There are some ventilators today that include PRVC and VS modes.

This modes were developed by Siemmens several years ago.
Are those modes trademark (patented) by Siemens or can be used for any ventilator´s manufacturer??

Horacio,
I do not know if they are patented or not, but most vent manufactures would not want to use the same name of a mode that another manufacturer uses becasue it does not show that their vents are different. PRVC on the Servo products is prettty much the same as CMV with Auto flow on the Drager (which I believe has been out longer than PRVC on the Servo's, but I will probably be proven wrong by somebody), and VC+ on the 840. This is true for APRV on the Drager, Bivent on the Servoi, Bilevel on the 840 and you can go on and on and on. I wish manufactures would use a standard but they don't. They want to be able to come around and show that their products are different and better (supposedly). VS is simmulair to VAPS (volume assusred Pressure Support) I forget on which vent this one is on.

Horacio,
To the best of my knowledge the name of the mode is patented, but the mode itself can be utilized by any. i.e. PRVC from Servo is the same as VC+ for the PB840. The best way to get around the names of the modes is to really understand what it is accomplishing. You can call it whatever you like as long as you know what you are doing and get the best results for the patients.

Mr. Light is correct in that he is wrong. Servo has had PRVC since 1991. Other ventilator manufactures have follow suit just as Drager came out with APRV first and others have followed them.

To some , PVRC is a lot like Autoflow, ot VC+, or V sych, or VG, or any ting that supports volume in a pressure like mode..

again, any "mode" that allows pressure support to manoevrers in such a way that it,s accomadates a function (Vt, WOB, Ve, Raw ext,....) would work like VA, would be like VA.

A lot of people work on these subjects..

I,am not a laywer...


But, a volume is a volume and a pressure is a pressure, flow dependent or not...

Thanks for starting this thread Horacio. I am not certain if the mode or function designations specific to individual vents are patented. I would bet some are, some aren't. It is interesting that some modes or functions if you prefer depending on the situation that were once specific to one machine or another are working their way from the machine they originated on and into the functions of others. The one's you mention specifically PRVC and VS are a good example. Regardless of the machine you find this type of breath delivery logic on, it is essentially a pressure based breath. By that I mean the same flow and breath termination characteristics as PC (time) or PS (flow). I prefer a more generic way of referring to these breath types. Volume targeted pressure control and volume targeted pressure support work better for me. With perhaps slightly different logic a PC or PS breath is delivered and based on volume delivered or returned the machine adjusts the next breath's delivery pressure if off target to come closer to the target. My first in-service on PRVC the therapist explaining it to m e compared it to a tiny little RT in the box adjusting the pressure a little up or down with every breath to give the volume we want. My guess is that even if one manufacturer patents a specific name for a function that another can take up that same strategy of breath delivery as long as they don't call it the same thing, and the machine's internal logic for making it happen is different.

The other ironic thing about all this is that when the vent manufacturers are trying to sell us any new mode or adjunct it's touted as if it's something totally new under the sun. But when they're dealing with the FDA it's "hey this is just gas in and gas out, meet the new mode same as the old mode". (with credit to Richard Branson for pointing this out in some conference sometime).

Let's all raise a glass to the alphabet soup.

With all due respect to Dr. Branson and JeffWhitnack, I do not believe it is as simple as breath in, breath out. Would you rather be on a ventilator like an 840 or a Sechrist. Sure, a car can take you from the east coast to the west coast, but do you want to travel in a Yugo or a Volvo... a Chevette or a Corvette?

Although these modes (PRVC, Autoflow, VC+) are alike (like 4 wheels on a car), its how the ventilator performs doing it that counts the most. An example I can think of is the Servo 300 (who first came out with this dual mode)... and the Viasys Avea have a start-up process that essentially takes 3-5 breaths to get to its idea pressure level to deliver your set tidal volume. If the patients coughs constantly or the circuit breaks, the process has to "reset"... again 3-5 breaths. This may not be ideal for your patient. The Servo-i on the other hand takes just 1 test breath to acheive its ideal pressure level. Big difference. Again, its not that the car gets you there... its how it gets you there.

Push on the gas pedal... do you get immediate response or a delayed response? Makes a world of difference to a patient who needs air now.

Breath in Breath out? 840 or Sechrist?