Research shows that approximately 20 percent of multiple myeloma patients develop kidney failure. Kidney failure occurs as a consequence of elevated calcium levels in the blood or when proteins called light chains are produced in excess - overloading the kidneys with protein.

Normally, the kidneys remove wastes, extra fluids, and minerals from the blood. But when they stop functioning, harmful wastes build up and this can cause other complications such as high blood pressure. Generally, kidney failure can worsen for multiple myeloma patients with fluid depletion, hypercalcemia, infection, nephrotoxic drugs (chemicals that are harmful for the kidneys) and proteinuria (when patient’s urine is presented with excess proteins).

When kidney failure is irreversible, patients undergo a procedure known as dialysis to help their bodies filter blood. Dialysis removes the extra fluid and waste from the blood, and it can prolong the overall survival for multiple myeloma patients.

In the procedure, blood flows by a few ounces each time through a dialyzer or artificial kidneys, and removes excess wastes and fluid. The dialyzer contains two fluid compartments, with blood flowing through one compartment, and a solution called dialysate flowing through the other in the opposite direction. While the patient's blood has a high concentration of solutes like urea, potassium, and proteins; the dialysate has a low concentration of solutes. The dialysate therefore acts like a sponge to soak up the excess solutes from the blood. As the two liquids flow in opposite directions, a semi-permeable membrane allows the excess water and solutes to diffuse out of the blood and into the dialysate.

Hemodialysis requires a strict schedule. The total treatment follows a regular schedule, usually three times per week, and takes three to five hours for each session. Treatment can be done at a center or at home. Some patients even have dialysis done overnight.

Before hemodialysis treatment begins, patients may want to prepare a designated site of access on their body for the blood to be removed from and returned to. This is known as a vascular access and it allows for a more efficient procedure. More information about vascular access for hemodialysis can be found here ^[3].

There are some side effects from hemodialysis, but most of them are due to the change in salt and fluid amounts between dialysis treatments. Side effects include low blood pressure, lightheadedness, shortness of breath, abdominal cramps, muscle cramps, nausea, or vomiting. They can be minimized by diet and fluid intake.

For more information about hemodialysis, go to the National Institute of Diabetes and Digestive and Kidney Diseases Web site ^[4] and the UpToDate patient's guide ^[5] on hemodialysis. Also, visit the Beacon articles in this series ^[6] and related Beacon articles ^[1] on kidney failure.