Dialysis Professionals

Health professionals responsible for the care of dialysis patients are well aware of the complex relationship between treatment variables and patient outcome. Much depends upon the interaction between the patient's blood and the extracorporeal circuit, especially within the hemodialyzer. Even with systemic heparin anticoagulation, clotting within the dialyzer reduces delivered "dose" of dialysis, increases blood loss, and limits dialyzer reuse. Dialyzer clotting is further accelerated in cases where heparin anticoagulation is contraindicated, for example, in patients with antibodies to this agent. These complications result in additional staff time required to treat the problems, as well as higher costs for additional supplies (dialyzers, blood lines, etc.).

Management of postsurgical and trauma patients with increased risk of bleeding limits the use of heparin, making the dialysis especially challenging. The alternatives to heparin therapy in this group are limited to periodic flushes of the circuit or to regional citrate anticoagulation. Although widely used, line flushing is relatively ineffective and increases fluid load to the patient. The alternative, regional citrate anticoagulation, is difficult to deliver properly and expensive to set up and monitor. Both methods involve significant additional effort on the part of the staff.

Furthermore, in patients receiving uncomplicated, "routine dialysis," the goal is to optimize treatment by increasing the dose of dialysis within the constraints of available time and cost. Advanced Renal Technologies (ART) has developed a new dialysate formulation that addresses these problems and brings treatment to a more effective level. Containing citric acid as the acidifying agent, it is the first major change in dialysate formulation in over two decades, breaking away from traditional formulations that contain acetic acid. It is cleared for use by the FDA, and is already on the market and in use in clinics.

Citrate dialysate is not to be confused with regional citrate anticoagulation, in which high concentrations of citric acid are infused into the arterial blood line to bind calcium, and a corresponding infusion of calcium is delivered into the venous line or through the dialyzer to counteract hypocalcemia. Citrate dialysate has been used successfully in place of in-hospital regional citrate anticoagulation, and it is more effective than repeated saline flushing of the extracorporeal circuit. (ref. 1)

Citric acid content of both Citrasate® and DRYalysate® is only 2.4 mEq/L in the final diluted concentration within the dialyzer, well below the 7-15 mEq/L threshold of true anticoagulation (ref. 2). Calcium levels in the patient remain within the normal range when citrate dialysate is used, and no supplemental calcium replacement measures are needed.

Making the conversion from conventional dialysate to citrate dialysate is effortless. The conversion is "transparent" for both staff and dialysis equipment.

• No adjustment in the dialysis system is required; simply substitute citrate concentrate for the A concentrate normally used.
• Additional staff training is unnecessary.
• There is no need to perform additional patient monitoring beyond ordinary measures. No blood tests are needed.

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Clinical Use

Compared with traditional acetic acid-containing dialysates, citrate dialysate has the following documented benefits:

• Citrate dialysate increases the delivered "dose" of dialysis for the patient, including improved Kt/V and URR and increased predialysis serum bicarbonate levels. (ref.3)
• Citrate dialysate can raise average dialyzer reuse by more than 60% on all patients, and by over 100% on patients considered "problem clotters." Consequently, for the facility seeking to cut operating costs, ART's citrate dialysate is an effective solution. (ref. 4)
• Citrate dialysate can be used for heparin-free dialysis of patients with antibodies to heparin. (ref. 1, 5)
• Where heparin anticoagulation is contraindicated, citrate dialysate can be used for dialysis of patients with acute renal failure who are at risk of bleeding. In most cases, citrate dialysate reduces or eliminates the need to flush the extracorporeal circuit with saline. (ref. 5)
  
         
  
  

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Frequently Asked Questions

Q: Is citrate dialysate the same as regional citrate anticoagulation?
A: No. Performing citrate dialysis is no different operationally than doing regular dialysis. There is no regional infusion of citric acid employed. "It's all in the dialysate."

Q: Is it necessary to do continuous calcium infusions into the venous blood line, as is done for regional citrate anticoagulation, in order to avoid problems associated with hypocalcemia?
A: No. Calcium binding by dialysate citrate is so small that no significant alteration in calcium occurs during dialysis (ref. 3). The citrate content of the dialysate is only 2.4 mEq/L.

Q: How does citrate dialysate provide the noted patient benefits?
A: As you know, citric acid is an anticoagulant. Its presence in the dialysate in 2.4 mEq/L concentration provides some anticoagulation effect in the dialyzer and venous blood line that is quickly neutralized upon reentry into the systemic circulation.

Q: Is it necessary to check clotting times when citrate dialysate is used?
A: No.

Q: Is there reason to be concerned about bleeding risk, hypocalcemia, or hypomagnesemia when treating patients with citrate dialysate?
A: No. Because the concentration of citrate in the dialysate is well below the level needed to produce anticoagulation of the patient's blood, there is no risk of bleeding or low blood mineral levels from citrate use.

Q: Are Citrasate® and DRYalysate® cleared for clinical use by the FDA?
A: Yes.

Q: How do I adapt my present dialysis system to allow the use of Citrasate® or DRYalysate® ?
A: You don't need to adapt your system to the new dialysate formulation. No changes are necessary. Citrasate® concentrate is available in all the standard concentrations and formulations. You simply pour it into your standard A concentrate container and attach it to your dialysis system as you always do. If you prefer to mix A concentrate from powder, DRYalysate® is available for this purpose, and it can be mixed in your facility to make concentrate.

Q: What steps are necessary before citrate dialysis can be started?
A: Both Citrasate® and DRYalysate® may be used in existing dialysis systems without altering them. Also, there is no additional patient or system monitoring needed beyond that normally employed in treatment with standard dialysate formulations. Consequently, no staff training is necessary for the conversion to citrate dialysate.

Q: Can citrate dialysate be "spiked" with potassium or calcium?
A: Yes, it can be spiked just as you do with traditional dialysate concentrates.

Q: How is citrate dialysate supplied?
A: It is available in two different forms, each with a final citric acid concentration of 2.4 mEq/L: Citrasate® is a liquid A concentrate that comes in 1 gallon jugs and barrels, in concentrations of 35X, 36.83X, and 45X. The jugs are packed four to the case. DRYalysate® is the dry equivalent of Citrasate® . For those facilities that prefer to mix A concentrate from dry ingredients, DRYalysate® is the choice. Because dry citric acid is already included, no separate liquid acid needs to be added which makes it possible to ship and store a completely dry formulation until it is needed. DRYalysate® comes in boxes that make 50 liters of A concentrate in any of the three concentrations noted.

Q: How do I obtain Citrasate® and DRYalysate® ?
A: Advanced Renal Technologies is the sole source for these two products.

References

1. Pinnick RV, Wiegmann TB, Diederich DA. Regional citrate anticoagulation for hemodialysis in the patient at high risk for bleeding. N Engl J Med. 308(5):258-261, 1983.
2. Ahmad S, Callan R, Cole JJ, Blagg CR. Dialysate made from dry chemicals using citric acid increases dialysis dose. Am J Kidney Dis. 35(3):493-499, 2000.
3. Tu A, Ahmad S. Heparin-free hemodialysis with citrate-containing dialysate in intensive care patients. Dial Transplant. 29(10):620-626, 2000.
4. Tu A, Ahmad S. Heparin-free dialysis using citrate dialysate. Abstr. J Am Soc Nephrol. 11:A1591, 2000.
5. Ahmad S, Callan, R, Cole JJ, Blagg CR. Effect of citrate-containing dialysate on dialyzer reuse. Abstr. J Am Soc Nephrol. 11:A0919, 2000.