Chemistry 101: Fresenius' GranuFlo Associated with Sudden Cardiac Death

GranuFlo is a dialysate (A.K.A concentrate or bath). The purpose of a dialysate is to clean the blood, control PH and correct metabolic acidosis in dialysis patients. It is comprised of 3 fluids: 1) ultrapure water, 2) bicarbonate concentrate and 3) acid concentrate. GranuFlo is that third component. It is the acid concentrate used in a dialysate.

Fresenius manufactures GranuFlo, one of the first dry acid concentrates. In the past, liquid acid concentrates were used in the dialysate. Fresenius promoted GranuFlo as the safest and most cost effective choice for dialysis clinics. GranuFlo was designed to lower labor cost, storage cost and shipping cost

Fresenius did not communicate to nephrologists or dialysis clinics the true nature and make up of GranuFlo. It is important that nephrologists are familiar with the contents of the dialysate to achieve acid-base balance within the body and to avoid health issues like metabolic acidosis and metabolic alkalosis. This balance centers on what is known as the total buffer level. It is a mathematical equation: the amount of bicarbonate + the amount of acid concentrate = total buffer level.

GranuFlo contains dry sodium diacetate - NaH(C2H3O2)2. The “di” doubles the amount of acetate in GranuFlo compared to other products. Other products contain 4 mEq/l of acetate but Fresenius’ GranuFlo contains 8 mEq/l of acetate. Thus, it delivers twice as much acetate. Since the body rapidly metabolizes acetate into bicarbonate this exposes dialysis patients to a higher total buffer level then intended by the nephrologist. Here is an example:

OTHER PRODUCT: 33 mEq/l of Bicarbonate (base) concentrate + 4 mEq/l of Acid concentrate = 37 mEq/l

GRANUFLO: 33 mEq/l of Bicarbonate (base) concentrate + 8 mEq/l of Acid concentrate = 41 mEq/l

The increased total buffer level due to GranuFlo puts dialysis patients at risk for metabolic alkalosis, which can lead to cardiopulmonary arrest. In fact, Fresenius’ own documents about GranuFlo show the following:

  • Elevated bicarbonate levels increase mortality
  • Metabolic alkalosis is a significant risk factor for cardiopulmonary arrest
  • The main cause of metabolic alkalosis is inappropriately high dialysate total buffer concentration
  • GranuFlo is associated with a 6 to 8 fold greater risk of cardiopulmonary arrest and sudden death