Blue dialysers

[Chris Bates]

hi all,
A while ago (2024) we had some dialysers which appeared to have blue blood in them. Staff noticed when washing back. There were no reported patient symptoms. However, this was also reported earlier in the year when we had some anaemia incidents.
I have yet to find an explanation and it hasn't happened since.
Any ideas? I have some thoughts but I want to hear what others think could have caused this. There was no failure of hardness or chlorine from the tests performed before each dialysis session.
Chris

[Chris Pearson]

Got to be either hemolysis or iron residue to me ????

[Gareth Murcutt]

Any other correlations Chris B? All in one unit/ certain days/shifts/patients etc? Fistula or catheter access? Any difference in consumables?

[fraser gilmour]

Oxidised haemoglobin

[Ian Wilde]

My first thought was Methemoglobinemia.

[Gareth Murcutt]

Agree it almost certainly metHb - the cause is trickier though. Attached is a Journal Club discussion from 2007
JC2007-05_Final_v1.doc

[Chris Pearson]

I seem to remember the most recent similar occurrence was in Aberdeen but haven't been able to find any reference to it.
If  it's fairly widespread on the ward this would point towards a batch of faulty blood tubing sets with either slightly occluded venous line or blood pump over occlusion .

[Chris Bates]

Hi again,
My suspicion was also acute methaemogloginaemia.
I wondered if I was jumping the gun because of the well known blue-baby syndrome, however I couldn't find much about blood going blue in adults or dialysis patients.
There are references to blue skin and lips but I suspect that would be after serious or more prolonged methaemogloinaemia?
Both incidences were after heavy rain so I wondered about short term surges in incoming nitrate levels (none reported by the water supplier).
There were anaemias in the earlier incident, but the plant was running in single pass for some of the time due to other problems. The total chlorine measurements carried out by the staff 4-5 times a week never showed any evidence of chlorine/chloramine.
No conclusions were reached as to the cause, and there has been no further colour change reported, but it has niggled me ever since.
Nobody had mentioned iron until Chris P but the source would be more difficult to identify.
The dialysers were all Fresenius Cordiax (I think) but different batches and sizes and only in the one unit.

"Methemoglobinemia is a rare blood disorder that affects how red blood cells deliver oxygen throughout your body. It occurs when red blood cells contain methemoglobin at levels higher than 1%. Methemoglobin results from the presence of iron in the oxidized ferric form (Fe 3+) instead of the usual reduced ferrous form (Fe 2+), which results in a decreased availability of oxygen to the tissues. Not everyone has symptoms, but nearly all people with this condition have skin, nails or lips that are a distinctive shade of blue or purple. In some cases, methemoglobinemia can be life threatening."

[Gareth Murcutt]

I applaud your tenacity Chris - I hate not knowing what's happened in these situations. Met-Hb should have shown up in blood results - I assume they took them? Nitrites are much more powerful oxidising agents than nitrates. I seem to remember they had a much lower limit in drinking water but the two were combined in a later revision.