Ease of Use and Blood Clotting for the Gambro Polyflux HD-C4 Big Dialyzer

Primary outcomes

1. Ease of Use: Priming Blood Side

   Time frame: Priming at each treatment

   For every study treatment/dialyzer, the nursing staff rated the ease of priming blood side as follows:

   Very Easy:Air is easily removed without knocking or clamping procedures. Acceptable:Knocking and/or clamping required for efficient air removal. Difficult:Knocking and/or clamping and additional volume of saline or extended recirculation needed to remove air.

   Very Difficult:Air could not be removed.

2. Ease of Use: Priming Dialysate Side

   Time frame: Priming at each treatment

   For every study treatment/dialyzer, the nursing staff rated the ease of priming dialysate side as follows:

   Dialysate Side at 500 ml Priming Volume (check one):

   Perfect: No air visible. Acceptable: Some air visible, but considered insignificant. Not Acceptable: Additional actions needed to sufficiently remove air.

3. Dialyzer Assessment: Fiber Condition

   Time frame: Each treatment: assessment of the condition of the dialyzer fibers after rinse-back

   For every study treatment/dialyzer, the nursing staff rated the condition of the dialyzer fibers after rinse-back as follows:

   Very Good:All fibers appear white. Good:Few fibers (less than 10) appear PINK / RED. (check one) Poor:Several fibers (more than 10) appear PINK / RED. (check one) Very Poor:Most fibers (more than 75%) appear PINK / RED. (check one)

4. Dialyzer Assessment: Arterial Header Condition

   Time frame: Each treatment: assessment of the condition of the arterial header after rinse-back

   For every study treatment/dialyzer, the nursing staff rated the condition of the arterial header after rinse-back as follows:

   Very Good:Surface as clean as expected. Good:Distinct red ring appears at the dialyzer wall. Poor:Significant appearance of clots, randomly distributed on the surface. Very Poor:Completely red and/or covered with clots.

5. Dialyzer Assessment: Venous Header Condition

   Time frame: Each treatment: the assessment of the condition of the venous header after rinse-back

   For every study treatment/dialyzer, the nursing staff rated the condition of the venous header after rinse-back as follows:

   Very Good:Surface as clean as expected. Good:Distinct red ring appears at the dialyzer wall. Poor:Significant appearance of clots, randomly distributed on the surface. Very Poor:Completely red and/or covered with clots.