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Servo I (NAVA mode)
Picture of ric crt
Another mode from Servo I. The NAVA mode, any idea on this mode.

ric mandanas jr
c/o rt dept.
hamad medical corp.
p.o. box 3050
doha, qatar
Posts: 30 | Location: doha qatar | Registered: April 27, 2003Reply With QuoteReport This Post
Picture of JeffWhitnack
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Basically it is PAV (or PPS for Drager) with triggering moved to diaphram's electrical stimulus.

So two issues....

Pro/Con for PAV

Pro/Con for diaphragmatic electrical trigger.
Posts: 171 | Location: Palo Alto, CA USA | Registered: November 14, 2002Reply With QuoteReport This Post
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NAVA- neuroligically adjusted ventilaory assist.Its going to be the future of ventilation and is a very dynamic mode of support that responds to neural triggering at the crural/diaphragm level via an edi catheter thats positioned via ecg waveforms on the servo i screen.Patient must be able to breath spontaneously. The NAVA level or gain control is set that responds to the proportionality of the electrical signal. The response time reduces WOB compared to the pneumatically controlled pressure or flow triggering. The catheter can also double as a feeding tube. We have tried NAVA in the NICU and have been able to validate its effectivity with several patients.Its potential is enormous. It can help monitor and reduce sedation levels, reduce time on intubated patients.The window of opportunity is open. There is much to be learned about this mode.It is relatively simple to set up. The costs however, to obtain the module, software and catheters are expensive.Current modes of ventilation can be considered static after you try SERVOi/NAVA.
Posts: 6 | Registered: May 14, 2007Reply With QuoteReport This Post
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I'm sorry, but it just sucks...

Call me when neg pressure vents will really work...
Posts: 49 | Location: Ste-Agathe-Des-Monts, Québec, Canada | Registered: October 14, 2005Reply With QuoteReport This Post
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You're an idiot.
Posts: 21 | Registered: December 10, 2007Reply With QuoteReport This Post
VentWorld Director
Picture of GaryMefford
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Renton, please support your position.
From all that I have read on NAVA, which hasn't been much, and the majority of which was provided in Maquet materials makes it look interesting. Gklein seems to be having some success with it. I have not had much of an opportunity as yet to speak with anyone who is dealing with the day to day issues with this on real and complex patients. Renton may have more experience with it than some others so may recognise that there are issues that are difficult to deal with in certain cases and I sense some frustration. So seatac, I am going to request in the future, rather than hurling insults when someone expresses an opinion you don't agree with please express it somewhat more tactfully and ask them to support their position. And Renton have you gotten your hands on the United Hayek RTX. It is not exactly NPV, but it will offer some new options and uses Neg. and Pos. curass ventilation. Not having had my hands on one of the I's with NAVA as yet, can someone fill us in on how it works beyond what Gklein and Jeff have provided? Using diaghramatic muscle firing as the trigger seems a very logical way to get maximum synch., but what is set on the machine? PAV means a percentage of total work effort or desired VE? I would really appreciate some thoughts on the questions that Jeff suggested. Is this a new outcome improver (few new bells and whistles that come along really are) or is this a exensive gimick? I would really appreciate learning more. If you have an opinion; however please take a few minutes to provide at least anectdotal support for it.
Posts: 147 | Location: Buckeye Az | Registered: January 27, 2006Reply With QuoteReport This Post
Picture of JeffWhitnack
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And Seatac can you provide any EBM that Renton is an "idiot"? Smile

Seriously...what this forum SHOULD be about is for someone who uses NAVA to enlighten us as to...

1) what the specific advantage of diaphragmatic triggering is? I don't see any problem to be solved with using pressure trigger on our vents. But maybe the patient does feel a lag time between the signal getting out and the breath coming in. And maybe such a disconnect is a source of induced stress or needlessly increased P0.1?
2) what the advantage is of using PAV (which NAVA uses by default).
3) and tie that to a clinical scenario in which a patient improves better or faster than with other modes. Which justifies the extra money and potential problems.

Why is NAVA/PAV on Servo better than PAV on 840 and/or PPS on Evita? Or different?

It seems to me that someone could use NAVA and either optimize or screw up both the pacing aspect of it and/or the PAV aspect of it.

If inducing biologic variability is beneficial (and I think it is) do we need to have the patient doing it? Or could we just as easily program the vent to "dance" around certain parmaters?
Posts: 171 | Location: Palo Alto, CA USA | Registered: November 14, 2002Reply With QuoteReport This Post
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I stand by my assessment.

NAVA is new and fascinating. The majority of RT's are unable to grasp, comprehend and embrace new concepts. It takes a physician in your hospital to appreciate the far reaching possiblities that NAVA has to offer and make the RT staff come along. Monitoring alone with a NAVA catheter gives the staff a new vital sign, electrical activity of the diaphragm, and what effect changes we make with the vent or sedation do to our patients.

I certainly do not know what the future holds for NAVA as many studies are just starting to ramp up. But I'm sure that was said about many other, often life saving therapies; ECMO, nitric, surfactant, oximetry, pressure support! Now all the standard of care in many situations. Check out to see what research is in the works.

Why is NAVA 'better' than PAV. PAV is based on a mathematical calculation not physiologic response from the patient. The other is that NAVA is for all patient populations neonate to adult. For those of us in the NICU and PICU, PAV is useless. To my knowledge PPS is not available in the US so again for us irrelevant.
Posts: 21 | Registered: December 10, 2007Reply With QuoteReport This Post
Picture of JeffWhitnack
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I hate to get into a quasi name calling type thing....but it sounds like you're saying "sour grapes", all you ignorant RT's are too stupid to figure NAVA out, and the brilliant MD's will be falling head over heels in love with NAVA, so get ready for the Tsunami of NAVA (hey a movie title or a new cocktail name?)

NAVA IS JUST A TRIGGER FOR PAV! If you are using NAVA in Peds, neonates, geriatric centarians with end stage Lupus, whatever, then you are also using PAV. And if you are already using a pressure or flow trigger in the above named populations then there is no FDA ruling I am aware of banning PAV also.

I believe PPS is currently available on Drager Vent....

NAVA is just a trigger for PAV or PPS (same thing essentially)

Richard Branson has described NAVA as being a trigger for PAV, that any discussion or evaluation of NAVA must have a dual nature---the value/benefit of the trigger and the value/benefit of PAV (or PPS)

The fact that you would slam RT's as being not up to snuff as regards evaluating NAVA---and then demonstrate rank ignorance yourself of some pretty basic apsects is, well, ironic and humorous to say the least.

But you may be right that the combination of NAVA trigger with PAV/PPS together will open up some better way to apply mechanical ventilation. But it would help in elucidating such if you better understood the mode yourself

see below....From Google search for "Is PPS on Drager Ventilators FDA approved yet?"

New Mode of Ventilation for Evita XL Ventilator

By Jodi Wright, MD Buyline Associate Analyst

February 4, 2009

Draeger has announced FDA clearance of its PPS mode of ventilation for the Evita XL ventilator (from Draeger Press Release No. 8us/January 26, 2009.)

PPS (Proportional Pressure Support) offers pressure supported breaths proportionate to patient effort. With this mode engaged, the ventilator continually measures the compliance and resistance in the patient’s lungs. The delivered pressure adjusts to meet the needs of the patient. The benefit is increased patient comfort and decreased work of breathing. This can lead to successful weaning and fewer ventilator days.

According to Edwin Coombs, MA, RRT, Associate Director of Marketing for Draeger Medical, "In a patient with healthy lungs, breathing gas flow and thus tidal volume are more or less proportional to the inspiratory effort. The greater the inspiratory effort, the greater the volume inhaled."

"In contrast, a patient with a lung disorder characterized by increased resistance and/ or reduced compliance may be faced with a higher work of breathing, which is increased to such an extent that the same inspiratory effort results in a much smaller volume being inhaled.

"As the patient will always attempt to get sufficient ventilation, there is a risk of muscle exhaustion. Using Proportional Pressure Support, however, the 'comfort' for the spontaneously breathing patient can be increased significantly by deliberately reducing the work of breathing."

This option is expected to be available by March 2009 and the company says that existing Evita XL ventilators are upgradeable. New Evita XL ventilators will offer the PPS feature as an option.

We do track Draeger equipment and Evita ventilators in the MD Buyline database. Members can look up specifics about this company and equipment there.

For more information about the Evita XL, visit the company's website.
Posts: 171 | Location: Palo Alto, CA USA | Registered: November 14, 2002Reply With QuoteReport This Post
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For clarification:
PAV (proprietary PB term) on the 840 is not intended for less than a 6.0 ETT and you cannot have a leak. This makes is unusable in the Neo/Ped population. NAVA (servo term) performs in spite of a leak and autopeep as the trigger is moved inside the body at the level of the diaphragm and away from the airway.

NAVA is true proportional assist in relation to the neural output of the brain, not based on a mathematical calculation. There is a vast difference. NAVA is based on how we breath on a moment to moment basis. Our brain tells us how much minute volume we need to keep our acid/base balance normalized and we contract our diaphragm to get it. The problem is if we are diseased, and get sick, we can tell our diaphragm to contract harder but we may not be able to generate adequate ventilation. So we may get put on a ventilator. NAVA gives the option to continue spontaneous breathing and observe objective unloading of muscle work. If NAVA is not appropriate we can use it to monitor and sedate appropriately and possibly fine tune current ventilator settings to match the patient a bit better. Though in A/C modes we have found this extremely difficult. It can be done much easier with pressure support.

NAVA is a whole new concept that takes into account physiology and neural response of the human body to ventilation and sedation. Many RT's cannot even describe basic modes of ventilation to a doc or nurse. Those that can are the exception not the rule. Our docs need to be involved as they understand these physiologic responses on a whole different level than a bedside RT. We have many RT's that engage and others that simply walk away to go give a neb tx when we are running NAVA. I assume it's either because they are too overwhelmed or really just don't care.

For those that comment , such as Branson, on what NAVA is and isn't I would ask if they have actually used it or seen it in action. I do not take their comments as exceedingly useful if they have not used it. I agree we do not know if it will change outcome but we won't know that unless we explore the possiblities. If you see no value in NAVA don't use it. This is especially true if you don't use Servo's. Sort of impossible. But stop saying what you think it is until you actually gain some experience with it.

In regards to PPS it appears per the FDA notice it is available however their online brochures still exclude it as available in the US. They may want to update their brochure.
Posts: 21 | Registered: December 10, 2007Reply With QuoteReport This Post
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