the original video is here 吃辣食物時(shí)喝了一瓶口腔噴劑

? hey, Dr Bernard here,

? this throat numbing(麻醉) spray(噴劑) is medicine, there is a label on the bottle required by law telling you how to take it, and there is a warning on that label, saying what can happen if you take too much,

? like this, that's a lot of sprays,

? He looked online for ways to handle extreme spice(重度辣味) and came across throat numbing spray, usually used to treat sore(痛) throat and canker(爛) sores,

? he went to the store, found a bottle, tried one spray in his mouth to understand what he was working with, and he determined, it was his time to outshine his roommates, again,

? later that week, on the day of the spice(吃辣比賽的日子), the friends were ready to have some delicious chicken wings,

? one of the roommates dropped out quickly because she didn't like spice foods, she just wanted to taste flavor and enjoy what they ate, but everyone else knew that they wanted to show each other up,

? RJ hided the throat numbing spray underneath his napkin, occasionally sneaking in a spray here and there while everyone else was eating,

? at first, he would make it look like he was wiping his mouth when really, he was pumping that spray,

? the sauces they moved onto got spicier, some of the friends were having trouble handling it, but RJ wasn't going back down, he wasn't going to admit that this was spicier than he could handle,

? he felt like the sprays were starting to not do anything, and the bottle was kinda tall under the napkin, maybe looking kind of obvious, he started to suspect that the others were catching on to him,

? as he unscrewed(擰開(kāi)) the bottle of throat numbing spray so he could take a couple of swigs(一大口), but accidentally, he spilled(倒出來(lái)) the bottle into his mouth, and some it started dripping down his chin(下巴),

? in an effort to not make it obvious to his friends that he was adding a little help on the side to handle the spice, he swallowed what was in his mouth,

? RJ felt like his tongue was too big for his mouth, he could bite down on it and feel nothing,

? but then he felt like his head was pounding, he could feel his heart beating in his neck, as the air coming out of his nose felt warmer than normal,

? one of the friends suspected something was wrong, but they just didn't know what,

? he called RJ out and said, "check out Papa Smurf(藍(lán)精靈) over here.", as everyone noticed that RJ was blue in the face,

? the throat numbing spray that he was hiding was blue and some of it was dripping off his chin,

? panicked, thinking that everyone knew what he was doing, RJ got up and quickly ran to the bathroom, but the moment he got up, his field of vision turned dark,

? in the bathroom now, RJ was grasping for air, the sounds in his ears couldn't make any sense to him,

? one of the friends found the empty bottle of throat numbing spray on RJ's seat, and realized what he had been doing,

? at first, they found it hilarious(搞笑), but when they looked closer at the bottle, they saw a warning to seek immediate medical attention if blue colored skin devlops during the use of this product,

? and when RJ wouldn't come out of the bathroom, they went in and saw his complexion(臉色) an even paler blue color,

? he was laying down on the floor, as they drive him to the emergency room, where we are now,

? immediately, medical staff notice RJ's cyanosis(皮膚呈現(xiàn)青藍(lán)色), "cyan" from Ancient Greek, referring to the blue-green color, and "osis" meaning abnormal state,

? his face, his lips, and his nail beds were a bluish green color, indicating that there's some lack of oxygen in RJ's blood,

? they quickly gave him supplemental oxygen in order to remedy this,

? the throat numbing spray that RJ dumped into his mouth is the same cyan color that his complexion was now,

? but, he spilled some of it onto the skin of his face, it's possible that some of the food coloring dyed his lips blue, and that nothing at all was wrong with RJ, meaning that maybe that oxygen wasn't going to do anything,

? but as the time passed, it became clear that oxygen wasn't going to do anything, but there's definitely something wrong,

? the oxygen didn't change the color of his complexion, even worse, he's starting to become unresponsive, meaning that something was happening to his brain,

? when he presented to the emergency room, they had put a pulse oximeter(測(cè)血液氧氣的裝置) on his finger in order to check oxygen saturation in his blood, that is the measure of how much his hemoglobin, the protein in red blood cells that's supposed to carry oxygen, is actually carrying oxygen,

? the pulse oximeter shines a light on one end, and measures how much remaining light is received on the opposite end, to determine that percentage of oxygen absorbed by his red blood cells,

? if they'd been giving him oxygen, but he's still blue, and the pulse oximeter was saying that his hemoglobin wasn't carrying a lot of oxygen, and it's clear now his brain was shutting down because it's not getting enough oxygen, then what could be happening?

? the medical team drew some blood from RJ's arteries to test, and found that huge amounts of oxygen were in his blood, this should make sense, the oxygen that RJ was receiving was going into his lungs, and put into the blood that's coming from his heart,

? this oxygenated blood then flows back to ther heart where it's pumped out to the rest of the body through the arteries, which is where the medical team drew his blood,

? but if all of this was happening, why was the pulse oximeter saying that RJ's oxygen saturation was low, and more importantly, why was he still blue and grasping for air,

? red blood cells are supposed to carry oxygen, and they do this through a protein called hemoglobin, which contains iron, and that's what carries the oxygen,

? if the arterial blood that the medical team collected from RJ shows that he had a large pressure of oxygen in his blood, but the pulse oximeter was showing there wasn't much oxygen attached to his blood cells, then it means that oxygen was in the blood, but for some reason his red blood cells couldn't hold on to that oxygen,

? and if iron in hemoglobin is supposed to carry that oxygen in normal function, then this is where RJ's problem was, this is methemoglobinemia(高鐵血紅蛋白癥),

? 意思是，正常血里有II型鐵離子，可以結(jié)合氧原子，結(jié)合后使II型鐵離子變成III型鐵離子，II型比III型多一個(gè)電子，「高鐵」意思是鐵離子在結(jié)合氧原子前，已經(jīng)大量以III型鐵離子存在，而不是II型鐵離子，于是跟氧原子結(jié)合不了。

? "met"from "Meta", in this case referring to "between", or a kind of altered state while rataining some structure and characteristic of the original, but being different in a very important aspect of function,

? hemoglobin being the protein that holds on to oxygen,

? and "emia" meaning presence in blood, an altered hemoglobin presence in blood, but why was this happening?

? the active ingredient in the spray that RJ used is benzocaine, the "caine" suffix int the name denotes a local(???) anesthetic(????), meaning that it's a medicine that's supposed to numb the area to where it's applied,

? the nerves rely on sending eletrical signals to the brain for the sensation of pain, but benzocaine generally dampens(???) that eletrical signal so that the pain sensation isn't sent,

? this happens at regular doses, which for this throat numbing spray is one pump(?????), that's spit out after leaving it in the mouth for a minute,

? but that's not even close to the amount that RJ took and put inside his body, and at doses like the one that he took, the chemical structure of benzocaine explains everything happened to RJ,

? we're familiar with metallic iron, when metals are used for normal function in the human body, they're not in their solid metal form, they're usually ions, meaning that they are eletrically charged,

? the problem with iron, is that it can have different electrical charges, this is why is special, but why does it do that?

? electrical charges on elements are because of the changes in how many electrons are on the atom, if there's more electrons than normal, then that ion is negative, if there's less electrons than normal, then that ion is positive,

? "normal" is dictated by the number of protons in the atom, which are positively charged,

? so when the number of electrons equals the number of protons, the atom isn't charged at all,

? nature has a tendency towards stability, in this case referring to less energy,

? electrons on atoms are laid out in energy levels, the larger the element, the more energy it has, and that means it can become more reactive, because it can release, or wants to release that energy and react with something to become more stable,

? the reason why iron is special is because of exactly how many protons it has, and how energy levels are arranged in nature,

? the layout of the periodic table of elements tells us the energy levels of every single element,

? each of the columns on the left and right denote groups(???????塱), and members of each group tends to exhibit some similarities with each other,

? while going along a row denotes an incremental increase(????) in protons, and elements will tend to behave differently as you count up,

? iron is the first of its group, but the row that it is in is called the Transition Metals(???????),

? as we count upwards on irons energy levels, nature says we can remove 2 electrons, and iron can be stable,

? actually, while regular hemoglobin is holding on to oxygen, the iron II becomes iron III plus oxygen, and becomes iron II again when it lets go of the oxygen,

??but as this methemoglobin circulated around in RJ's body, none of his organs can get oxygen because his blood cells can't transport it in, as they started to shutdown, his brain was starving of oxygen as he becomes unconscious,

? but what did this have to do with benzocaine spray? well, RJ sprayed too much, when he was still only spraying, the oral mucosa(黏膜) is highly vascularized(血管多), meaning that lots of blood is flowing through,

? so he was getting benzocaine absorbing into his blood here, and he was swallowing the sprays, but then, he accidentally dumped the bottle in his mouth and swallowed even more,

? the benzocaine spray then went into his stomach, absorbed from his small intestines into his liver, where it was metabolized, or broken down, adding even more to the amount in his body,

? one goal of liver metabolism is to make the chemical more water soluble(易溶解), meaning it can dissolve in water, so it can concentrate in the urine and be elimited from the body, this is called making the chemical more hydrophilic, "hydro" meaning water, and "philic" meaning affinity for,

? water is made of oxygen and hydrogen, so adding oxygen to a chemical in this way, should increase hydrophilicity,

? but for benzocaine, doing this brings us back to the problem of stability,

? we already established that electrons play a role in the stability of iron,

? when benzocaine is metabolized, one of the resulting chemicals that happens to be hydrophilic, is a phenyl(苯基) hydroxyl(親水) amine(胺), the electrons in this molecule are delocalized(不在該在的位置), meaning that they are distributed among the structure, a little different from how elemental iron places them on energy levels,

? phenyl hydroxyl amine is hydrophilic, but it is not stable, it has an extra electron it wants to get rid of to establish stability, therefore making it reactive,

? the human body has an abundance of oxygen, so phenyl hydroxyl amine gives its extra electron to oxygen and becomes nitrosobenzene,

? while that receiving oxygen becomes superoxide, an oxygen with an extra electron,

? superoxide is reactive, meaning that it is not stable, so the body tries to handle this by reacting it with water, but that creates hydrogen peroxide(過(guò)氧化氫), which is an unstable chemical that takes electrons to become stable,

??and if hydrogen peroxide is in the blood, an easy target to take electrons from is iron II in hemoglobin,

? this brings us to an idea called equilibrium(平衡),

? the nitrosobenzene from phenyl hydroxyl amine produced by the metabolism of benzocaine, is also unstable, it pulls electrons from elsewhere in the body to become phenyl hydroxyl amine again,??

? the two of these species, exist together, endlessly cycling between one another, shuffling electrons around and creating massive amounts of superoxide, and exerting heavy oxidant stress, reacting with iron II in the blood, turning significant parts of RJ’s hemoglobin into methemoglobin, incapable of transporting any oxygen throughout the body despite the direct administration of oxygen into his lungs,

? this mechanism of oxidant attack in the blood happens with several different chemicals when they are put into the body, all of which result in methemoglobinemia, and can cause all the organs to shutdown due to a lack of oxygen,

? 比如亞硝酸鈉，

? in the hospital, the medical team already picked up on what was happening, they may not have known that benzocaine was the cause at first, but the clue to methemoglobinemia were all there, RJ’s blue face and lips and grasping the air, the low oxygen saturation on pulse oximetry when supplemental oxygen was being given, the high oxygen pressure during blood test, and the chocolate appearance of the blood when it was drawn, not being a bright red like normal,

? if RJ’s problem was electrons being extracted from the iron in his blood, how is one supposed to replace those electrons? This brings us back to equilibrium,

? methemoglobin exists in normal function, its just that our bodies can easily add the extra electron to iron III to make it iron II, so there isn’t normally a lot of methemoglobin,

? but when an endless cycling of pheny hydroxyl amine from a huge ingestion of benzocaine keeps creating stress, the body’s mechanism to reduce iron III is quickly overwhelmed,

? however, there is another approach the body can use, it just need an intermediate to help carry the electrons around,

? and ironically, as RJ’s skin and lips were blue, the antidote that will replace the electrons in the iron in his blood, is a dye called methylene blue,

? the medical team noted RJ’s methemoglobinemia, but it was one of the friends who showed staff the bottle of benzocaine throat numbing spray that they thought he drank,

? the medication label has a clear warning on the back to not misuse it, and all of this prompted the medical team to start methylene blue when they gathered the information they needed to know,

? and very quickly, an improvement was found in RJ’s cyanosis,

? but more time was needed to observe him in the hospital, because while methylene blue was indicated in his case, because of how severe his methemoglobinemia was, it wasn’t without risk, and RJ took enough benzocaine, that just one dose of methylene blue probably isn’t going to be enough,

? misusing throat numbing spray isn’t new, its not hard to find videos of people doing it, not all throat numbing sprays are made the same, some have different active ingredients that aren’t benzocaine, and thus, may not cause methemoglobinemia, althrough they could cause other problems when misused,??

? benzocaine is also found in some cough drops, and has that same methemoglobinemia warning which if you look,

? the US FDA has issued warnings several times throughout the years about this,

? also, because benzocaine is a topical(局部的) anesthetic, there could be misused in other sensitive parts of the body, there is no limit to what you can shoose to imagine here,

? medical literature has documented? risks with benzocaine spray, sometimes during endoscopic(內(nèi)視鏡) procedures, and I remember a time in the mid 2010s, when the spray was something hard to get in the hospital in part because of this problem of methemoglobinemia,

? throat numbing spray can be helpful when you have the common ailments of cold, flu, sore throat, canker sores, not to eat more spicy foods than your friends,

? please be careful, because this dosage form can be easy to want to take more, the directions for use are right on the label,

? last point, the antidote methylene blue is used here because RJ had an active poisoning, if you don’t have an acute(問(wèn)題明顯的) illness, or a diagnosed pathological(病理的) condition, if you don’t need to put it in your body, don’t put it in your body,

? as RJ was monitored in the hospital, he needed a bit more methylene blue,

? but finally as the days passed and he was watched closely by the medical team, he was discharged from the hospital as he learned a lesson about not needing to argue and show up his friends all the time, and about not misusing throat numbing spray, as he was able to make a full recovery,

? thanks so much for watching, take care of yourself, and be well.

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