# CPAP in ASTHMA? Absolute contraindication?



## Av8or007

Hey

I'm from Ontario, Canada, and I'm really needing an answer to this question. 
Firstly, I know that I need to follow the local medical directives, this is a theoretical WHY question.

Is an acute asthma exacerbation an absolute contraindication for normal CPAP (not BiPAP) based on the CURRENT MEDICAL EVIDENCE? Our MOHLTC (ministry of health and long term care) standards state that asthma is an absolute contraindication to cpap, since according to the CPAP learning package:
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"Asthma
Asthma is the result of an adverse reaction to a stimulus resulting in the contraction of smooth muscle and mucous production in the bronchioles. Stimuli such as an allergen, stress, exercise, and cold weather may cause this increased responsiveness of the bronchi and bronchioles, resulting in bronchoconstriction and mucosal edema. Patients experiencing an asthma attack will present with high pitch wheezing on expiration, tachycardia, tachypnea, positional breathing and in severe cases, cyanosis and Status Asthmaticus (severe asthma attack that is unresponsive to bronchodilators lasting several hours). The use of CPAP for acute asthma has not been well documented in the pre-hospital setting. CPAP in the treatment of an asthma attack may cause increased air trapping and increased intra thoracic pressure, or irritation of the bronchioles further potentiating signs and symptoms. A patient suffering from asthma is in need of treatment with Salbutamol or Epinephrine depending on severity and treatment should not be delayed. As such, CPAP is not indicated for asthma, and is absolutely contraindicated in the presence of asthma exacerbation."
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What I do not understand is that there are many US based EMS agencies using CPAP in asthma and seeing a benefit in PTS that do not respond to meds. Also, they are at least seeing that it does not do harm in most cases, and that there is certainly enough time to discontinue therapy before major problems occur.

Any ideas? I'd like to hear your experiences using CPAP for asthma exacerbation and any relevant studies.


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## NomadicMedic

We do use CPAP concurrently with nebulized albuterol, and while I haven't seen a study on its effacy, my anecdotal experience has been that it works like a champ.


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## Hunter

n7lxi said:


> We do use CPAP concurrently with nebulized albuterol, and while I haven't seen a study on its effacy, my anecdotal experience has been that it works like a champ.



I think CPAP alone sounds like a bad idea since asthma patients have trouble exhaling air, with albuterol though it might help deliver the medication to the let respiratory tract? Or am I just talking out of my butt?


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## Handsome Robb

Hunter said:


> I think CPAP alone sounds like a bad idea since asthma patients have trouble exhaling air, with albuterol though it might help deliver the medication to the let respiratory tract? Or am I just talking out of my butt?



CPAP alone? Bad idea. CPAP plus a neb is accepted. I had trouble getting my head wrapped around it to but from my understanding you're spot on about "forcing" the treatment into the airways, along with "splinting" the airways open and allowing the trapped air to be exhaled. I've always been taught to start at a low PEEP, think 2.5 mmHg, and work your way up from there.

Ever seen a real bad asthmatic pursed-lip breathing to create auto-PEEP for themselves? Same concept only the CPAP allows them to focus on breathing rather than having to focus on using extra breathing techniques on top of breathing.

Let me know if that makes sense at all, I'm 9.5 hours into my 12 and it's 0145 and I'm sleepy so it may be all gibberish for all I know.


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## Av8or007

NVRob said:


> CPAP alone? Bad idea. CPAP plus a neb is accepted. I had trouble getting my head wrapped around it to but from my understanding you're spot on about "forcing" the treatment into the airways, along with "splinting" the airways open and allowing the trapped air to be exhaled. I've always been taught to start at a low PEEP, think 2.5 mmHg, and work your way up from there.
> 
> Ever seen a real bad asthmatic pursed-lip breathing to create auto-PEEP for themselves? Same concept only the CPAP allows them to focus on breathing rather than having to focus on using extra breathing techniques on top of breathing.
> 
> Let me know if that makes sense at all, I'm 9.5 hours into my 12 and it's 0145 and I'm sleepy so it may be all gibberish for all I know.



That makes perfect sense. Those PTS need drugs, but CPAP may help deliver the meds. It makes perfect sense to titrate up SLOWLY from a low pressure. What do you think about CPAP after a Salbutamol MDI (repeated doses as necessary) for BLS? Again I'm just curious and will obviously follow all local protocols. Does anyone have a solid paper/study that shows the benefit of CPAP w/ an albuterol neb?

I guess my major question is, is asthma an absolute contraindication or more of a relative contraindication that requires... OMG... _CLINICAL JUDGMENT!!!!_ Back to reality, all i mean is that can CPAP benefit PTS in a acute asthma exacerbation once you've put meds on board. 

I'm


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## Christopher

Av8or007 said:


> Again I'm just curious and will obviously follow all local protocols. Does anyone have a solid paper/study that shows the benefit of CPAP w/ an albuterol neb?



There are a lot of small studies into the potential usage of Noninvasive Positive Pressure Ventilation (NIPPV or NPPV) for the treatment of acute/severe Asthma and COPD, beginning in the early to mid-1990's and extending through today. There doesn't seem to be many larger scale RCT's into the M&M reductions with it.

*Shivaram U, et al* looked at the cardiopulmonary responses to CPAP in asthma (n=21) and found that CPAP levels at 5-7.5 cm H2O, _"were tolerated without deleterious side effects...These data show that application of CPAP in acute asthma reduces respiratory rate and dyspnea with no untoward effects on gas exchange, expiratory airflow, or hemodynamics."_

*Fernandez MM, et al* also looked at NPPV usage in the ICU for status asthmaticus (n=22) and found that it improved alveolar ventilation, decreased the need for intubation, and was effective for the management of patients with severe asthma.

Although from 2002, the only good review of the treatments available for Severe Asthma is *Marik PE, et al*: The Management of Acute Severe Asthma, and it lays out the literature supporting each indicated treatment.

As it stands there is only LOE B regarding the usage of NPPV for the management of acute severe asthma:


> At least fair scientific evidence suggests that the benefits of the clinical service outweighs the potential risks. Clinicians should discuss the service with eligible patients.



To put this in perspective, it seems that magnesium is on most protocols for severe COPD and Asthma, yet only expert opinion and small case reports exist supporting this usage!

Basically: inhaled beta-2 agonists, then NPPV (like CPAP or BiPAP), then anti-cholinergics, then Epi, then corticosteroids.


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## OzAmbo

We give the beta 2's via PMDI if the presentation is not too severe. Anticholinergcs are given concurrently with the beta 2's in more severe cases as well as corticosteroids. Adrenaline if they drop their bundle. Magnesium would be tops but i dont have it.

The use of CPAP routineley in asthmatics has my head spinning, i cant figure out the mechanism for providing CPAP in a patient when its intrinsic PEEP that is trying to kill them

I imagine you would have to start with low pressure and work your way up

Response from IMI adrenaline in status patients is amazing


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## mycrofft

I can see where a PEEP would help the airways  "stay open" against the surface tension and obstruction from fluids exuded into the airway, but it seems a lot of pressure. 

Aside, being a cardiac pt myself (a-fib), the epi could do me in. Over a decade before my diagnosis, I knew epi with lidocaine at the dentist gave me chest "tightness", and carbocaine or lido, without, didn't. FOr folks ike me, have something on hand to moderate the epi if needed?

Sidetrack: we used to inject a sustained activity version of epi called "Sus-Phrine".  Extended activity, but hold pin to for butt if you couldn't take epi. Maybe that's why it's off the market.

PS: Over the counter epi inhalers (Primatene) were removed form sale after 31DEC'11 due to use of CFC's as a propellant.


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## Christopher

OzAmbo said:


> The use of CPAP routineley in asthmatics has my head spinning, i cant figure out the mechanism for providing CPAP in a patient when its intrinsic PEEP that is trying to kill them.
> 
> I imagine you would have to start with low pressure and work your way up.


I'm going to quote from Shivaram U. et. al. (available in PDF from my Google Drive), the emphasis is mine:


> In the past, PEEP and CPAP were often avoided in patients with obstructive airway disease (OAD) because of the risk of barotrauma and adverse hemodynamic effects. *However, there are no published reports to support this hypothesis, and on the contrary, recent studies indicate that CPAP or PEEP may help to reduce the work of breathing in patients with OAD.*


Later,


> This reduction in dyspnea and RR may be mediated through various mechanisms that affect inspiratory and expiratory events. First, *CPAP has been shown to reduce the inspiratory work of breathing during acute asthma*, as shown by a reduction in the pressure-time product of the inspiratory muscles and in the fractional inspiratory time...Furthermore, during expiration, CPAP may reduce dynamic airway collapse by increasing the intraluminal pressure within the downstream flow-limiting segment, thereby "pneumatically" splinting the airways, which may reduce expiratory airway resistance, improve expiratory airflow, and reduce dyspnea. *This mechanism has been postulated to explain the frequent observation of spontaneous exhalation through pursed lips in patients with OAD.*


And in regards to gas exchange:


> ...as assessed by PaO2, PaCO2, and P(A-a)O2 was unchanged with 5 cm H2O of CPAP. Because the airways are inhomogeneously affected by OAD, regional ventilation and time constants may vary widely. CPAP may further distend the previously open airways while recruiting previously collapsed airways and allowing deflation of their corresponding alveolar units...*More important, however, is the lack of CO2 accumulation following CPAP*, as may be seen when the dead space-to-tidal volume ratio is significantly increased with progressive hyperinflation.



I hope this helps explain why some CPAP is good for COPD/Asthma.


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## Av8or007

Another question on physiology, how would BiPAP possibly be better than CPAP in asthma. In Ontario, our air ambulance service will BiPAP asthma PTS, even though the land EMS cannot use CPAP. 

How would PEEP (CPAP) be contraindicated (according to our protocols/ALS standards), but PEEP + Pressure support (BiPAP) be used?


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## DrankTheKoolaid

*re*

Taken from the Incredible Dr. Weingart.  At the end right before the intubation, its not that the patient can no longer exhale it's that they are so fatigued they can no longer draw in a breath to exhale.  Adding pressure support will allow increased tidal volume which will assist with the beta agonist delivery and in a backwards way assist with exhalation


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## mycrofft

*Spell check typos and haste*

For the second time today I'm apologizing for comments that look like I was having a Broca's CVA. I'll try to do better!:blush:


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## ditchdoc125

Av8or007 said:


> Another question on physiology, how would BiPAP possibly be better than CPAP in asthma. In Ontario, our air ambulance service will BiPAP asthma PTS, even though the land EMS cannot use CPAP.
> 
> How would PEEP (CPAP) be contraindicated (according to our protocols/ALS standards), but PEEP + Pressure support (BiPAP) be used?



I wondered this myself... Its quite common to follow the whole algorithm with a asthma patient only for the ED to slap on some BiPAP and fix them... Our protocols state asthma is a contraindication for CPAP as well, but there's the odd medic who will use it concurrently with a combivent neb. Unfortunately our system uses a low-tech CPAP so its 5cm H2O or nothing.


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## OzAmbo

Christopher said:


> I hope this helps explain why some CPAP is good for COPD/Asthma.



Clear as mud 

Seriously,  perfectly unerstand how CPAP works, i too was under the information that CPAP was absolutely conraindicated in asthma (not COPD) as the mechanism of exudate and bronchospasm in small calibre airways being quite different from the increased alveolar surface tension and loss of surfactant in APO i guess i just took it as gospel.

Interesting reading, i should spend more time in pubmed and CINAHL looking at this stuff :blink:


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## MSDeltaFlt

Bare in mind that merely saying COPD you're referencing two common and yet very different diseases: Emphysema and Chronic Bronchitis. 

Emphysema (especially end stage) will have the alveoli collapsing. CPAP is great for this in that it can splint the alveoli open improving gas exchange.

Chronic Bronchitis is literally that.  Inflammation of the the bronchi and bronchioles (just proximal to the alveoli).  Depending on the severity, CPAP can also help splint the airways open improving gas exchange similar to asthma. 

Now the kicker here is that CPAP inline with nebs can benefit even more because CPAP will add or keep some pressure against exhalation. What that does is keep the bronchodilator on the lungs a little longer. The longer the drugs stay on the lungs the better they will work.

So, CPAP is not an absolute contraindication to asthma.  CPAP is respiratory FAILURE is.  And respiratory failure is just before respiratory arrest.


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## 18G

With COPD/Asthma, there is air trapping which translates to auto-peep. The auto-peep creates a positive pressure in the terminal airways at the end of expiration which makes it extremely hard for the patient to inhale (ie increased work of breathing). Normally at the end of exhalation in a normal patient the pressure should be equalized... hence no airflow?

So, the patient has to work extra hard to inhale since they have to overcome this auto-peep pressure to create the pressure gradient to allow airflow in. 

For patients who are refractory to treatment or are already in extremis, application of CPAP works by creating a pressure that is higher than the intrinsic auto-peep pressure... thus creating a pressure gradient allowing better airflow and taking the workload off the patient. With the CPAP exerting the positive pressure, the patient no longer has to expend high levels of energy and experience muscle fatigue to generate this pressure on their own.


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## ZootownMedic

I had a patient last week that had asthma and COPD. When I got to him he was tripoding, with accessory muscle use, satting at 73% on RA. We gave him a albuterol neb and then a duoneb and we ended up using CPAP enroute. It saved us from intubating him. How would you know if it was a COPD exacerbation or a asthma exacerbation? Audible wheezes? He could have that with both right? Would it even matter? I am not gonna immediately CPAP an asthma patient without a neb first......


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## 46Young

An absolute contraindication of CPAP is the acute asthmatic would be a total loss of alveolar plateau as observe on the ETCO2 waveform. That's what Bob Page told us at the "Slap the Cap" lecture, anyway.


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## Doczilla

n7lxi said:


> We do use CPAP concurrently with nebulized albuterol, and while I haven't seen a study on its effacy, my anecdotal experience has been that it works like a champ.



In line nebulizers are money. I'm guessing OPs system dosent have em


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## 18G

SmokeMedic said:


> I had a patient last week that had asthma and COPD. When I got to him he was tripoding, with accessory muscle use, satting at 73% on RA. We gave him a albuterol neb and then a duoneb and we ended up using CPAP enroute. It saved us from intubating him. How would you know if it was a COPD exacerbation or a asthma exacerbation? Audible wheezes? He could have that with both right? Would it even matter? I am not gonna immediately CPAP an asthma patient without a neb first......



During an exacerbation it doesn't matter if it's COPD or asthma. Treatment is going to be the exactly the same and you're not going to be able to definitely say which process is more of the culprit. 

Now if the patient is febrile, has had URI S/S the past few days, weakness, chills, etc, then I would lay money on COPD since 75% of COPD exacerbations are the result of a respiratory infection. Chances are though its still a combo of both. 

Beta-2 agonists (inhaled and injection - epi or terbutaline), anticholinergic (Atrovent), mag sulfate and steroids (solu-medrol) and CPAP, are treatments that are appropriate and necessary in both COPD and asthma. 

Good question.


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## OzAmbo

MSDeltaFlt said:


> Bare in mind that merely saying COPD you're referencing two common and yet very different diseases: Emphysema and Chronic Bronchitis.


I intentionally stated COPD specifically because it is a disorder consisting of the two diseases listed.


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## zmedic

18G; said:
			
		

> With COPD/Asthma, there is air trapping which translates to auto-peep. The auto-peep creates a positive pressure in the terminal airways at the end of expiration which makes it extremely hard for the patient to inhale (ie increased work of breathing). Normally at the end of exhalation in a normal patient the pressure should be equalized... hence no airflow?
> 
> So, the patient has to work extra hard to inhale since they have to overcome this auto-peep pressure to create the pressure gradient to allow airflow in.
> 
> For patients who are refractory to treatment or are already in extremis, application of CPAP works by creating a pressure that is higher than the intrinsic auto-peep pressure... thus creating a pressure gradient allowing better airflow and taking the workload off the patient. With the CPAP exerting the positive pressure, the patient no longer has to expend high levels of energy and experience muscle fatigue to generate this pressure on their own.



This isn't really right. Yes as airways narrow it is a little harder to breath in, but the problem with asthma is really the exhalation. The problem is that when you breath out, the pressure inside the chest (and outside the airways) is higher than the pressure in the airway. This is even worse in patients with destructive lung disease like COPD. So the CPAP helps COPD by helping splint these open. Now BiPAP works by assisting the patient taking the breath in, like using a BVM. There is also some PEEP which helps keeps the airways open, but you set it low in asthma as others have said. CPAP alone isn't really going to help people breath in much. Think about it, it's a constant pressure. If you are setting your pressure at 2mmg of Hg for CPAP (to keep PEEP low), the patient only gets 2mmg for inspiration. When you are doing BiPap, the inspiratory pressure is usually set around 10mmhg. 

As others have said, Bipaps role in asthma is really to help the tiring patient, giving them more time for the meds to open them up and try to avoid intubation. But it isn't the end all be all. 

This is very different from other conditions like CHF with pulmonary edema, or COPD exacerbation where BiPAP alone can really turn people around.


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## 18G

zmedic said:


> This isn't really right. Yes as airways narrow it is a little harder to breath in, but the problem with asthma is really the exhalation. The problem is that when you breath out, the pressure inside the chest (and outside the airways) is higher than the pressure in the airway. This is even worse in patients with destructive lung disease like COPD. So the CPAP helps COPD by helping splint these open. Now BiPAP works by assisting the patient taking the breath in, like using a BVM. There is also some PEEP which helps keeps the airways open, but you set it low in asthma as others have said. CPAP alone isn't really going to help people breath in much. Think about it, it's a constant pressure. If you are setting your pressure at 2mmg of Hg for CPAP (to keep PEEP low), the patient only gets 2mmg for inspiration. When you are doing BiPap, the inspiratory pressure is usually set around 10mmhg.
> 
> As others have said, Bipaps role in asthma is really to help the tiring patient, giving them more time for the meds to open them up and try to avoid intubation. But it isn't the end all be all.
> 
> This is very different from other conditions like CHF with pulmonary edema, or COPD exacerbation where BiPAP alone can really turn people around.



Anyone else's thoughts? 

An increase in airway resistance (ie bronchoconstriction, increased mucus production, inflammation, exudative junk) = increased work of breathing / atelectasis. 

The patient must expend extra energy and utilize accessory muscles to generate a pressure high enough to overcome the pressure present inside the chest to allow airflow to take place. This needs to happen for inspiration or expiration to occur. For example, in order to drop the pressure inside the lungs, the auto-peep pressure must be overcome so air can leave the chest and become more negative. CPAP can overcome this auto-peep pressure in some cases. 

With Asthma, there is bronchoconstriction, inflammation, increased mucus, etc. so there is a component of difficulty inhaling with the increased airway resistance which needs to be addressed as well. 

With CPAP, alveolar recruitment takes places and more alveoli are able to participate in gas exchange and they aren't as prone to collapse. 

It seems counter intuitive that CPAP would work in asthma and does get kinda confusing.   

To go along with my explanation I discovered this article which does a great job at explaining auto-peep with use of CPAP. 

http://www.ccmtutorials.com/rs/peep/page7.htm


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## Merck

I'm not sure that I would use CPAP in an acute exacerbation of asthma.  In my experience 95% of patients can be controlled with the usual nebulized meds.  Those that are not usually respond admirably to judicious IV beta-lovin'.  (i.e. epi).  In the rare event that these are successful and/or things are trending poorly the best course of action is to intubate them anyway allow for very long expiratory phase, despite the hypercarbia that results.
There is a 2011 paper in CMAJ that outlines recommendations for NIPPV/CPAP and it does not state any recommendations for CPAP in asthma exacerbation as there is no evidence to support its use.
Just my 2 cents.


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## Doczilla

Again, the only use I've seen it in is in-line neubulizer. I wonder why it hasn't been brought up much?


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## 18G

Merck said:


> I'm not sure that I would use CPAP in an acute exacerbation of asthma.  In my experience 95% of patients can be controlled with the usual nebulized meds.  Those that are not usually respond admirably to judicious IV beta-lovin'.  (i.e. epi).  In the rare event that these are successful and/or things are trending poorly the best course of action is to intubate them anyway allow for very long expiratory phase, despite the hypercarbia that results.
> There is a 2011 paper in CMAJ that outlines recommendations for NIPPV/CPAP and it does not state any recommendations for CPAP in asthma exacerbation as there is no evidence to support its use.
> Just my 2 cents.



I've seen studies regarding use of CPAP in Asthma with favorable results.


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## NomadicMedic

18G said:


> I've seen studies regarding use of CPAP in Asthma with favorable results.



Post the citations.


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## 18G

http://pats.atsjournals.org/content/6/4/367.full


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## Smash

18G said:


> http://pats.atsjournals.org/content/6/4/367.full



Garbage in, Garbage out.  The quality of a review or a meta-analyses is only as good as the original studies that it looks at.  And quite frankly, the studies they discuss in this paper are pretty useless.  The vast majority of the studies look at BiPAP, not CPAP.  The ones that do look at CPAP are so small as to be ridiculous (N=2!)  The _largest_ study that looks at CPAP as opposed to BiPAP is a retrospective review with N=22.  Not exactly practice changing material.

The vast majority of literature I have come across deals with COPD, which has a different pathology to true asthma, as zmedic has pointed out.

The other issue I have when trying to interpret the (lack of) data is the terminology used.  For most of us (certainly for me) CPAP means CPAP.  I personally am limited to a fixed pressure of 10cmH20.  I have no capacity to alter inspiratory support at all.  I suspect that many of us in the pre-hospital field have the same limitations (ie we can't provide actual BiPAP)

However many studies use the terms CPAP, NIPPV, BiPAP and so on interchangeably.  Whilst this may be technically correct, there is obviously a vast difference between slapping on 10cmH2O CPAP with 4/10 BiPAP (or whatever).  So it makes interpreting the results of studies (such as they are) for use in the pre-hospital field problematic.  Maybe some can provide actual BiPAP, but I know that this is limited for many.


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## 18G

Smash said:


> Garbage in, Garbage out.  The quality of a review or a meta-analyses is only as good as the original studies that it looks at.  And quite frankly, the studies they discuss in this paper are pretty useless.  The vast majority of the studies look at BiPAP, not CPAP.  The ones that do look at CPAP are so small as to be ridiculous (N=2!)  The _largest_ study that looks at CPAP as opposed to BiPAP is a retrospective review with N=22.  Not exactly practice changing material.
> 
> The vast majority of literature I have come across deals with COPD, which has a different pathology to true asthma, as zmedic has pointed out.
> 
> The other issue I have when trying to interpret the (lack of) data is the terminology used.  For most of us (certainly for me) CPAP means CPAP.  I personally am limited to a fixed pressure of 10cmH20.  I have no capacity to alter inspiratory support at all.  I suspect that many of us in the pre-hospital field have the same limitations (ie we can't provide actual BiPAP)
> 
> However many studies use the terms CPAP, NIPPV, BiPAP and so on interchangeably.  Whilst this may be technically correct, there is obviously a vast difference between slapping on 10cmH2O CPAP with 4/10 BiPAP (or whatever).  So it makes interpreting the results of studies (such as they are) for use in the pre-hospital field problematic.  Maybe some can provide actual BiPAP, but I know that this is limited for many.



There is limited data from evaluating CPAP in asthma. But there is some which shows benefit. Yes, COPD and asthma are different but they also share a lot of the same components as well. I never claimed these were groundbreaking or ne thing but do lend support for benefit.


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## MSDeltaFlt

46Young said:


> An absolute contraindication of CPAP is the acute asthmatic would be a total loss of alveolar plateau as observe on the ETCO2 waveform. That's what Bob Page told us at the "Slap the Cap" lecture, anyway.



More clinically relevant for an absolute contraindication Got CPAP would be respiratory failure: acute hypoxia with severe hypercapnia, fatigue, and/or a 2-3 point drop in GCS in your presence.  Oh yeah, one more absolute contraindication: apnea. 

Not just one item on a machine taught by someone with no pulmonary background.  I like Bob's classes. I learn a lot from him. But if you want to learn respiratory components learn from RT's and pulmonologists.  Just my humble two cents.


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## ZootownMedic

MSDeltaFlt said:


> More clinically relevant for an absolute contraindication Got CPAP would be respiratory failure: acute hypoxia with severe hypercapnia, fatigue, and/or a 2-3 point drop in GCS in your presence.  Oh yeah, one more absolute contraindication: apnea.
> 
> Not just one item on a machine taught by someone with no pulmonary background.  I like Bob's classes. I learn a lot from him. But if you want to learn respiratory components learn from RT's and pulmonologists.  Just my humble two cents.



Yeah I would hope nobody would try to CPAP a apneic patient.....guess it needs to be said or else someone willl do it though. Probably some dumb Paramedic intern :rofl:


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## TYMEDIC

The last couple of CPAP administrations ive did really didnt work well and just had to discontinue them on status ashmatics. The patient just didnt tolerate the mask, and ended up just using peep attachment via BVM and bagging albuterol+atrovent in. To me, its still the same. The real question is, not everybody has the ability to use bronchodilators via neb attachments to CPAP. It just ends up being inneffective. Why waste your time trying to hook all that crap up when you can just as easily bag a neb into someone. Ive been studying this method of treatment for a while now with CPAP. Those patient's are auto-peeping and can seriously cause damage.


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## Aidey

TYMEDIC said:


> Ive been studying this method of treatment for a while now with CPAP. Those patient's are auto-peeping and can seriously cause damage.



Citation?


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## WTEngel

I have seen success with BiPAP and in line nebs. It wasn't all that uncommon to do this with acute exacerbation patients. 

The real question is, when do they cross the threshold of acute exacerbation into full on status asthmaticus. 

It has been my experience, and I have see a LOT of asthmatics, that once they are status, they need IV meds, bottom line. No matter what type of respiratory set up you want to use, CPAP, BiPAP, ET intubation with specific vent settings, etc. there comes a point where you need to pull the trigger and give mag, terb, theophylline, or aminophyilline as appropriate. 

So there in lies the crux of the matter. 

For the patients who are simply "tired" and just need a little adjunctive therapy to bridge that gap and stave off intubation, I think BiPAP with inline duoneb and IV solumedrol does the trick. 

For the status patients, mag, solumedrol, BiPAP with inline duoneb.

I have seen status patients pushed to the verge of respiratory arrest with poorly applied CPAP or BiPAP used in without in line nebs and/or IV med therapy. 

The real trick is having the experience to recognize when enough is enough and pull the trigger on mag, terb, theophylline, or aminophylline, depending on the patient presentation.


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## zmedic

TYMEDIC; said:
			
		

> The last couple of CPAP administrations ive did really didnt work well and just had to discontinue them on status ashmatics. The patient just didnt tolerate the mask,



I've found that when people are clawing away the mask (NRB or BiPap), that's the signal to intubate them. They are usually starting to get altered from hypoxia/hypercapnea at that point. Those patients either crash or get intubated. But sick asthmatics+pushing away mask=bad new bears.


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## Christopher

zmedic said:


> I've found that when people are clawing away the mask (NRB or BiPap), that's the signal to intubate them. They are usually starting to get altered from hypoxia/hypercapnea at that point. Those patients either crash or get intubated. But sick asthmatics+pushing away mask=bad new bears.



Ativan has helped in some of these situations, but this is where Ketamine would really shine!


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## Doczilla

+ over 9000.

Plus, ketamine is the induction agent of choice for status asthmaticus


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## JakeEMTP

WTEngel said:


> I have seen success with BiPAP and in line nebs. It wasn't all that uncommon to do this with acute exacerbation patients.



What device are you using for BiPAP in prehospital?

We have the LTV 1200 on CCT but none of the other trucks carry it.


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## WTEngel

We used the LTV 1000. 

BiPAP can be a pain in the rear on the LTV if you don't use it often. It is a little more complicated to set the vent up (as far as pushing buttons and getting to the right menus) but if you run it enough, like anything, you get the hang of it.


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## zmedic

Christopher; said:
			
		

> Ativan has helped in some of these situations, but this is where Ketamine would really shine!



Sure, it may help them tolerate the mask, which is what Scot Whiengart advocates to help you oxygenate while you get set up for intubation. But I don't think it's usually a long term solution. If you have someone who is that sick from asthma, if you sedate them so they tolerate the BiPap, and ten minutes later they've already gotten Solumedrol, mag, epi, continuous nebs and they are not improving I think you are very close to needing to tube. 

Note I'm not saying intubation is manditory, but if their person isn't awake they aren't safe to leave on Bipap. So the question is how long are you going to sit there and watch them. I think in the next 10-20 minutes they are either going to tire, start getting hypoxic and get tubed, or they are going to improve and you've dodged a bullet. But I just want to be clear that I don't think the answer is "sedation and BiPap and you are done with them."


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## medicconnor

I use CPAP with inline Neb, Some sort of Steriod and even go the point of using SQ epi, or A Mag Sulfate drip often on bad Patients, I have only seen Patients improve from this treatment.


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## Christopher

zmedic said:


> Sure, it may help them tolerate the mask, which is what Scot Whiengart advocates to help you oxygenate while you get set up for intubation. But I don't think it's usually a long term solution. If you have someone who is that sick from asthma, if you sedate them so they tolerate the BiPap, and ten minutes later they've already gotten Solumedrol, mag, epi, continuous nebs and they are not improving I think you are very close to needing to tube.
> 
> Note I'm not saying intubation is manditory, but if their person isn't awake they aren't safe to leave on Bipap. So the question is how long are you going to sit there and watch them. I think in the next 10-20 minutes they are either going to tire, start getting hypoxic and get tubed, or they are going to improve and you've dodged a bullet. But I just want to be clear that I don't think the answer is "sedation and BiPap and you are done with them."



I'd tailored my comments to their care prior to the ED. Prehospital if I can optimize their ventilation/respiration without RSI, I'm going to take that approach (perhaps I'm in the minority). In the ED, or if unlucky enough and we're still in the field, if they've not improved then we're on the same page: RSI.


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## CWATT

It looks like the original poster answered their own question.  Reasons stated were:

- Lack of evidence in prehospital setting 
- May cause increased air-trapping  [It makes sense - the wheezing sound heard on expiration is due to the bronchioles constriction and the increased respiratory effort to exhale the processed gas. So adding positive pressure infront of it is only creating more resistance to exhalation.]
- Increased intrathorasic pressure.  [This is more of a venous-return/hypotension problem.]
-  Irritatoin of bronchioles exacerbating the problem [I think this is a bit of a stretch.]

Another way to think of why this is consideration of the benefits to CPAP...
- Positive alveolar pressure to redistribute (push out) pulmonary edema and effusion [Not a problem with asthma]
- Alveolar recruitment [Not a problem with asthma]
- Ventilation/Perfusion ratio restoration [Not a problem with asthma]

The core of the problem is the bronchiole constriction, so the correct Tx is medication therapy.  I think that's where they're going with the 'absolute contraindication' because you would be moving in the 'wrong' direction in your patient care plan.

Now, there's a fair argument to be made about delivery of inhaled medications in persons with reduced tidal volumes... so who knows.


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## luke_31

Necro thread from over four years ago


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## RocketMedic

Complete anecdote here as far as I know, but we actually carry both Flowsafe in-line neb-capable CPAP and PEEP valves for BVMs for asthmatics. Works like champs.


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## TXmed

Im pretty agressive when it comes to asthmatics, i usually hit them with epi early, even the moderatly severe payients. But am usually hesitant with the CPAP. Ive seen it make the patient better in the short term (oxygenation) but do little about the airtrapping that is occurring. 

But every patient is different and some do improve with inline neb and PPV. 

If i do have to RSI its include alot of epi and ketamine.


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## Eden

Our protocols allow cpap for asthma patients, but paramedics usually dont really go for it. The other day we had a sick asthma patient and we couldn't get a line started to give magnesium. So i was like lets cpap this guy.  The paramedic tutoring me was like nah i dont do that. The em doc agreed its not really accepted in asthma patients but then again, you got a quite sick asthma patient, tube still preventable, i thought its worth trying. The literature i looked at wasnt conclusive but most did say it might help. (Eg tintinali's em)


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## CWATT

Eden - I'm curious, do you carry EZ-IO?  If so, what are your protocols for its use?


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## Eden

CWATT said:


> Eden - I'm curious, do you carry EZ-IO?  If so, what are your protocols for its use?


We got BIG/NIO ( i'd rather have ez io) and protocols wise its an alternative for iv line. We thought about it but we were close to the hospital so it ended with a neb and epi IM.


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## Eden

Eden said:


> We got BIG/NIO ( i'd rather have ez io) and protocols wise its an alternative for iv line. We thought about it but we were close to the hospital so it ended with a neb and epi IM.


We can also sedate and tube with ketamine IM 5mg/kg


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## Underoath87

Eden said:


> We can also sedate and tube with ketamine IM 5mg/kg



I'm assuming you mean 0.5 mg/kg (IBW)?


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## Eden

Underoath87 said:


> I'm assuming you mean 0.5 mg/kg (IBW)?


Nope, I mean 5mg/kg Intramuscular. Definitely not something we do routinely but could do.


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## Underoath87

Eden said:


> Nope, I mean 5mg/kg Intramuscular. Definitely not something we do routinely but could do.


Where do you put it all?  The only ketamine I've seen is 10mg/ml, which would be 50ml for a 100kg pt...


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## Eden

Underoath87 said:


> Where do you put it all?  The only ketamine I've seen is 10mg/ml, which would be 50ml for a 100kg pt...



50mg/ml here.


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## MonkeyArrow

Eden said:


> 50mg/ml here.


That's still 10 mL for a 100 kg patient. Where do you inject all that?


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## Eden

MonkeyArrow said:


> That's still 10 mL for a 100 kg patient. Where do you inject all that?



 Lets say rectus femoris 5cc each side.. or 3 and 2 in each deltoid
Definitely not the optimal route. But if all fails..


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## Handsome Robb

Underoath87 said:


> I'm assuming you mean 0.5 mg/kg (IBW)?



Most any IM dose of ketamine is going to be 2x the IV dose. A "normal" induction dose is 2 mg/kg IV.

We routinely give 5 mg/kg IM for combative patients. 


Sent from my iPhone using Tapatalk


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## Carlos Danger

Eden said:


> Nope, I mean 5mg/kg Intramuscular. Definitely not something we do routinely but could do.


Well, like most drugs, it actually _should_ be dosed based on LBW. If you use TBW you end up giving quite a bit more than you need to, in the average American.

But 5mg/kg is on the low end of an induction dose so it probably doesn't matter in most people. You may well be underdosing some of your young, lean males at that dose though.


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## E tank

Remi said:


> But 5mg/kg is on the low end of an induction dose so it probably doesn't matter in most people. You may well be underdosing some of your young, lean males at that dose though.



Yeah, IM induction dose goes up to 8 or more I think.

 As to CPAP vein of the thread, the PEEP element can actually decrease work of breathing and allow the patient to exhale more completely by pressure "stenting" or "splinting" of constricted airways. As long as the CPAP setting is less than the intra-alveolar pressure, it should be beneficial, and 6 - 8 will be less than that in a symptomatic asthma patient. 

The issue of requiring some anxiolysis to accept the mask is a real one, but anything other than ketamine (Ativan was mentioned) wouldn't be a great idea, IMO, because of the central depressive effects of benzodiazepines, narcotics, whatever.


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