This is a new one for me (after 30 years!)  An ER patient presented recently with a MCV of 107 and low MCH, MCHC.  This patient was in house at our hospital just last week, with all  normal indices.  Called the RN in ER who commented that she is expected to have a very high glucose.  Googled it and sure enough, hit a few articles like this;

https://www.ncbi.nlm.nih.gov/pubmed/7259094

The patient had a glucose over 1400 g/dl.  My question is this:  for those of you who are aware of this phenomenon, do you attempt a correction and report that  out?  Apparently this is a in vitro pj=henomenon related to hyperosmolality when the blood sits in the EDTA tube before processing on the ananlyzer.  The "cure" is to do a saline replacement and let it sit a bit.

Thanks, Scott

Sysmex recommends making a 1:5 dilution of the sample and letting it equilibrate before analyzing. This would be the same procedure for abnormal sodium levels, also.

We've seen this once. If we're lucky enough to realize that's the problem, we would saline replace to allow the cells to get re-acquainted with the proper osmolality. (The MCV on our particular patient was 134, so it was a bit obvious)

We have seen this on a number of occasions - Usually a significant delta change MCV failure, with low MCHC.

We don't do a correction, but make a comment: Note the discrepancy with previous MCV.  Hyperglycaemia may interfere with RBC indices, esp. MCV. Suggest correlate with glucose levels