PEEP valve on BVM's

[Jeremy89]

Just wondering if anyone here has used a PEEP valve when bagging a pt during ARD? If you haven't seen em, its a small valve that attaches to the end of the ambu bag where the O2 would otherwise just escape.

We use em all the time in the hospital for pre-intubation oxygenation. Are we as basics allowed to apply PEEP?, as there are a few contraindications... But if someone's in respiratory arrest, a little extra PEEP is the least of their problems...

 

[TccEMT]

Never even seen it. So it just up the O2% or does it make the volume more?

 

[VentMedic]

We use em all the time in the hospital for pre-intubation oxygenation. Are we as basics allowed to apply PEEP?, as there are a few contraindications... But if someone's in respiratory arrest, a little extra PEEP is the least of their problems...

We use the PEEP valve only if it is an oxygenation problem that is pulmonary and not circulatory.

It the pt is in a respiratory arrest with falling BP and declining cardiac status, I will be not be using a PEEP valve.

If the person has relatively normal lungs there is no reason to use a PEEP valve for pre-oxygenation as the medications given may drop the BP and the additional PEEP may further bottom it.

 

[Jeremy89]

We use the PEEP valve only if it is an oxygenation problem that is pulmonary and not circulatory.

It the pt is in a respiratory arrest with falling BP and declining cardiac status, I will be not be using a PEEP valve.

If the person has relatively normal lungs there is no reason to use a PEEP valve for pre-oxygenation as the medications given may drop the BP and the additional PEEP may further bottom it.

Oh. I've seen our RCP's do it on many pt's. :-S

But our clientele includes a large number of older pt's with underlying conditions. Maybe that's why I see it done, i dunno.

But for your everyday asthma exacerbation, you wouldn't use any peep?

 

[Jeremy89]

Never even seen it. So it just up the O2% or does it make the volume more?

Positive End Expiratory Pressure (as I understand it) keeps a variable amount of pressure in the pulmonary system at the end of the breathing cycle. This helps keep the alveoli and bronchioles open for better oxygen/CO2 exchange.

Ask Vent if you need more detail

 

[VentMedic]

Oh. I've seen our RCP's do it on many pt's. :-S

But our clientele includes a large number of older pt's with underlying conditions. Maybe that's why I see it done, i dunno.

Your RRTs also have access to ABGs and know the oxygenation issues.

But for your everyday asthma exacerbation, you wouldn't use any peep?

That depends on the air trapping, the oxygenation and the hemodynamics. One recipe does not fit all patients even with the same "diagnosis".

 

[VentMedic]

Ask Vent if you need more detail

All about PEEP:

http://www.ccmtutorials.com/rs/PEEP/index.htm

 

[MrBrown]

We have just gotten PEEP, I'm gonna go out on my *** here and say it seems like a poor man's CPAP

 

[exodus]

Your RRTs also have access to ABGs and know the oxygenation issues.




That depends on the air trapping, the oxygenation and the hemodynamics. One recipe does not fit all patients even with the same "diagnosis".

It sounds like using this device always can only help? If the alveoli remain open longer for more O2 transfer, does not this mean they pt can oxygenate and perfused better?

 

[VentMedic]

We have just gotten PEEP, I'm gonna go out on my *** here and say it seems like a poor man's CPAP

Exactly!

That is why we are excited when the better transport vents come out with something other than a resistive valve for PEEP.

 

[VentMedic]

It sounds like using this device always can only help? If the alveoli remain open longer for more O2 transfer, does not this mean they pt can oxygenate and perfused better?

I see you haven't gotten to hemodynamics yet in Paramedic school and hopefully that subject is taught very well.

Also, if you are bagging with 100% O2 and have a PaO2 of 450 mmHg, what more are you trying to accomplish?

 

[MrBrown]

It sounds like using this device always can only help? If the alveoli remain open longer for more O2 transfer, does not this mean they pt can oxygenate and perfused better?

Oxygenation and ventilation are often confused and the concepts used interchangably. They are not the same thing are infact two different physiologic proceses.

The amount of air breathed in is not the amount of oxygen that will reach the brain and tissues.

- Air is about 21% oxygen, yet in Denver it's lower (I don't know the exact forula to figure out how much lower) so altitude plays a part

- The ability to change pressure inside the thorax is also important; if Stanley my immaginary grey pet elephant sits on your chest you will have a very hard time creating a negative pressure gradient to draw air in as you can't expand the throacic cavity enough.

- Just because oxygen is inhailed does not mean it will reach the bronchioles, alveoli, blood, cells and tissues. Any number of obstructions may prevent this - eg choking, hypovolemia, obstructive lung disease/pulmonary edema, carbon monoxide poisioning or a haemothorax.

It is also important to recognise that not all the air inhailed will reach the respiratory zone for the oxygen to diffuse out of the alveoli and into the blood.

The lungs have what is called dead space either anatomical (bronchi and bronchioles that do not have alveoli and pulmonary capillaries, I believe this is the first 20 or 21 divisions of the bronhcial tree) or alveolar; alveolar dead space is any buggered alveoli that can't exchange gas either because they have collapsed or are full of puss or the marbles I ate for dinner.

Dead space is an important concept as about 150ml of air will occupy the anatomical dead space at any one time, this will increase if there is additional alveolar dead space such as in infection or APO/CPE.

This is where PEEP (and I believe also CPAP) are important as they only work on pulmonary problems by decreasing surface tension and assisting the alveolar surfactant to decrease alveolar dead space and ensure more gas exchange.

Doesn't work on a circulatory issue such as V/Q mismatch or anemia.

 

[Shishkabob]

- Air is about 21% oxygen, yet in Denver it's lower (I don't know the exact forula to figure out how much lower) so altitude plays a part

Nope. Every single place you go to in the world will have an air concentration of 21% Oxygen and 78% nitrogen.


The difference is barometric pressure.

 

[MrBrown]

Nope. Every single place you go to in the world will have an air concentration of 21% Oxygen and 78% nitrogen.


The difference is barometric pressure.

Fascinating

 

[VentMedic]

Nope. Every single place you go to in the world will have an air concentration of 21% Oxygen and 78% nitrogen.

Unless you decide to go lower than 21% for specific treatment or to simulate high altitude.

 

[Melclin]

May as well post this here as well.

As a point of (un)interesting trivia...

Oxygen concentration does change with altitude above the turbopause because the thinning atmosphere reduces molecular interaction, allowing the the elements to stratify based on molecular weight.

...

...Prrrobbbably not going to affect Denver though...

 

[Jon]

Exactly!

That is why we are excited when the better transport vents come out with something other than a resistive valve for PEEP.

Umm... OK. Gonna take the bait.

Are you saying there's a different way to generate PEEP on a transport vent? Or a different setting that accomplishes similar objectives?

 

[VentMedic]

Are you saying there's a different way to generate PEEP on a transport vent? Or a different setting that accomplishes similar objectives?

The setting is generated internally rather than attempting to twist s PEEP valve that resembled the cheap ones on the BVMs in hopes of coming close to the setting desired.

LTV 1200 is a good example. You can compare it with the LTV 1000 to see the difference. When transporting patients on higher levels of PEEP like 20 cmH2O, the internal PEEP function generates a more reliable setting. It is also a lot quieter.

 

[Akulahawk]

Nope. Every single place you go to in the world will have an air concentration of 21% Oxygen and 78% nitrogen.


The difference is barometric pressure.

Unless you decide to go lower than 21% for specific treatment or to simulate high altitude.

Or you dive... and breathe some type of mixed gas. (air/EAN/Nitrox/Tri-mix)

The concentration of the various gasses you'd breathe at depth can be kind of interesting when compared to sea level... as in, you do NOT want to breathe that same gas blend by percentages when you're AT sea level...

I, for one, find rebreathers interesting...

 

[Akulahawk]

We have just gotten PEEP, I'm gonna go out on my *** here and say it seems like a poor man's CPAP

Poor man's? That's putting it mildly. I'd probably go so far as to call it "Broke Man's"... While it does maintain a positive pressure, I don't think that there's as good control of that pressure. I'd almost call it a crappy Bi-PAP... where you ARE getting some increased pressure above the PEEP during ventilation, that increase wouldn't be as well controlled as you'd find with an actual Bi-PAP unit. Especially if you're bagging by hand...