Renal replacement therapy is a term that describes life-supporting treatments used to replace normal kidney function. It is primarily used to treat patients who have kidney failure. In some cases, however, it is also used for treating patients who have been poisoned. There is more than one type of renal replacement therapy. This category of treatment includes hemodialysis, intermittent hemodialysis, continuous hemofiltration, and peritoneal dialysis.
Hemodialysis is a type of renal replacement therapy that involves the removal of waste and unnecessary liquid from a person’s bloodstream. The removal of this waste and fluid is usually handled by the kidneys but is inadequate when kidney function is depleted. In hemodialysis, a patient's blood is drawn from a vein and passed through a dialyzer, which is a machine used to filter waste and fluid. The filtered blood is then pumped back into the patient’s body via a blood vessel. In most cases, dialysis involves the repetition of this process at least a few times, and with each cycle, more of the waste and fluid is removed from a patient’s blood.
A person may undergo either intermittent or continuous hemodialysis. The goal of the treatments are the same: to handle the removal of waste and fluid from a person’s bloodstream when his kidneys are unable to do so. In most cases, continuous hemodialysis is used for people who are dealing with a case of acute kidney failure. It provides for a slower removal of waste and fluids that can be easier for a patient with a kidney crisis to tolerate. A person with chronic kidney failure is more likely to receive intermittent hemodialysis.
Continuous hemofiltration is another type of renal replacement therapy. Like other types of renal replacement therapy, its intent is to remove waste and fluid from the body when the kidneys are unable to do so. With hemofiltration, blood is removed from the body and then filtered. Replacement fluid is then added to the blood before it is returned to the body. This technique does the same job as hemodialysis, but a different method of filtration is used.
The renal replacement therapy category also includes a technique called peritoneal dialysis. This technique is used to remove waste from a person’s blood without removing the blood from his body. With this method of renal replacement therapy, a solution called dialysate is injected into a part of the abdomen called the peritoneal space. A membrane in a patient’s abdomen acts as a filter and allows excess waste and fluid to move into the dialysate. Medical professionals then pump the dialysate from a patient’s body.
