MD190 Frequently Asked Questions

1.Why is the arterial and venous port positioned in that way?
The unique design of the two compartment header cap and corresponding groove in the potting compound create two discrete yet serially connected blood compartments within the fiber bundle.

Think of it as two dialfilters in one device.

Tracing the flowpath within the diafilter will assist with understanding the “unique” design of the OLpr™ MD 190 and why the arterial and venous ports are positioned in this fashion.

The blood will flow first through the first compartment which is called the “annular” blood compartment or the “outer fiber bundle”.

The blood will then be diluted in the mixing header with substitution fluid.
The flow reverses 180° to enter the “core” blood compartment or the “core filters”. The blood will then exit the OLpr™ MD 190 filter via the venous blood port.

2. Will we have a lot of recirculation?
The diafilter design does not contribute to recirculation.

In theory, the admixing of blood would occur due to the admixing of blood from the vascular access. This can occur with central venous catheters or the close proximity of the arterial and venous needle placement.

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3. Why is the replacement fluid directly entering the filter?
The “unique” design of the OLpr™ MD 190 combines post-dilution and pre-dilution diafiltration. This mid dilution dialfiltration allows substitution fluid to flow at 200 ml/min. As a result, superior urea clearance of post-dilution hemodiafiltration and unsurpassed clearance of toxins in the middle molecule range.

4. What is the priming volume and which side needs to be upright while priming?
A minimum of 400- 500 ml of priming solution should be used for air removal with the substitution port (SP) oriented upward. After this initial priming phase rotate the device so the substitution port (SP) is oriented down to further assist in air removal. Typically a total of 1000 ml. or 1 liter of priming solution is used. Be certain to prime the device until the air has been substantially purged from the circuit.

Note *Follow any specific manufacturer’s instructions for operation of equipment and clinic specific protocols.

5. How much blood does the filter hold?
The blood volume is 140 ml.

6. What type of membrane is it?
The membrane is Polyethersulfone which is a synthetic material.

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7. Will this shorten treatment time?
Treatment time is determined on an individual basis and prescribed by a physician.

8. Can we use it for HD only?
The OLpr™ MD 190 was specifically designed for use in hemodialfiltration therapy.

This therapy is prescribed by a physician.

9. During treatment which side needs to be upright?
During operation, the blood ports on the OLpr™ MD 190 are oriented up and the substitution port is oriented down to achieve optimal mixing of the substitution fluid with blood.

10. During rinseback which side needs to be upright?
During rinseback (washback) the OLpr™ MD 190 is positioned with the substitution port (SP) oriented up. This will allow for optimal conditions for blood return. (Refer to Fig 1 located in the Instructions for Use)

11. What is the urea clearance compared to our current filters?
The OLpr™ MD 190 has excellent urea clearance.

12. How do you remove the dialysate port caps- twist off or pull?
Position the port cap tabs in the center, grasp the port cap and pull off. This may require a “twisting” motion to place the tabs where you can easily grasp and remove with a “pulling” motion.

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