Can someone share their process for performing saline replacement on lipemic patients.  Our method is outdated and I can't find a reference for it. Thank you!

Spin the specimen down, mark the level of the lipemic plasma on the tube, remove said plasma (careful to not disturb anything near the RBCs), refill to the  mark with saline, remix. Run.

Scott

Thank you Scott. Then you use all parameters from the saline replaced specimen?

We prefer doing a plasma blank as opposed to saline replacement. 

A lot of times we can correct for Lipemia with a 1:5 dilution when we can't we do the following.

Plasma Blank:

• If severe lipemia is present, spin an aliquot of the patient’s blood at 3400 rpm for 10 minutes.
• Remove the plasma to a small glass tube and run this “plasma blank” in manual mode to obtain the Hgb value for the plasma.
• Calculate the corrected Hgb:

  • Corrected Hgb = Whole blood Hgb - ((1-Spun Hct) X Plasma Hgb)

• Use the corrected Hgb and original RBC result to recalculate the MCH and MCHC as required.

 

By performing the saline replacement, there are no calculations necessary.  All parameters can be used as reported by the instrument.  The WBC, RBC, and platelet counts can be checked against the original to make sure you didn't over or under-replace too much plasma.

Our lab used to have a policy allowing for both methods.  We discovered we were getting the exact same results with the saline replacement and got rid of the messy math.

Thank you!

 

I have a very old but valuable reference from a Coulter workshop.....years ago (it references STKS and MAXM analyzers).....

Using MCH to correct Hgb for plasma interferences; we don't do saline replacement unless we absolutely have to!CBC CORRECTIONS.PDFCBC CORRECTIONS.PDF

I've attached an excerpt of the handout from the workshop.

It seems like those guys at Coulter 30 years ago had too much time on their hands...

Scott

Scott, do you have a reference for this method of saline replacement?  I can't seem to find one.  Thank you!