Fresenius Medical Care 2008K Operator's Manual page 94

Chapter 4—Monitoring the Treatment
In cases of unsatisfactory Kt/V, the operator should check:

For proper needle placement and connections to the bloodlines.

That the machine is set for prescribed blood flow rate.

That the proper dialyzer is being used.

That the dialysate flow rate is as prescribed.

That the blood and dialysate lines are properly connected to the dialyzer so that the blood
and dialysate flow are countercurrent (blood flow down, dialysate flow up).

If the preceding is correct, check the patient's access flow rate (fistula or graft).
A substandard Kt/V could also indicate a problem with clotting, recirculation within the patient's
access, or other problems.
While a treatment is in progress, the Kt/V may be increased by increasing the flow rate of the
blood pump or increasing the dialysate flow rate. Changes to the prescribed treatment
parameters, however, should be consistent with a physician's orders.
Note: The OLC self test should be run occasionally (1 – 2 times per month) or any time that
you suspect that the OLC results may be erroneous
Access Flow
How Access Flow is Derived
In order to determine the patient's access flow rate (AF), two OLC tests are done, one with the
bloodlines connected in the normal position and one in the reversed position. In the reversed
position, recirculation is induced. The higher the patient's access flow rate, the lower the
recirculation. With the two OLC tests, the access flow rate can be calculated. The measurement
is more accurate at lower access flow rates. Because it may be difficult to obtain high blood flow
rates with the bloodlines in the reversed position, it may be necessary to reduce the blood flow
rate for both tests. The result will be more accurate if both tests are done at the same blood flow
rate.
94 2008K Operator's Manual rev. K