Why methaemoglobinaemia is a bad thing

19 Jul

This is no small topic. And I don’t plan to give a definitive take on this but here’s some thoughts.

I’m also planning one on why methaemoglobinaemia is a good thing. Seriously.

1 What is methaemoglobinaemia?


2 Causes


3 Clinical Features?


4 How do you make the diagnosis?


5 Treatment?


6 How Does Methylene Blue Work?


7 Some observations

12 Replies to “Why methaemoglobinaemia is a bad thing

  1. I’ve seen one case of it. Took care of him in the ICU. Diagnosed by one of my stellar third year residents in the ED, got methylene blue, and then had undiagnosed G6PD deficiency, and started hemolyzing. Very very sick.

    We frequently talk about “you give a blue drug to a blue patient and they turn red,” but our blue patient got a blue drug and turned him red, then turned him white (anemia), and then turned him yellow (hyperbilirubinemia).

  2. Pingback: Why methaemoglobinaemia is a good thing | Emergency Medicine Ireland

    • Thank you for your informative site. My brother before me died at 1 month from methaemoglobulin anemia from the nitrates in the well water in Southern Alberta. Canada. on the farm They had no idea at the time of the cause (circa 1950) I was born in 51
      and was breast fed..probably saved my life. The DR at the time thought i was blue as I was born breach with umbilical cord double wrapped on neck. I am 61
      and the symptoms have been managable…..it is a good thing because though I have had to fight like hell to keep on the weight or stay warm….I am a thinner person thereby not having to deal with many of the side effects of FAT. And I do love my potatoes . CL

  3. Two quickies –
    1) I saw 3 cases over 3 years (I work in Australia). The first 2 were an asian couple who had imported Chinese meat product containing a boric acid & nitrite compound. The second was a young soldier who had been on chloroquine for malarial prophylaxis. Apparently recluse spider bites can do it too (Not likely to be a big threat in Ireland)
    2) The diagnostic clue pattern is a combination of a cyanosed patient who usually doesn’t feel too bad and has a low SpO2 with a fairly normal PaO2 and whose cyanosis and SpO2 fail to improve with increased FiO2. Also, deoxygenated blood reds up nicely when exposed to air, but Met-Hb blood keeps its chocolatey colour.
    Watch that SpO2 when you give the methylene blue! It usually takes a spectacular dive as the ferrous-Hb is released.

  4. Is there anyway to find out if this exhists up your bloodline? Are there any studies currently being conducted of the long term effects on bloodlines or future generations?

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