Transcript for:
Solving Arterial Blood Gas (ABG) Problems with Tic-Tac-Toe and Row Method

there are different methods you can use the solve arterial blood gas problems and in this video I'm going to show you the Tic-tac-toe and the row method to do that first let me demonstrate the row method so what are we looking for whenever we're solving these ABG problems well we're looking for a potential acid base imbalance and for exams they're going to give you three things and you're going to have to look at the value of those things and determine what is going on with the patient so they're going to give you the blood pH level along with the carbon dioxide level which is represented as CO2 and the bicarb level which is represented as hco3 and you want to remember that CO2 carbon dioxide represents the respiratory system and bicarb hco3 represents the metabolic system and what's really cool about our body is when this Blood pH decreases too much where we have acidosis or it increases too much where we have alkalosis these two systems the rest story metabolic system will try to balance that blood pH to get it back to normal so whenever you are solving these arterial blood gas problems there are three things that you want to ask yourself along with applying the method that you are using to help you solve these problems so the first question you want to ask yourself is this a respiratory or metabolic problem second you want to ask yourself do we have acidosis or do we have alkalosis and then third you want to ask yourself do we have compensation you're either going to have no compensation where it would be uncompensated or you're going to have partial compensation or you're going to have full compensation and I want to show you how to solve those problems with all three different scenarios so before you even try to solve an arterial blood gas problem you have to have this table committed to memory because you're going to pull from your memory bank these values and apply it to whatever method you're using to solve that ABG problem so let's quickly go over this table pH a normal blood pH is 7.35 to 7.45 anything less than 7.35 is considered acidotic anything greater than 7.45 is considered alkalotic then carbon dioxide CO2 a normal level is 35 to 45. anything greater than 45 is acidotic and anything less than 35 is alkalotic then we have hco3 a normal level a bicarb is 22 to 26 and anything less than 22 is acidotic and anything greater than 26 is alkalotic now let's look at the acronym Rome R stands for Respiratory o for opposite M for metabolic and E for equal and I like to keep the r and the O together in the m and the E together to help me keep my information separated so one the world does respiratory opposite mean well what value represented respiratory that was our carbon dioxide level or CO2 so whenever your carbon dioxide level is high and your blood pH is low hence the opposite it's respiratory acidosis when your CO2 level is low but your blood pH is high again they're opposite it's respiratory alkalosis now what does metabolic and equal mean well metabolic was represented with bicarb hco3 so whenever your hco3 is low and your blood pH is low hence they're equal because they're both low it's metabolic acidosis when your bicarb is high and your blood pH is high they're equal because they're both high it's metabolic alkalosis so now let's take this method and work some problems so our problem tells us that we have a blood pH of 7.28 a carbon dioxide level of 50 and a bicarb level of 24. and I went ahead and set up a problem and I wrote out Rome r-o-n-e remember that's respiratory opposite metabolic equal and then I have our blood pH over there so our blood pH and normal level is 7.35 to 7.45 we're at 7.28 so we're on the low side and it's abnormal and it's considered acidotic so I'm going to put a down arrow over here a blood pH and just write acid to let myself remember that the respiratory system which is represented with CO2 or carbon dioxide level and it's 50. a normal carbon dioxide level it's about 35 to 45 and we're on the high side of this so we're going to put it's elevated and anything greater than 45 is considered acidotic so we're going to write acid over there then we're going to look at our bicarb level and that's represented with the m of our acronym metabolic and it's 24. a normal level is 22 to 26. so we're actually normal with our metabolic level now let's apply Rome we have opposite going on our respiratory system is high pH is low so according to Rome we have respiratory acidosis so I'm going to write that out respiratory acidosis so we've answered our first two questions we figured out that we have a respiratory problem and we figured out that we have acidosis going on but our third thing we need to figure out is do we have compensation and this is where you have to look further at your problem depending on whatever method you're using you have to dive a little bit deeper with it so first we'll ask ourselves do we have compensation going on at all well whenever you have compensation going on full compensation that means the body has fully compensated it's corrected itself our blood pH should be normal it is not normal so whenever you're solving these problems and you see a normal blood pH level you should be thinking full compensation but we don't have that so we can rule that out now do we have partial compensation going on maybe or are we completely uncompensated for so partial compensation would be another system that is trying to balance it out for instance we have a respiratory problem we've determined that well if we had partial compensation our metabolic system should be abnormal because it should be trying to throw itself into like an alkalotic state so we can bring this actually increase this Blood pH back because remember they're trying to balance each other out like how I talked about at the beginning we don't even have that our metabolic system is still normal it's just hanging out and it's like hey what's going on nothing's really going on so I'm not going to be doing anything it doesn't really know to compensate yet so we have no compensation going on so this is respiratory acidosis uncompensated our next problem says that our blood pH is 7.30 our carbon dioxide level is 40 and our bicarb level is 18. so let's analyze blood pH normal again what was it 7.35 to 7.45 we're at 7.30 so we're on the low side specifically acid saw our respiratory system which is represented with carbon dioxide so we're going to put it up here is 40. normal level is 35 to 45. so we're actually normal here and our bicarb is 18. again a normal is 22 to 26 so we're on the low side for our bicarbon that was represented the metabolic system so we're low for that and we're on the acidotic side so with using Rome we see we have an equal metabolic is low ph is low so we have metabolic acidosis so we've answered our first two questions now the third question do we have any compensation going on is our blood pH normal no so we're not fully compensated but are we partially compensated so our system that should be helping balance this out because we already have a metabolic problem should be a respiratory system and a respiratory system right now is normal so it's not trying to make itself abnormal to help balance this acidotic Blood pH out so we don't have any compensation going on so we have metabolic acidosis uncompensated our next problem says that our blood pH is 7.42 our CO2 or carbon dioxide level is 26 and our bicarb is 18. so let's look at our blood pH normal levels 7.35 to 7.45 we're at 7.42 so we're normal so right now if you're thinking about compensation you should be thinking ah I bet we have full compensation I bet you're right but we've got to determine is this a respiratory problem or metabolic problem so whenever we're looking at this Blood pH we're normal but what side of normal are we on are we on the acid oxide normal or the alkalotic side normal and to help you do that remember that the absolute normal blood pH is 7.40 so anything greater than that would be on the alkalotic side of normal and anything less than that would be on the acidotic side so we're at 7.42 so we're on the alkalotic side so we're just going to put it's elevated and just put alkalotic to help us remember that now let's look at respiratory those represented in carbon dioxide and we are at 26 a normal level is 35 to 45 so we are on the low side so we're going to put low and it's alkalotic so put that there and then our metabolic is 18 normal is bicarb is 22 to 26. so we are on the low side so we're going to put low and we are on the acidotic side because it's less than 22. so using the row method we look at our blood pH which is elevated we're looking at a respiratory metabolic system we have opposites going on because metabolic isn't what isn't low and the pH isn't low so they're not equal so we definitely have a respiratory problem going on specifically we have respiratory alkalosis and we already know our third answer to our third question we have full compensation going on because our blood pH is normal our body has thrown the metabolic system out of normal levels to help balance that blood pH and help get it back to normal so we have respiratory alkalosis fully compensated the next problem says our blood pH is 7.37 our carbon dioxide level is 32 and our bicarb is 17. so let's look at our blood pH normal level is 7.35 to 7.45 we're at 7.37 so we're normal and again if you're thinking about compensation that third question oh we have full compensation going on but we got to figure out the other two questions is this metabolic a respiratory is this alkalosis or acidosis so with our blood pH it's normal but what side of normal is it on absolute normal is 7.40 so it's 7.37 so it's lower than that so we're on the acidotic side of normal so we are low and we're just going to put acid to help us remember okay respiratory um normal carbon dioxide is 35 to 45 we're at 32 so we are low and we're on the alkalotic side so we're going to put alkalotic here our bicarb is 17 normal is 22 to 26. we are low so we are going to put low on the metabolic part of our acronym and what side of low are we on we're on the acidotic side so we're just going to write acid here Now using the row method when we look at our pH which is on the low side and we look at our metabolic it's also low so they're equal so this is where we're at we have metabolic acidosis and we are fully compensated our blood pH is back to normal but our respiratory system because remember these two systems balance each other out also when abnormal on the alkalotic side to help balance those acidology conditions we are having so we are now fully compensated our next problem says that the blood pH is 7.51 carbon dioxide is 47 and our bicarb is 32. so let's analyze the blood pH normal blood pH is 7.35 to 7.45 so we are elevated because we're at 7.51 so it's increase and it's alkalotic hey our respiratory system which is represented with carbon dioxide is 47. normal carbon dioxide level is about 35 to 45 so we are on the high end so we are elevated and it's acidotic and our bicarb which represents the metabolic is at 32. normal bicarb is 22 to 26 so we are elevated and we are elevated on the side of alkalosis okay and using the row method we see that we have something that's equal we have metabolics elevated pH is elevated according to our row method that would make it metabolic alkalosis so we're going to write that now we have to answer that third question do we have compensation and if so are we uncompensated or are we partially compensated fully well let's look at the blood pH it is abnormal so we know we don't have full compensation so we can write that off now do we have partial compensated station or are we uncompensated well let's look pH is abnormal but we have a metabolic problem so is a respiratory system trying to help out did it go abnormal to try to correct our blood pH and it did but it hasn't achieved the results that we need yet because our blood pH isn't normal yet so it's trying to compensate so we have partial compensation now it would be uncompensated if this respiratory system its value the carbon dioxide is still normal because it's not really trying to compensate to help us correct this metabolic alkalosis now let me demonstrate the tic-tac-toe method okay the first problem I want to go over is something where we don't have any compensation going on and then we're going to add on partial compensation full compensation and you can see how these values are changing and how we're getting our answers using the tic-tac-toe method and looking at those normal values that we've commit to memory so our problem is our pH is 7.22 our paco2 is 49 and our bicarb is 24. so we have our tic-tac-toe set up and we have acid over here normal over here alkalotic here if you're not familiar with that how to do the tic-tac-toe method I'm going to show you okay so we're going to look at each of these values and we're going to put them in the column that they go and we're looking for a tick to attack toe and again as I said at the beginning of the lecture if we have some type of especially full compensation going on we're not going to get a tic-tac-toe because our pH will be normal okay so pH is 7.22 what's the normal value 7.35 to 7.45 so it's less than 7.35 so we know it's acidotic so we're going to put our pH here our paco2 which represents the respiratory system is 49. normal paco2 is 35 to 45 since it's 49 it's greater than 45 it's on the acidotic side so we're going to put it over here oh we have a tic-tac-toe right here but we're not done yet let's mess with our bicarb our bicarb is 24. what's a normal bicarb 22 to 26. this is normal it's falling with a normal range so we'll put that here well looking at this we know that we have acidosis going on and we have respiratory acidosis because paco2 represents respiratory so we have respiratory acidosis now do we have compensation going on that's the next thing you ask yourself and the answer is no and how do I know that we don't have compensation going on well our blood pH is abnormal still it hasn't been corrected it's not Fallen within its normal range and the system that helps balance everything out either the respiratory or the metabolic system it's still normal our bicarb isn't trying to throw itself in an abnormal range to help combat this acidotic so it could if it was going to compensate it would start increasing itself to make things a little bit more alkalotic but it's not doing that so this is uncompensated so we have respiratory acidosis uncompensated now let's look at that same problem again but let's change the value let's change our bicarb instead of being 24 let's make it 28. so we know that we still have respiratory acidosis going on because our blood pH is low and our paco2 is high putting it on the acidotic side however our bicarb now is not normal it's 28 so it is greater than 26 so it's on the alkalotic side so we'll put it over here now next thing we want to ask ourselves do we have compensation going on yes we do now is it full compensation or partial compensation it is partial compensation how do I know that well it would be only full compensation if our blood pH was normal once that blood pH is normal either the respiratory or the metabolic system has helped balance that blood pH out and got it normal however it's not normal here it's still normal so it's partially compensated we have the metabolic system trying to increase our bicarb to help balance out these acidotic conditions because by trying to make it more basic the blood will hopefully push that blood pH a little bit higher to make it normal so we have respiratory acidosis that is partially compensated now let's look at our next problem okay our blood pH is 7.42 our paco2 is 32 and our bicarb is 18. so what we're going to do is we're going to plug it into our tic-tac-toe so our blood pH what's a normal blood pH 7.35 to 7.45 and this Falls within normal range so our pH is normal now right now you should be thinking compensation full compensation because we have got our blood pH back to normal but let's look at those other values okay pco2 which represents the respiratory system is 32. normal range is 35 to 45 it's on that low side so it's alkalotic so we'll put it under here and our bicarb is 18. normal bicarb is 22 to 26 it's less than 22 so it's on the acidotic side now this is when you've set up your Tic-tac-toe and you look and you're like I don't have a tic-tac-toe but we know that we have full compensation going on because our blood pH is back to normal however we have to determine is this respiratory or metabolic problem and to help us do that we have to further look at this Blood pH so even though our blood pH is within range it's 7.42 what side of the spectrum is it falling on is it on that acidotic side or is it on the alkalotic side and it falls on the alkalotic side so what's happened is that our bicarb has decreased and it's trying to make things a little bit more acidic in that blood to bring that high alkalotic blood back down so our bicarb is out of whack because it's been trying to do that and it's achieved it because we have full compensation but it's still a little bit that blood pH on the alkalotic side and it's originated from a respiratory issue so it's respiratory alkalosis with full compensation now let's look at our next problem our blood pH is 7.37 our paco2 is 33 and our bicarb is 17. so let's plug it in our pH Falls within normal range it falls within 7.35 to 7.45 so we'll be put it here and you should already be thinking oh compensation our pH is normal we probably have full compensation but let's look at our other values our paco2 is 33. normal is 35 to 45 it falls less than 35 so it's on the alkalotic side so put it here and again that represents the respiratory system and their bicarb is 17. so it's less than 22 so it's on the acidotic side and bicarb again represented the metabolic part so we see that we have full compensation going on we don't have a tic-tac-toe so we had to look further at our blood pH and it's normal so we have full compensation but is this respiratory or metabolic so we have to look at blood pH closely a normal blood pH the absolute normal is 7.40 ours is 7.37 so it's on the acidotic side so we have metabolic acidosis going on that is fully compensated and how it got fully compensated is because that respiratory system tried to decrease the carbon dioxide and whenever it does that it's making things more alkalotic to help push that blood pH higher into that normal range than it did but it's still on the acidotic side but it finally got it to normal and achieved what it was supposed to do now let's say that this was 7.27 instead so that changes things a little bit here our blood pH is now 7.27 so it's not normal anymore it's fell less than 7.35 so it's on the acidotic side so let's move it over here now this has changed things a little bit do we have full compensation going on anymore nope we have partial compensation and I want you to see that because we have our tic-tac-toe so we have metabolic acidosis and we have partial compensation the paco2 has taken itself out of normal range to make things more alkalotic but it hasn't corrected it yet by making that blood pH become normal so this would be metabolic acidosis partially compensated okay so that wraps up this compilation on how to solve abgs using these two methods and if you'd like more practice you can access the quiz in the YouTube description below