# Targeted tidal volume?



## TransportJockey (Jun 30, 2014)

Ok just a quick question. I'm going over stuff as a refresher before I take my next critical care class and am wanting to know... is there one accepted tidal volume range? 
I've seen 4-8ml/kg
6-10ml/kg
And 4-10ml/kg
I'm just curious if there's one that's accepted more than others or not. And yes I'm aware that it's based on ideal body weight


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## Carlos Danger (Jun 30, 2014)

TransportJockey said:


> Ok just a quick question. I'm going over stuff as a refresher before I take my next critical care class and am wanting to know... is there one accepted tidal volume range?



Yes. The ONLY correct range is 4-15 ml/kg.


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## TransportJockey (Jun 30, 2014)

Remi said:


> Yes. The ONLY correct range is 4-15 ml/kg.


Lol so all of the above and then some. Thank you, I was hoping you'd see this thread


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## Carlos Danger (Jun 30, 2014)

Yeah, the recommendations are all over the place. In anesthesia the tendency is towards higher Vt, and in CC it seems they generally try to stay as low as possible. Protocols vary from hospital to hospital and even from ICU to ICU.

My understanding is that the only scenario where low Vt's have really been shown to have a positive impact on outcomes is in the ARDS/ALI patient. Still, it seems reasonable that exposing the lungs to as little shear stress as possible is a good thing.

There also seems to be little consensus about using total body weight vs. LBW or IBW. I've heard of using TBW unless the BMI is over a certain point. One of the ICU's I used to work in the RRT's used BSA.


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## Ewok Jerky (Jul 1, 2014)

BLS forum? Enough to get chest rise?


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## ThadeusJ (Jul 2, 2014)

The goal is to minimize barotrauma and volutrauma.  4-8 mL/kg ideal body weight in critical care.  I don't understand how one could rationalize doubling or tripling tidal volumes for obese patients; their lungs aren't any bigger.


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## blindsideflank (Jul 2, 2014)

ThadeusJ said:


> The goal is to minimize barotrauma and volutrauma.  4-8 mL/kg ideal body weight in critical care.  I don't understand how one could rationalize doubling or tripling tidal volumes for obese patients; their lungs aren't any bigger.



this. and to the other poster, yes its a BLS forum but the chest rise theory is no good. this often requires too high of tidal volumes, especially in the settings we are usually bagging patients (post arrest is a great example of a time when we love to induce lung injury and start the ARDS process.)

now for specific numbers, its obviously pathology dependent but 4-6ml/kg of LBW has always been my generic answer


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## Carlos Danger (Jul 2, 2014)

blindsideflank said:


> this. and to the other poster, yes its a BLS forum but the chest rise theory is no good. this often requires too high of tidal volumes, especially in the settings we are usually bagging patients (post arrest is a great example of a time when we love to induce lung injury and start the ARDS process.)



This might be true with very obese folks or inexperienced baggers, but when I ventilate I watch both chest rise, a manometer, and a spirometer and visible chest rise definitely does not usually correlate with excessive airway pressures.


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## avdrummerboy (Jul 10, 2014)

I've always been told 5-7mL/kg, but as with most numbers, there are a lot of variations.


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## systemet (Jul 26, 2014)

I think this depends a lot on what you're trying to do. If you have someone with a large minute volume, who's compensating for some sort of underlying metabolic acidosis, then obviously both your frequency and tidal volume are going to have to be high.

If you've got an ARDS / ALI situation, you're probably starting at 8 ml/kg, and titrating down based on your Pplat.  You're probably going to be in a 6-8 ml/kg range, but might go lower, or the ICU may have gone lower for you.

If they're bronchospastic, you're probably looking at a lower volume, but your primary concern is going to be maximising expiratory time.

If the lungs are healthy, you've got much more of a range to play with.

Or at least that's my (probably oversimplistic) understanding.


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## Drax (Jul 26, 2014)

beano said:


> BLS forum? Enough to get chest rise?



Nailed it.


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## TransportJockey (Jul 26, 2014)

Drax said:


> Nailed it.



Not quite. BLS in my neck of the woods can use autovents with SGA's and a working knowledge of VT is as necessary as a working knowledge of CO. It should be a basically taught part of physiology.


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## Drax (Jul 26, 2014)

TransportJockey said:


> Not quite. BLS in my neck of the woods can use autovents with SGA's and a working knowledge of VT is as necessary as a working knowledge of CO. It should be a basically taught part of physiology.



I would like to compare protocols, if you've got an online version. I'm pretty positive nothing mentioned in this thread would be found on a NREMT-B exam though.


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## TransportJockey (Jul 26, 2014)

Drax said:


> I would like to compare protocols, if you've got an online version. I'm pretty positive nothing mentioned in this thread would be found on a NREMT-B exam though.


My service protocols I don't. But I can get yoy the NM scope of practice which shows the allowable skills and guidelines for basics


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## Aprz (Jul 26, 2014)

I think breathing is an ALS-only skill too? Stop breathing. Who cares if this was posted in the BLS or ALS forum? I find it ridiculous that people are refusing to properly answer this because it was posted in the BLS forum. Perhaps this is a scary question because he mentioned that he was using this to set the tidal volume in a vent, but the concept of tidal volume is definitely introduced at the BLS level. In my area, paramedics cannot use vents so if he had posted it in ALS, I would have to give him a dumb answer too, and then hint to him to post it on ALS again, but make sure to include [CCT] in the title for me to properly answer this, or he needs to post it on a nursing forum because only RNs in my county can use a ventilator. Since I don't push drugs, do I not need to know how to convert lbs to kg? I don't need to know how BGL? Pulse ox? In my area, EMTs can't do that. Should I not know that room air FiO2 is 0.21? Really?

Anyhow, the question was already answered, but I find it appalling that EMTs are unwilling to learn something so basic because this basic information is used for something that's outside of their scope in many areas. How dare the OP for posting this in BLS instead of ALS or put [CCT] or post in a prehospital forum at all. Terrible.


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## Drax (Jul 26, 2014)

Aprz said:


> I think breathing is an ALS-only skill too? Stop breathing. Who cares if this was posted in the BLS or ALS forum? I find it ridiculous that people are refusing to properly answer this because it was posted in the BLS forum. Perhaps this is a scary question because he mentioned that he was using this to set the tidal volume in a vent, but the concept of tidal volume is definitely introduced at the BLS level. In my area, paramedics cannot use vents so if he had posted it in ALS, I would have to give him a dumb answer too, and then hint to him to post it on ALS again, but make sure to include [CCT] in the title for me to properly answer this, or he needs to post it on a nursing forum because only RNs in my county can use a ventilator. Since I don't push drugs, do I not need to know how to convert lbs to kg? I don't need to know how BGL? Pulse ox? In my area, EMTs can't do that. Should I not know that room air FiO2 is 0.21? Really?
> 
> Anyhow, the question was already answered, but I find it appalling that EMTs are unwilling to learn something so basic because this basic information is used for something that's outside of their scope in many areas. How dare the OP for posting this in BLS instead of ALS or put [CCT] or post in a prehospital forum at all. Terrible.



This is an over reaction. No one here has an objection to learning, we've just have not had formal training on the subject matter. From outward appearances the subject appears to be ALS, based on the dialogue, nothing like it was covered in my course. The intent is post it in a location where it may get the attention it deserves. I don't need to get into an argument about basic skills one might or might not know/might or might not want to know and whether or not they are required to being success at one's profession.


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