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NAVA mode of ventilation in Servo i

Have you heard about NAVA

Is a mode of ventilation that available on SERVO I ventilator, delivers assist in proportion to and in synchrony with the patient's effort as reflected by Edi signal (the electrical activity of the diaphragm)

since the diaphragm is the main respiratory muscle so they use the its electrical signal to trigger spontaneous breath from the ventilator, which lead to better synchrony between the patient and the ventilator, also decrease WOB.

NAVA using special feeding tube carrying 10 electrodes, this tube goes down to the stomach so it can be used for feeding also it picks the signal from the diaphragm and send it to the ventilator.

Potential benefits of NAVA:
Improve synchrony
Decrease WOB
Prevent over or under supporting of the patient (the patient will determine the amount of PS)
NAVA works independent of leakage (Neural triggering not flow or pressure) so it is excellent with neonate and small babies

Any body have experience with NAVA can share us his information ??

Attachments:

NAVA.jpg, 13 KB
CCN_art25_First_experiences_with_NAVA_in_a_University_Hospital_setting.pdf, 398 KB

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Replies to This Discussion

Permalink Reply by Antonio on August 3, 2009 at 9:21pm

The technology has a catheter positioning screen that give the clinician the ability to gauge that the catheter is in the correct position.

The initial measurement is taken, then the positioning screen also helps with confirmation that it is picking up the diaphragm signal. There are many alarms to alert the user of catheter malposition. As far as electrolyte imbalance, well if the conduction is slowed down the neural pathway (phrenic nerve) or the action potential is affected then the signal will show the same affect. Remember that the signal is the closest signal to what the body is asking the diaphragm to deliver, NAVA just uses this signal so in essence the ventilator is a prosthetic diaphragm and the ng or edi catheter is a prosthetic phrenic nerve.

it's no different than a balloon pump being synchronized to optimize cardiac performance.

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Permalink Reply by Ahmad on July 18, 2009 at 1:19am

Signal used in NAVA measured by micro volt while ECG signals milli volt, also there is a filter inside the NAVA module to eliminate any artifact or unwanted signal.

Regarding breath termination or cycling off, in PS modes you can change it as a % of peak flow,but in NAVA the neurally triggered breath will be terminated When the Edi (electrical diaphragmatic impulse) decreases below 70% of the peak value,
ie, if the patient took a breath by creating a signal of 10 micro volt, expiratory phase starts when the signal decreases below 3 microvolt.

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Permalink Reply by Ahmad on July 19, 2009 at 9:39pm

This technology available on Servo i ventilators only.

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Permalink Reply by Anas Abdelrahman Moqbel Mansi on July 25, 2009 at 4:38pm

I'm not well oriented yet to the new mode, But as I know this mode is mode of weening so we cant give the patient any sedative_ our Low dose _ and with no muscle relaxant agents, I think that the signal will not be affected by muscle relaxant because it well be captured from the phrenic nerve but it well be affected by the sedative agent.

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Permalink Reply by Ahmad on July 26, 2009 at 9:04am

As NAVA is a weaning mode, so the patient is not supposed to be under sedation, one of the main potential benefits from NAVA is to reduce the level of sedation. the main player in NAVA is Edi (electrical diaphragmatic impulse) or diaphragmatic contraction, presence of sedation means absence of Edi (or low Edi).

Regarding muscles relaxants, giving muscle relaxants will not affect the signal which coming from the respiratory center in the brain, BUT, it will block the receptors inside the muscle it self which means no contraction, so NAVA is not going to work because there is not diaphragmatic contraction

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Permalink Reply by Marilou V. Carlos on July 15, 2011 at 11:00am

Dear ahmad,

Iam Marilou Carlos in Tawam Hospital and we have been using NAVA for almost a year now in NNU, It is a very nice and advance technology.We started also NIV NAVA here in NNU.

Thanks for sharing us your knowledge re: NAVA

It's me

Malou