistry and filters wastes and fluid from the blood.
For haemodialysis, two needles are inserted into the patient’s arm. One needle withdraws the blood and the other returns the filtered blood to the patient’s body.
The blood, which is withdrawn by the first needle, travels outside the body through tubing and the dialysis machine then pumps this blood through a filter called a dialyser, which is attached to the dialysis machine. The dialyser cleans the blood and it is returned to the patient’s body through the other needle.
The dialyser is also called an artificial kidney because it is an artificial replacement for the patient’s damaged kidneys. During the process of haemodialysis, the haemodialysis machine circulates the dialysate (fluid with chemicals that helps to remove wastes from the body) to the artificial kidney. Haemodialysis is typically performed at a dialysis centre.
o What is haemodialysis?
o How long is the procedure of haemodialysis?
o When is haemodialysis initiated?
o Does haemodialysis cure kidney failure?
o What are the requirements for haemodialysis to be started?
o What exactly is done during haemodialysis?
o How long is haemodialysis required?
o What is vascular access?
o Are there any complications during haemodialysis?
What is haemodialysis?
Haemodialysis is a process of cleansing the blood of the impurities with the help of artificial kidney.
How long is the procedure of haemodialysis?
Haemodialysis is usually done for four hours.
When is haemodialysis initiated?
Haemodialysis is initiated when the kidney function drops below 10-15%.
Does haemodialysis cure kidney failure?
No. Haemodialysis is only a substitute for the kidney function.
What are the requirements for haemodialysis to be started?
From the patient’s side, a vascular access is required. Either a temporary or permanent vascular access is needed. Haemodialysis machine, dialyser (artificial kidney), pure water (about120-150 litres per haemodialysis session), dialysis concentrate solution, uninterrupted power supply are all required to start haemodialysis.
What exactly is done during haemodialysis?
During haemodialysis, patient’s blood is withdrawn, purified with help of artificial kidney and then returned to the patient.
How long is haemodialysis required?
In patients with acute kidney failure (reversible), dialysis is performed till recovery of kidney function occurs which may take 1-3 weeks. In patients with end stage renal disease, dialysis needs to be performed lifelong/till patient undergoes Kidney Transplant.
What is vascular access?
For haemodialysis to be done, blood flow in the order of 250-300ml/min is required. This cannot be obtained from an ordinary blood vessel, and hence the need for a vascular access. Temporary accesses include jugular catheter (neck vein), & femoral catheter (thigh) Permanent accesses include AV fistula & AV graft. If the dialysis is started on an emergency basis, temporary access is inserted. If dialysis is planned well before, permanent accesses are placed sufficiently early in the patients. (atleast a month before the requirement of haemodialysis).
Are there any complications during haemodialysis?
Yes. There are some complications which can occur during haemodialysis. Most of them are mild like nausea, vomiting, temporary drop in blood pressure, back pain, headache.
Rarely serious complications like cardiac arrest can occur during haemodialysis.