The Ins and Outs of CPAP

Don’t you hate when two regulatory bodies (both in the same country, underwriting the same profession) can’t get along?

I do. It’s confusing.

And it’s all over a little CPAP (or no CPAP as the case may be).

I’ll start at the beginning: CPAP (Continuous Positive Airway Pressure) is a treatment method for various forms of respiratory distress and disorders.

The apparatus is a highly attractive accessory looking something like this……

cpapIt also sounds like Darth Vader. Awesome!

The CPAP machine delivers a constant flow of air through tubing and a mask and into your airway. The CPAP machine creates enough pressure in your airway to hold the tissue open, so your airway doesn’t collapse. 1 It can be titrated for effect. The improvement seen following CPAP administration most likely occurs through a combination of 1) decreased work of breathing and reduction of fatigue; 2) recruitment of alveoli and improved oxygenation; and 3) splinting of larger airways, bronchiolar and bronchial to reduce airway collapse and mucous plugging. 2

CPAP is the main treatment for obstructive sleep apnea. Obstructive sleep apnea means you have short pauses in your breathing when you sleep. These breathing pauses – called apneas or apnea events – last for 10 to 30 seconds, maybe longer. People with obstructive sleep apnea can stop breathing dozens or hundreds of times each night. 3 People with sleep apnea will use their personal machine at home while (you guessed it) sleeping. CPAP is also useful in scenarios such as CHF (congestive heart failure), COPD (chronic obstructive pulmonary disease), and pulmonary edema.

When we were kids my cousin used to have to use a CPAP machine while he slept. He had some pretty terrible juvenile asthma (which thankfully he grew out of). I thought sleepovers at his house were a bit creepy. 😀

So there you have it, my first personal encounter with CPAP was as a treatment for asthma. You can imagine my surprise when studying in PCP school I learned that asthma is a contra-indication for CPAP in the emergency setting (in Ontario protocols).

The reason, as stated by the Southwest Ontario Region Base Hospital Program Manual, is this-

“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 pontentiating 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.”4

So that is what I believed. CPAP in emergent asthma will potentially make things worse (although we aren’t really sure because no one’s really studied it). Ok fine. We have other, better, treatments anyways (in Ontario).

But then I moved to Saskatchewan.

My SCOP protocols state that asthma is an indication for the use of CPAP. Ok, now I’m just uncomfortable! I just finished learning that applying CPAP to my asthmatic patients could make things worse, but now I’m supposed to do it?? That’s it- show me the studies!

Again I started asking questions, this time to my regional manager. According to him, the potential for air trapping caused by CPAP is outweighed by the patient’s likeness of moving into respiratory failure without it. Ah- a good point. CPAP could even prevent patients from needing intubation if initiated early enough. Which is good! According to JEMS, “In asthma, intubation rarely treats the primary problem, which is bronchial and bronchiolar in nature. Intubation is usually only indicated to provide relief for profound fatigue with secondary respiratory failure. Issues and concerns with intubation in these patients are obviated with the use of CPAP. Thus, CPAP has allowed us to reduce intubation in all types of acute respiratory disease by two-thirds or more.” 5

Furthermore, as an EMT in Saskatchewan I do not have the authority to use bronchodilators for respiratory distress outside of a patient’s personal prescription (sadly, no epi, no ventolin, no nebs). So basically, my only offline choice beyond regular 02 delivery is CPAP. So I’m going to use it (take that Ontario!)….and also be prepared to manually ventilate in case it doesn’t work.

My final thoughts….

1. Ontario Base Hospitals- Why don’t you look at Saskatchewan’s prehospital studies of CPAP use in asthma? If you are nice they might let you look at their PCR’s.

2. SCOP- Please let your EMTs administer Epi, Ventolin, nebs for respiratory issues. Alberta is laughing at you.

3. Canada…national regulation is long overdue.

4. I think I’m going to start my own private CPAP study because sometimes you just don’t know who to trust.




9 thoughts on “The Ins and Outs of CPAP

  1. First off… Do SCOP’s allow you to administer CPAP for any appropriate tx, ie: pulmonary edema, COPD and apparently asthma.. without a single bronchodilator? That’s whack!!
    As an EMT in Alberta we can do Ventolin, atrovent but thats it really. Epi IM for anaphylaxis only.
    However, as a medic obviously your choices open up quite a bit. Alberta health has protocols which we can look to for reminders if we need during the “big calls”. Bronchospasm protocol is as follows..

    Ventolin 5mg, Atrovent 500mcg NEB
    Prednisone 50mg or Dexamethasone 8mg IM/IV/IO
    Ventolin 5m, Atrovent 500mcg
    Consider CPAP if bronchospasm is due to COPD
    Magnesium Sulfate 2grams IV over 10min drip
    Still unimproved…
    Epi 1:1000 IM 0.3mg
    Start thinking about Advanced Airway… Assist ventilations…
    Then online medical control if need be.

    In school we were also taught Epi 1:10,000 IV, 0.2mg but apparently AHS doesn’t see it that way. But these are just guidelines, if you breech them just prepare to justify it to the medical director. But that goes with any protocol and any tx outside.

    I enjoyed this entry, as a Paramedic student and someone who is soon to “fly solo” as a medic; CPAP “rules” don’t always make sense. It seems like every Paramedic has different opinions. However, CPAP in asthma was kind of a no, no but then it wasn’t truly well known… no black and white. But that’s EMS, ya I know. However, if you think of the patho around asthma it kind of makes sense why you would steer away for CPAP. It could maybe put on for a short period, to buy you sometime during your transport.. prolonging the need to RSI. You quoted JEMS and I respect their opinion and they are way more experienced medics then me.

    But this quote “In asthma, intubation rarely treats the primary problem, which is bronchial and bronchiolar in nature. Intubation is usually only indicated to provide relief for profound fatigue with secondary respiratory failure” It has some truth but some error as well. Yes, intubation is fixing the fatigue factor but you can still treat the primary issue… run EPI IV, side stream NEB’s while bagging the pt. This tube will give you a go at trying to balance out the end-tidal which at this point has shifted for sure.

    Anyways, I don’t really have a point… oh wait!!! I do… You can argue or “discuss” this till everyone is blue in the face. Bottom line, if you justify your tx and your patient benefited… then you probably did the right thing. CPAP will be controversial with asthma, does it have to be? I’m not sure, is it now? YES. ha ha. So just be careful, each patient will be different… As we all know too well.

  2. The first time I used CPAP was actually for a status asthmaticus who had no relief from bronchodialators. The CPAP worked and greatly diminished the patients work of breaing and decreased patient anxiety. The service medical director was perfectly happy with that was done that day. However in an ACP scenario i did recently I had nearly the exact same scenario. i initiate CPAP. the instructor stops the scenario stating I killed the patient due to air trapping leading to a pneumothorax and later a tension pneumothorax.

    The rational I was given was the dogma from an Ontario base hospital. The instructor worked at that same place and had it beaten into him that death will occur if you cpap an asthmatic. When asked for studies he was unable to support his position.

    its an interesting topic to be sure. I wish the provinces would share more information with each other regarding protocol and procedure development. The contradictions between provinces help no one.

  3. An easy mistake to make when you are brought up in the Ontario system is to take the base hospitals’ word as gospel. There is evidence for a lot of things we should be doing differently in Ontario but don’t because no one in the base hospitals has cared to implement them.

    There is evidence that CPAP can be beneficial for asthma exacerbations. We seem to be bad in paramedicine when it comes to teaching how it actually helps anything other than pulmonary edema. To really understand how it can be beneficial for obstructive conditions, you need to get your hands on a good medical physiology book and read about the equal pressure point and dynamic airway compression. This will help it to all make sense in a much better way than simply saying that CPAP “splints the airways open” and will allow you to fully understand the counter-intuitive reality that continuous positive airway pressure can be helpful in conditions that we associate with air trapping.

    Bryan E. Bledsoe, DO, Eric Anderson, MD, Ryan Hodnick, DO, Larry Johnson, Steven Johnson,
    Eric Dievendorf


    Posted: May 30, 2011 | 2:01 a.m.
    Updated: May 30, 2011 | 12:28 p.m.
    Stephen Letso has asthma, so shortness of breath isn’t that unusual. But on an early morning in February, when an inhaler wouldn’t control his symptoms, he was afraid he would never catch his breath again.
    Wheezing and coughing almost uncontrollably, the 72-year-old retiree managed to call a neighbour .
    “My friend dialed 9-1-1 right away,” Letso said recently as he sat in his North Las Vegas home. “I was just about out of it.”
    Within minutes of the emergency call, a Medic-West ambulance arrived. Almost immediately, paramedics realized a regular oxygen mask — which delivers oxygen but requires effort by the patient to breathe it — wouldn’t solve Letso’s distress.
    Turning blue from oxygen deficiency, he simply didn’t have the wherewithal to breathe on his own.
    At that point in the past, Letso would have been intubated, a tube placed down his throat so the oxygen he desperately needed could be pushed into his airway on the drive to the hospital.
    But the paramedics decided to use “continuous positive airway pressure,” or CPAP, a less invasive treatment that is new to Southern Nevada and is part of a current University of Nevada School of Medicine study.
    A special CPAP ( 02-RESQ )mask was put over Letso’s face and continuous high-pressure air was delivered through his trachea and down through his lungs as he was taken to MountainView Hospital.
    CPAP devices, studies by other ambulance services around the country have shown, are effective therapy for patients with compromised air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place. Oxygen-rich gas is supplied at flow rates high enough to increase airway pressure. And then the patient exhales against a resistance called positive end expiratory. This combination helps reduce the work of breathing.
    Soon after the mask was put on him, Letso’s breathing improved.
    “That may well have saved his life,” said Larry Johnson, clinical manager for the MedicWest and American Medical Response ambulance companies that are associated with the study that has University Medical Center as the lead hospital.
    How CPAP may have saved his life isn’t measured at the scene — intubation certainly would have gotten Letso breathing — but rather by what happened to him later at the hospital.
    Generally when someone is intubated by first responders, that individual must stay on a mechanical ventilator at the hospital, often ending up in intensive care.
    And that, says Dr. Bryan Bledsoe, clinical director for emergency medicine at the state’s school of medicine in Las Vegas as well as the author of several books on the subject, greatly increases health risks for a patient.
    “If we can keep patients off the ventilator, their outcomes will be a lot better,” said Bledsoe, a UMC emergency physician and medical director for MedicWest and American Medical Response. “Their risk for dangerous hospital-acquired infections and pneumonia is much higher. And there is also the risk for elderly patients that they become ventilator dependent, never become weaned from the ventilator, and they die that way.”
    MountainView Hospital doctors found out pneumonia had caused Letso’s severe breathing problems .
    “Intubation probably would have exacerbated his condition,” Johnson said, pointing out that Letso isn’t young and strong and would probably have had a difficult time building up the strength to ever get off the ventilator.
    On a ventilator, Bledsoe noted, patients are in particularly precarious position, sedated and having to be chemically paralyzed so they can’t move. They require constant nursing care. Invasive catheters and other tubes, which can carry infection, are commonplace.
    Emergency medical service directors have reported in the Journal of Emergency Medical Services that as many as 50 percent of intubated patients admitted to hospitals ended up being treated for respiratory infections, particularly ventilator-associated pneumonia, and that 54 percent of these patients eventually died from their infections.
    According to the Centers for Disease Control, more than 99,000 people in the United States die each year from hospital-acquired infections. And for every person who dies from an infection, another 20 suffer through infections that sometimes leave them in the hospital for months or with a permanent disability.
    In fact, about 5 percent of people admitted into the hospital each year (or about 2 million people) become infected with a hospital-acquired infection, costing the health care system between $30 billion and $40 billion.
    So far the study carried out in Las Vegas has found that of the 106 patients on which the CPAP mask was tried since February, 70 percent benefited, with medical officials reporting that the patients did not have to go on a mechanical ventilator.
    “CPAP was highly effective in the treatment of dyspnea (difficult or labored breathing) associated with asthma, chronic obstructive pulmonary disease, congestive heart failure, and pneumonia,” states a preliminary report written by Bledsoe and Johnson to the Southern Nevada Health District.

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