CPAP Question

[jamie83002]

I have a CPAP question that I hope saome of you can help me with. The EMS service that I work with has recently aquired CPAP and we are using it for Pulmonary Edema, CHF, and COPD. There is some controversy about the initial pressures we should be using. Most of the studies I've been able to find, as well as the surrounding counties protocols reccomend an initial pressure of 10 cm/H2O. I've also read in several studies that barotrauma would rarley occur in pressures less than 25 cm/H2O. The training we have recieved on CPAP was that we should never administer over 2 cm/H2O, with that being the lowest setting on the CPAP machine. That doesn't leave much room for titration off of CPAP and most other prehospital people I have talked with feel that such a low initial pressure would be ineffective. My concern is that maybe the ones training us aren't as familiar CPAP and are being a little too cautious. Is 2 cm/H2O really even enough positive pressure to reduce preload and afterload with CHF patients? I'd love to hear your thoughts and expereinces with this:

Thanks,

 

[Flight-LP]

2 is too low and will be insufficient. Personally, I start at 7.5 and work my way up to 10 with our unit. Many people start at 5. But anything below 5 is really at the same level, if not lower, than the body's physiological response.

Also, I would use extreme caution with CPAP'ing your COPD'rs. Remember that CPAP is designed to force air into the alveoli allowing a more efficient exchange of gases. COPD'rs and especially asthmatics have an obstructive issue, usually not associated with the alveoli, but with their bronchioles. These folks need a longer expiration time (secondary to hypercapnia), an option not afforded by CPAP.

Other considerations........

If your pt. vomits, your screwed. The can and probably will aspirate. Then they will die from aspiration pneumonia.

If your COPD'r has a simple pneumo (or worse a tension pneumo), they will suffer barotrauma and probably die.

CPAP will increase the intrathoracic pressue and will reduce systemic venous return. Use with caution in your hypovolemics, anemics, and possible ACS pts associated with CHF or they will die.

See a trend???? Sorry, just feeling dramatic today! But in all seriousness, be cautious. Scary part is that some services actually believe this device is safe in a BLS providers hand............

Just my experiences, you may want to ask VentMedic, our in house respiratory pro.............................

 

[eggshen]

At least I don't have to pull that nasal intubation thing as much now. You can have that one.

Egg

 

[VentMedic]

At far as the precautions and concerns...everything Flight-Lp wrote.

What device are you using?

That will actually affect what you can get away with for inital CPAP.

I usually like 5 cmH2O and see if the patient's anxiety level and BP is going to tolerate it. Then 7.5 and/or 10, again watch anxiety level and BP. Again as Flight-Lp mentioned, use caution with COPD that may have blebs.

The patient should also be able to protect their own airway to decrease aspiration risks. Airway clearance may be needed prior to applying mask. I have seen way too many misplaced scrambled eggs by pre-hospital CPAP at the beginning of my shift in the ER.

Depending on the device used, its flow valve, operating pressure, working flow or flow retard device will determine work of breathing. Work of breathing caused by the device will make or break the success of the CPAP.

I posted a pretty detailed post on another forum which I can PM the link to you later if you would like more detailed info.

 

[Airwaygoddess]

Ventmedic, I think it would be great to have an inservice on CPAP for prehospital folks!

 

[Bongy]

Well..We have no CPAPs in EMS in Israel,but regarding my clinical expirience - 5 is goon for initiation...Then - clinically.
My other quession is:
WHAT SIZE OF AN OXYGEN BALLONS YOU HAVE??!!!
CPAP demands A LOT of oxygen and pressured air...How you succes to arrange that ammounts in a truck??

 

[VentMedic]

Bongy,
We get alot of mileage running ventilators off of E-tanks with a 50 psi adapter. We've been doing that for almost 30 years. The Bird and Servo 900 series were very popular transport machines in the 1980s. Technology has since advanced to light weight and more portable.

Some of the pre-hospital CPAP devices out there are "gas guzzlers" and may last an average of 15 minutes. I have seen the studies where those running off a 50 psi flow generator like the vents, may give a few extra minutes.

Although some portable ventilator that can do CPAP have mini air compressors, compressed air is not necessary since most machines utilize the Venturi principle for air entrainment.

 

[Tincanfireman]

Ventmedic, I think it would be great to have an inservice on CPAP for prehospital folks!

I'd like to add my vote to Goddess's, but maybe a step approach would be better so you don't leave us CPAP noobs in the weeds. (and it would be less intensive keyboard time for you, too)

 

[Emtgirl21]

I am a HUGE CPAP fan....it has keep me personally off a vent more than once. Its a great tool.

 

[VentMedic]

I am a HUGE CPAP fan....it has keep me personally off a vent more than once. Its a great tool.

I think you could probably provide some of the most valuable information about what it feels like to use CPAP as a patient. Have you used pre-hospital and hospital devices? If you have, did you notice a difference? Did you notice any difference when the RT was "fine tuning" the settings to your comfort and work of breathing?

As when working with any piece of technology, feedback from the patient by watching, listening and assessing will guide you more than arbitrary numbers. Not all CPAP machines are the same especially in the pre-hospital setting.

Probably, the best I can offer in present time is already provided by Respironics, the current leader in CPAP/BiPAP technology. The company offers free online short educational programs (some for CEUs). Just sign up at:

http://elearning.respironics.com/index_f.asp

After you do, you will see a screen with Product Training Modules and
CE Training Modules headings.

Product Training Modules: in this section you will find EMS related information about a few of Respironics products including the WhisperFlow CPAP system.

CE Training ModulesCourse Catalog) Here you will find the basic theory of NPPV or CPAP and BiPAP (aka BiLevel) as well as capnography. Although the Noninvasive discusses primarily one of our most popular hospital CPAP/BiPAP machines, it will give you an idea of how to compare other systems. This module will also elaborate on some of the highlights of the previous posts. The first feel minutes are a little boring, but it gets better at the halfway mark to the end.

Granted, we want the patient inside the hospital to be able to endure our equipment for possibly a good length of time. So, comfort and synchrony with the technology are key elements.

In other words, don't be offended if in the ER we quickly switch to our technology which costs several thousands of dollars and is capable of a flow delivery of 220 liters per minutes. Don't be shocked by that number which is the speed of flow delivery from a rapid demand system. In the RT world, we discuss ventilators like some discuss cars. Some are high performance and responsive, others are Yugos.

Now for specific CHF information:

It has been demonstrated that by increasing intrathoracic pressure, CPAP reduces left ventricle afterload and unloads the inspiratory muscles of patients with CHF.

CPAP, will reduce myocardial and inspiratory muscle energy demands, allowing redistribution of blood flow to other organs to better match their energy requirements. CPAP can enable a reduction in heart rate in patients with CHF which could potentially improve subendocardial perfusion and allow for better left ventricular diastolic filling.

Overview of the basics:

Good website for general CC knowledge, respiratory and ventilators.
http://www.ccmtutorials.com

Respiratory and ventilators
http://www.ccmtutorials.com/intro/overview/page_04.htm

PEEP vs CPAP
http://www.ccmtutorials.com/rs/mv/page14.htm

 

[Emtgirl21]

I do not really know much about CPAP, how it works or why. I do know what it feels like to be on CPAP. Last time I was on CPAP was for an asthma attack.

Before arrival at the ER I had recieved 2 breathing treatments, had IV in place and had passed out on my medic once. I was speaking in one word whispers, air trapping in lower lungs, my SpO2 was 80 something. I was tired and no longer wheezing. I was breathing bout 30 times a minute. I had the attack while i was on duty and was about an hour and a half into the attack.

The ER doctor decided to not wait on RT and to place me on the CPAP machine. I dont know the settings or what not. The first couple breaths with CPAP were a fight with the machine. It felt like having someone BVM you and your still beathing a little and they arent bagging with your respirations. When RT finally arrived they changed the settings and that helped ALOT. They also connected a breathing treatment to the CPAP which was cool.

I was given IV steriods and was left on the machine for about 30 minutes. Pre and post attack lung x-rays were taken.

Post attack and Post CPAP I actually felt better than I usually do. I was still tired but I wasnt as SOB as usual after an attack. My post attack x-rays looked better than they usually do. My Spo2 was only 93% on room air which was still a little low.

Over all I prefer the CPAP when i get that tired. It seems to be able to get the air and the meds into my lungs when i cant do it myself. I think the breathing treatments are more effective with the machine and that the meds get deeper into my lungs. I could see how it is uncomfortable at first and especially if the machine isnt set right. Oh and getting a proper seal with the mask can be a little difficult i guess.

I have never used one pre hospital. I couldnt definately see the advantages of having one on the truck.

It definately kept me from sucking plastic that night. And trust me sucking plastic isnt fun!

 

[Airwaygoddess]

Thank you Ventmedic for hooking us up to those links and giving us information and education on the devices! Emtgirl21, thank you! For giving us insight on how a patient feels while going though an experience like that. In this profession, we always keep on learning, from the education to the patients!