February 10, 2002 - The January issue of the journal Dialysis and Transplantation (D&T) has an article by two prominent nephrologists that touts a new index for measuring hemodialysis adequacy, the Hemodialysis Product (HDP).

Drs. Belding Scribner and Dimitrios Oreopoulos describe the current standard, Kt/V, as flawed as it fosters short dialysis sessions and does not address the importance of removing middle molecues during hemodialysis. They state there is irrefutable support for the conclusion that the adequate removal of middle molecues correlates better with survival and well-being than the clearance of the smaller urea molecue (which is used for Kt/V).

The full text D&T article, entitled "The Hemodialysis Product: A Better Index of Dialysis Adequacy than Kt/V", is available on-line as a PDF file.

The HDP index is somewhat unusual in that it does not measure any blood work value, but instead simply uses:

• the number of dialysis sessions per week and
  
• the number of hours per session.

A typical hemodialysis patient in the United States has an HDP equal to 36 (three four-hour sessions per week). The paper suggests an HDP above 70 should be provided.

An HDP of 72 could be achieved for a typical patient by dialyzing six times a week for two hours per session. This would be the same amount of time on the dialysis machine per week and would deliver the same Kt/V dose, but would double the HDP value from 36 to 72.

Hemodialysis is most efficient at solute removal at the beginning of the treatment due to the higher concentration gradients at that time. Clearances (clearing a volume of blood of a solute) are essentially constant throughout the hemodialysis treatment.

The authors state that "for reasons unknown, these remarkable (HDP and more frequent dialysis) results have been largely ignored by the U.S. hemodialysis community, which still bases its definition of minimum adequate dialysis on a Kt/V=1.2 per dialysis 3x/week."

Medicare, the largest payer for hemodialysis services, provides reimbursement for only three hemodialysis sessions per week. Until this policy is changed, the adoption of this new therapy approach is economically unfeasible for most dialysis centers and patients.




[This message has been edited by Gary Peterson (edited 02-12-2002).]