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Pulse Ox?
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BeachMedic
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Either way I stand by my original statement!
Pulse oximetry is a lie! Sometimes.
That and I hate worrying about things like cold fingers, nail polish remover, calluses, and feces fingers.
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NomadicMedic
I know a guy who knows a guy.
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I think a pulse ox (with a good pleth), in conjunction with side stream ETCO2 will give you a pretty good indication of a Patients oxygenation and ventilatory status. I make it a habit to use both when there's any question.
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Nebraskas protocol is every patient should get Oxygen for difficulty breathing, regardless of pulse ox reading.
Pulse ox readings can read wrong for carbon monoxide posioning. So you are never 100% sure.
Are you under the assumption that all of your patients have CO toxicity?...
You have come to the right place, young one. Please, open your ears and allow us to pass our wisdom unto you
Nebraskas protocol is every patient should get Oxygen for difficulty breathing, regardless of pulse ox reading.
Pulse ox readings can read wrong for carbon monoxide posioning. So you are never 100% sure.
We titrate our O2 as much as possible. Especially chest pain.
Carbon monoxide, O2 for sure, wont get an accurate reading with a regular pulse ox.
DesertMedic66
Forum Troll
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Are you under the assumption that all of your patients have CO toxicity?...
You have come to the right place, young one. Please, open your ears and allow us to pass our wisdom unto you
All of my patients do seem to have CO poisoning...
It's not an either/or, they tell you about two completely different functions. Entirely possible to be hypoxic with perfect EtCO2 and give versa.
Plus if you know about alveolar status and cardiac output you'll realize that EtCO2 can be just as much of a lie.
:unsure:
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BeachMedic
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I know, "they tell you about two completely different functions."
If I had to choose one i'd still take EtCO2 (with waveform) over SpO2 every day of the week. Heck, I'd rather go without SpO2 all together and just go with skin signs and respiratory rate. I don't think pulse oximetry is the most useful tool in the world and I feel too many people are entirely too dependent on it. I use it but I've also had to make due without it plenty of times. Sometimes for the reasons I've stated above, and other times because it seems like pulse ox extensions break and decide to stop reading fairly frequently.
You win the one up contest though. I owe you a super mario t-shirt. I don't know how alveolar status and cardiac output affect EtCO2 readings(causing false positives). Aside from being a useful tool for measuring the quality of CPR and jumps in EtCO2 indicating possible ROSC. Feel free to enlighten me. It hasn't been taught in any of the curriculum I've been presented.
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truetiger
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In the presence of low CO, you'll get false low values. IE your EtCO2 could be say 20 yet your PaC02 could be much higher. You're lacking the cardiac output to move the CO2 to the lungs for removal.
Then why are we discussing them in a one or the other fashion? It's like saying you can have a 12 lead or labs, but not both. You're not alone in this, I've heard a lot of people make this statement.
Had a patient last night, palish centrally. Normal respiratory rate, not a particularly increased work of breathing. SpO2 was in the mid 80s. Switched to a mask from a NC and his sats jumped to the mid 90s. Looking at this guy you never would have guessed his sats were that low. Another situation, we have established that giving oxygen to pt's having STEMIs causes increased oxidative damage. Every STEMI I've seen looked like they needed O2, but the vast majority were not hypoxic. Without SpO2 I wouldn't have known that.
Glad you feel that way. Pretty much the rest of medicine disagrees about its utility.
Making due without because it breaks is not the same as saying "its not useful, I could easily do without it".
Passive agressiveness....awesome
So you admit you don't know about the limitations of this particular tool, but its worse than SpO2?
Think about WHY you get that EtCO2 jump post arrest. The EtCO2 reading may have nothing to do with overventilating a patient, it may have everything to do with the fact that your patient isn't getting enough of the products of metabolism back to their lungs to actually breathe them out (hypotension). Alveolar status is important because if the alveoli are full of junk, CO2 isn't going to diffuse out very well. The PaO2 to EtCO2 gradient is an important thing to know when evaluating the quality of your EtCO2 reading, but its not something your going to know without a blood gas. Also explore the dilution effect that occurs when its being used on anything other than an ETT.
It hasn't been taught because the people teaching likely didn't know. EtCO2 has NOT been explained well to the majority of medics. It's sold as a silver bullet when the fact is its not.
BeachMedic
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Done thread hijacking. Sending PM.
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For all practical purposes in the field, Etc02 and Sp02 tell you pretty much the same thing: is the patient ventilating & exchanging gas well enough to meet metabolic demands, or not?
A patient who is exchanging gas poorly can often have their oxygen demand met by the administration of high-flow oxygen. Which is exactly why the NRB is such a staple of EMS care. High-flow O2 is a very blunt instrument, and there are times when it won't help or when it could (rarely) even hurt, but much more often than not, high-flow oxygen during transport will do far more good than harm.
I would much rather see people giving oxygen unnecessarily, than withholding it from people who need it based on an incomplete understanding of gas exchange physiology and poor interpretation of Etco2 waveforms. There are lots of things that affect the serum pH.
Other than confirming ETT placement and monitoring ventilation in an intubated patient, I can't think of much utility for Etc02 in the prehospital arena. Sure there are times when it may be nice to have, but I just can't think of many instances in which it would actually change treatment.
A patient who is exchanging gas poorly can often have their oxygen demand met by the administration of high-flow oxygen. Which is exactly why the NRB is such a staple of EMS care. High-flow O2 is a very blunt instrument, and there are times when it won't help or when it could (rarely) even hurt, but much more often than not, high-flow oxygen during transport will do far more good than harm.
I would much rather see people giving oxygen unnecessarily, than withholding it from people who need it based on an incomplete understanding of gas exchange physiology and poor interpretation of Etco2 waveforms. There are lots of things that affect the serum pH.
Other than confirming ETT placement and monitoring ventilation in an intubated patient, I can't think of much utility for Etc02 in the prehospital arena. Sure there are times when it may be nice to have, but I just can't think of many instances in which it would actually change treatment.
truetiger
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Nope, not even close. Here's an example. We have a pt we run frequently that calls for sob. She has a hx of chf and copd among other things. Many times the crew will just roll out there, put her on the pulse ox, and get a reading of 100, leave her on nrb, and say she's fine. If you don't put her on etco2, you can't gauge how sick she actually is. She'll be in ventilatory failure with a pa02 100+. You're just pissing in the wind with your nrb mask. This pt works very hard to maintain that 100%, but it'll get dismissed as anxiety. She'll eventually tire and require intubation in the hospital. By using both tools, and understanding them, intubation and respiratory acidosis can be avoided in the pt.
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And the Etco2 changes your care of this patient exactly how?
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truetiger
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By being super aggressive in improving her ventilation. Bronchodilators, steroids, etc.
Aidey
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Or earlier intubation.
DrankTheKoolaid
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This is exactly why continuing education should be just that. And not just taking the same crap card courses over and over and in house training on the same subjects year after year
Brandon O
Puzzled by facies
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The sense to viewing pulse oximetry as a nigh-vital sign is that it's a physiologic endpoint. Many things contribute to maintaining that sat, and if you only consider the endpoint you can totally fail to account for those compensatory or pathological processes, but nevertheless it's valuable and irreplaceable insofar as endpoints like that (or blood pressure, for instance) are always important.
Is end-tidal capnography the same? Yes, but it combines several endpoints (cellular metabolism, pulmonary exchange, ventilatory adequacy, pH, etc.) into one number and one waveform, which makes it both powerful and less immediately clear.
Is end-tidal capnography the same? Yes, but it combines several endpoints (cellular metabolism, pulmonary exchange, ventilatory adequacy, pH, etc.) into one number and one waveform, which makes it both powerful and less immediately clear.