Also known as renal replacement therapy, dialysis is a treatment that rids your body of waste products, toxins, and excess fluids. When the kidneys fail and are no longer able to handle the functions of healthy kidneys such as filtering wastes and cleaning the blood, dialysis can perform these functions and help a person live longer. Typically, dialysis is initiated when a patient reaches stage 5 CKD and their kidneys are functioning less than 10-15% and when patients become symptomatic from kidney failure. Sometimes dialysis is needed in those hospitalized with acute renal failure. Symptoms of uremia which would necessitate the onset of dialysis therapy in someone with CKD 5 and/or acute renal failure include: weakness, fatigue, nausea, vomiting, bitter taste in mouth, itchy skin(pruritis), mental status changes. Other indications necessitating dialysis include acidic blood(acidosis) and high potassium(hyperkalemia) refractory to treatment with conventional medical management.
Dialysis works by filtering blood of wastes and fluids through a semipermeable membrane. There are two main modalities of dialysis:
2. Peritoneal Dialysis
Hemodialysis utilizes a filtering membrane ( a dialyzer) which is inside a dialysis machine. Blood is circulated from the body through a catheter or av fistula/graft through the dialysis machine and cleaned before being returned to the body. In peritoneal dialysis the filtering membrane is the natural lining of the peritoneum encasing the abdomen. Fluid is infused into the peritoneum and toxins and fluid are removed through convection, osmosis. Blood is not circulated with peritoneal dialysis. Both types of dialysis also use a dialysate solution in the filtering process to remove wastes and excess fluid. Dialysis has enabled and empowered individuals with end stage kidney disease to live longer, productive lives. It can often also be the bridge during the time gap before transplantation which would ultimately obviate the need for dialysis.