Dialysis is a treatment that replaces the function of kidneys when the kidneys fail to keep the body in balance and when the kidneys are not able to perform normally. Dialysis performs these functions:
Removes waste, salt and extra water from the blood to prevent these substances from building up in the body and then returns the cleansed blood back to the body
Keeps a safe level of certain chemicals (potassium, sodium and bicarbonate) in the blood
Helps to control blood pressure
In cases of acute kidney failure, the kidneys may improve after treatment, and dialysis may be needed only for a short time. In cases of chronic or end-stage kidney failure (end-stage kidney failure is defined as a loss of about 85% of kidney function and a GFR of less than 15), the kidneys do not get better and dialysis is required for the rest of the patient’s life. In some cases, the physician may determine that the patient is a candidate for kidney replacement.
One form of dialysis is called hemodialysis, which involves pumping blood out of the body to an artificial kidney machine and returning the cleansed blood to the body via tubes that connect the patient to the machine. Hemodialysis is done at a dialysis center to which the patient must travel to be connected to an artificial kidney.
To facilitate hemodialysis, the physician must have access to the patient’s blood vessel using one of three methods:
Fistula—made by joining together an artery and a vein to make a larger, high-flow blood vessel
Graft—Placement of a soft plastic tube between an artery and a vein to create an artificial high-flow blood vessel
Catheter access—Insertion of a narrow plastic tube into a large vein
Hemodialysis performed at a dialysis center
Other procedures related to dialysis that are performed at SIR to evaluate and improve kidney function include the following:
Renal Arteriography—An imaging test that uses a contrast dye to look at the veins in and around the kidneys; also used to determine the cause of high blood pressure
Declotting—A procedure that helps to improve blood flow in fistula and grafts that have clogged or narrowed
Fistulagram— An X-ray procedure that looks at the blood flow and checks for blood clots or other blockages in the fistula
Temporary Catheter Placement—A procedure to insert a catheter into a large vein in the neck or groin to facilitate dialysis
Tunneled Dialysis Catheter Placement—A procedure to place a catheter into a large vein for long-term use, again to facilitate dialysis
These procedures are performed with conscious sedation by SIR’s board-certified anesthesiologists. Conscious sedation is done with a combination of medicines (a sedative and an anesthetic) that help the patient relax and help to minimize pain and discomfort during a medical procedure. The patient is usually able to stay awake and respond to verbal cues but may not be able to speak. The patient’s heart rate, blood pressure, breathing, oxygen level and alertness are carefully monitoring during and after the procedure. Conscious sedation is safe and effective and allows patients to recover quickly.
A second form of dialysis is peritoneal dialysis (PD), which is not done at a dialysis center but instead is done at home or work and can even be done while traveling, thus giving the patient more independence. PD involves the process of filling the abdomen with a dialysis fluid that pulls the body wastes and excess fluids through the peritoneum (the membrane that lines the abdominal cavity) and into the abdomen and then draining these wastes and excess fluids out of the abdomen. The process of draining and filling, usually done 4 times per day, is called an exchange that takes about 30-40 minutes. The amount of time that the dialysis fluid stays in the abdomen is called the dwell time, which ranges from 4-6 hours.
There are two forms of PD:
Continuous ambulatory peritoneal dialysis (CAPD) does not require a machine and allows the patient to be ambulatory (walk around) with the dialysis solution in the abdomen.
Automated peritoneal dialysis (APD) requires a machine to fill and drain the abdomen, usually while the patient is asleep.
Regardless of which form of PD is used, the patient requires placement of a catheter into the abdomen to transport the dialysis solution into and out of the abdomen. A catheter is guided through a slit near the navel and into the peritoneal cavity. Catheter placement, repositioning, and replacement are done at SIR with anesthesia.