what's up future respiratory therapist coming at you again with an updated version of the non-invasive ventilation presentation talking all about bipap and cpap you don't want to miss it let's dive all right so there are some key elements that you need to understand when you were talking about bipap versus cpap both of them are non-invasive positive pressure ventilation devices now they don't both ventilate and that's a key difference so let's jump in and talk about the difference when we say non-invasive ventilation we're saying niv that's the acronym that niv stands for now you can take it a step further and you can say non-invasive positive pressure ventilation that would be acronymed or short-handed to in ppv now from there we can go into bipap versus cpap and what it all comes down to is what do you need to do for your patient do you need a focus on ventilation or oxygenation or perhaps both so let's jump in and see what the two differences between bipap and cpap are so when it comes to bipap bipap stands for bi-level positive airway pressure that's what it is now the word by means two which is exactly what bipap is there are two pressure settings in this mode there is an ipap and there is an epap the ipap stands for inspiratory positive airway pressure epap stands for expiratory positive airway pressure now this is important because when you understand how the inspiratory pressure and the expiratory pressure or the ipap in the epap relate to each other and what happens with this change in pressure then you understand that bipap aids in ventilation as well as oxygenation so we're going to show you how here in just a few minutes now when we look at cpap cpap stands for continuous positive airway pressure it's only one pressure setting okay one pressure that we call cpap and it is a continuous baseline pressure now the thing to remember about cpap is that it aids in oxygenation only keyword there only so if you ever have a patient who is having trouble with ventilation what is ventilation ventilation is the removal of co2 oxygenation is adequate oxygenation or the bringing in of oxygen so if you have a patient with ventilation problems then we're going to consider bipap if you have a patient with a pure or strictly oxygenation problem then we're going to be thinking cpap now there's also situations where bipap also is indicated to help us with oxygenation so we'll talk a little bit about that as well to understand what these modes do let's look at these graphs right here okay so this is bipap and cpap i'm going to draw a line right here just so you can keep them separate the bipap center remember i told you has two settings it has an epap as well as an ipad now what happens here is this is baseline the patient takes a breath and the inspiratory pressure increases to ipap it holds during the duration of the breath and then on exhalation returns back to epap this is important because it is this pressure gradient between epap up to ipap that generates a pressure support and leads to the augmenting of spontaneous tidal volume a more effective alveolar title tidal volume and better removal of co2 so what i'm telling you is that the difference between epap and ipap and back down the epap this difference is called pressure support that's essentially what it is and when we think about pressure support we know what pressure support does it overcomes the resistance of the artificial airway and the tubing we're really not talking about an artificial airway when we talk about bipap so that one kind of goes to the wayside but the fact that pressure support still augments spontaneous tidal volume is very very important because we know by making this gradient larger then we can increase pressure support and increase tidal volume and therefore increase co2 removal and help us restore a normal ph balance okay so that's that's bypass on cpap you're looking at one pressure the patient takes the breath the diaphragm drops the the pressure waveform drops but then it comes back up to baseline this is what cpap looks like this little dip right here is the patient's spontaneous breath now you may be thinking yourself well why doesn't it look like up here where the pressure rises and that's because it doesn't work like that cpap doesn't have an inspiratory pressure it is one continuous baseline pressure that is is held and maintained to improve and increase the baseline for which title volume happens on right now if we think about this we could draw the old school box right we could draw this box right here and we could put tidal volume we could put erv we could put rv and we could put irv now if you think about this erv and rv these two equal frc frc is the baseline that title volume happens on top of that's the practical application of the volumes and capacity box and there's other things that we could draw from but for this conversation that's what it comes down to so when we think about cpap in regards to this then we understand that cpap impacts frc it raises the tidal volume by recruiting alveoli increasing frc and creating a more functional residual capacity for which tide of volume then happens on this will aid us in oxygenation by having more functional alveoli now when you see these terms you need to also understand that epap serves the same purpose as cpap so our expiratory positive airway pressure in bipap serves the same purpose as cpap in pure cpap it's going to increase frc and raise the baseline for which tidal volume happens upon now interesting about this is that once you get into mechanical ventilation you learn that this is the same concept as peep peep also increases frc and tidal volume happens on top of that so what i'm trying to tell you right now is that peep epap and cpap are all essentially the same thing they're just associated with different modes of mechanical ventilation that's the truth okay and that's what it is now let's talk about how this looks when we start trying to adjust these things to um to to fix arterial blood gases okay so so how do you how do you how do i know what to do when i have a blood gas do i do cpap do i do bipap what do i do well let's look at it all right so here's the blood gas you have a patient listed on a non-rebreather they have a ph of 7.39 a co2 of 41 and a po2 of 52. okay now we know this isn't a good blood gas right the ventilation aspect of it is spine though when we think ventilation we're looking at co2 in relationship to ph do we have a respiratory acidosis present and the answer is no we do not have a ventilation problem do we have an oxygenation problem the answer is yes 100 percent we have an oxygenation problem so in this case initiating a cpap of 8 to 12 might be sufficient to fix this po2 of 52. this person might be presenting with congestive heart failure and we just need to step open alveoli increase that frc and improve their oxygenation we can do that with eight to twelve of cpap leave them on a hundred percent titrate down from there that'll fix give them lasix fluid comes off we can titrate the cpap and the next thing we know we're back to a nasal cannula and the patient's dismissed from the hospital that's how this looks now how come i didn't think bipap in this situation well i didn't think bipap because there was no ventilation problem remember i told you cpap fixes oxygenation bypass fixes ventilation as well as oxygenation so would you could you have put this person on a bipap yes you could have okay i'm not going to say the answer of bypass is completely wrong you could have put them on bipap and perhaps if i would have given you more information such as this is the blood gas you have but your patient also presents with nasal flaring and intercostal retractions now you have an increased work of breathing to accompany your hypoxemia and now perhaps bipap would be appropriate because that inspiratory pressure would aid them in getting those better tidal volumes which could keep their co2 where it is reduce their work of breathing and improve their hypoxemia so that's scenario number one scenario number two let's look what this one says here we have a patient who's already on bypass 10 over 5 and 30 percent okay so let's say we already have a patient on bipap let's say we put that previous patient on bipap okay and and this is now the blood gas we have based off of these settings well now when you look at it the question is do we have a ventilation problem or an oxygenation problem what do we have well when we look at our co2 and our ph our bicarb is normal we have a high co2 and a decreased ph we have a ventilation problem 100 percent we're going to have to help this patient breathe easier take a larger more effective tidal volume more effective alveolar minute ventilation and get rid of more carbon dioxide do we have an oxygenation problem no not at all so when you think about this 10 over 5 this is ipap over epap remember epap functions like cpap and peep which we know aids in improving oxygenation but we don't need to improve oxygenation we're already adequately oxygenated so our epap is 100 sufficient so in this case what we need to do is we need to increase our ipad maybe we go to 15 over 5. now how does this help with ventilation goes back to what we started with the difference that we started with was 10 over 5 that's a pressure support of five we are now after increasing our ipap to 15 we have now increased our pressure support or our pressure gradient to 10 centimeters of water pressure and that rise in pressure gradient that rise in said pressure support is going to lead to a more effective tidal volume it will increase tidal volume and if you increase tidal volume then it increases alveolar tidal volume and it enhances and improves co2 removal which will help get the co2 down and the ph up okay so that's how we tackle this scenario now we might have a scenario here if we look at it we now have a patient who is on a bypass of 15 over 5 and 50 percent well what do we have going on here well do we have a ventilation problem the answer is no 7.36 i don't want to mark that out for you 7.36 with a co2 of 44. we do not have a ventilation problem here but look we do have an oxygenation problem so we are going to have to fix this patient's oxygenation now when you're on bipap you have to understand that the the the goal in fixing oxygenation if you remember is epap cpap peep all of those increase frc increase oxygenation so if we're on 15 over 5 then what we would want to do is we could increase the five to ten so we just increase our epap knowing that epap will improve oxygenation and that's all fine and dandy but look what happened when we did that look what happened our pressure support was 10 to start with and we were good after raising epap to 10 our pressure support now is only five which means we have cut down the pressure support that the patient was receiving to generate that tidal volume to keep that ventilation exactly where it is so don't be shocked if when this happens your ventilation becomes worsen your co2 goes higher and your ph goes down because we've affected the amount of pressure support and now tidal volume will decrease tidal volume goes down co2 goes up ph goes down well we're right on the cusp right now anyways so what we want to really do here is keep our pressure support the same from where we started from so we increased our epap by 5 to 10. to keep our pressure support at 10 we need to increase our ipap by the same amount so if we increased our epap to 10 then we would be better served by rising or raising our ipap to 20. this keeps us at a pressure support of at 10 as well so you see now our pressure support is 10 and it's still at 10 which means our ventilation will stay the same we've raised our e path to 10 which is going to help fix this pao2 of 59 and address our oxygenation problem one last scenario here patient is currently on a bypass 10 over 5 and 50 what are we going to do well do we have a ventilation problem the answer yes we do high co2 low ph 100 what about oxygenation problem yes we do we are hypoxemic what this is is an illustration an example of when you have an oxygenation and a ventilation problem now you have both problems existing so what do we need to do we know we're starting at 10 over 5. we know to address our ventilation problem we need to improve the gradient between our ipap and our epap or essentially increase our pressure support so what we can do here is we could increase ipath to 15. keep e-path the same when we do that our gradient right here is 5. we will increase our gradient to 10 increasing it to 10 will increase alveolar tidal volume improve co2 removal improve ph so this is good to address ventilation but we have done nothing to address oxygenation now there is a small chance that potentially if you fix the hypoventilation then you will fix the hypoxemia that might happen but let's say for this scenario that doesn't happen okay let's just say that we run another blood gas and we're still hypoxemic well now we're going to have to address the hypoxemia so we're going to go up on epap we're going to raise it to 10 we're going to keep our pressure support the same so we're also going to increase ipap to 20 we're going to go 20 over 10 where we start at 10 over 5 pressure support increased to fixed ventilation epap increase to fix oxygenation and that's the answer to this question one last thing before i leave you with this a lot of people say okay so ipap equals ventilation and epap equals oxygenation not true let me show you why let's say you have a patient on 15 over 10. you have another patient on 12 over five which of these patients has a higher ipad well clearly this patient right ipap is higher now if ipap is what drives ventilation then this patient would be removing more co2 because they have a higher ipad than they do epap but that isn't the case and that's not true in this scenario you see the difference goes back to what i've been talking about this entire video for at least the second half of it the what matters is the difference between the pressure support so if you look at option two here we have a pressure support of seven where option a has a pressure support of 5 this patient actually is receiving more villatory support this patient is receiving more support to aid in better ventilation removal of co2 and re-establishment of ph so it's not about ipap it's about the relationship between ipap and epap and that's the truth all day every day look i hope you found this video helpful if you did smash that like button leave me a ton of comments and by all means if you haven't already subscribed what are you waiting on all i do is bring a little bit of content that hopefully brings a whole lot of value to you and your role as a respiratory therapist and perhaps maybe as a respiratory therapy student aiding you in these concepts as you work through the insane rigor of rt school i thank you so much for watching appreciate you as always and as always i leave you with this don't ever ever forget average is easy so don't be it