OXY-PEEP for CPAP?

[Spock]

VentMedic--Which disposable CPAP system "isn't to bad." I've been researching this in order to recommend a system for my service. Through chart reviews I've determined that we would probably use CPAP at least once per week so we do have a need. Unfortunately my experience with CPAP is all in hospital so these prehospital units leave many questions especially oxygen consumption. Any help would be appreciated.

Live long and prosper.

Spock

[VentMedic]

I am fairly impressed with the WhisperFlow. The flow generator is non-disposable but very portable and durable. I look for a high flow rate to meet demand. This does NOT translate necessarily into high O2 consumption from the tank. We do own a couple of different WhisperFlow models by Caradyne (now owned by Respironics) in the hospital for back-up in the ER and PACU. Respironics is a supplier of our ICU BIPAP/PAV/CPAP machines. They have been around a long time as have some of their products. They also offer good education and decent support.

Excellent article that shows some of the factors looked at when selecting CPAP units.

http://www.cardinal.com/mps/focus/respirat...3%20Branson.asp

http://whisperflow.respironics.com/Features.asp

http://www2.uchsc.edu/anes/ArticleOfMonth/...the%20month.htm

[UMSTUDENT]

I am fairly impressed with the WhisperFlow. The flow generator is non-disposable but very portable and durable. I look for a high flow rate to meet demand. This does NOT translate necessarily into high O2 consumption from the tank. We do own a couple of different WhisperFlow models by Caradyne (now owned by Respironics) in the hospital for back-up in the ER and PACU. Respironics is a supplier of our ICU BIPAP/PAV/CPAP machines. They have been around a long time as have some of their products. They also offer good education and decent support.

Excellent article that shows some of the factors looked at when selecting CPAP units.

http://www.cardinal.com/mps/focus/respirat...3%20Branson.asp

http://whisperflow.respironics.com/Features.asp

http://www2.uchsc.edu/anes/ArticleOfMonth/...the%20month.htm

VentMedic do you know any literature that compares PEEP only devices like the OXY-PEEP to devices like the WhisperFlow and CPAPos that deliver inspiratory pressure? Specifically on the effectiveness of these two devices when compared to the other?

[VentMedic]

There is some literature on the Boussignac CPAP system which is similar in principle function. Much of it is off the pilot study which is many times sponsored by the manufacturer. :shock:

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

Once again; Terminology:

PEEP - Positive End Expiratory Pressure

PEP - Positive Expiratory Pressure

CPAP - Continuous Positive Airway Pressure

PAP - Positive Airway Pressure

WOB- Work of Breathing

The PEEP valves (a.k.a. as PEP valves in other uses) externally are resistive valves designed to hold to the set "PEEP" in cmH2O then bleed out (like a pop-off). If flow is adequate you will maintain a PAP continuously and in turn may achieve PEEP. If flow is inadequate with patient's respiratory pattern, the bleed out point is not reached, PAP is not maintained and patient expends energy against PEP to exhale. Thus PEEP is not maintained or achieved. The idea is the "stent" with PEEP the airways open while exhaling without increasing WOB.

Thus the PEEP can be regulated by maintaining a constant PAP with PEP.

CPAP can also be illustrated in "hose jockey speak" as far as flows and pressure. Will the right pressure valves in lines at the hydrant, the illusion of more water is achieved by a constant pressure done by valves and nozzle size. With out the adequate pressure, more water is expended without the same effect.

Think of taking a drink from a garden hose. The same flow is running from the turn-on faucet but depending on the bore size of the tube it may come out as a trickle. A resistive valve in line will increase continous pressure to achieve a more desirable flow.

We could also get into a discussion of the venturi effect and Bernoulli's principle as it applies to gas at this point.

The pressure at the generator can utilize the 50 psi port to increase flow speed in terms of driving pressure without necessary increasing the gas usage.

1 mmHg = 1.36 cmH2O = 0.133 kPa = 0.0193 psi = 1.3332 mbar

I believe this article is close to what you asked for.

Comparison of 3 CPAP Systems for pre-hospital use. (research done by a Registered Repiratory Therapist)

http://www.jems.com/pdf/Respironics.pdf

Simple lightweight disposable continuous positive airways pressure mask to effectively treat acute pulmonary oedema: randomized controlled trial.

http://www.medscape.com/medline/abstract/15953223

Boussignac continuous positive airway pressure device in the emergency care of acute cardiogenic pulmonary oedema: a randomized pilot study.

http://www.medscape.com/medline/abstract/12972896

Laboratory testing measurement of FIO2 delivered by Boussignac CPAP system with an input of 100% oxygen

http://www.medscape.com/medline/abstract/12706763

Dynamics of pressure and flow curves of various expiratory pressure valves

http://www.medscape.com/medline/abstract/9235483

Boussignac CPAP - aritcle from JEMS

http://www.jems.com/jems/31-6/106692/

Boussignac CPAP

http://www.vitaid.com/usa/boussignac/index.html

When there is talk of sedating patients to keep them on CPAP, then something is not being achieved or taken into consideration. 1) the device may not work on this particular patient 2) pt doesn't like masks 3) high flow may actually be frightening to pt. 4) time for plan B

In the hospital, if our pts have to be physically or chemically restrained for CPAP, we start looking for another alternative quickly. Our newer equipment is capable of PAV which is not to be confused with BIPAP or BILEVEL. And no, BIPAP is not CPAP with Pressure Support Ventilation. This is where PAV comes in. Many times we will run the NIV off of our ICU machines as PSV/PEEP or CPAP.

This is a whole lecture for another place and time.

[Spock]

Thanks for the information VentMedic. We are looking at the Boussignac and the Whisper flow. The Boussignac is appealing because it is completely disposable so when we arrive at the hospital we can just connect to the hospital oxygen supply and get back in service. Our crews have been calling in and asking for CPAP to be ready upon their arrival but the hospitals are slow to respond so there is significant lag time. Pittsburgh EMS added the Boussignac a few months ago.

One of the biggest issues is getting the services around us to agree with one type of system. That way the hospitals to which we transport most of our patients can stock one circuit for replacement. That would cut down on the cost not to mention possible cost savings with bulk purchases. Unfortunately we have some service directors that don't even know what CPAP means.

Live long and prosper.

Spock

[UMSTUDENT]

There is some literature on the Boussignac CPAP system which is similar in principle function. Much of it is off the pilot study which is many times sponsored by the manufacturer. :shock:

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

Once again; Terminology:

PEEP - Positive End Expiratory Pressure

PEP - Positive Expiratory Pressure

CPAP - Continuous Positive Airway Pressure

PAP - Positive Airway Pressure

WOB- Work of Breathing

The PEEP valves (a.k.a. as PEP valves in other uses) externally are resistive valves designed to hold to the set "PEEP" in cmH2O then bleed out (like a pop-off). If flow is adequate you will maintain a PAP continuously and in turn may achieve PEEP. If flow is inadequate with patient's respiratory pattern, the bleed out point is not reached, PAP is not maintained and patient expends energy against PEP to exhale. Thus PEEP is not maintained or achieved. The idea is the "stent" with PEEP the airways open while exhaling without increasing WOB.

Thus the PEEP can be regulated by maintaining a constant PAP with PEP.

CPAP can also be illustrated in "hose jockey speak" as far as flows and pressure. Will the right pressure valves in lines at the hydrant, the illusion of more water is achieved by a constant pressure done by valves and nozzle size. With out the adequate pressure, more water is expended without the same effect.

Think of taking a drink from a garden hose. The same flow is running from the turn-on faucet but depending on the bore size of the tube it may come out as a trickle. A resistive valve in line will increase continous pressure to achieve a more desirable flow.

We could also get into a discussion of the venturi effect and Bernoulli's principle as it applies to gas at this point.

The pressure at the generator can utilize the 50 psi port to increase flow speed in terms of driving pressure without necessary increasing the gas usage.

1 mmHg = 1.36 cmH2O = 0.133 kPa = 0.0193 psi = 1.3332 mbar

I believe this article is close to what you asked for.

Comparison of 3 CPAP Systems for pre-hospital use. (research done by a Registered Repiratory Therapist)

http://www.jems.com/pdf/Respironics.pdf

Simple lightweight disposable continuous positive airways pressure mask to effectively treat acute pulmonary oedema: randomized controlled trial.

http://www.medscape.com/medline/abstract/15953223

Boussignac continuous positive airway pressure device in the emergency care of acute cardiogenic pulmonary oedema: a randomized pilot study.

http://www.medscape.com/medline/abstract/12972896

Laboratory testing measurement of FIO2 delivered by Boussignac CPAP system with an input of 100% oxygen

http://www.medscape.com/medline/abstract/12706763

Dynamics of pressure and flow curves of various expiratory pressure valves

http://www.medscape.com/medline/abstract/9235483

Boussignac CPAP - aritcle from JEMS

http://www.jems.com/jems/31-6/106692/

Boussignac CPAP

http://www.vitaid.com/usa/boussignac/index.html

When there is talk of sedating patients to keep them on CPAP, then something is not being achieved or taken into consideration. 1) the device may not work on this particular patient 2) pt doesn't like masks 3) high flow may actually be frightening to pt. 4) time for plan B

In the hospital, if our pts have to be physically or chemically restrained for CPAP, we start looking for another alternative quickly. Our newer equipment is capable of PAV which is not to be confused with BIPAP or BILEVEL. And no, BIPAP is not CPAP with Pressure Support Ventilation. This is where PAV comes in. Many times we will run the NIV off of our ICU machines as PSV/PEEP or CPAP.

This is a whole lecture for another place and time.

Thanks VentMedic. I took this information to our county medical director, and after much of the same conversation and a demonstration, he also came to the conclusion that the OXY-PEEP is not true CPAP. The discussion started with much of what you're explaining now, but more in line with Bernoulli's principle. Where the confusion seems to be is that the OXY-PEEP does not utilize any mechanism, say a restrictive valve or even progressively smaller tubing, to simulate an inspiratory pressure. The device works essentially as a nonrebreather mask with a PEEP blow-off valve attached. The FiO2 adjustment device in no way controls the flow. All you're getting is a standard flow of 15 LPM of oxygen, because as you exhale against the PEEP the oxygen being delivered is simply blown off too. There is no subsequent build-up of inspiratory pressure.

I'm going to look over some of these studies. Thanks again!

[tniuqs]

DustDevil, you're right on mark with the terminology here.

I usually prefer graphics when trying to explain CPAP and respiratoroy phases.

You just made me reminiscent of Nancy Caroline's Text and the adventures of "Sidney Sinus node" for the dumbing down part. I see it is still presumed that some texts must be written at that level.

RT principles and fundamentals haven't changed; just a few more knobs and buttons on sleeker looking technology.

They always wanted us to use a PEEP valve on self-inflating bags but I find them a little futile at times. It retards the exhalation phase momentarily but ends before the next breath and the manometer drops to zero. I will run a valve in line with a free flow anesthesia bag (Jackson-Rees system) and try to maintain an elevated baseline with flow..."flow PEEP" from the DOWNES and EMERSON days. There is one disposable CPAP system that reminds me of a DOWNES generator and actually isn't too bad.

There are two devices that I have recently seen on the trucks that are essentially "nebs with a restrictive valve" running on 6- 10 liters off the flowmeter. One patient was being physically restrained to stay on the device. I've been wanting to toss a manometer in line to see what the baseline is holding at with this devices. I've just been too busy switching them to my technology so they can be unstrained and breathe.

Darn I missed all the fun on this one, a day late and a dollar short....rats.

Just one passing comment to throw a screw into this topic, the diffence of non-threshold PEEP and threshold PEEP, ie On a Vent if inspiratory demand (at the mouth) exceeds the set PEEP then the Machine then triggers an and additional valve kicks in to maintain true threshold PEEP, in the cheaper devices this is acomoplished with the use of Ball and spring type assemblys or valves...this is "the purist definition true PEEP" but it can make major differences to the success in oxygenation of the critical patient. Sounds picky but pulmonary mechanics can be quite complex, ie BEST PEEP, vs Optimal PEEP, la la la... and the beat goes on.

Fact remains (and as I always caution) with applications of PEEP/CPAP---- these methods whatever the type of delivery should be approached as a drug would be used --- arbitrary numbers can be a real concern in the circling the drain crowd that said this is an area that Paramedics need MORE edjumication, one can stave off the tube and provide improved care as well as save the costs of a Ventilator and an ICU bed, so please remember some of the patients have not read any of books!

cheers good thread.

Vent medic should we discuss the CPAP vs Pressure Support ?

WOB increases with CPAP, not PS...

[PhillyD]

I'm having a bit of difficulty understanding something. Recently, one of the systems I work in finally decided to implement CPAP in the CHF protocol algorithm; however, they decided on using a device called the OXY-PEEP by Smiths Medical.

The device is purely a PEEP mask according to the manufacturer's specifications and from my own observations. It allows you to adjust the end expiratory pressure, but does not deliver continuous pressure during inspiration. This has not been my experience with the Emergent PortO2Vent or other devices that I've used or been trained on in the past. While I understand that PEEP is better than nothing at all, I find it hard to justify calling it CPAP on a patient care report.

Am I missing something here? I want to make sure I'm not catching something before I go complaining.

No you are not. Congratulations, you are practically the very first to figure this out on their own!

High FIO2 w PEEP is not CPAP, but it helps the same patients better than a NRBM. Of course no inspiratory pressure support means you really can't call this thing CPAP. It's helpful, but does not do Continuous, or Constant (both Inspiration & Expiration) Positive Pressure.

The single most popular reason to use it - is when an agency has a whole lot of different ED's they go to. Then the ability to just put them on ED wall flowmeter and leave is appealing to many.

It is in my opinion, better than the Boussignac disposable which only does low FIO2 w PEEP. No reservoir, no inspiratory flow support.

I have a decent ppt on Oxy-Peep if you want, e-mail phillydan@hotmail.com

[VentMedic]

High FIO2 w PEEP is not CPAP, but it helps the same patients better than a NRBM. Of course no inspiratory pressure support means you really can't call this thing CPAP. It's helpful, but does not do Continuous, or Constant (both Inspiration & Expiration) Positive Pressure.

"Inspiratory Support" is a whole different "mode". This is a pressure supported breath and is available on ventilators and home sleep apnea machine. The common name for that is BiPAP which is a trade name of respironics.

CPAP is Continuous Positive Airway Pressure which utilizes priniciples of flow with an end resistive valve in the simplest of systems. Some prehospital devices make better uses of the flow principles than other. (I described the flow principles earlier in this thread)

Even on an ICU ventilator, there is no "inspiratory support" pressure with CPAP. This requires a machine capable of a 2 pressure level mode. Some patients can not tolerate just CPAP and is not appropriate for everyone.

I know there is a lot of confusion with different terminology and "trade names". However, if you understand the basic principles and look graphically, it is easy to distinguish the difference between CPAP and BiPAP (trade name) which offers inspiratory support.