I am chuckling. In the past I have described it as pressure starvation, and been corrected that it's actually the low flow output--since the pressure target is minimal to zero above set peep the flow output is low cuz the pressure target is low.

Can we just say "whatever"? If the pressure target was higher then the flow would be higher also. If the pressure target stayed the same yet some type of P.01 sensor ramped up flow (over the set target) then that might be a solution also. Some tout PAV as a solution, but the ARDSnet guidelines might be subverted as the resultant VT may be over desired (better to sedate/paralyze---a recent study suggests paralysis may help unless steroids being given---will post it later).

The point is that the more the patient pulls over the set VT the less he/she gets. If the patient is only being kept on the ventilator becasue of airway issues (i.e. airway edema) this may not be a problem at all. But if the patient needs substantial support yet is also in extremis and pulling over the set VT then a vicious and detrimental cycle can ensue.

The patient may be able to freely breathe and pull in more...but if in need of substantial support then it may be analogous to a fish removed from aquatic support and "free" to flop around in the dirt.

I go more with your first impression of pressure hunger, but whatever. Detrimental is detremental. But low flow and low pressure are not always the case when you are talking about a mode that allows the patient to breath what ever flow and volume they want. Many times these patients have inspiratory flows of 60-80 L/min and volumes of 800 plus ml's but only have inspiratory pressures of 10-15 cmH2O. So in this case their flow is great but they are sucking down the pressure, breath by breath and they are now having pressure issues, becasue the vent is backing down the inspiratory pressure to try and achieve our target volume ,which in turn increase their WOB and decreases their MAP, neither which we want.

Jeff, I know you know this it is more for others that might read it.

My opinion it is still pressure hunger

Hey we coudl differentiate between "demand side" and "supply side" for both flow and pressure. In your example the flow was high, yet generated by the patient. In old fashioned VC control, if flow set high then the patient might have "Double clutched" and cycled two breaths, essentially doubling the VT set.

Demand side Pressure would come in if one dialed in ATC and then the ET size and patietn flow created a new ATC Autoflow pressure target---even though targeted carinal pressure was only 1 above set peep.

thank you guys for the responds. sorry i toke a several day before coming back.any one using smart care by drager? could someone help me to understand this smart care?

Icebox... how is it that you are a therapist and you seem so confused about such simple issues? I am scared.

quote:

Originally posted by idiopathic:
Icebox... how is it that you are a therapist and you seem so confused about such simple issues? I am scared.

I am sorry to disagree with you idiopathic. This person is from another medical care system, one might assume that the respiratory care is not given by an RRT "to the north american standard". He says he is knew to the field of RT; what if he is a nurse or physical therapist in the process of getting trained in ICU?

And lest say that he IS an RRT... I rather like the type that asks and get the right answer...

Beside, isn't it the main goal of this forum?

With all respects sir.

Thanks Renton for clearing that up for ideopathic. There is some strong expertise that frequents this forum, and some of the discussions are certainly deeper than many less experienced or studied might feel ready to jump into. That is a shame. One of the true strengths that should come with more knowledge is the ability to share it with others. Icebox's questions are quite probably ones that many appreciated being asked. We have many lookers, but few that participate in the exchanges. Ideopathic we appreciate you having joined, and participating. We also hope you bring your knowledge here to share, but we also appreicate Icebox and his openess in asking in order to gain better understanding from the strength of this group. Jeff and Light are two very impressive RT minds, and I found the discussion in this thread pretty great, and have Icebox to thank for it. I want to encourage those who pass through, and have a question that they fear might seem silly or trivial to ask it anyway as long as it is on topic. Often issues that seem simple to one might be complex and snarled to others so asking is encouraged. That is one way that I get to learn as well. It seems we did not really get to the response to Icebox's final question in this thread about Smartcare. Here is a link to another discussion that might help some https://ventworld.infopop.cc/eve/forums/a/tpc/f/2616042361/m/9951074932