As far as I understand, SpO2 (pulse oximetry) can be falsely high or low in methemoglobinemia. The higher MetHb is, the closer your pulse ox will read to 85%.
What is the best indicator to see if oxygen is being carried and delivered by hemoglobin? Is SaO2 on an ABG relevant? Why or why not? If not, would pO2 be the next best indicator? Any other measures to determine oxygenation?
So my gf had benzocaine at the dentist. She started shaking and lost consciousness. It looked like a seizure and she was sent by ambulance to ER. They gave her Benedryl and sent her home. Later on that night after doing research I noticed the FDA released a statement about benzocaine and how it can cause Methemoglobinemia. She was showing all the symptoms like tremors, shortness of breath etc. We were worried so we went back to ER later that night. When we went back to doctor I told them everything I knew and her symptoms. The doctor says “ no that can only be given by genetics or intravenous benzocaine”. I said “I read a statement from FDA that said it’s actually from topical benzocaine.” He grabbed my phone from me and read the fda info I had and said “ok it says to do a blood gas on your phone so we will do one”. As unprofessional as that was I was just happy he was going to test for it. He came back and said the blood gas was normal and he didn’t know what to tell her and he can’t figure out why she had this reaction and symptoms. So a week or so goes by and she still has shortness of breath, confusion, minor tremors, etc. So she logged in tonight and viewed her medical charts and she saw the results of the blood gas had some areas marked critical. I have no idea what these mean so maybe someone can just look and determine if those would be caused by methoglobanemia.
pH Art 7.50 (critical)
pC02 Arterial 31 mm hg (low)
p02 Arterial 77 mm Hg (Low)
RDW 14.1% (High)
Those are the items that were in red from blood gases. Does anyone know what they mean? I know no one can diagnose but they would know if she should go back to hospital and if these could possibly potentially methoglobanemia? It’s also worth noting it says on the charts that the doctor and nurse discussed the results with her and let her know the items marked red which they absolutely never did. The only discussion we got was when the doctor came back in and said well blood gas was normal and I don’t know what to tell ya I don’t know why you had this reaction and then looked at me like “I told you so”
I am 27 year old male. I am actually a medical student, so feel free to give a detailed explanation.
I did something pretty stupid. I have a canker sore in my mouth that has been incredibly painful. It's been annoying me, and I wanted to treat it. I was somewhat familiar with benzocaine, and I thought it was relatively harmless. I have gotten it multiple times at the dentist, and I even used a topical benzocaine numbing cream back in undergrad when I closed a heavy door on my toenail.
I thought it was pretty benign stuff, so I ordered it on Amazon. It was a 20% gel with the trade name "Anbesol." It said to apply a "pea-sized amount" to the affected area. I was in a lot of pain, so I'd say I probably applied a pea and a half. I was immediately really surprised how strong it was. For an OTC product, I didn't expect to feel like I was literally at the dentist's office getting ready for some drilling. I let it dissolve but then got nervous it was too strong and wiped it off. I hope I didn't swallow any of it.
I then got curious and started reading about potential benzocaine overdose online. And I see it's been strongly implicated in methemoglobinemia. It seems benzocaine encourages the production of methemoglobin over hemoglobin. Methemoglobin cannot bind oxygen as effectively, and a high amount of it can severely reduce the amount of oxygen delivered to tissues.
Am I really at risk for getting methemoglobinemia? It's been about an hour since I took it. I am concerned something could happen. I've read that the onset is generally about two hours, so will I likely be ok if I do not develop symptoms by then? I've also read that a lot of the cases of this are in infants given benzocaine during teething. Is this unlikely given the fact that I'm a ~200 lb 27 year old?
Any thoughts would be helpful. It's very surprising they do not list this on the label of these medications. There literally are no warnings whatsoever. When looking this up, one of the top results was a class action lawsuit for failure to adequately warn consumers about this. Maybe I'm being a little paranoid, but this was definitely a surprise to read about. Thanks!
So my friend who listens to the show told me that sydnee mentions methemoglobinemia (also known as blue baby syndrome) in one of the episodes— and as one of the extremely rare cases of an adult diagnosed with that I’m trying to find it! My friend told me that it was mentioned in passing, but I’m still super curious to find out what sydnee knows/thinks about it (and also I maybe wanted to try reaching out to her about it).
Does anyone know which episode it could be in, or if it was talked about at all?
I know this is a weird question, but I feel like I'm overthinking it. CO2 is carried in the blood via dissolution, being carried by hemoglobin, and being converted to bicarbonate. Would methemoglobinemia cause less CO2 to be carried by hemoglobin and thus increase PCO2? I have a feeling this isn't correct but just wanted to confirm. Thank you!!
I'm Meg and I have an extremely rare disorder, idiopathic familial methemoglobinemia, it has killed me twice and makes my skin take on a blue color.
http://imgur.com/KMQaHj2 http://imgur.com/ldXwoNX http://imgur.com/GipUrrp
Still looking for a good explanation - maybe I am just understanding oxygen dissociation curve incorrectly
So I've read that methemoglobinemia causes a left shift in the O2 dissociation curve due to the remaining sites binding tighter to the O2.
MHb has decreased SaO2,decreased O2 content, and normal PaO2.
So how can it have low SaO2 and left shift? Isn't the Y axis of the O2 dissociation the Hb saturation, which is what SaO2 is?
I’m in the medical field and also a Kentuckian so this is extremely interesting to me. If this seems too invasive I will take it down, as the article does mention the reluctance of the family to ever comment for an interview. A cosmetic cure was found and no health issues were ever observed in the Fugates!
Hey science friends, I was born with a genetic variant of methemoglobinemia but I have never come across anyone in my life beside my family who has the disorder. I’m happy to answer any questions that people may have about it, and would be ecstatic if any of you knew someone who also has this condition. Thanks!
The diagnosis of methemoglobinemia is suspected when a person looks cyanotic but the arterial partial pressure of oxygen is normal on an arterial blood gas. I just don't get it. If methemoglobin has a higher affinity for oxygen (left shift on the O2 saturation vs pressure curve), then wouldn't you expect venous hemoglobin to be oxygenated and thus the people to be red or pink, not blue?
Female 37 y/o Non smoker Takes blood pressure medicine for high blood pressure No drug use or anything like that
So my gf had benzocaine at the dentist. She started shaking and lost consciousness. It looked like a seizure and she was sent by ambulance to ER. They gave her Benedryl and sent her home. Later on that night after doing research I noticed the FDA released a statement about benzocaine and how it can cause Methemoglobinemia. She was showing all the symptoms like tremors, shortness of breath etc. We were worried so we went back to ER later that night. When we went back to doctor I told them everything I knew and her symptoms. The doctor says “ no that can only be given by genetics or intravenous benzocaine”. I said “I read a statement from FDA that said it’s actually from topical benzocaine.” He grabbed my phone from me and read the fda info I had and said “ok it says to do a blood gas on your phone so we will do one”. As unprofessional as that was I was just happy he was going to test for it. He came back and said the blood gas was normal and he didn’t know what to tell her and he can’t figure out why she had this reaction and symptoms. So a week or so goes by and she still has shortness of breath, confusion, minor tremors, etc. So she logged in tonight and viewed her medical charts and she saw the results of the blood gas had some areas marked critical. I have no idea what these mean so maybe someone can just look and determine if those would be caused by methoglobanemia.
pH Art 7.50 (critical)
pC02 Arterial 31 mm hg (low)
p02 Arterial 77 mm Hg (Low)
RDW 14.1% (High)
Those are the items that were in red from blood gases. Does anyone know what they mean? I know no one can diagnose but they would know if she should go back to hospital and if these could possibly potentially methoglobanemia? It’s also worth noting it says on the charts that the doctor and nurse discussed the results with her and let her know the items marked red which they absolutely never did. The only discussion we got was when the doctor came back in and said well blood gas was normal and I don’t know what to tell ya I don’t know why you had this reaction and then looked at me like “I told you so”
