End tidal C02 at BLS level

[Benjamin Henry]

Does anyone utilize end tidal C02 at the BLS level? (EMT -B) In the state I live in (CT) many BLS only units have 12 lead monitors with the capability.

 

[DrParasite]

No, but I wish we could. they do make pocket sized ETCO2 devices (like a portable pulse ox), but I haven't found a BLS agency that carry them. and they are much cheaper than a 12 lead monitor.

Tbh, their are only a few uses in the pre-ALS environment. Definitive diagnosis of asthma attacks, effectiveness of cardiac arrest, and an objective way to count respirations would be all I can think of off the top of my head.

 

[medichopeful]

No, but I wish we could. they do make pocket sized ETCO2 devices (like a portable pulse ox), but I haven't found a BLS agency that carry them. and they are much cheaper than a 12 lead monitor.

Tbh, their are only a few uses in the pre-ALS environment. Definitive diagnosis of asthma attacks, effectiveness of cardiac arrest, and an objective way to count respirations would be all I can think of off the top of my head.

I’ll also use it along with other information to determine opioid overdose treatment.

 

[E tank]

paralysis by analysis comes to mind. kinda reminds me of that TV spot with the folks stuck on an escalator that has stopped working. there is a point of diminishing returns with that technology and it is one that depends heavily on other technologies for reliable utility. With just a couple of notable exceptions, IMHO, use in a non-intubated person is a solution looking for a problem.

 

[Peak]

What ever happened to a good physical exam and history? 80% of diagnoses is based on history. I'd rather have really good EMTs than add capnography to the bus.

I also think there is an under appreciation of the limitations and inaccuracies of end tidal capnography. We use it to continually monitor intubated patients in the unit and it isn't uncommon for it to be off by 10mmhg and I've had a couple (with good waveforms) off my more than 20.

It's a tool that is most useful when trended, which I think limits it utility in EMS.

 

[DrParasite]

What ever happened to a good physical exam and history?

I agree, it's something that too many providers, especially at the BLS level, fail to do. and it gets ever worse the longer they are out of class and away from an ambulance....

80% of diagnoses is based on history.

respectfully disagree. How many STEMIs have been diagnosed without a 12 lead? How many fractures have been diagnosed without an x ray (and by diagnosis, no most testings need to be done, now the intervention starts)? When I tore my meniscus, and was misdiagnosed by the ortho PA because I "didn't have a good enough story", it wasn't until my PT said i had a tear and told me i needed a CT to confirm, was I scheduled for surgery with an ortho surgeon. How often does the ER send a patient's blood to get lab values?

Can a doctor diagnose without all the bells and whistles, and treat and intervene based solely on their physical assessment and history? absolutely, and some do it surprisingly well. But many/most will use their assessment to create their differential diagnosis, and then back it up with an objective lab work, especially when it's available to them.

I'd rather have really good EMTs than add capnography to the bus.

agreed.

I also think there is an under appreciation of the limitations and inaccuracies of end tidal capnography. We use it to continually monitor intubated patients in the unit and it isn't uncommon for it to be off by 10mmhg and I've had a couple (with good waveforms) off my more than 20.

I've heard the PS02 had several limitations, but thought ETCO2 was fairly accurate. Can you provide some literature which documents these limitations?

It's a tool that is most useful when trended, which I think limits it utility in EMS.

Again, respectfully disagree. It is standard practice in this region to connect every respiratory patient to ETCO2. It's used on every cardiac arrest (if its super low, we won't even work them), as well as every intubation or SGA. At the BLS level, it can be the difference between giving albuterol for the respiratory arrest and hooking the patient up to CPAP.

Is trending useful? absolutely. but it can be a very useful tool in EMS.

And for some references from people who are smarter than me:
How to Read and Interpret End-Tidal Capnography Waveforms
Capnography: A vital sign for every EMS patient
Non-intubated Use of Capnography in the EMS Environment
5 things to know about capnography and respiratory distress: Understand how monitoring end-tidal carbon dioxide helps assess and treat a patient in respiratory distress

 

[StCEMT]

Gonna throw out my general disagree thought as well. That statement seems to be along the lines of "treat your patient, not the monitor". I agree with what people are trying to say with that, but not how they say it.

Treat your patient and know how to use the monitor to further guide your treatment. Treating the monitor isn't wrong, there are plenty of times to do it relying heavily on the monitor.

Just like everything though, time and place. Look at your patient that tuns marathons that feels fine with the heart rate of 40 and don't whip out ACLS on them. Titrate your vasopressor dosage based off the art line, because your sedated patient isn't gonna say "hey bro, I don't feel too good".

Knowing how to jump between both is where you clinician vs technician shows. I'd rather have really good providers who are good with patients and utilizing their equipment to further enhance their patient care.

 

[Peak]

respectfully disagree. How many STEMIs have been diagnosed without a 12 lead? How many fractures have been diagnosed without an x ray (and by diagnosis, no most testings need to be done, now the intervention starts)? When I tore my meniscus, and was misdiagnosed by the ortho PA because I "didn't have a good enough story", it wasn't until my PT said i had a tear and told me i needed a CT to confirm, was I scheduled for surgery with an ortho surgeon. How often does the ER send a patient's blood to get lab values?

Can a doctor diagnose without all the bells and whistles, and treat and intervene based solely on their physical assessment and history? absolutely, and some do it surprisingly well. But many/most will use their assessment to create their differential diagnosis, and then back it up with an objective lab work, especially when it's available to them.

I think that a MI is a great example of the value of a history. For example if I have a 32 year old man present with a hour of epigastric burning and chest pain that started shortly after an dinner where he had pasta with red sauce and a glass of wine. He reports no personal or family cardiac or other high risk history. He reports he took a tums PTA which helped, but that it didn't completely resolve his pain and is starting to get worse again. He denies any recent stress or other psych/social considerations. Certainly this history appears low risk, but lets look at a brief exam without fancy toys. He has a normal BMI, is P/W/D and well perfused, non-toxic appearing. Normal cardiac sounds. Pain on palp to LUQ/Epigastrium, no pain on palp to the chest. He has a normal BP, HR, RR, and temp.

The chances that this gentleman would have an abnormal EKG or troponin are very low, and in the vast majority of cases the patient is going to be having some reflux and not an MI. Of course most clinicians would run a trop and EKG, but once they come back normal he is going home with his low HEART score.

Conversely lets consider a 53 year old male. He reports sudden onset of chest pain and nausea that awoke him from his afternoon nap. He reports a personal history of CABGx3 and currently has 3 stents as well. He denies radiation to his arm or jaw, but reports nausea and a feeling of anxiety. He reports that this feels the same as his prior MI. He reports a history of 4 prior MIs, all of which required emergent cardiac catheterization and one of which resulted in the CABG after the cath as they felt they could not open his arteries well enough with stents. He reports that he is supposed to take ASA and Plavix, but he was taken off of xarelto four months ago by his cardiologist so he felt that he could stop the plavix as well. He reports that his grandfather died from a heart attack at 48, and his father died of cardiac failure at 64 but had been a cardiac cripple and had multiple MIs. The patient reports a history of DM2 that he reports is well controlled however he only takes metformin, he tells you that his physician wants him to start taking insulin but he doesn't like the idea of poking himself with needles. The patient also reports a history of hypertension and uses smokeless tobacco. He reports that he usually drinks 2-3 beers a day in the evening, he has not had anything to drink today.

This patient screams MI and even if he had a normal EKG and trop would be staying in the hospital for observation. There is a pretty good chance cardiology would take him for an elective cath even if he has normal labs and EKG since he has such a high risk presentation. Of course he would get an EKG and trop as well as other routine labs, but they exist to confirm or rule out diagnosis based on his physical exam and history.

I think that a history is very useful in joint injuries especially for the hip, shoulder, and knee. I think that with a good exam most soft tissue injuries can be well assessed without imaging, however I also think that the exam most people are taught is not suffient (be in EMTs, medics, nurses, or even most docs).

Specific to this topic is there a reason people feel a need for capnography in asthma? Do they feel that their physical exam needs to be confirmed with a high ETCO2? Do they need that classic shark fin wave form? What are people trying to differentiate from that they cannot based on history and physical? Are they trying to use waveform analysis to assess if the patient has improved, if so why is no one advocating for peak flows in EMS?

I've heard the PS02 had several limitations, but thought ETCO2 was fairly accurate. Can you provide some literature which documents these limitations?

Again, respectfully disagree. It is standard practice in this region to connect every respiratory patient to ETCO2. It's used on every cardiac arrest (if its super low, we won't even work them), as well as every intubation or SGA. At the BLS level, it can be the difference between giving albuterol for the respiratory arrest and hooking the patient up to CPAP.

Is trending useful? absolutely. but it can be a very useful tool in EMS.

We run a gas on all of our intubated or trach/vent patients in the units (with varying frequencies) when they are on capnography. My personal experience drives my distaste for using a ETCO2 for diagnosis since I have seen so much variation personally. This is unknown in the literature, i just a very quick search and found some references, certainly the accuracy is affected by certain disease states but are known to be off by at least a couple of mmhg in most patients.

Accuracy of end-tidal CO2 capnometers in post-cardiac surgery patients during controlled mechanical ventilation - PubMed

A good correlation between etCO2 and PaCO2 was shown with the three capnometers in the present study. However, etCO2 measurements were not valid to estimate PaCO2 in these patients. Therefore, capnometry cannot be used to replace serial blood gas analyses completely, but may be a good...

www.ncbi.nlm.nih.gov

Superiority of transcutaneous CO2 over end-tidal CO2 measurement for monitoring respiratory failure in nonintubated patients: A pilot study - PubMed

We found large differences between EtCO2 and Paco2 in spontaneously breathing nonintubated ICU patients admitted for acute respiratory failure. Our study argues against the use of EtCO2 monitoring in such patients but raises the possibility that PtcCO2 measurement may provide reasonable...

www.ncbi.nlm.nih.gov

End tidal carbon dioxide as a predictor of the arterial Pco2 in the emergency department setting | Emergency Medicine Journal

 

[StCEMT]

Asthma is kinda the softball of capno uses though. Yeah, I could treat an asthmatic with absolute confidence and 0 deviation regardless of if I had it or not.

However I can use it for other things like a pneumo. Any GSW to the chest I get gets capno and lung sounds and I trend both. Capno allows me to be more hands off so I can do the other long list of things I need to address. If I notice a significant change, then I have something to catch my attention and let me know I need to do something.

 

[DrParasite]

Of course most clinicians would run a trop and EKG, but once they come back normal he is going home with his low HEART score.

so even though the chances are slim, they are not relying on just the history and physical, because those tests are definitive and objective evidence that it isn't cardiac in nature. Otherwise they wouldn't even bother with them, because H&P will give them all he needs.

There is a pretty good chance cardiology would take him for an elective cath even if he has normal labs and EKG since he has such a high risk presentation. Of course he would get an EKG and trop as well as other routine labs, but they exist to confirm or rule out diagnosis based on his physical exam and history.

that guy sounds like a trainwreck, but even you said "they exist to confirm or rule out diagnosis." They don't rely solely on the H&P, they use all the tools at their disposal.

Specific to this topic is there a reason people feel a need for capnography in asthma? Do they feel that their physical exam needs to be confirmed with a high ETCO2? Do they need that classic shark fin wave form? What are people trying to differentiate from that they cannot based on history and physical? Are they trying to use waveform analysis to assess if the patient has improved, if so why is no one advocating for peak flows in EMS?

As my former medical director said, if you hear wheezes, and the ETCO2 waveform is a shark fin, go with albuterol. If you hear wheezes and no shark fin, skip the albuterol and break out the CPAP. Both of which are BLS interventions BTW.

You still got to do a H & P, but you give them additional information with objective technological evidence to confirm and guide their treatments, Why would you not want to give your EMTs the best tools to treat the patients appropriately?

We run a gas on all of our intubated or trach/vent patients in the units (with varying frequencies) when they are on capnography.

You know what? I agree with you. Arterial blood gases are much more accurate, but a little more invasive, and I don't know how practical it is in the field.

I do think that a good H&P is the baseline of all medical assessments, and, sadly, many can't do them, or don't do them well, and no using technology as a crutch shouldn't be allowed (how many nurses have issues taking a manual BP in the hospital? how many doctors?). But giving them more tools, especially non-invasive and minimally invasive ones, such as a glucometer, pulse oximeter, ETCO2, and thermometer, to obtain objective information about their patient, can only help them make better treatment plans and better treatment decisions.

 

[E tank]

But giving them more tools, especially non-invasive and minimally invasive ones, such as a glucometer, pulse oximeter, ETCO2, and thermometer, to obtain objective information about their patient, can only help them make better treatment plans and better treatment decisions.

1000's of medmal attorneys would disagree. Failure to treat is a very common element that pays large in these claims. We're talking about ETCO2 in the BLS setting, yes. But the principal applies to ALS and care in the hospital as well. The greater role that interpretation plays in the processing of "objective information", the greater the liability for even possessing the ability to measure becomes.

 

[DrParasite]

The greater role that interpretation plays in the processing of "objective information", the greater the liability for even possessing the ability to measure becomes.

So your saying the the quidelines say "if you see a sharkfin, give albuterol, if you don't, give cpap" is more litigious that simply saying give albuterol for all wheezes? or "if you take a BGL, and it's 50, give oral glucose" is more litigious than "if you have a confused patient with a history of DM, who is acting out of the ordinary, and is a little sweaty, give oral glucose"?

Of course, treating solely based on the machines (and not doing a good H&P) is not appropriate however having that objective assessment (you can look at a ETCO2 monitor or BGL or temp and it's an objective shape or number), vs a subjective lung sounds, feeling skin temp with your hand, or guessing on BGL, and treat accordingly.

 

[E tank]

So your saying the the quidelines say "if you see a sharkfin, give albuterol, if you don't, give cpap" is more litigious that simply saying give albuterol for all wheezes? or "if you take a BGL, and it's 50, give oral glucose" is more litigious than "if you have a confused patient with a history of DM, who is acting out of the ordinary, and is a little sweaty, give oral glucose"?

I'm saying, perhaps what goes without saying...that if you have the technical ability to gather data, you are obligated to use it, discern the presence of artifact or not, interpret the data appropriately and act on it appropriately. So, yes, if we're reducing the question to legal risk, reducing complexity reduces legal exposure in this case.

A single number doesn't require interpretation. A waveform does. The determination of whether the higher stakes is worth it or not, I guess, depends on the setting/agency.

 

[Peak]

so even though the chances are slim, they are not relying on just the history and physical, because those tests are definitive and objective evidence that it isn't cardiac in nature. Otherwise they wouldn't even bother with them, because H&P will give them all he needs.that guy sounds like a trainwreck, but even you said "they exist to confirm or rule out diagnosis." They don't rely solely on the H&P, they use all the tools at their disposal.

We don't use all the toys at our disposal though. It is balanced with the needs of the patinet. We could order CK-MBs, cardiac angiograms, and so on, but they all have a place. The same is true for the ambulance, and you also have to consider the role of EMS evaluation; the diagnositic adjunts are going to be different for EMS, ED, ICU, the floor, clinic, and primary care.

As my former medical director said, if you hear wheezes, and the ETCO2 waveform is a shark fin, go with albuterol. If you hear wheezes and no shark fin, skip the albuterol and break out the CPAP. Both of which are BLS interventions BTW.

I can count on one hand the number of times I heard a cardiac wheeze without other adventitious heart or lung sounds and without a reactive airway component. Every time the patient's history would be strongly suggestive of a cardiac etiology. I don't think having used capnography on those patients would have made diagnosis any easier.

You still got to do a H & P, but you give them additional information with objective technological evidence to confirm and guide their treatments, Why would you not want to give your EMTs the best tools to treat the patients appropriately?
You know what? I agree with you. Arterial blood gases are much more accurate, but a little more invasive, and I don't know how practical it is in the field.

The cost of healthcare is already high, and more tools are going to drive that up. I think we need to make sure that the tool actually benfits patient care before we implement it. I'm sure we can all name some tools we have used (diagnostically or interventionally) that are no longer considered effective and are collecting dust in some closet or were sent to project cure.

How many EMTs or medics do you think actually listen to all of the patient's lung fields before putting them on capno? How many patients listen to at least 5 cardiac sites before taking a 12 lead, or at least at some point during a transport? How many can identify the significance of a shifting PMI? How many grade murmurs, can identify normal versus pathological gallops, can identify a rub and the signficance of it in different patient populations?

I'm not against a tool that benefits a patient, but most people don't even know how to effectively use what they already have. I also think that many clinicians are very quick to adopt some new tool without understanding the limitations of it.

Specific to ABGs I don't expect the vast majority of even CCT services to draw or run a gas, but those who do carry an EPOC or iStat can get a pretty good assessment of CO2 with a venous gas as well. I personally don't like capillary gasses but that option exists as well. For us a CG4+ costs well under $5, and an abg kit is under a buck; with that I can have a ABG or VBG (of course drawing off of an IV or line rather than art stick or A-line) and a lactate. Inline capnography or a capno-cannula costs roughly $10-20 depending on which one we need to use. Of course a gas doesn't give me waveform interpretation but they are of course two different tools with two different costs and benefits. iStats are pretty expensive to buy in the first place and many ems agency monitors are purchased with capno already integrated, but cost analysis will vary based off of the number of gasses you run, if you run anything else (lytes, trops, HCGs, H/H, et cetera), and many other systemic factors.

I do think that a good H&P is the baseline of all medical assessments, and, sadly, many can't do them, or don't do them well, and no using technology as a crutch shouldn't be allowed (how many nurses have issues taking a manual BP in the hospital? how many doctors?). But giving them more tools, especially non-invasive and minimally invasive ones, such as a glucometer, pulse oximeter, ETCO2, and thermometer, to obtain objective information about their patient, can only help them make better treatment plans and better treatment decisions.

I don't think that more tools always allow for better care. The last multiple GSW I ran never got placed on the monitor. Myself and my medic were able to treat the patient and his priority interventions with a palp BP, palp pulse rate, a sthetoscope, and physical exam. Putting him on the monitor, measuring temps, or whatever else would have delayed either our ability to make life saving interventions or have delayed transport. He did begin to decomp en route, and I do think that he probably wouldn't have survived surgery if we had delayed at all in the process. I was prepping blood and chest tubes while my medic was prepping his vascular access, and by the time we made it to the ED we ran out of time to do anything else.

 

[rick813p55]

I agree, it's something that too many providers, especially at the BLS level, fail to do. and it gets ever worse the longer they are out of class and away from an ambulance....respectfully disagree. How many STEMIs have been diagnosed without a 12 lead? How many fractures have been diagnosed without an x ray (and by diagnosis, no most testings need to be done, now the intervention starts)? When I tore my meniscus, and was misdiagnosed by the ortho PA because I "didn't have a good enough story", it wasn't until my PT said i had a tear and told me i needed a CT to confirm, was I scheduled for surgery with an ortho surgeon. How often does the ER send a patient's blood to get lab values?

Can a doctor diagnose without all the bells and whistles, and treat and intervene based solely on their physical assessment and history? absolutely, and some do it surprisingly well. But many/most will use their assessment to create their differential diagnosis, and then back it up with an objective lab work, especially when it's available to them.

agreed.I've heard the PS02 had several limitations, but thought ETCO2 was fairly accurate. Can you provide some literature which documents these limitations?Again, respectfully disagree. It is standard practice in this region to connect every respiratory patient to ETCO2. It's used on every cardiac arrest (if its super low, we won't even work them), as well as every intubation or SGA. At the BLS level, it can be the difference between giving albuterol for the respiratory arrest and hooking the patient up to CPAP.

Is trending useful? absolutely. but it can be a very useful tool in EMS.

And for some references from people who are smarter than me:
How to Read and Interpret End-Tidal Capnography Waveforms
Capnography: A vital sign for every EMS patient
Non-intubated Use of Capnography in the EMS Environment
5 things to know about capnography and respiratory distress: Understand how monitoring end-tidal carbon dioxide helps assess and treat a patient in respiratory distress

I believe that capnography would be a good tool for the BLS kit. It’s non-invasive, and even if you are not looking at wave forms, the numbers give some great information. Knowing the correct limits you can tell if a patient is oxygenating properly. It is a good indicator if your patient is about to go to **** quicker than a pulse ox. The numbers on the canography will drop a lot faster when a patient gets into respiratory distress or stops breathing by a minute or two depending on how well the patient was oxygenating before he decided to make you **** your pants.
There is absolutely no reason I can see not to put that piece of equipment in the BLS took kit. I have been a Paramedic and instructor for 32 years. If am EMT can read a glucometer and tell if a patient’s glucose is too high or low, of course with the exam, surely they can look at the numbers of a canograhy and tell if the patient is in trouble. It is not rocket science

 

[Tigger]

I believe that capnography would be a good tool for the BLS kit. It’s non-invasive, and even if you are not looking at wave forms, the numbers give some great information. Knowing the correct limits you can tell if a patient is oxygenating properly. It is a good indicator if your patient is about to go to **** quicker than a pulse ox. The numbers on the canography will drop a lot faster when a patient gets into respiratory distress or stops breathing by a minute or two depending on how well the patient was oxygenating before he decided to make you **** your pants.
There is absolutely no reason I can see not to put that piece of equipment in the BLS took kit. I have been a Paramedic and instructor for 32 years. If am EMT can read a glucometer and tell if a patient’s glucose is too high or low, of course with the exam, surely they can look at the numbers of a canograhy and tell if the patient is in trouble. It is not rocket science

How does capnography measure oxygenation?

 

[silver]

I believe that capnography would be a good tool for the BLS kit. It’s non-invasive, and even if you are not looking at wave forms, the numbers give some great information. Knowing the correct limits you can tell if a patient is oxygenating properly. It is a good indicator if your patient is about to go to **** quicker than a pulse ox. The numbers on the canography will drop a lot faster when a patient gets into respiratory distress or stops breathing by a minute or two depending on how well the patient was oxygenating before he decided to make you **** your pants.
There is absolutely no reason I can see not to put that piece of equipment in the BLS took kit. I have been a Paramedic and instructor for 32 years. If am EMT can read a glucometer and tell if a patient’s glucose is too high or low, of course with the exam, surely they can look at the numbers of a canograhy and tell if the patient is in trouble. It is not rocket science

Using numerical values and waveform of your capnography for a non-closed system such as a nasal cannula (as found on a BLS rig) can inaccurate due to many different factors (including mouth breathing, low tidal volumes, nasal prongs getting stuck on the nasal mucosa, condensation on the sample line). I almost never use the number itself as a result as they are often lower than actual alveolar CO2. Capnography is prone to misreading and it takes an astute person to quickly determine the reason why there is no waveform. Is it because the patient isn't breathing, are they obstructed or is one of the other factors at play that I mentioned? And chances are you won't see a shark fin on the asthmatic or get good end tidal on an non-intubated arresting patient.

 

[E tank]

How does capnography measure oxygenation?

And this illustrates a significant point. That a modality is non-invasive does not make it suitable for an application in a setting that might include a BLS ambulance. Misinterpretation and misunderstanding outweighs any benefit you might derive from the technology. Chest rise, fogging a mask, back of the hand against the nose and mouth....perhaps even a stethoscope...emt's still have those, yeah? Lot's cheaper in lot's of ways.....

 

[MackTheKnife]

The more you add diagnostic adjuncts, or "tools" to the BLS toolbox, the more you solidify the argument for getting rid of EMTs and going full-medic. In Tropic Thunder terms, "full retard".

 

[MackTheKnife]

Gonna throw out my general disagree thought as well. That statement seems to be along the lines of "treat your patient, not the monitor". I agree with what people are trying to say with that, but not how they say it.

Treat your patient and know how to use the monitor to further guide your treatment. Treating the monitor isn't wrong, there are plenty of times to do it relying heavily on the monitor.

Just like everything though, time and place. Look at your patient that tuns marathons that feels fine with the heart rate of 40 and don't whip out ACLS on them. Titrate your vasopressor dosage based off the art line, because your sedated patient isn't gonna say "hey bro, I don't feel too good".

Knowing how to jump between both is where you clinician vs technician shows. I'd rather have really good providers who are good with patients and utilizing their equipment to further enhance their patient care.

But we're talking EMTs, not medics. Your examples speak to medic-medicine, not Basics.