Blood Volume

[derekliz]

Do all POTS patients have low blood volume?

http://www.daxor.com/PRquery.aspx?date=7%2f11%2f2013&title=Daxor+Corporation+Announces+Publication+of+%22Blood+Volume+Determination%2c+A+Nuclear+Medicine+Test+in+Evolution%22

[Chaos]

Don't know that ALL POTS patients have anything. But I think a significant percentage of POTS patients may have low blood volume. I know that in the CFS literature they are saying that a very large percent of those patients are chronically about a liter short on volume. Given the overlaps between the communities, I wouldn't be surprised if POTS patients had similar findings. It may not be documented very well yet as I don't know how many of the POTS centers do routine blood volume studies. I know Cleveland Clinic did when I was there a couple years ago. Not sure about any of the others.

[Guest Alex]

I know that some doctors evaluate the hypovolemic status of a POTS patient by using the sodium levels in a 24 h urine catch (under 100 mEq/L).

Daxor labs have come up with a new method/technology for analyzing the blood volume of a patient, but the more "classical" methods have been around for quite a while and involve injecting a radioactive substance into the patient's blood stream and collecting samples to be analyzed at certain times after that.

Alex

[derekliz]

Is it pretty standard to be dx'd with POTS and not have a blood volume test in conjunction with a TTT?