CPAP discussion

[JakeEMTP]

People with pneumonia may need fluids for a variety of reasons. The goal of CPAP is not to dry out secretions; however, I suppose there is a potential concern of that occurring in the field, maybe. In the hospital, we often heat and humidify patients receiving NIV. In fact, there are reports that NIV may help clear retained secretions.

Just so I can wrap my head around this, would you support the use of humidified O2 instead of blowing the pt.'s face off with just high flow O2 in the pre-hospital setting? I have never come across a pt. that had pneumonia that I would have considered the use of CPAP. That being said, it is not out of the realm of possibilities. I have already learned a great deal in this discussion. Love it.

[Richard B the EMT]

Unfortunately, for the purposes of this discussion, I enter from left field to mention that a CPAP, humidified or not, is also used to treat Acute Sleep Apnea. I admit I suffer ASA, and use a CPAP now set to an airflow of 9MM, and am about to get a 5 year re-evaluation to possibly up that.

Is either use "off lable? No clue.

[chbare]

I'm not exactly sure what we are talking about regarding the term "high flow."

Richard, I'm not clear on why CPAP for sleep apnoea would be considered off lable. I would not call sleep apnoea an acute issue however. Also, we generally divide sleep apnoea into two broad classes; obstructive and central. I would agree that treating central with CPAP could be off lable.

I don't really want to go that far off from the OP's main point because it is a good point to consider. Even though there is a lack of evidence except with community acquired pneumonia, with more literature, the current paradigm very well may change.

[croaker260]

Ok, for what its worth, here is our states CPAP training wich I helped develop.

http://www.slideshar...ng-presentation

We have had CPAP for about 4 years now give or take, and it has been HUGELY successful. We use it for CHF, Asthma, pneumonia, any of the non-traumatic respiratory causes including COPD. The pressure parameters are different (10 mm H2O for CHF, and 5 mm H2O for everything else) but the decision process is based on the severity of respiratory failure and the desire to avert intubation.

With that in mind, CPAP in pneumonia with respiratory failure has been used in our area with good success. Technically, it may be said that it was the respiratory failure that was the trigger point in general, but the point remains it can, and has, been used in pneumonia patients. This is concurrently with IV fluids and often nebulizers CPAP'ed in so to speak. It has been very effective in turning the patient around in many cases., buying time for a more deliberate approach to total care in others, and some...unfortunately...get a tube anyway.

Obviously it is not a universal treatment (i.e. every severe pneumonia ptient does not get it, only those in respiratory failure), but once our inversion gets here I can expect to use it every week or every other week until the flu/pnumonia/inversion/winter weather clears here in ID.

Edited January 13, 2012 by croaker260

[Richard B the EMT]

Acute Sleep Apnea is enough of a problem that I might have needed hospitalization for it. I'd been on C-PAP for treating it (ASA) for well over a decade, when I started hearing about C-PAP being used for Pneumonia, CHF, COPD, or other such uses. That is why, from the viewpoint of an ASA sufferer, I might see the other uses as being "Off Lable".

Again, as Science develops and refines, the "Off Lable" uses of any product or medicine will possibly, and probably, become the "ON Lable" uses. Rogain was a failure for whatever it was originally intended, now it's primary use is to grow hair, to make one example.

[croaker260]

R

Acute Sleep Apnea is enough of a problem that I might have needed hospitalization for it. I'd been on C-PAP for treating it (ASA) for well over a decade, when I started hearing about C-PAP being used for Pneumonia, CHF, COPD, or other such uses. That is why, from the viewpoint of an ASA sufferer, I might see the other uses as being "Off Lable".

Again, as Science develops and refines, the "Off Lable" uses of any product or medicine will possibly, and probably, become the "ON Lable" uses. Rogain was a failure for whatever it was originally intended, now it's primary use is to grow hair, to make one example.

For a bit of trivia, Rogain IIRC was originally a medication for HTN. Just as viagra was originally intended to be a nitrate for HTN and ACS.

Now from my reasearch for the presentation I posted above, I wish I could recall the original sources:

The earliest description of positive pressure airway support applied to a spontaneously breathing patient appeared in 1912, when Sterling Bunnell, an anesthesiologist, reported the use of a Teter mask to maintain lung expansion during thoracic surgery. He used a slider and spring mechanism to oppose exhalation.

In 1936 Poulton and Oxon designed a ‘pulmonary plus pressure machine’ to treat pulmonary edema. This was the combination of a vaccuum cleaner and an adjustable spring valve. The air was warmed by placing a hot water bottle in the dustbag compartment of the vaccuum cleaner and by sucking the air from in front of an electric fire!

Barach in 1937 worked with aviation researchers and applied positive pressure by face mask to pilots flying at high altitudes to prevent hypoxemia.

In 1956 Avery et al reported ‘internal stabilization’ of flail chest utilizing intermittent positive-pressure ventilation.

In 1967 Ashbaugh (who was a contemporary and friend of R Adams Cowley IIRC) used term CPPB to describe positive end pressure used in conjunction with IPPV supplied by a ventilator. This led to confusion as CPPB had originally applied to spontaneously breathing patients.

The term ‘continuous positive airway pressure’ was coined in 1971 by Gregory et al to describe an elevated airway pressure therapy for spontaneously breathing, intubated neonates. CPAP has supported countless neonates while their underdeveloped lungs matured. It was, and in many places still is, the primary mode for weaning patients from mechanical ventilation. Current application has expanded to include adults and more recently patients without an artificial airway.

In 1972 Civetta used CPAP to treat acute respiratory failure (ARF) and in 1973, Barach used CPAP for COPD patients.

In the early 1980s, CPAP was tried successfully in patients with obstructive sleep apnea, who experience airway obstruction with resultant apnea caused by relaxation of airway muscles during sleep. In the later 1980s, CPAP helped reduce work of breathing and improve oxygenation in patients experiencing respiratory distress following cardiac surgery. CPAP also was tried with congestive heart failure patients, also with encouraging results.

In 1981 JB Downs et al invented a new venturi device for administering CPAP. This was known as the Downs generator and was first marketed as the Vital Signs 8230.

In 1982 Sarah Kielty expanded the definition of CPAP to include adults and more recently patients without an artificial airway. The successes during the 1970s led other investigators to treat a variety of diseases with mask CPAP.

So, CPAP has an extensive History prior to ASA...

Side note: Does on/off lable apply to devices, or just medications?

Edited January 14, 2012 by croaker260

[mo_medic]

We do not have cpap where i work now, however at my previous department our protocol for using cpap was respiratory distress of any etiology as long as the patient had spontaneous respirations. More or less that was it, but we had special t adapters so we could also run a nubulizer treatment through the cpap. I had used it numerous times on pneumonia patients with some success. BP just had to be over 90 systolic. I actually had a pneumonia patient today (double pneumonia actually) from a local nursing home that had coarse diminished sounds with some wheezing, low initial spo2 but jumped up to 98-99 on nrb. Before i gave the bronchodilator i spoke to our med control doc for the day and he also had me give solu-medrol. Has anyone heard about giving a steroid for pneumonia before?

[Richard B the EMT]

So, CPAP has an extensive History prior to ASA...

Side note: Does on/off label apply to devices, or just medications?

OK, I now have a better knowledge of CPAP, but no answer as to the terminology "Off Label" being applicable to either or both meds and/or devices.

By the way, the American Sleep Apnea Association link is http://www.sleepapnea.org/

[Eydawn]

Why is CPAP contraindicated in folks with hx of asthma? Just curious.

I would think that the overall goal with its' use in respiratory distress secondary to edema (from cardiogenic or infectious origins) would be to increase total available volume for gas exchange by forcing open the alveoli, correct? And, if you're lucky, forcing that fluid across that nice thin membrane back into the place where it belongs... naughty fluid... In that case, would the inflammation inherent in infectious processes make the lungs more susceptible to trauma from CPAP, (rupturing alveoli) or are we working at low enough pressures that this is not a consideration?

Wendy

CO EMT-B

[chbare]

Forcing fluid across a membrane may be a mechanism, but it's not an adequate way of looking at what is going on. The fluid issue is largely a consequence of decreased preload from positive pressure and decreased myocardial workload along with a decrease in fluid backup. Of course, this can lead to decreased cardiac output. In addition, you have a degree of pulmonary splinting and possible alveolar recruitment. You also increase your FRC and overall alveolar surface area and can decrease overall work of breathing (see law of LaPlace). In summary, several complex mechanisms occur.

I would add that asthma or other forms of COPD are not contraindications for CPAP; however, medical director guidelines can vary significantly. There is evidence that CPAP can be helpful when used on asthma patients. Also, I want to emphasise that using CPAP for pneumonia (non-community acquired) is not contraindicated per se. The data is just limited at this time. Moby may be back here saying "I told you so" in a few years for all we know.

Edit: "Not adequate" seems a bit harsh and that is not the tone I wanted to convey. I wanted to emphasise a more complete picture.