Can anyone advise what the effect on " normal range" results low blood volume would have? For FBC, liver function panel and homocysteine I have done a quick google but not much comes up Could this be a factor in pwme tests being read as normal when things are far from this? Our GP is generally willing to be persuaded on things and can be proactive ( h. Pylori testing was her idea to try and bottom out fatigue / brain fog possibilities) Is this something that should be in the mix to focus more on symptoms?
I migh5 be completely wrong here but I think I saw someone had a slide on blood volume in one of the presentations recently but I can’t remember who. Possibly Dr Montoya. This entry in me pédia might be useful https://me-pedia.org/wiki/Low_blood_volume
This is an aside, but interesting. I am doing a part time course, so I sit in on the full time classes for the modules that I have chosen; there are a number of modules that different courses share as part of the syllabus. Monday morning is a carbon management module, and the other course attending are agricultural science students (as farming is a major contributor to GGH emissions). Monday was a strict attendance for them as the CEO of The James Hutton Institute was giving a guest lecture via video conferencing on the role of carbon in soils and as a natural currency. There were problems with the link so it ran 40 mins late and they were frantically comparing notes on an upcoming lab report hand in -this was the first formal one they had done - they were using different methods to do a FBC and had also to interpret a range of " normal" and "abnormal" results. I had a great discussion with then at the mid morning break. They appreciated how to interpret a value within normal range relative to the distribution criteria of the test ( this I think was part of the lab reports key learning outcomes) ; what difference in blood volume would potentially mean. The impact of bacteria in gut ( SIBO/ L - lactate acidosis etc), ketosis and the impact on Krebs cycle. So it may be that we would be better having consults with Vets....
None, basically. If blood volume is acutely lowered there may be changes but in the long term there is no specific relationship. Acute volume lowering could be due to bleeding, where concentrations of cells and molecules will not change, or due to acute dehydration from heat or exercise, where they will, but in all sorts of different ways. Changes are not very significant until dehydration is marked - which will be indicated by passing no urine. As far as I can see these situations are not relevant to ME.
Thank you @Jonathan Edwards . I had mistakenly thought that there would have been some effect ( to have same range for a reduced volume did not make sense to me - like homeopathy in reverse. ) More confused than ever.
If low blood volume in ME has other normal results, then it might mean that numbers are down but homeostatic mechanisms are trying to maintain concentrations. So for example there might be low red blood cell numbers over the entire circulation. This would resemble anaemia and yet fail to meet the criteria. Anything where concentration is less important that absolute count will be a problem. For everything where concentration is the only issue there should be no problem. Some patients have been reported with enough blood volume loss that in other circumstances it might be fatal or very dangerous. However we are likely to be partly adapted to low blood volume. In particular additional serious risks such as dropped blood pressure from acute blood less will not occur. However it may well impact orthostatic intolerance and low blood pressure to some extent. We are decades overdue for proper serious studies into this issue.
The point is that the body's feedback systems would rapidly readjust all the concentrations back to what they should be, just in a smaller volume.
Thanks. It would be interesting to know if this has been looked at in ME , particularly given @alex3619 ' s comments re absolute counts. Does anyone know if this has been studied? I would love to think that all the feedback systems work as intended : calibration is a finicky thing.
There is research that says that RBC total mass is down, and others showing total volume is down... all within that brief flash of time they were actually looking at this. These are my random notes on the studies: Fukuda & <5 hrs upright/ day; Bell is an MD, so likely they were dxed by him 1998 Circulating blood volume in CFS Streeten & Bell Low RBC volume is common in orthostatic intolerance, and OI is common in ME. Is there low RBC volume in ME? 51Cr-labeled autologous red blood cells & 1251-labeled human serum albumin respectively, in five university-affiliated radiology departments. RBC mass & plasma volume measured in a small cohort (19 patients) with severe ME. RBC mass was significantly reduced and plasma volume was reduced by about half. Some patients had less than half predicted RBC mass and less than half of predicted blood volume. Small study. Unfortunately, no control group. ________________________________________________ “physician-referred”; required confirmation of CFS from a clinician.[1] 2008 Chronic fatigue syndrome: illness severity, sedentary lifestyle, blood volume and evidence of diminished cardiac function. Hurwitz, B., Coryell, V., Parker, M., Martin, P., LaPerriere, A., Klimas, N., … Bilsker, M. The study examined whether deficits in cardiac output and blood volume in patients were present and linked to illness severity and sedentary lifestyle. “dual tag” radiologic Both sedentary and active patients had lower total blood volume, lower plasma volume and lower erythrocyte volume. Differences were significant, from 13.2 – 19.1 %. (This means 6 S.D. below the mean!) Low RBCV may indicate a type of anemia that isn’t picked up on ordinary tests (normochromic normocytic anaemia, e.g.).[2] Data here is very useful, but conjecture is not always logical. E.g. relying on CDC exclusionary diagnoses as the final word in such a poorly-understood illness is not wise. [1] From symptom prevalence, it looks like patients were diagnosed by Fukuda? [2] Sudden normochronic normocytic anemia can be a sign of severe, long-term infection. Alternately, it can be a sign of endocrine system failure: low pituitary hormones, adrenal hormones, or thyroid hormones. ___________ As always, grain of salt, folks.
Low cortisol common - also tie in with endocrine symptoms.... Hopefully the current research into hormones may shine a light on this area
