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I am running Good evening and welcome to this week's Webinar being given. But I got an artificial. It's going to be on the topic of our two blood gases, which is something that any medical professional probably benefit from a little bit of of teacher. So without any further, you know it's gonna end over to take it away. Hi, guys. Welcome everybody to tonight's webinar. So before we get started, tonight's Webinar is sponsored by MD. You. Every doctor that works in the UK needs the have defense protection to practice an MD. You are somebody that provide that so neat stuff thinking about that. If you're finally a student, Gordon F warn you, and definitely that you have in the moment, as a medical student warned automatic review in the effort. So show you just a quick video. Perfect. I just put there and presentation about so moving forward. So what is tonight's weapon are going to be about? So first of going to talk about what are terrible August is our went to do them and then they have on to how to interpret it them on. Then some cares presentations where you can try, interpret in the BGC Selves but warm and ask us any questions that you have to give you a little bit of an explanation off the insist of them. I'm more than happy to have questions throughout if you just want to write them in the fierce boot tract or, alternatively, would collect all the questions together and China into them all. At the end, we'll be more more than enough time there, answer any questions or address any concerns that you might have. So what are taking a blood gases? A tibial samples of bloods, uh, blood samples that taken from the arteries like the name suggests rather than from a V. So when people normally say that the team some bloods, the normally mean that they're getting a venous some people rather than not able sample. However, I tell you, your blood gases can be used to find more information out on a person's oxygen. Saturations. We're not gonna cover how you actually take an ABG tonight. What will provide the link in the chat now, just giving you a little bit of a run through on how to take them just a bit of a tricky process. So Normally, the body tightly controls the bodily functions the pH to see or to the head to your three. And it does that because for the body systems toe work, they need all be within a very narrow margin. However, stuff like organ dysfunction to organ dysfunction of the loans of the heart condition up the pH and that causes the bodily functions and the P here to do not work as well. So in medical emergencies, often it ABG will be taken is it provides vial information very quickly and can help the team that are looking after the patient decide what to do and what management is needed is junior doctors. I'm sure you'll take hundreds of these Junior Korea, So let's move on on how to interpret them. So the normal values that the body works towards will always be down the right hand signed of the screen. So let's start. The first thing to look at is the pier or two, so appear or two of over 10 is normal in bloom, and healthy individuals that don't have any underlying conditions under 10 is known as High Pac senior, and under it is severe hypoglycemia or respiratory failure. This value of over 10 is in Brumer. In a normal individual, however, when people are, um, well, often require additional oxygen and name. If that is the case, the PA or two should be 10 less done. The oxygen that the person is being delivered. This will make a little bit more sense when were switched to the next life. So these are common Oxygen's a livery devices, and I'm sorry that second picture hasn't care more problem to why, to about nasal cannula, simple face max, then to remastered or a reservoir mask. Normally breathe mask and the amount of oxygen that could be delivered very significantly dependent on patients with spirituality, it the depth of the breath and how well, really, the mask is fit into their fees. If there's a lot of gaps, there's a lot of oxygen that's being delivered. Just escape into the atmosphere that the Senate of oxygen that each of these masks can potentially deliver given on the slide. So see if somebody has a nasal cannula run off to leaders 20%. You therefore would expect their PA or two to the 18, because that's 10 less than the 28. Eventually remastered. Give an accurate delivery oxygen concentration in 24% or 28% or what I recommended in COPD on the reservoir masks or the number we breathe. Masks are what are used in medical emergencies. So we've looked at their PA or two on one off the patient's hypoc. Sick or not, this whether the rumor or whether they have a oxygen's of ice in situ, were then going to look at their peers. See or two. So if the patient, you know, has a law pa or two, you know the hypoc See you. Thank God, look at that pace, so you're too, and that will decide if they went tight. Warmest booty failure or type two respond to failure Time. One has a little oxygen with normal C or two. Take two has a little oxygen with high C or two, so type one misspoke. You failure is normally do to a ventilation profusion mismatch or VQ mismatch for short and nothing's. The volume of air that is anything in the lungs is not equal to the volume of blood that's flowing to the lungs. So an example of that might be if mental a shin is lower. But this normal perfusion that might be in things, which is probably you're doing that or from, or obstruction. Where is it? Profusion is low, so they might be like a blockage in the blood vessels, but there's normal ventilation that would also cause type almost okay failure, and that would be in something like a pa. Where was Type two is beautiful? Ear is due to a Bueller hyperventilation, and that might be due to airway obstruction and increased resistance. And COPD may be due to decreased compliance of lung tissue in a rib fracture or a new morning in more new one disease that might be due to decreased strength of the muscle, often in someone who has taken a lot of opioids. That might just be decreased ventilation do to decrease respiratory drive. So we're gonna look at the oxygen first if the oxygen's law with them going to look at the PS PSI or to to determine if it's type one or type two spiritually failure moving on, we're now going to look at the P hedge, some what's like, I was saying before small changes in the pH can have a big effect on the body on the physiological processes that go on. If the p here to get too high or too long, the body will start to shut down three different kinds of peer to do. You have issues. You have your normal range where everything's working really well. The body's happy. Everything's going good. The pH is lower than 7.35. It's what's called a sonic, and if it's above 7.45 or galactic changes are disruption in the pH due to an imbalance of C or two on here, see or three and that corresponds to a respiratory cause off a disturbance in the pH or a metabolic cause in the disturbance of the period. Let's see your tube in inspiratory and history or three mean the metabolic because so the first thing to do when you get given any a BG after you've looked at the oxygen on the CO2 and decided if the person's in any respiratory failure is to look at the pH. If it's normal, that's fantastic. If not, you need to decide. Is it acidotic our alkaline? It The next thing you want to do is look back at the CT or C PS psi or two. Sorry, so you've already looked at that a little bit when you were looking at the respiratory. See if the patient is in Ms Pretty fairly or not. But, you know, I want to look at that INC to the P hit. So if you pee, it is abnormal. So it's us to don't think or it's alcoholic. You. Then when you look at the PS psi or two and see if the PFC or two correlates to the P hitch. If the seal PS psi or two was absolutely normal, you can move on from this so spiritually acidosis might be caused by COPD, asthma or drugs on the cause. There is when the body has too much carbon dioxide, it combines with water to produce hedge to see or three, which is carbonic acid, which is what causes the page to become acidotic some causes of respiratory. Other below HSAs are anxiety hypoventilation on in CNS trauma, and in that case there's less SSI or two. So there's less water forward to combine with. So there's less carb onek asset, so we'll move on to hit, see or three minus. So you've looked at the pa or tea. You've looked at the T A. C or two on. Do you determine if the person's have a spirit? You fairly or not? If they're looked at the P hitch on, Do you have looked at the PS psi or two again to see if there is a respiratory cause off the patients disturbance? If the PFC or two is normal, you may want to move down to here to see or three to see if there's a metabolic cause off the patient's pH disturbance, and I apologize. This table hasn't came up on the screen, and sure, you were copy of it and a little bit in a little bit. So if they're here to see or three is normal, you can again revolt. But then, if it's not normal, you need a work out. What's going on. So causes of metabolic acidosis, maybe sepsis, daycare or metaform and poisoning with causes of metabolic alkalosis might be vomiting Christians, disease or even diarrex to further investigate what was causing metabolic acidosis. You can work out that and I got, and this allows you to determine the presence of one measured and I owns in the blood. So you do Saudi impulse potassium. Take away. All right, proceed, see, or three minus in. The normal value is 4 to 12. If you got a high and I am got so above 12, that's due to increased acid production or ingestion. So that would be in things such as DKA in diabetes or lactic acidosis, whereas if you've got a lower, annoying gonna so less than four that would be due to decrease acid secretion or loss of here to see or three. And that would be things such as diarrhea, Addison's disease or renal tubular acidosis. You don't necessarily always have to do the an eye on back, but if your little bit unsure what school going on, it could be agreeing were to just lower your differentials a little bit further and try and work out what's going on with the patient. So compensation. The body always wants to keep that a sequel. Embrey, Um, and wants to always stay within them. PH values that 7.35 and 7.45, which is sort of the Golden Range where everything is working really well. So therefore it tries to adapt incompetence it in order to counter act what's going wrong. So if it's a respiratory problem, that metabolic system will try and compensate. If it's a metabolic problem with the spirit, your system will try and compensate it. So the metabolic system in the nutrivit is quite slow to compensate where, as the respiratory system is a lot, lot quicker, you can speed up, be breathing a lot together, and you can speed up your bodily processes. In people who have COPD, they constantly have a high see or two, then people without COPD. And that's because they use that to drive there scrutiny system and therefore they always have a little bit of metabolic compensation. So that hit, see or three minus will always be a little bit above normal. Because that's just there where the body works to compensate, having increased seal to all of the time, just the quick word on base excess. This access is another value that you get given on a BG's, and it's a bit of a sudden go to for hitch see or three miners so high THC or three minus call. It's too high this excess on a low hit 03 correlates to a low base excess. And they're just another thing that you have a look at the A BJ to try and work out what's going on. There is a thing called mixed acidosis and alkalosis, which I know sounds very odd because of just been telling you for quite a while that something is a there acidotic or alcoholic. But the issue conditions where there is a mixed picture so mix acidosis might be in something like, um, I normally organ failure. If somebody's renal failure than the one in the spirit you failure kid and liver failure all at once, they might get a very mixed picture and mixed up the losses. Courses might be student thing because, like Hebert, amorous gravity, um, and people that are pregnant so you can definitely get it. So now we just moved on. To some cases, I know we discussed how to interpret in a BG, but it never is that you just get given an ABG in isolation. That every cheese always get given on always corresponds to a patient case. So it's always best to find out little bit more about the patient. Find out what's going on with, um what they brought a horse for what? The being taking? Because this could really aids your interpretation off a BJ. So if you have a lot of weight of the case, I haven't read of the air BJ. I give you a few minutes and if you work for the different steps, So if you look at the p 02 on the pier, see or two, find out if there's any respiratory problems. Move on to look at the pH than the PS psi or two. It's two or three and this access and see if you can work out. What's going on do is give you a few minutes to do that. Okay, Perfect. So we'll try and work through it now. So reading the history we've got quite a young lady who is presented to any unconscious little is known about her on examination is multiple ulcers seen, and she's called sweet smelling breath. So I'm already starting to get a few ideas what this could be, but we'll move on. So appear or two is 12, which is absolutely normal. So that's which is not in any respiratory failure or anything like that. So it moved to the pH. The pee it is law. So it's acidotic. So then we want to look at this, See, or to the C or two is normal, maybe on the lower side of normal, but still normal boundaries. So then we want to move to the hitch, see, or three, which is 19, which is law. And then we can confirm that by looking at the base excess, which is minus four, which is also law. So from that we've got a low pH, a low hit 03 and a low base access so we can formulate that this lady is in metabolic acidosis with no compensation from the C or two to them. Uh, start to think what are the possible causes off metabolic acidosis on what could be going on with this lady. So the sepsis, which is one option, she just say that you're has ulcers on on our limbs. So it might be that that holds is infected. And then she's got sepsis from that, and it could be that much is taken some medication and has some poisoning, the main one that causes metabolic acidosis is metformin, and there's no mention that you has type two diabetes or anything like that. But we don't know a drug history. However, The main thing that is leading me to think and DKA as the cause of this lady's metabolic acidosis and daycare is diabetic. He toe acidosis is the fact that the lady's got this sweet smell and breath, which is the key tone breath that you often get in and take a. The lady also has these old says, which could correspond Teo Type one diabetes that isn't that well controlled. So the answer for this one is metabolic acidosis. Do toe diabetic Keto acidosis, so we'll move on. The next one is a gentleman, Mr Smith. He's a little bit older, it evil, and he's been admitted to hospital on. Well, yes, a social history of working in the minds. Many Yes, on examination, he's got the low body weight and yellow still into his hands. He's every genes given below. So if again, if you work through it the same day before you want to look at these pa or two, then it's PSCD or two, then you work with the Ph seat is any disturbance work for the PS psi or two you'd see or three and the best excess and see if you lick it all together and find out what's going on. I give you a few minutes for that. So we're getting lots of Lantus coming through. Suggesting compensated. Respiratory acidosis is losis that there's this comfortable. It is a bit of a debate in the comments. Okay, thank you, but I wouldn't go to it. So this gentleman's a little bit older. That's the first thing not, and he's unwell. It's a social history of been in the minds. So the first thing I'm thinking now is has he got some respiratory condition going on? You saying about the law? Body weight on a yellow standing to his hands to the yellow stain. And the smell is thing that is a smoker is a tar scaling something like that. So we're going to look at his A B J. So is Pier or two is 80 and that's on four ladies. So four leaders you would normally get ideal oxygen saturation of 36% so 36 take away. The 10 would be 26 so it might be that this gentleman is one desaturated a little bit, but he might be gentlemen who sat with a little bit lower because he is a stable to be Tina. So then we're gonna look at the page. PH is slightly acidotic, but it's it's very close to being normal to them. Look at the C or two, which is a little bit high. And then we'll come down to the hits. Your three, which is again a little bit high on the basic basic access agrees with that. So, yes, it could be that this gentleman has respiratory acidosis with metabolic compensation on what was leaving us. To think that there is something going on is that this gentleman is required in the oxygen on that is coming in on. Well, it might be that this these figures are very similar to his baseline, considering that it sounds like he has an underlying diagnosis of some spiritually conditions. But the fact that is he is unwell is latest. To think that he is off, he is unwell and needs some support. Is that all right? Is there any questions with the gods up? Well, we'll move on to the next one. There's just one question that comes up skiing. If if it's know if the pediatrician within normal range, then can we say that this is a fully compensated acidosis? No. So you can see it's fully common said. That's exactly right. You would say that it was partially that's federal depression. The president. Perfect. So we'll just move on to the last case. So the last case is a young gentleman who's gay and be admitting admitted to shortness of breath. No person that I got a history of knowledge normally very fitting well on examination, is very tall and stature with Long Layton's. So it's a B J has his follows. So if you start again by looking at the or two, then looking at the CO2 saying, If there's any spirit, e failure, see what's going on, then look at his pH you see or two. And he's here to see or three and see if we can piece together what's going on with you a minute. So So there seems to be a bit of a consensus in the comments suggesting acute respiratory alkalosis with no compensation. Yeah, okay, so let's look good. She's a young gentleman, shortness of breath. It's got tall stature, long limbs, not really giving us a lot of information. There might be significant, we're not sure yet. So yet. That's exactly why it's pa looking for. Start with his PA or two. It's 32 on four leaders. So normally on four liters is again. You will be 36%. Take 10 away you'd be even for about 26%. So might be that this gentleman is actually being over saturated. Might try to turn his oxygen down a little bit. It might be a better on three liters. Might be of manage on truly this. So then we want to look at his See is P hit 7.48. So this gentleman is are allergic like is the same is seen Your two is down on his hits The or three is I'm banging middle Really? On his This excess is absolutely normal. So yes, that's exactly right Spiritually alkalosis on what I was going for with this case presentation waas that just gentlemen M could have something like Marfan's disease on the Marfan's disease is called something like a pneumothorax And that's why he's got his respiratory alkalosis. They have a hard one to put together, but that's what I was going with that. So that's the end of the case presentations. So more than happy to answer any questions anybody has or have any comments is anybody's hurt? Anybody taken any ABG is themselves that the firm quite tricky. Has anybody seen any extremes on a BJ's that would like to tell us about anything like that? So there's been one question that's coming through from early now, asking if you could just go over the, you know, calculating what Pa or two you'd expect? Yeah, when, When, when they're on some sort of off oxygen therapy, just just regular. How much for you to use? Expect it to be on the blood. Guess Yes, soldiers school, back side. So on a normal individual who hasn't got any response she dysfunction on, it's just breathing room air. You'd expect their PA or two to be over 10, and if it's under 10, that's when there's a problem. But then some people needs help with mental in their oxygen saturations so the might get put on one of these devices said. Maybe in ears, a cannula, face mask or Venturi on. If you get given one of these well, obviously increasing the amount of oxygen that the person is being given and you've given them a high amount of oxygen that's just in normal room. So then, when you're doing the collision, you'd expect that p it or to to be 10, to be 10 less than what they're being given. So if somebody is having acnes a cannula in place, which is a really full leaders that suggest that amount of oxygen they're going to be getting is 36% and therefore you expect that P it or two on an ABG to be 26 if it was higher than 26 again, all the oxygen it it efforts the law 26 the knock it and love oxygen. Obviously, 36 is like the suggested what the person using that, If I should get what it depends on the person some spiritually, it how tight the masters and how big the gratz that are. The person's taken thanks and uh, no, I think that was a really good explanation, Actually, um, there's another question with regards to the last case. Why, Ah, lot of people actually got that. It was more funds, which was really good somewhere. Yeah, someone just asking why more funds would result in that. So Marfan's is a connective tissue disease. A local way, I think about it, is that tape with Marfan's just have extra stretchy skin. So Marfan's and earliest Alice that just have extra sketches game with extra long arms. The very tall on, because is that they just pull toward you, have spontaneous pneumothorax, is so it might be that you just take two big, deep breath. Or that the coughing on that the list off their loans just come apart. The noticed A. Because the overly stretched and that's what causes them to have a pneumothorax, not by any means in that everybody with Marfan's disease will have a pneumothorax. It's just the more likely in that disease, and I thought it might be a nice link for the case, you know, perfect. I think that's a really good way to remember. Actually stretch your limbs and making it more is making them more at risk. There's another question, um on, uh um, does hyperventilation lead to a respiratory alkalosis. Yes. If I eventally eating your body is not working the bodies. Cons. It's not. It's a hard expect if you had eventually. And you know there isn't as much CO2 in your blood because you're, like, breathing so quickly and that causes those less see or to to combine with the water. And that causes you to record alcoholic that because you just breathe in so quickly. Yeah. No, exactly. It's the case that your breathing so quickly that you're getting rid of a lot of common look at Is that right? Yeah. Yeah. Perfect. Um, another question. I mean, I'm not sure if you if you know, White the, uh, numbers and things here, but one was Why do you take 10 away from, um, the the amount of leaders being given to calculate the PA or two for you? I apologize. I don't know. And and that's just a figure that all thought medical professionals seem to use. Whether in any on the ward's anywhere, it's just sort of a ballpark figure that people use. Yeah, and I I think that's fine. And, uh, when would you do a VBG rather than an ABG. So if you were worried that somebody was unwell, but you weren't necessarily thinking that it was a respiratory course, you might want to take a VBG because you still get all the information on it, too, with regards elected electrolyte and values. But you just don't get the values with regards or two, so you still would get a here to see or three on your VBG. So if you're worried about person, that's on well, but you don't think it's necessarily respiratory. The material in the sat on the OBS machine they've started quite high over. So 90 for 98 on Idiot and to and COPD and you think it's not really something respiratory. Then you might just want to get a VBG to see what's going on. In addition, and the beaches could be done while taking other bloods. So if you're taking a full blood count using knees a quack anywhere, you might want to take a VBG because you get there is a lot quicker than you do the other blood test that can give you a quick indication of what's going on and try and start your management off from there But if there's any concern with regards hospira tree distress or dismiss Pootie feeling anything like that, you want to get me a BG? Yeah, I know. Exactly. I think that's right. And the other thing would you say, I know that when you're worried about the oxygenation you doing on a BG because it's our tier. Your blood that's leaving the heart hasn't quite been used by the organ yet. Whereas if you get a VBG, which is from the venous blood, the oxygenation will be a lot lower. Because that that that's been used by the organ now. Yes, that's exactly right. You wouldn't be able to interpret, appear or two from a venous blood gas. Yeah, no, exactly. And I think one of the thing on a Danish you to agree. But VBG and ABG, they're both really good for Ph. And you know, I mean, I was eating something of the day, and one of the consultants told me that the pH difference between VP's and ABG is actually only about no point in your five and yeah, yeah, that's exactly right. Mm. Very similar. Yeah. Um, someone's mentioned. Can you talk a little bit about active. Would you? Have you got any key points about the lactate and, uh, and is about you Get on a VBG or you get on an ABG. You can also just send a blood ball off elected itself. If you wanted to do that on blocked, it is quite non specific, but it can be an indication that something is going wrong. So if somebody has a high lactate, do you know that something going wrong in the body or something has just gone wrong? So, like that is being cell death? The person's just had a seizure, so lactate it come the a good measurement. Teo. Either reassure you or concern you, so if you get someone's lucked it on, it's quite law on. You could be quite happy that this patient sort of walk here is a little bit more stable, whereas if you take get a lack of value that high. So I think the number is over to to get some ones and value that is higher than two. That's when you need to start worrying what's going on. Is it something intraabdominally that's going on? Has the person had, like a cardiac event? It's it's something like a k A. Anything like that conveys you active. So it is great, but just quite non specific here. Perfect. Thank you, Andre. Another question. Can you explain the idea of basics s? And when you would look at that when, like me, that might be clinically useful. Yeah. So basic cess, for all intentional purposes is just the surrogate for here to see or three on. Some people just look at the base access instead of looking ahead, See, or three. I know. When I first started learning right ages, we got a whole to look at this access instead of the m P H C or three minutes. I know I just find it easier to look at the head, say, or three, but it's honestly that up to you which one you want to look at some. I'm saying that based excessive jewelry off. This is definitely right, doesn't And because the values are a smaller range, it doesn't move as much. So for somebody, somebody who is in metabolic acidosis, the base excess value might not have changed as much as the head. So your three minus house does that make sense. But that makes sense. Yeah, that makes sense to me, if any. If anything, not clear, then they can pop it on the comments. Anyway. Um, Anything else? No. No, really. I mean, someone's asked, um, and a pa Oh, two off 26 on a BG. Would that be close to over a surgeon? A shin on and 20 year or 2. 26. But I think it would depend on the situation. And it is the person on oxygen or just a room at I mean, I guess that must be Yeah. I think it will be quite high if they were just on room air, but then 20 six. It would just depend what device that were used in. Really? Uh, yeah. No, I would agree. Sorry if they want to give us more information more than happy to help them a little bit further. No. No, I think that's perfectly right. It depends on the oxygenation. That there. That there on, I think. I think that's about that. Uh, thank you so much. I was really, really useful Lecture. Yeah. And guys, if you would like to give us any feedback, that would be absolutely fantastic in just scar milky. Well, cord or use the link. That'd be great. Thank you. And please get in touch with this anymore questions and try and answer them as best we can.