Xopenex in place of Albuterol for Suspected Cardiac Wheeze

n7lxi said:
Doesn't anyone else use end tidal caponography as a diagnostic tool? Asthma/COPD and CHF have very different looking wave forms.
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I'd be careful referring to capnography as diagnostic. I don't think there is any evidence to show it to be diagnostic. I don't know of any numbers on the sensitivity and specificity or PPV and NPV of different waveforms in different conditions. I'd wager that the waveform assoc'd with bronchoconstriction is specific but very non-sensitive. Also if there is bronchiolar narrowing w/ cardiac wheeze (combination of edema and actual construction) and also with COPD, wouldn't the waveform potentially be similar? Basically, do you have any evidence to back you claims?
 
Well then let me recant my position a bit, in the interest of semantics. End-tidal waveform capnography may help differentiate between CHF and COPD. Waveforms between CHF and COPD are vastly different, even with slight bronchial constriction that may occur during CHF exacerbation. What you're looking for, is the expiratory plateau. CHF patients are not retaining CO2, however they may just have some bronchoconstriction which might give you a slight slur at the expiratory upstroke, but you see a relatively flat plateau.

Conversely, COPD patients are having difficulty in exhalation, and never can fully complete a true, CO2 rich exhale. That's why you won't see any of that flat plateau.

And I'm on my phone at the moment so I can't get any databases, but a quick Google scholar look for peer-reviewed papers found this study that showed some significant differences in end-tidal CO2 capnometry, that is without waveform. The sample was small and they were not able associate anyone number with a predictor., however if they had had end tidal waveforms I'm sure it might've been a different story.

http://journal.publications.chestnet.org/article.aspx?articleid=1071323
 
...And this this 2008 study that showed bronchodilator therapy in CHF patients resulted in the need for more aggressive treatments and the potential for less optimal outcomes?

http://www.medcontrol.com/omd_pub/bronchodilators.pdf

So, If you had the opportunity to use end tidal capnography to help guide your treatment, wouldn't that make more sense than blindly administering a beta agonist?
 
n7lxi said:
Well then let me recant my position a bit, in the interest of semantics. End-tidal waveform capnography may help differentiate between CHF and COPD. Waveforms between CHF and COPD are vastly different, even with slight bronchial constriction that may occur during CHF exacerbation. What you're looking for, is the expiratory plateau. CHF patients are not retaining CO2, however they may just have some bronchoconstriction which might give you a slight slur at the expiratory upstroke, but you see a relatively flat plateau.

Conversely, COPD patients are having difficulty in exhalation, and never can fully complete a true, CO2 rich exhale. That's why you won't see any of that flat plateau.
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I'm denying that expiratory obstruction can cause changes to the wave form, I just question how reliable the changes are (or their lack). I used nasal EtCO2 frequently when I worked 911 - almost all respiratory patients, patients treated with opiates or benzos, some altered mental status, etc. By and large, I noted some degree of "sloping" frequently in non asthma/COPD patients. Unless the EtCO2 was particularly high or if the wave form was particularly slurred, I wouldn't hang my hat on it. I personally find the greatest value of nasal EtCO2 to be for trending. As far as I can tell, there is little information available on differentiating CHF from COPD with EtCO2, and most of what is out there seems to be anecdotal at best.

And I'm on my phone at the moment so I can't get any databases, but a quick Google scholar look for peer-reviewed papers found this study that showed some significant differences in end-tidal CO2 capnometry, that is without waveform. The sample was small and they were not able associate anyone number with a predictor., however if they had had end tidal waveforms I'm sure it might've been a different story.
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In other words, the study yield no usable information.

n7lxi said:
...And this this 2008 study that showed bronchodilator therapy in CHF patients resulted in the need for more aggressive treatments and the potential for less optimal outcomes?
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Yeah, I'm familiar with this study. The study is interesting and makes a great case for the need for more research, but it does not show anything but correlation. We do NOT know if bronchodilators made anyone worse; it is very well possible that their use indicates a sicker patient (just like that morphine and NSTEMI study from years back).

So, If you had the opportunity to use end tidal capnography to help guide your treatment, wouldn't that make more sense than blindly administering a beta agonist?
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It would be another piece of information to be considered, for sure. I don't think anyone has advocated blindly giving bronchodilators to CHF patients, though.
 
medicsb said:
I'd be careful referring to capnography as diagnostic. I don't think there is any evidence to show it to be diagnostic. I don't know of any numbers on the sensitivity and specificity or PPV and NPV of different waveforms in different conditions. I'd wager that the waveform assoc'd with bronchoconstriction is specific but very non-sensitive. Also if there is bronchiolar narrowing w/ cardiac wheeze (combination of edema and actual construction) and also with COPD, wouldn't the waveform potentially be similar? Basically, do you have any evidence to back you claims?
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I had a status asthmaticus patient a few days ago I transferred IFT. Pt. was intubated and on the vent. Initial EtCO2 was around 80mmHg with near absent lung sounds. The EtCO2 wave form was normal and not the characteristic "shark fin". So this is a good example of not hanging your hat on the capnography waveform.

I gave my patient a Duoneb followed by continuous albuterol treatments over the 45min transport. EtCO2 came down to 59mmHg.
 
You would expect to not see a shark fin on a vented pt with a high level of PEEP, right? (I'm not a vent whiz, just trying to think this through...)

Prior to the vent, I'd guess that bagging the patient still showed a sharkfin... With it only disappearing as the PEEP was increased.
 
So my question is why even use capnography then for anything other than confirming ETT placement if you aren't going to use the information it gives you along with a good assessment to guide your treatment?
 
FLdoc2011 said:
http://www.ncbi.nlm.nih.gov/pubmed/18572345

J Emerg Med. 2011 Feb;40(2):135-45. Epub 2008 Jun 24.
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Thanks for the reference! Don't know how I missed it, but the result fits with how most of us practice.

This subject is fascinating, and comes up frequently on this forum. Back in the spring people were weighing in in the thread " Administration of bronchodilators for pulmonary edema?" It was a "spirited" discussion, and it got me thinking, and reading.

I put together a small review of the topic, to be used for an EMS talk in the future: "All that wheezes" - CHF and albuterol. My summary:
  1. Medics are able to diagnose CHF with pretty good accuracy, and capnograhy may be a helpful adjunct for them.
  2. CHF frequently presents with wheezing, especially in older patients.
  3. The dangers of giving beta-blockers are controversial, and was mentioned earlier, may just be a marker of the sick patient.
 
18G said:
I had a status asthmaticus patient a few days ago I transferred IFT. Pt. was intubated and on the vent. Initial EtCO2 was around 80mmHg with near absent lung sounds. The EtCO2 wave form was normal and not the characteristic "shark fin". So this is a good example of not hanging your hat on the capnography waveform.

I gave my patient a Duoneb followed by continuous albuterol treatments over the 45min transport. EtCO2 came down to 59mmHg.
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But following my other comment about the shark fin not showing up with a high-level of peep for patient on a vent… Your patient also had a history of asthma, correct? This was also an IFT, not an original presentation. Would you expect to see a shark fin presentation on end title capnography with the original status asthmaticus patient?

If this were a 911 call, would you, not knowing the patient's current situation, administer bronchodilators simply because the patient has a history of asthma?

Of course you would. It's only prudent.

But if this same patient presented with a flat topped capnography waveform, had no history of asthma or COPD but did have a history of CHF and expiratory wheezes ... would you still go down the bronchodilator route?

I understand your reasoning of "not hanging your hat on a waveform", but common sense and past medical history will give you a pretty good idea as to what road you're going down. I think capnography is useful when I'm trying to weigh the differential between CHF and COPD when the patient has a history of both. I may be going out on a limb, but I feel a CO2 retainer who may, or may not, present with a shark fin waveform, it's going to be a COPD/reactive airway disease patient vs CHF. I'll be sure to examine all the other clinical findings… But capnography is a great tool to help guide me down the road of treatment.
 
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KellyBracket said:
Since most paramedics are 1) intelligent, 2) clever, and 3) convinced they are more clever than the other medic they're arguing with
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:rofl::rofl::rofl:
 
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