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Old 08-27-2015
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Default Methemoglobinemia

Can anyone explain what is the difference between methemoglobin and cyanide toxicity, there is attached picture from FA 2015

I can't get it

another question about B12 def, why when we treat it with folate only the neurologic dysfunction may worsens, I mean why does it worsen instead of remaining the same as before the initiation of folate supplementation?
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Methemoglobinemia-screen-shot-1436-11-13-10.04.52.png  

Last edited by Dr 2015; 08-28-2015 at 12:34 AM.
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Old 08-28-2015
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Quote:
Originally Posted by Dr 2015 View Post
Can anyone explain what is the difference between methemoglobin and cyanide toxicity, there is attached picture from FA 2015

I can't get it
CAUSE:-
methemo: nitroglycerin followed by sodium thiosulfate or benzocaine
cyanide: nitroprusside, cyanide intake

PATHO:-
methemo: oxidize Fe2+ to Fe3+,cant bind with O2
cyanide: asphyxiant at cellular level

HALLMARK:-
methemo: chocolate colored appearance
cyanide: bitter almond oil smell

RX:-
methemo: i/v methylene blue + vitamin C
cyanide: inducing methemoglobinemia(nitrogylcerin followed by sodium thiosulfate or benzocaine) or hydroxycobalamin

Your Welcome 🇵🇰
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Old 08-28-2015
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Meth Hb is an issue with Hb, due to nitro containing compounds; CO; or cytochrome b5 reductase deficiency. This prevents reduction of fe3+ to 2+. 3+ can't deliver/unload o2; hence left shifted curve. (Red skin)

Cyanide inhibits cytochrome oxidase. Hence, is a mitochondrial toxin. So, there will be hypoxia, which causes lactic acidosis and death. (Anaerobic glycolysis) (normal/pink skin - since veins have normal o2 ; secondary to impared o2 uptake/extraction - mitochondrial toxin)

Quote:
Originally Posted by drjgsu View Post
CAUSE:-
methemo: nitroglycerin followed by sodium thiosulfate or benzocaine
cyanide: nitroprusside, cyanide intake

PATHO:-
methemo: oxidize Fe2+ to Fe3+,cant bind with O2
cyanide: asphyxiant at cellular level

HALLMARK:-
methemo: chocolate colored appearance
cyanide: bitter almond oil smell

RX:-
methemo: i/v methylene blue + vitamin C
cyanide: inducing methemoglobinemia(nitrogylcerin followed by sodium thiosulfate or benzocaine) or hydroxycobalamin

Your Welcome 🇵🇰
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