DIP Episode 399 - The 3 Confusing Poisonings (HY for Step 1-3)

Okay, welcome. My name is divine. This is episode 399 of the divine intervention podcasts. I need to list podcast I'm gonna be addressing our three simple topics. It should be a short podcast, but it's just something that You know, it's tested very frequently on exams and people mess it up a lot So we're gonna be talking about the three classic poisons when we're talking about Kaboom on oxide poisoning We're gonna be talking about Sanite poisoning We're gonna be talking about meth him of lobeemia These are things that people often confuse on exams now if you're taking your US Emily exams if anytime soon We have a few courses that may be helpful to you have an MB me test taking strategies course It's gonna be From five to seven thirty p.m. Pacific standard time on the ethos July What is cost a lot of approaches for Really dealing and being successful with MB me questions Avoiding traps and things like that. I made a podcast recently where I kind of talked about what will be achieving in the course tons of people have taken these courses. It has helped them improve their uro cube bank percentages It has helped them improve their MB me test scores and then from the 11th to the 16th of July You know accept when's the the 13th of July will be having a 20 hour review course We'll go for internal medicine p. It's surgery.

You'll be going side neural Ethics biostatistics communications healthcare systems multi systems processes and disorders And then on the 21st of July from four p.m. Pacific standard time We'll be having the four hour biostatistics of bootcamp. So if you're interested in any of these Just shoot me an email through the website. I'll give you some more information and then you can you can sign up Okay, so let's get right into it right so Kaboom on oxide poisoning again I'm gonna give you what you need to know to do it on your exams on your exams First how do people get this problem? Okay, usually people get this problem in certain classic ways, right? You can they can make it a question of how to call minor right a call minor Right or a person that's using a space heater right or a person that was in a house fire Um many times they will say something about how You know this person has like a really bad headache. They may have like altered mental status Those are usually the things.

So you see a person trying to commit suicide in a garage In an enclosed garage in an enclosed space And for whatever reason many times when people have Kaboom on oxide poisoning on nimbim exams It's usually going to be in the winter which makes sense because the winter is a period where people use space heaters So or you know they may try to be conserving some money on heating so these space heaters What do you use like these um Fireplaces fire pits these things can all cause Kaboom on oxide poisoning Right, so those people the permanent feature is gonna be um headache and addition to the headache. They're going to have altered mental status Now why is Kaboom on oxide poisoning bad? Well, it's bad because it kind of those two things First it has an affinity for oxygen. I mean for yeah for Himo globin that is like 240 times The affinity for oxygen for Himo globin. So he just has a stronger affinity for Himo globin that oxygen So a lot of your Himo globin is going to be filled with a Kaboom on oxide Um, but they're not uh They will not be filled with oxygen, right?

So that can be a problem So if you look at the blood oxygen content equation The thing that goes down is your SAO2 or SEO2 is gonna go down with Kaboom on oxide poison um Another thing that also it also causes is that many times It causes a left shift of your oxyhimo globin dissociation curve What's that left shift that left shift just means that whatever oxygen Is already bound to the Himo globin before the Kaboom on oxide binds It's It's gonna be harder for your tissues to release that So when you see stuff like that that should make you Essentially think that okay, wow this person is not gonna do well because if on the oxygen they have They cannot release it to their tissues. So that's problematic So those are the problems with Kaboom on oxide poisoning. So how do we diagnose Kaboom on oxide poisoning? We diagnose Kaboom on oxide poisoning by checking the carboxy Himo globin levels, okay? You'll check the Kaboxy Himo globin levels and remember you know Kaboxy Himo globin levels You know very by individual if you're a smoker You have higher Kaboxy Himo globin levels compared to a non smoker Because if you're present that chronically smok cigarettes you're building up Kaboom on oxide in your body So we have like you know Just a higher threshold for saying oh This is too much Kaboxy Himo globin in a person that is a smoker That's a nice tidbit of information to know for your test So how do we treat Kaboom on oxide poisoning?

Well, we're gonna treat Kaboom on oxide poisoning typically by giving you know You know, personally supportive care, but they need like high flow oxygen they need hyperbaric oxygen The thing is is not every MBME question that you will see hyperbaric oxygen do we just put oxygen therapy or high flow oxygen therapy? That'll be correct, right? Because basically it just reduces The half life of Kaboom on oxide being on your Himo globin, right? So if you use like hyperbaric oxygen, right? Obviously is the fastest is the quickest is the most effective But if you're using like high flow 100% oxygen that's also pretty effective, right? So those are the things you do for Kaboom on oxide poisoning Remember that when people have Kaboom on oxide poisoning they're gonna have image-in findings If I were you and I don't worry specifically about the image-in findings But usually they'll have like a high-poor dense global spallitus Okay, they'll have a high-poor dense global spallitus. Just remember that there's something wrong with the global spallitus in the person that has Kaboom on oxide poisoning Now one thing I also want to say about Kaboom on oxide poisoning is that usually people get that problem After a prolonged graduated exposure, right?

So like many times you'll be over a few hours you've been exposed to the constant stream of Kaboom on oxide That's how you ultimately get in trouble You'll see that that differentiating feature becomes very prominent When we're talking about cyanide poisoning in fact that's the next thing we're gonna go to So what are the classic patient presentations that you mission and in being an exam Now we'll leave you down the path of cyanide poisoning Well typically it can be a person that comes in with a hypertensive emergency And in that hypertensive emergency they are being treated with IV nitro-perside Nitro-perside Contains a lot of cyanobrups, right? So many times many many times it can cause cyanide poisoning Especially when you give a prolonged infusion of it Alternatively you can also get cyanide poisoning from consuming drugs that you know Many times they are powerful oxidants but a lot of them contain cyanide, right? Or they can lead to the generation of cyanide, right? So these are going to be things like trimethyprimsophamethoxasol Right These are all drugs that can cause they can cause this problem um Oh sorry, I mean spoke there I was thinking about that move You see I almost confused myself there Uh with methemoglobinemia my apologies there.

Sorry These other drugs besides nitro-perside I mentioned that for methemoglobinemia I'll talk about that in a bit So I just corrected myself there But if you see a person you know that's in a house fire house fires can also be associated with cyanide poisoning Right and also another thing you may see as we have the house uh cyanide poisoning is a person that's consuming a lot of uh uh Apple seeds, a lot of apricot seeds. These things are all associated These things are all associated with uh with cyanide poisoning, okay? The all of those cyanide poisoning So how do cyanide poisoning present? First things first is usually these people are going to have a lactic acidosis I'll say this right now. This is what we're going to have a lactic acidosis and usually it's not a gradual exposure that causes the problem when you're exposed to cyanide You're going to have significant issues very quickly especially if you have a significant exposure The person can be dead within minutes or seconds Samite is very toxic. So you see a person the exposure they were exposed to like Thin for hours just very quick exposure and you see those people crashing and burning always think about cyanide Poison, okay?

Always think about cyanide poison and again if they give you the relevant exposures again Please I misspoke earlier about the oxidizing drugs the only drug you really should think about with cyanide poisoning is nitro-perside So think of nitro-perside think of um eating apricot seeds eating apocedes right and think of a person that's in a house fire and you see them They have a very powerful acidosis rapidly Developing lactic acidosis think of cyanide poisoning. So why do cyanide poisoning cause a lactic acidosis? Well it causes a lactic acidosis Because it inhibits complex four of the electron transport chain It inhibits complex four of the electron transport chain So if you inhibit complex four the electron transport chain your electron transport chain does not work That's going to be a huge massive problem for you. You know why? Because you can you then have to depend more on anaerobic glycolysis And if you're depending on anaerobic glycolysis again, that's not a big deal right? General a lot of lactic acid from from that right? So cyanide poisoning can be very deadly very quick Okay, can be very deadly very quick. So again Many times the relevant exposure will be helpful And also if you see a very powerful lactic acidosis And you see this person from They were normal to oh the aggression I'm burning is a few minutes Not hours and hours and hours like we see with carbon monoxide poisoning Okay, so how do we treat cyanide poisoning?

What's the first line treatment the first line treatment for cyanide poisoning is actually hydroxyl cobalamine Hydroxyl cobalamine again instead of putting hydroxyl cobalamine on your exams They can put the term vitamin B12 derivative But in B12 derivative basically that hydroxyl cobalamine is converted very rapidly To cyanocobalamine cyanocobalamine right? That's like a very harmless B12 form right? And that's excreted from the body, which is not a big deal Now another way you can also treat this but it's not preferred is the use of The use of like nitrates like immunite rate Um, so how does that work? What's the mechanism behind that working? Well the thing is your hemoglobin contains iron in the two-plus form.

That's the fairest form Right, but there is such a thing as methemoglobin where the iron is in the three-plus form It has the ferric form of iron iron with a three-plus Oxidition number three-plus charge Now the thing is no more hemoglobin that has ferrous iron Fe2 plus iron uh, you know Doesn't bind cyanide as well as hemoglobin that has the three-plus iron hemoglobin of the three-plus iron right It binds cyanide extremely well um So that's helpful right because you're like oh wow this person has the cyanide problem I don't want them to die So we use a nitrate like immunite rate no Oxidize the iron in their hemoglobin from Fe2 plus to Fe3 plus so it generates methemoglobin And that essentially helps with fixing the problem But if you think about it methemoglobin which is iron that has the three-plus form Does not have the ability to carry oxygen So since it doesn't have the ability to carry oxygen that's going to be very very problematic right Because You can only induce methemoglobinemia so far that you throw the person into a worse thing hypoxia From that circumstance So that's just something you want to keep at the back of your mind for exams That's why that is why it is it is literally not first line okay.

It's literally not first line It is literally not first line So you just got to be careful with that because again the thing you're inducing to bind the cyanide and help you deal with the problem Also does not carry oxygen right the methemoglobin literally I mean there's there's literally a reason where we have this whole disorder called methemoglobinemia Okay, so that's something you want to keep at the back of your mind for for exams Okay, something you want to keep at the back of your mind for exams And then a third way You can treat this is with thiosolfeid The only problem is maybe let me explain how this works right so thiosolfeid Essentially he serves as a substrate for an enzyme known as rodonis Is like a it's like a thiosolfeid So far transfer is but Basically, what are the needs does is it fix thiosolfeid fix cyanide and converts it to thiosyanid Thiosyanid so that's great. You're like well, the mind. This is a great mechanism.

Well, it it is It's just really slow right and you don't want your patients dead by the time your intervention fully kicks in That's why again, it is not first line okay Hypoxia cobalamin is where it's at if you want to treat cyanide poison But if you don't see hydroxyl cobalamin as an answer that's where you can pick The combination of immoranitrade and thiosolfeid many times we combine both of those things together Okay, now let's talk about methemoglobinemia right so what are the classic patient presentations you may see on your exam That will guide you down this methemoglobinemia pathway Well, the things that will guide you down the methemoglobinemia pathway are going to be things like um a person That is taking something that is a patholoxidic agent right so like you saw for my antibiotics like trimethyperum So from a thoxazole dapsone pentamidine So HIV patients are pretty pretty good setup for cyanide I mean for methemoglobinemia And then also if you see people taking these nitrates right like nitropercide nitropercide Libert or not can also induce a methemoglobinemia or a nitrate so they can give you like a patient that has angino of some sort That is on chronic nitrate therapy right Think about methemoglobinemia in those people right and also you can also see a person That uh it was exposed to a lukula anesthetic recently right so all these anesthetics that end in the word king benzocaine that's a classic one on exams right Lido cain all these cains cains cains right so you mean the material that all the person just went for a dental appointment Or had like a minor pin procedure or nerve block and then you see them developing peri-orosanosis That's very high-o you're gonna see peri-orosanosis peri-orosanosis is a pretty classic homework of methemoglobinemia Okay, you'll see the person they'll have peri-orosanosis and many times they'll have chocolate colored

blood Okay, they'll have chocolate colored blood when you see all these things I want you to think about methemoglobinemia So why is methemoglobinemia a problem?

Well, it's a problem because that iron in the 2 plus form right is now in the 3 plus form again We said 2 plus iron is ferrous iron 3 plus iron is ferric iron ferric iron has no ability to bind oxygen Ferrous I or let me not see no ability but a very diminished ability to bind oxygen Ferrous iron Fe2 plus has a much better ability to bind oxygen So if a lot of your hemoglobin is has iron in the ferric form the 3 plus form You're gonna have a huge problem on your hands, right? So how do we treat this problem? We will treat this problem on inbibing exams Is you're gonna treat it by giving methylene blue, okay? You give methylene blue Now methylene blue essentially So Helps you reduce the 3 plus iron to the 2 plus iron it helps you get methemoglobin All the way back to hemoglobin that's the tripping of choice for methemoglobinemia So again, peri-oral cyanosis that is something you'll almost likely You'll be very unusual for you to see peri-oral cyanosis With cyanide poisoning or carbon monoxide poisoning You see as I'm going I'm trying to give you like key differentiating features Between these things is all I know the very critical difference I'll talk about in a bit Right what are some other things you can do besides methylene blue you know you can give vitamin C You can also help, okay?

You can give vitamin C can also help It promotes that process of reducing methemoglobin to hemoglobin So it's helpful in those circumstances Now another thing you want to keep at the back of your mind is people that have certain kinds of alpha thalacemia Especially people that because remember in alpha thalacemia you have all four You know that if you think about it genetically they are for alpha-globin genes Right if you lose one you're probably gonna be fine you have much of any issue if you lose two probably gonna be fine You don't have much of any issue if you lose three you're gonna have something called hemoglobin H disease Right so because you're very down on your alpha globin chains Then your beta your beta globin your beta globin chains are gonna start coming together So you can form like beta-4 for example like a beta tetramer right those things Generally don't respond very well to methylene blue That the hemoglobin H is not very responsive to reduction right So those people may have like a worse prognosis in the setting of a methemoglobin in it and also the thing is um The enzyme that helps you convert That helps you you know the enzyme that helps you are Convert methemoglobin back to hemoglobin.

I mean it uses two important co-factors You probably want to know use this any deep as a co-factor Also uses any deep each as a co-factor right so the thing is People that have any DH or any deep each generating problems They may have a kind of a bigger issue with methemoglobinemia right because they don't have enough co-factor Because typically in the body you know because of all the oxygen in the body the friarity goes blah blah blah blah blah Every now and then you can generate methemoglobin right both that in Zendrous Hops right so If you have a lack of its co-factors like any DH or any deep each right that can put you in some very big Troubles right so say for example if a person has a g6pd deficiency right to remember that's excellent for excessive So it's gonna be in boys on exams Those people cannot make enough any deep each so they may have a lot of problems with methemoglobinemia Or you see a person that has like pyruvate kinase deficiency for example if you have pyruvate kinase deficiency Then you're not gonna be able to make enough any DH right You're gonna be able to make enough any DH you're gonna have quite a number of issues with any DH production So that can cause you to have more issues with methemoglobinemia right so you're just gonna keep that at the back of your mind on exams And then one other thing I want you to keep in mind actually two things the first thing I want to say is that um Methyline blue which is the therapy for Methyline globinemia you kind of want to be careful giving it to a person that Is being treated for depression from a co-therapy the thing is methylene blue is a very powerful mononine oxidase in hebert So because it's a very powerful meoi You know it can raise your serotonin levels or so you can consider a tuning syndrome So you can give you a question about a person that you know was recently started on from a co-therapy Yo

u know because they're exposed to local anaesthetics and then they have pyruus and osseus So the imbibies are kind of counting on you knowing that oh okay, this is methymoglobinemia And then they tell you that oh you know like a few hours after therapy the person starts having myoclonus And things like that think of serotonin syndrome and usually they'll give you like a possible to go history of depression or anything like that Right so basically just any of these things that you can combine that can jack up your serotonin levels just be careful Right so like for example like The linesolid right linesolid is a drug that you know is a It's very good for for merse but it's also an meoi Right so you wouldn't be careful about kind of combining those two things together right or like Just really like anything that is serotonergic right like a tricyclic antidepressant and And meoi in and of itself right just not a very stellar idea to Combine one trasodone right trasodone ecstasy those things are all serotonergic right st.

John's word those things are serotonergic So you can already begin to see all the questions that our friends at the imbibies could literally create from from this stuff Now one thing I want to say to round all of this up I didn't imagine that this podcast would be this long is comparing Uh the response of a person that has couple monoxide poisoning sunlight poisoning And met himoglobinemia to oxygen exposure right so obviously for person has couple monoxide poisoning They're gonna respond well to oxygen their hypoxia will respond to oxygen supplementation right because again Literally by giving more oxygen you're gonna be displacing more and more of those couple monocytes from your hemoglobin Okay fine Now if you also look at sunlight again We literally said that cyanide inhibits complex four of the electron transpotching right so those people Essentially they they're not very they're not very participatory in aerobic respiration So they depend a lot on anaerobic respiration So even more oxygen should help right because it's almost like a supply and Electron acceptor to try to salvage whatever activity you have left with your electron transpotching So people that have cyanide poisoning their hypoxia will actually respond to oxygen administration Like they'll they are symptoms. Let me put it this way.

Let me not necessarily see their hypoxia because really The the thing that you know like for example in couple monoxide is your SEO to that is low right But basically those people the are symptoms will improve with oxygen administration right But then contrast this for the person that has met himoglobinemia so people that have met himoglobinemia It's actually pretty high out to know that these people um their Their hypoxia Their blood oxygen content is not gonna respond to oxygen administration Because literally you're given oxygen to a person that has a lot of himoglobin That have iron in the three plus four which literally have no ability to carry oxygen right so if you see A person that has hypoxia that is not responding to oxygen supplementation Um and you're looking at a poisoning kind of question think about met himoglobinemia People that have come on oxide poisoning and cyanide poisoning they respond more to oxygen supplementation Although I guess maybe As an added point here if you're dealing with a pediatric question Where child is getting oxygen and the old two sets are not rising You want to think about some kind of cyanotic congenital heart defect That's a pretty classic tip off to a cyanotic congenital heart defect when it being exempt So we're gonna go ahead and pause here um so again As we as I do I think the very podcast I'll throw one on one tutoring on a very limited basis for all the USM Exam step one to step three um also help with your application so like Personal statements rec letters things like that um Uh Just I help with it in these things have literally been a member of an admissions committee I've worked with tons of students over the years that have matched At very successful residency programs in very highly pleased residencies So I have a lot of experience with this process.

So if you're interested again I'll reach out to me through the website I'm again the early reach out to me the better because again my schedule feels are pretty pretty quickly And then also I have these review courses as I mentioned I have the 20 hour step two step three review course Which also is helpful for complex level two or three Out the nbm testing and strategy scores which is very helpful for step two step three And also your 30-year shelf exams. So if your student is just studying of your 30-year med school Attending the nbm testing and strategy scores will be very beneficial for you And then I have the four-hour biostatistics bootcamp That one is attuned to step one all the way to step three because biostatistics is tested on each and every one of these exams And then um I have this podcast on Apple podcasts on Google podcasts and Spotify. So at least the most recent 150 You should be able to find find them or just look for the divine intervention podcasts And then I have a youtube channel. It's called the divine intervention USMLE podcast and videos. That's where I post the videos that I make And then finally finally I do have um A new website I call it divine intervention life lessons.com In fact, there is a podcast associated with it. It's on Apple podcasts It's called the divine intervention life lessons podcast every week I make two podcasts that reflects a life lesson That is bible based Most of them are about 10 minutes long again.

I think if you listen to them you'll be blessed right now I believe we have like 95 episodes of that so very very very helpful Um, and then finally the thing I want to say I want to give a life lesson today Right, I want to give a life lesson today So the thing is Be very careful of The way you handle guilt Be very careful of the way you handle guilt Um, guilt is something that I feel like many people in medicine experience Because we make mistakes we screw up Right, but the thing is at the end of the day I'm not supposed to be People make mistakes.

Let's put it that way people make mistakes Right, but unfortunately just with the way medicine is set up and the stressors of medicine sometimes People just seek very wrong outlets for their mistakes which you know, it's not helpful in the long term So what am I trying to say here when you're in a situation of guilt where you're feeling like a failure It's always helpful to take a step back and seek some help seek some help Sips some six some counseling six some um Just support right call your family The thing I'll encourage you to keep in mind is just be careful of I feel so sad saying this but just be careful of where you seek help Because some people you seek help from them and then they use that to destroy you Kissing point, you know certain administrators in medicine Um, they cannot take it as an opportunity to say oh this person has mental health issues Let's label them as such and then let's not mess in them up right so you know just Maybe outside the confines of your training program outside of the confines of your med school seek help again I feel very bad saying this but unfortunately we just have this culture in medicine That does not treat people that have mental health crisis the best which is extremely unfortunate Again, it's no surprise where you see a lot of suicides in medicine right one of the most common causes of death Amongst medical professionals especially young medical professionals is suicide right because unfortunately You see people take that as an outlet right so please I'm encouraging you Don't use suicide as an outlet for a guilt When you say that's an outlet for guilt you can always come back from something I'm telling you It doesn't matter how disastrous a situation or a circumstance can be You can always come back from it and telling you this there's no condition that is permanent There's no condition that does not have an expiry date

so I'm encouraging you Be careful of the way you handle guilt just be careful right let guilt be used as a stepping stone as a launching part for you being successful Learn from your mistakes try not to make those seem mistakes again Come up with a good action plan for success going forward But you know don't uh don't don't don't don't use that as something to pull you down Like literally guilt can either pull you down or take you up right but just think of you know what I can start fresh again I can I can achieve great things with my life.

I'm not a failure. I'm a success Right there's this part of the bible that says we have this treasure in earth in vessels So right now you may be be or look like a failure But it doesn't mean that you're gonna be a failure forever. That's the truth You've heard me see this on this podcast before and You know another original person that made this statement But don't let your background keep your back to the ground right the fact that you're failure now You feel really like the fact that you failed now doesn't mean you're a failure forever right You can always come back. You can always start doing the right thing you can change right But if you if a person commits suicide then that failure has got in the best of you All right, you've ended your life look at all the thousands of patients. You probably could help then you're just not able to help and it causes just A very unusual level of pain for your family your friends and things around you again. I'm not trying to be I'm not trying to say oh, I don't know people that commit suicide. I'm telling you those people have significant emotional pain I'm telling you like really the way the healthcare system is set up in this country Just in terms of training and everything is almost like a perfect setup for Mental health problems. That's why it's kind of important to take care of yourself take some time to rest Don't overextend yourself right again You should take care of yourself.

That's just a very important thing All right, so just be careful of the way you handle guilt handle guilt constructively so that you can One save yourself and also save the lives of the other people you're gonna be taking care of So thank you for listening to the spot cast have a wonderful weekend. I'll see you in the next podcast. God bless you. Thank you

House fires, ingestion of apricot/apple seeds, or administration of nitroprusside (IV).

Severe lactic acidosis.

Carbon monoxide (CO) poisoning.

Chocolate-colored.

Hydroxocobalamin (Vitamin B12 derivative).

Methemoglobinemia.

Complex IV (cytochrome c oxidase) of the electron transport chain.

Local anesthetics ending in -caine; nitrates (e.g., nitroprusside).

CO has a high affinity for hemoglobin, displacing O2 and causing a left shift of the dissociation curve.

Hydroxocobalamin.

Rhodanese (which converts cyanide to thiocyanate).

Methemoglobinemia, because Fe$^{3+}$ cannot carry oxygen.

Complex IV (cytochrome c oxidase) of the electron transport chain.

Local anesthetics ending in -caine; nitrates (e.g., nitroprusside).

CO has a high affinity for hemoglobin, displacing O2 and causing a left shift of the dissociation curve.

Hydroxocobalamin.

Rhodanese (which converts cyanide to thiocyanate).

Methemoglobinemia, because Fe$^{3+}$ cannot carry oxygen.