•  NAVA: New Technology
•  Some of the potential benefits
•  SERVO-i with NAVA monitoring
•  The SERVO Story
•  References

The NAVA option may be pending regulatory approvals to be marketed in your country. Please contact your local Regulatory /sales reponsible for latest update on the situation in your country.

NAVA: Neurally Adjusted Ventilatory Assist (NAVA) is a new approach to mechanical ventilation based on neural respiratory output.
The act of breathing depends on rhythmic discharge from the respiratory center of the brain. This discharge travels along the phrenic nerve, excites the diaphragm muscle cells, leading to muscle contraction and descent of the diaphragm dome. As a result, the pressure in the airway drops, causing an inflow of air into the lungs.

Image: NAVA senses activity in the diaphragm and responds by providing the requested level of ventilatory assist. The Edi signal is obtained by an electrode array mounted close to the distal tip of the Edi catheter. This catheter can also serve as a conventional nasogastric feeding tube. Click image to enlarge.

Conventional mechanical ventilators sense a patient effort by either a drop in airway pressure or a reversal in flow. The last and most slow reacting step in the chain of respiratory events is used to sense the patient effort. Hence, creating a system that is sensitive to hyperinflation, intrinsic PEEP and secondary triggering problems.

With NAVA, the electrical activity of the diaphragm (Edi) is captured, fed to the ventilator and used to assist the patient’s breathing. As the ventilator and the diaphragm work with the same signal, mechanical coupling between the diaphragm and the ventilator is practically instantaneous.

Improved synchrony: In NAVA the ventilator is cycled-on as soon as neural inspiration starts. Moreover, the level of assistance provided during inspiration is determined by the patient’s own respiratory center demand. The same applies for the cycling-off phase - the ventilator cycles off inspiration the instant it is alerted to the onset of neural expiration. By utilizing the Edi signal, maintenance of synchrony between the patient and the ventilator is improved.

Lung protection: With NAVA the patient's own respiratory demands determine the level of assistance. NAVA gives the opportunity to avoid over or under assistance of the patient.

Unique monitoring capability: The Edi signal is a new unique parameter in mechanical ventilation. It can be used as a diagnostic tool to monitor the electrical activity of the diaphragm (Edi). The Edi curve and its associated value can thus be used as a powerful monitoring tool in all ventilation modes, providing information on Respiratory Drive, Volume requirements and the effect of the ventilatory settings, and to gain indications for sedation and weaning.

NAVA for infants: The Edi signal provides a tool that allows the clinicians to interpret the background of the chaotic breathing pattern so often seen in the infants. The direct access to the respiratory center output gives prompt information on the effect of any intervention relating to ventilation of the lung. PEEP adjustment and the degree of unloading can now be based on informed decisions.

Patient comfort: With NAVA, the respiratory muscles and the ventilator are driven by the same signal. The delivered assistance is matched to neural demands. This synchrony between patient and ventilator helps minimize patient discomfort and agitation, promoting spontaneous breathing.

Decision support for unloading and extubation: The Edi signal can be used as an indicator to set the support level from the ventilator, and to optimize unloading. As the patient’s condition improves, Edi amplitude decreases, sulting in reduction in ventilator-delivered pressure. This pressure drop is an indicator to consider weaning and extubation.

Image: Edi Catheter Positioning tool helps ensure optimal positioning. Please click image to enlarge.

NAVA is as straightforward to use as it is technically advanced: The only equipment required in addition to a SERVO-i ventilator is NAVA software, an Edi Module and an Edi catheter.

Image: The NAVA Preview tool indicates the level of calculated ventilatory assistance the patient will receive upon changing to the NAVA mode. Please click image to enlarge.

The Edi Catheter also functions as a nasogastric feeding tube, and comes in dimensions ranging from 6Fr-16Fr to cover all patient categories from neonatal to adult.

Image: NAVA ventilation mode window showing the correlation between the Edi amplitude and pressure/flow curves. Please click image to enlarge.

The clinicians can view NAVA functions on the SERVO-i User Interface. Shown here are some key examples.

Image: Existing SERVO-i machines can deliver the new NAVA treatment mode. This adaptability highlights the open design and scalability that lets SERVO-i evolve to exploit treatment advances. Please click image to enlarge.

NAVA technology: The latest in a long line of SERVO innovations that promote a more natural recovery. Such as the Open Lung Tool, to guide gentle opening of collapsed parts of the lungs. SERVO-i features for lung protection include PRVC, Volume Support and Automode weaning tool. SERVO-i also has capabilities for inter-hospital transport and use during MR examinations.

Behind all these advances is a commitment to investing in research and development. It’s a longterm commitment.

SERVO-i with NAVA - Empowering human effort.

NAVA CLINICAL INFORMATION AND USER EXPERIENCES
For more clinical information and user experiences with NAVA, please visit Critical Care News, www.criticalcarenews.com

NAVA EYE-CATCHER VIDEO
To view this video, please click banner in the top right section of this page

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