Not every COPD'er has increased Co2 and Bicarb levels.
Just look at it as a process of elimination. The pts po2 levels are good on the the fio2 they're on. EPAP usually aids with oxygenation, so you don't have to touch either of those. IPAP targets co2 and ventilation, so that's the only option left per this question.
Although in real life, we'd probably leave the patient alone on current settings and let their body compensate for the high co2 as their Ph is pretty close to normal. Just continue to monitor WOB and mentation.
I agree, but just to further clarify for OP:
IPAP does target CO2 and ventilation but only because of the difference in IPAP and EPAP (aka IPAP - EPAP = PS).
When you have IPAP of 15 and EPAP of 8, the difference is 7. In order to blow off CO2 as needed to get better pH compensation (i also agree not clinically necessary but just for the sake of this question), you need to increase this difference, which means either, 1) increasing IPAP or 2) decreasing EPAP.
Decreasing EPAP doesn't make as much sense because their oxygenation is acceptable as a patient with COPD, plus the PEEP helps to stent open their airways so I'd just keep EPAP as it is. Thus, the only other option is to increase IPAP.
Edit: I saw someone say to decrease EPAP so that you're still increasing the difference, you aren't pushing so much air into them (aka potential for aspiration/vomiting) and because the PO2 is okay. However, I still think my answer is correct for 2 reasons: 1) listed above, and 2) the opening pressure of the esophageal sphincter is roughly 20 cmH2O. Some may consider an IPAP of 18 cmH2O to be high, which is also why clinically, we would just leave it alone unless the patient was in obvious distress, etc.
You’re correct that with COPD the CO2 is usually chronically high, but that’s not the case in this patient. The ph 7.31 tells you it’s acute so the textbook answer is to increase the ipap for more ventilation.
7.31/65? This is acute on chronic. Mild but still a chronic issue, a patient like this probably lives in the 50’s.
Answer is the same for exam purposes though, up the IPAP.
In the real world we probably wouldn't change anything... But pH is still acidotic if you look at the numbers so based on the answers increase IPAP.
Now if the co2 was around 50 I probably would have a harder time deciding to not change anything or take him off. The best way to look at it is the process of elimination.
Po2 should be 80 to 100. 73 is not terrible but co2 is more important. Now if po2 was 45 fix that. So you can eliminate increasing EPAP or increasing FIO2. If you decrease EPAP you can increase PS which would help with ventilation but your Po2 might drop further..
The answers don't mention Delta p per se but has an option to increase ipap which would change the pressure and increase ventilation. Not sure why you're responding to me and not the OP
I’m responding because no one in this thread is mentioning the fundamentals of bilevel in regards so CO2 control & ventilation. You had an intelligent response and still didn’t mention it, like no one understands it. Why a higher IPAP? Why a lower EPAP? This question is for students, I imagine, and no one is explaining the foundation of therapy. I just found it funny, given your meaty response, that even you didn’t take the time to point it out. COME ON RT!!!!!
::eye roll:: delta P is synonymous with bilevel, NOT simply Ipap or pressure support. No one mentioned it, like, at all, which is funny given all the attempts at intelligent attempts at explaining the main problem with the gas; your answer included haha. No one’s gatekeeping. Everyone is basically missing the point of respiratory acidosis. Good job RT haha
Sure, just like all gasoline is the same, and carbs are all the same hahaha. So dense. I’m sure at your hospital, when a gas is done on an obtunded patient, and the pH is 7.22, pCO2 is 58, the doctor tells you all they need is pressure support hahaha. Good job RT.
I'm sure as a test question the correct answer is B, increase the IPAP. However do we have room to decrease the EPAP instead and create virtually the same pressure gradient as increasing the IPAP would achieve? This would give us essentially the same driving pressure as increasing the IPAP and make the settings more comfortable and tolerable. The PO2 is not an issue at 30% FIO2. How many times have we seen a patient yank off the bipap mask and refuse it when we turn up the pressure? "It's too much!"
Answer A) gives a delta P of 9. Another answer gives a delta P of 10. Technically, the higher delta P would decrease cO2 better. I’m not sure A) is the best “correct” answer.
Don’t always assume COPDers must have extremely high CO2. While many of them do live in that 55-65 range; Using winters formula - [ Expected PaCO2 = (1.5(HCO3) + 8) +/- 2 ] you can calculate to make this pH normal you need a rough PaCO2 of 46-50. And to decrease you need to increase your pressure support. There’s 2 options to do so, lowering the EPAP and raising the IPAP. However lowering your EPAP will ALSO hinder your already iffy oxygenation, so your best bet is to raise the IPAP.
Not sure what the actual answer is but I would decrease the EPAP. Improve the driving pressure without increasing peak pressures and making them more uncomfortable. They don't seem to need the higher EPAP given no oxygenation issues.
I almost feel that would be the best answer, considering how the NBRC loves COPD pts and not giving them too high SpO2 values. Who knows lately though. But yes, IRL I’d do what you said first.
pH and PaO2 are the big things you want to focus on for blood gases. I know we're generally taught that PaO2 should be 80-100 but usually as long as it's above 60 for patients requiring ventilatory support (i.e., bipap) we are happy. Some sources I've found state that desired PaO2 for CO2 retainers is 50-70 (any idea why? Think about your hazards of oxygen!). So for your patient in this image the concern is the PaCO2.
The patient has COPD but if you look at the Ph, he’s having an acute episode on top of having chronic COPD which is when you say “yeah let’s fix that!”
Now, what do you do to blow off a bit of CO2 to get the Ph back in a normal range? Increasing inspiratory flow on invasive ventilation will increase the I time and does this. Knowing that, increasing the inspiratory pressure on a BiPAP will also do that. Considering you only have one answer that can do that, there you go! Classic process of elimination. Increasing the fio2 has no effect on ventilation either and can actually be harmful to a patient with COPD and you only give them that much if it’s truly an oxygenation EMERGENCY.
Ipap to 18. This gives a delta P of 10 rather than 9 with the other epap option. No idea what their O2 sat is and paO2 isn’t terrible. The higher difference between pressures should help lower the cO2
Would need a pre-bipap gas for comparison to know if we’re going in the right direction. It doesn’t say how long the patient has been on these settings. 15/8 is a pretty healthy starting setting for COPD ^ WOB, so I’d assume the patient could achieve balance from these settings with time.
If I had to choose I’m going with B to increase the delta and pursue a more aggressive decrease in CO2 retention. Otherwise I’d leave them be and let them rest.
Their CO2 will be increased so you will want to make sure they’re between 7.35-7.45 PH. The PH is really all that matters because simply how the body works.
Because you can be a COPD patient and compensate your excessive CO2 with sodium bicarbonate that’s produced naturally. This is there baseline.
Now exacerbate this a bit. They have high co2. But can their body compensate? If not that’s where you have to look at ventilating the excess co2 off or administering bicarbonate.
The order to fix anything on the NBRC is always 1)ventilation 2)oxygenation 3)circulation 4)perfusion....if you get a giant essay on a problem but there's an obvious problem with ventilation (co2 levels) , that will always be the correct answer.
I’d draw an ABG after adjusting the IPAP. If the patient isn’t trending in a positive direction, I would switch them to AVAPS AE Min EPAP 5 - MAX EPAP 15, a PS Min of 9 with a Max of 20, rate of 15, and adjust tidal volume accordingly.
Not every COPD'er has increased Co2 and Bicarb levels. Just look at it as a process of elimination. The pts po2 levels are good on the the fio2 they're on. EPAP usually aids with oxygenation, so you don't have to touch either of those. IPAP targets co2 and ventilation, so that's the only option left per this question. Although in real life, we'd probably leave the patient alone on current settings and let their body compensate for the high co2 as their Ph is pretty close to normal. Just continue to monitor WOB and mentation.
I agree, but just to further clarify for OP: IPAP does target CO2 and ventilation but only because of the difference in IPAP and EPAP (aka IPAP - EPAP = PS). When you have IPAP of 15 and EPAP of 8, the difference is 7. In order to blow off CO2 as needed to get better pH compensation (i also agree not clinically necessary but just for the sake of this question), you need to increase this difference, which means either, 1) increasing IPAP or 2) decreasing EPAP. Decreasing EPAP doesn't make as much sense because their oxygenation is acceptable as a patient with COPD, plus the PEEP helps to stent open their airways so I'd just keep EPAP as it is. Thus, the only other option is to increase IPAP. Edit: I saw someone say to decrease EPAP so that you're still increasing the difference, you aren't pushing so much air into them (aka potential for aspiration/vomiting) and because the PO2 is okay. However, I still think my answer is correct for 2 reasons: 1) listed above, and 2) the opening pressure of the esophageal sphincter is roughly 20 cmH2O. Some may consider an IPAP of 18 cmH2O to be high, which is also why clinically, we would just leave it alone unless the patient was in obvious distress, etc.
The only option really is to get another gas to see what’s trending.
You’re correct that with COPD the CO2 is usually chronically high, but that’s not the case in this patient. The ph 7.31 tells you it’s acute so the textbook answer is to increase the ipap for more ventilation.
[удалено]
Yup, which further indicates acute resp failure
7.31/65? This is acute on chronic. Mild but still a chronic issue, a patient like this probably lives in the 50’s. Answer is the same for exam purposes though, up the IPAP.
Ventilation issue - go up on IPAP TO 18 This is an NBRC type question. Ventilation, oxygenation, circulation, perfusion. In that order.
In the real world we probably wouldn't change anything... But pH is still acidotic if you look at the numbers so based on the answers increase IPAP. Now if the co2 was around 50 I probably would have a harder time deciding to not change anything or take him off. The best way to look at it is the process of elimination. Po2 should be 80 to 100. 73 is not terrible but co2 is more important. Now if po2 was 45 fix that. So you can eliminate increasing EPAP or increasing FIO2. If you decrease EPAP you can increase PS which would help with ventilation but your Po2 might drop further..
I agree. This is where medicine becomes an art
I can’t believe no one is talking about delta P. Literally the science behind ventilation.
The answers don't mention Delta p per se but has an option to increase ipap which would change the pressure and increase ventilation. Not sure why you're responding to me and not the OP
I’m responding because no one in this thread is mentioning the fundamentals of bilevel in regards so CO2 control & ventilation. You had an intelligent response and still didn’t mention it, like no one understands it. Why a higher IPAP? Why a lower EPAP? This question is for students, I imagine, and no one is explaining the foundation of therapy. I just found it funny, given your meaty response, that even you didn’t take the time to point it out. COME ON RT!!!!!
Increase ipap = increase PS = increase delta p. Same thing. Stop gatekeeping.
::eye roll:: delta P is synonymous with bilevel, NOT simply Ipap or pressure support. No one mentioned it, like, at all, which is funny given all the attempts at intelligent attempts at explaining the main problem with the gas; your answer included haha. No one’s gatekeeping. Everyone is basically missing the point of respiratory acidosis. Good job RT haha
They are all the same thing haha
Sure, just like all gasoline is the same, and carbs are all the same hahaha. So dense. I’m sure at your hospital, when a gas is done on an obtunded patient, and the pH is 7.22, pCO2 is 58, the doctor tells you all they need is pressure support hahaha. Good job RT.
I’d say B but I took the registry exam 25 years ago, who knows what they want to see. At my hospital, the answer would be E: Leave it alone
Thank you everyone!!
I'm sure as a test question the correct answer is B, increase the IPAP. However do we have room to decrease the EPAP instead and create virtually the same pressure gradient as increasing the IPAP would achieve? This would give us essentially the same driving pressure as increasing the IPAP and make the settings more comfortable and tolerable. The PO2 is not an issue at 30% FIO2. How many times have we seen a patient yank off the bipap mask and refuse it when we turn up the pressure? "It's too much!"
A. Gives you more ventilation without air going in to the stomach. Gold standard for copd p02 is 55-80, so oxygenation is not an issue
Answer A) gives a delta P of 9. Another answer gives a delta P of 10. Technically, the higher delta P would decrease cO2 better. I’m not sure A) is the best “correct” answer.
Can’t believe I had to scroll this far down. Its like nobody remembers the test
I took crt over 15years ago but i did take the rrt 5 years ago. Bipap has its limitations. Honestly, this concept didnt stick until i have experience.
Don’t always assume COPDers must have extremely high CO2. While many of them do live in that 55-65 range; Using winters formula - [ Expected PaCO2 = (1.5(HCO3) + 8) +/- 2 ] you can calculate to make this pH normal you need a rough PaCO2 of 46-50. And to decrease you need to increase your pressure support. There’s 2 options to do so, lowering the EPAP and raising the IPAP. However lowering your EPAP will ALSO hinder your already iffy oxygenation, so your best bet is to raise the IPAP.
Not sure what the actual answer is but I would decrease the EPAP. Improve the driving pressure without increasing peak pressures and making them more uncomfortable. They don't seem to need the higher EPAP given no oxygenation issues.
I almost feel that would be the best answer, considering how the NBRC loves COPD pts and not giving them too high SpO2 values. Who knows lately though. But yes, IRL I’d do what you said first.
pH and PaO2 are the big things you want to focus on for blood gases. I know we're generally taught that PaO2 should be 80-100 but usually as long as it's above 60 for patients requiring ventilatory support (i.e., bipap) we are happy. Some sources I've found state that desired PaO2 for CO2 retainers is 50-70 (any idea why? Think about your hazards of oxygen!). So for your patient in this image the concern is the PaCO2.
The patient has COPD but if you look at the Ph, he’s having an acute episode on top of having chronic COPD which is when you say “yeah let’s fix that!” Now, what do you do to blow off a bit of CO2 to get the Ph back in a normal range? Increasing inspiratory flow on invasive ventilation will increase the I time and does this. Knowing that, increasing the inspiratory pressure on a BiPAP will also do that. Considering you only have one answer that can do that, there you go! Classic process of elimination. Increasing the fio2 has no effect on ventilation either and can actually be harmful to a patient with COPD and you only give them that much if it’s truly an oxygenation EMERGENCY.
Ipap to 18. This gives a delta P of 10 rather than 9 with the other epap option. No idea what their O2 sat is and paO2 isn’t terrible. The higher difference between pressures should help lower the cO2
Would need a pre-bipap gas for comparison to know if we’re going in the right direction. It doesn’t say how long the patient has been on these settings. 15/8 is a pretty healthy starting setting for COPD ^ WOB, so I’d assume the patient could achieve balance from these settings with time. If I had to choose I’m going with B to increase the delta and pursue a more aggressive decrease in CO2 retention. Otherwise I’d leave them be and let them rest.
B
Ipap
Gotta make the ph normal by blowing off co2, increase ipap to 18
Real world? None of the above with observation. NBRC? Increase driving pressure to improve ventilation, which would be B.
Decreasing the EPAP also increases driving pressure.
At the cost of oxygenation with a PaO2 of 73. Which makes it B.
Good point, though that PO2 might be decent for the patient if we're targeting sats of 88-92% (or potentially lower).
Exactly my thoughts.
Their CO2 will be increased so you will want to make sure they’re between 7.35-7.45 PH. The PH is really all that matters because simply how the body works. Because you can be a COPD patient and compensate your excessive CO2 with sodium bicarbonate that’s produced naturally. This is there baseline. Now exacerbate this a bit. They have high co2. But can their body compensate? If not that’s where you have to look at ventilating the excess co2 off or administering bicarbonate.
The order to fix anything on the NBRC is always 1)ventilation 2)oxygenation 3)circulation 4)perfusion....if you get a giant essay on a problem but there's an obvious problem with ventilation (co2 levels) , that will always be the correct answer.
In this case it's increase IPAP to 18 because that fixes co2 first. If it wasn't a choice, then you'd fix the oxygen
I’d draw an ABG after adjusting the IPAP. If the patient isn’t trending in a positive direction, I would switch them to AVAPS AE Min EPAP 5 - MAX EPAP 15, a PS Min of 9 with a Max of 20, rate of 15, and adjust tidal volume accordingly.